Strategies for the stabilization of longitudinal forward flapping flight revealed using a dynamically-scaled robotic fly

International Nuclear Information System (INIS)

Elzinga, Michael J; Van Breugel, Floris; Dickinson, Michael H

2014-01-01

The ability to regulate forward speed is an essential requirement for flying animals. Here, we use a dynamically-scaled robot to study how flapping insects adjust their wing kinematics to regulate and stabilize forward flight. The results suggest that the steady-state lift and thrust requirements at different speeds may be accomplished with quite subtle changes in hovering kinematics, and that these adjustments act primarily by altering the pitch moment. This finding is consistent with prior hypotheses regarding the relationship between body pitch and flight speed in fruit flies. Adjusting the mean stroke position of the wings is a likely mechanism for trimming the pitch moment at all speeds, whereas changes in the mean angle of attack may be required at higher speeds. To ensure stability, the flapping system requires additional pitch damping that increases in magnitude with flight speed. A compensatory reflex driven by fast feedback of pitch rate from the halteres could provide such damping, and would automatically exhibit gain scheduling with flight speed if pitch torque was regulated via changes in stroke deviation. Such a control scheme would provide an elegant solution for stabilization across a wide range of forward flight speeds. (paper)

Flight Tests of a Remaining Flying Time Prediction System for Small Electric Aircraft in the Presence of Faults

Science.gov (United States)

Hogge, Edward F.; Kulkarni, Chetan S.; Vazquez, Sixto L.; Smalling, Kyle M.; Strom, Thomas H.; Hill, Boyd L.; Quach, Cuong C.

2017-01-01

This paper addresses the problem of building trust in the online prediction of a battery powered aircraft's remaining flying time. A series of flight tests is described that make use of a small electric powered unmanned aerial vehicle (eUAV) to verify the performance of the remaining flying time prediction algorithm. The estimate of remaining flying time is used to activate an alarm when the predicted remaining time is two minutes. This notifies the pilot to transition to the landing phase of the flight. A second alarm is activated when the battery charge falls below a specified limit threshold. This threshold is the point at which the battery energy reserve would no longer safely support two repeated aborted landing attempts. During the test series, the motor system is operated with the same predefined timed airspeed profile for each test. To test the robustness of the prediction, half of the tests were performed with, and half were performed without, a simulated powertrain fault. The pilot remotely engages a resistor bank at a specified time during the test flight to simulate a partial powertrain fault. The flying time prediction system is agnostic of the pilot's activation of the fault and must adapt to the vehicle's state. The time at which the limit threshold on battery charge is reached is then used to measure the accuracy of the remaining flying time predictions. Accuracy requirements for the alarms are considered and the results discussed.

Interaction of feel system and flight control system dynamics on lateral flying qualities

Science.gov (United States)

Bailey, R. E.; Knotts, L. H.

1990-01-01

An experimental investigation of the influence of lateral feel system characteristics on fighter aircraft roll flying qualities was conducted using the variable stability USAF NT-33. Forty-two evaluation flights were flown by three engineering test pilots. The investigation utilized the power approach, visual landing task and up-and-away tasks including formation, gun tracking, and computer-generated compensatory attitude tracking tasks displayed on the Head-Up Display. Experimental variations included the feel system frequency, force-deflection gradient, control system command type (force or position input command), aircraft roll mode time constant, control system prefilter frequency, and control system time delay. The primary data were task performance records and evaluation pilot comments and ratings using the Cooper-Harper scale. The data highlight the unique and powerful effect of the feel system of flying qualities. The data show that the feel system is not 'equivalent' in flying qualities influence to analogous control system elements. A lower limit of allowable feel system frequency appears warranted to ensure good lateral flying qualities. Flying qualities criteria should most properly treat the feel system dynamic influence separately from the control system, since the input and output of this dynamic element is apparent to the pilot and thus, does not produce a 'hidden' effect.

Are flying wildlife attracted to (or do they avoid) wind turbines?

Energy Technology Data Exchange (ETDEWEB)

Larkin, Ronald [Univ. of Illinois, Urbana, IL (United States). Board of Trustees

2010-03-31

A DOE-sponsored research project found strong evidence that flying wildlife avoid or are attracted to commercial-scale wind turbines from a distance. Some nocturnally migrating birds avoid flying near turbines and few or none change flight paths to approach them. High-flying bats less often avoid flying near turbines and some are attracted to them from a distance, although bats’ flight paths were often complex and convoluted. The findings are being prepared for submission to a peer-reviewed scientific journal (Larkin, in prep 2013).

Design and flight experience with a digital fly-by-wire control system in an F-8 airplane

Science.gov (United States)

Deets, D. A.; Szalai, K. J.

1974-01-01

A digital fly-by-wire flight control system was designed, built, and for the first time flown in an airplane. The system, which uses components from the Apollo guidance system, is installed in an F-8 airplane as the primary control system. A lunar module guidance computer is the central element in the three-axis, single-channel, multimode, digital control system. A triplex electrical analog system which provides unaugmented control of the airplane is the only backup to the digital system. Flight results showed highly successful system operation, although the trim update rate was inadequate for precise trim changes, causing minor concern. The use of a digital system to implement conventional control laws proved to be practical for flight. Logic functions coded as an integral part of the control laws were found to be advantageous. Although software verification required extensive effort, confidence in the software was achieved.

Formation flying as an innovative air transportation system for long-haul commercial flight : A focus on operational feasibility and potential gain

NARCIS (Netherlands)

Herinckx, L.E.; Gutleb, T.L.M.; Van Nunen, R.; Van Rompuy, E.; Bos, D.A.; Dijkers, H.P.A.; De Wit, J.; Radfar, H.; Sahin, S.E.; Beelarts van Blokland, W.W.A.

2011-01-01

Formation flying is introduced as a new and innovative air transportation system for long-haul commercial flight. With this paper the operational feasibility of formation flying is addressed, both from a market demand and economic, as well as an air traffic control perspective. Preliminary results

Flight control of fruit flies: dynamic response to optic flow and headwind.

Science.gov (United States)

Lawson, Kiaran K K; Srinivasan, Mandyam V

2017-06-01

Insects are magnificent fliers that are capable of performing many complex tasks such as speed regulation, smooth landings and collision avoidance, even though their computational abilities are limited by their small brain. To investigate how flying insects respond to changes in wind speed and surrounding optic flow, the open-loop sensorimotor response of female Queensland fruit flies ( Bactrocera tryoni ) was examined. A total of 136 flies were exposed to stimuli comprising sinusoidally varying optic flow and air flow (simulating forward movement) under tethered conditions in a virtual reality arena. Two responses were measured: the thrust and the abdomen pitch. The dynamics of the responses to optic flow and air flow were measured at various frequencies, and modelled as a multicompartment linear system, which accurately captured the behavioural responses of the fruit flies. The results indicate that these two behavioural responses are concurrently sensitive to changes of optic flow as well as wind. The abdomen pitch showed a streamlining response, where the abdomen was raised higher as the magnitude of either stimulus was increased. The thrust, in contrast, exhibited a counter-phase response where maximum thrust occurred when the optic flow or wind flow was at a minimum, indicating that the flies were attempting to maintain an ideal flight speed. When the changes in the wind and optic flow were in phase (i.e. did not contradict each other), the net responses (thrust and abdomen pitch) were well approximated by an equally weighted sum of the responses to the individual stimuli. However, when the optic flow and wind stimuli were presented in counterphase, the flies seemed to respond to only one stimulus or the other, demonstrating a form of 'selective attention'. © 2017. Published by The Company of Biologists Ltd.

Effect of video-game experience and position of flight stick controller on simulated-flight performance.

Science.gov (United States)

Cho, Bo-Keun; Aghazadeh, Fereydoun; Al-Qaisi, Saif

2012-01-01

The purpose of this study was to determine the effects of video-game experience and flight-stick position on flying performance. The study divided participants into 2 groups; center- and side-stick groups, which were further divided into high and low level of video-game experience subgroups. The experiment consisted of 7 sessions of simulated flying, and in the last session, the flight stick controller was switched to the other position. Flight performance was measured in terms of the deviation of heading, altitude, and airspeed from their respective requirements. Participants with high experience in video games performed significantly better (p increase (0.78 %). However, after switching from a center- to a side-stick controller, performance scores decreased (4.8%).

Flight Measurements of the Flying Qualities of a Lockheed P-80A Airplane (Army No. 44-85099) - Stalling Characteristics

Science.gov (United States)

Anderson, Seth B.; Cooper, George E.

1947-01-01

This report contains the flight-test results of the stalling characteristics measured during the flying-qualities investigation of the Lockheed P-8OA airplane (Army No. 44-85099). The tests were conducted in straight and turning flight with and without wing-tip tanks. These tests showed satisfactory stalling characteristics and adequate stall warning for all configurations and conditions tested.

High activity antioxidant enzymes protect flying-fox haemoglobin against damage: an evolutionary adaptation for flight?

Science.gov (United States)

Reinke, N B; O'Brien, G M

2006-11-01

Flying-foxes are better able to defend haemoglobin against autoxidation than non-volant mammals such as sheep. When challenged with the common physiological oxidant, hydrogen peroxide, haemolysates of flying-fox red blood cells (RBC) were far less susceptible to methaemoglobin formation than sheep. Challenge with 1-acetyl-2-phenylhydrazine (APH) caused only half as much methaemoglobin formation in flying-fox as in ovine haemolysates. When intact cells were challenged with phenazine methosulfate (PMS), flying-fox RBC partially reversed the oxidant damage, and reduced methaemoglobin from 40 to 20% over 2 h incubation, while ovine methaemoglobin remained at 40%. This reflected flying-fox cells' capacity to replenish GSH fast enough that it did not deplete beyond 50%, while ovine RBC GSH was depleted to around 20%. The greater capacity of flying-foxes to defend haemoglobin against oxidant damage may be explained in part by antioxidant enzymes catalase, superoxide dismutase and cytochrome-b ( 5 ) reductase having two- to four-fold higher activity than in sheep (P foxes.

Flight style optimization in ski jumping on normal, large, and ski flying hills.

Science.gov (United States)

Jung, Alexander; Staat, Manfred; Müller, Wolfram

2014-02-07

In V-style ski jumping, aerodynamic forces are predominant performance factors and athletes have to solve difficult optimization problems in parts of a second in order to obtain their jump length maximum and to keep the flight stable. Here, a comprehensive set of wind tunnel data was used for optimization studies based on Pontryagin's minimum principle with both the angle of attack α and the body-ski angle β as controls. Various combinations of the constraints αmax and βmin(t) were analyzed in order to compare different optimization strategies. For the computer simulation studies, the Olympic hill profiles in Esto-Sadok, Russia (HS 106m, HS 140m), and in Harrachov, Czech Republic, host of the Ski Flying World Championships 2014 (HS 205m) were used. It is of high importance for ski jumping practice that various aerodynamic strategies, i.e. combinations of α- and β-time courses, can lead to similar jump lengths which enables athletes to win competitions using individual aerodynamic strategies. Optimization results also show that aerodynamic behavior has to be different at different hill sizes (HS). Optimized time courses of α and β using reduced drag and lift areas in order to mimic recent equipment regulations differed only in a negligible way. This indicates that optimization results presented here are not very sensitive to minor changes of the aerodynamic equipment features when similar jump length are obtained by using adequately higher in-run velocities. However, wind tunnel measurements with athletes including take-off and transition to stabilized flight, flight, and landing behavior would enable a more detailed understanding of individual flight style optimization. © 2013 Published by Elsevier Ltd.

High-Speed Surface Reconstruction of Flying Birds Using Structured Light

Science.gov (United States)

Deetjen, Marc; Lentink, David

2017-11-01

Birds fly effectively through complex environments, and in order to understand the strategies that enable them to do so, we need to determine the shape and movement of their wings. Previous studies show that even small perturbations in wing shape have dramatic aerodynamic effects, but these shape changes have not been quantified automatically at high temporal and spatial resolutions. Hence, we developed a custom 3D surface mapping method which uses a high-speed camera to view a grid of stripes projected onto a flying bird. Because the light is binary rather than grayscale, and each frame is separately analyzed, this method can function at any frame rate with sufficient light. The method is automated, non-invasive, and able to measure a volume by simultaneously reconstructing from multiple views. We use this technique to reconstruct the 3D shape of the surface of a parrotlet during flapping flight at 3200 fps. We then analyze key dynamic parameters such as wing twist and angle of attack, and compute aerodynamic parameters such as lift and drag. While this novel system is designed to quantify bird wing shape and motion, it is adaptable for tracking other objects such as quickly deforming fish, especially those which are difficult to reconstruct using other 3D tracking methods. The presenter needs to leave by 3 pm on the final day of the conference (11/21) in order to make his flight. Please account for this in the scheduling if possible by scheduling the presentation earlier in the day or a different day.

Proceedings from the 2nd International Symposium on Formation Flying Missions and Technologies

Science.gov (United States)

2004-01-01

Topics discussed include: The Stellar Imager (SI) "Vision Mission"; First Formation Flying Demonstration Mission Including on Flight Nulling; Formation Flying X-ray Telescope in L2 Orbit; SPECS: The Kilometer-baseline Far-IR Interferometer in NASA's Space Science Roadmap Presentation; A Tight Formation for Along-track SAR Interferometry; Realization of the Solar Power Satellite using the Formation Flying Solar Reflector; SIMBOL-X : Formation Flying for High-Energy Astrophysics; High Precision Optical Metrology for DARWIN; Close Formation Flight of Micro-Satellites for SAR Interferometry; Station-Keeping Requirements for Astronomical Imaging with Constellations of Free-Flying Collectors; Closed-Loop Control of Formation Flying Satellites; Formation Control for the MAXIM Mission; Precision Formation Keeping at L2 Using the Autonomous Formation Flying Sensor; Robust Control of Multiple Spacecraft Formation Flying; Virtual Rigid Body (VRB) Satellite Formation Control: Stable Mode-Switching and Cross-Coupling; Electromagnetic Formation Flight (EMFF) System Design, Mission Capabilities, and Testbed Development; Navigation Algorithms for Formation Flying Missions; Use of Formation Flying Small Satellites Incorporating OISL's in a Tandem Cluster Mission; Semimajor Axis Estimation Strategies; Relative Attitude Determination of Earth Orbiting Formations Using GPS Receivers; Analysis of Formation Flying in Eccentric Orbits Using Linearized Equations of Relative Motion; Conservative Analytical Collision Probabilities for Orbital Formation Flying; Equations of Motion and Stability of Two Spacecraft in Formation at the Earth/Moon Triangular Libration Points; Formations Near the Libration Points: Design Strategies Using Natural and Non-Natural Ares; An Overview of the Formation and Attitude Control System for the Terrestrial Planet Finder Formation Flying Interferometer; GVE-Based Dynamics and Control for Formation Flying Spacecraft; GNC System Design for a New Concept of X

Comparison of in-flight and ground-based simulator derived flying qualities and pilot performance for approach and landing tasks

Science.gov (United States)

Grantham, William D.; Williams, Robert H.

1987-01-01

For the case of an approach-and-landing piloting task emphasizing response to the landing flare, pilot opinion and performance parameters derived from jet transport aircraft six-degree-of-freedom ground-based and in-flight simulators were compared in order to derive data for the flight-controls/flying-qualities engineers. The data thus obtained indicate that ground simulation results tend to be conservative, and that the effect of control sensitivity is more pronounced for ground simulation. The pilot also has a greater tendency to generate pilot-induced oscillation in ground-based simulation than in flight.

Distress Calls of a Fast-Flying Bat (Molossus molossus Provoke Inspection Flights but Not Cooperative Mobbing.

Directory of Open Access Journals (Sweden)

Gerald Carter

Full Text Available Many birds and mammals produce distress calls when captured. Bats often approach speakers playing conspecific distress calls, which has led to the hypothesis that bat distress calls promote cooperative mobbing. An alternative explanation is that approaching bats are selfishly assessing predation risk. Previous playback studies on bat distress calls involved species with highly maneuverable flight, capable of making close passes and tight circles around speakers, which can look like mobbing. We broadcast distress calls recorded from the velvety free-tailed bat, Molossus molossus, a fast-flying aerial-hawker with relatively poor maneuverability. Based on their flight behavior, we predicted that, in response to distress call playbacks, M. molossus would make individual passing inspection flights but would not approach in groups or approach within a meter of the distress call source. By recording responses via ultrasonic recording and infrared video, we found that M. molossus, and to a lesser extent Saccopteryx bilineata, made more flight passes during distress call playbacks compared to noise. However, only the more maneuverable S. bilineata made close approaches to the speaker, and we found no evidence of mobbing in groups. Instead, our findings are consistent with the hypothesis that single bats approached distress calls simply to investigate the situation. These results suggest that approaches by bats to distress calls should not suffice as clear evidence for mobbing.

Distress Calls of a Fast-Flying Bat (Molossus molossus) Provoke Inspection Flights but Not Cooperative Mobbing

Science.gov (United States)

Carter, Gerald; Schoeppler, Diana; Manthey, Marie; Knörnschild, Mirjam; Denzinger, Annette

2015-01-01

Many birds and mammals produce distress calls when captured. Bats often approach speakers playing conspecific distress calls, which has led to the hypothesis that bat distress calls promote cooperative mobbing. An alternative explanation is that approaching bats are selfishly assessing predation risk. Previous playback studies on bat distress calls involved species with highly maneuverable flight, capable of making close passes and tight circles around speakers, which can look like mobbing. We broadcast distress calls recorded from the velvety free-tailed bat, Molossus molossus, a fast-flying aerial-hawker with relatively poor maneuverability. Based on their flight behavior, we predicted that, in response to distress call playbacks, M. molossus would make individual passing inspection flights but would not approach in groups or approach within a meter of the distress call source. By recording responses via ultrasonic recording and infrared video, we found that M. molossus, and to a lesser extent Saccopteryx bilineata, made more flight passes during distress call playbacks compared to noise. However, only the more maneuverable S. bilineata made close approaches to the speaker, and we found no evidence of mobbing in groups. Instead, our findings are consistent with the hypothesis that single bats approached distress calls simply to investigate the situation. These results suggest that approaches by bats to distress calls should not suffice as clear evidence for mobbing. PMID:26353118

Distress Calls of a Fast-Flying Bat (Molossus molossus) Provoke Inspection Flights but Not Cooperative Mobbing.

Science.gov (United States)

Carter, Gerald; Schoeppler, Diana; Manthey, Marie; Knörnschild, Mirjam; Denzinger, Annette

2015-01-01

Many birds and mammals produce distress calls when captured. Bats often approach speakers playing conspecific distress calls, which has led to the hypothesis that bat distress calls promote cooperative mobbing. An alternative explanation is that approaching bats are selfishly assessing predation risk. Previous playback studies on bat distress calls involved species with highly maneuverable flight, capable of making close passes and tight circles around speakers, which can look like mobbing. We broadcast distress calls recorded from the velvety free-tailed bat, Molossus molossus, a fast-flying aerial-hawker with relatively poor maneuverability. Based on their flight behavior, we predicted that, in response to distress call playbacks, M. molossus would make individual passing inspection flights but would not approach in groups or approach within a meter of the distress call source. By recording responses via ultrasonic recording and infrared video, we found that M. molossus, and to a lesser extent Saccopteryx bilineata, made more flight passes during distress call playbacks compared to noise. However, only the more maneuverable S. bilineata made close approaches to the speaker, and we found no evidence of mobbing in groups. Instead, our findings are consistent with the hypothesis that single bats approached distress calls simply to investigate the situation. These results suggest that approaches by bats to distress calls should not suffice as clear evidence for mobbing.

Simulation to Flight Test for a UAV Controls Testbed

Science.gov (United States)

Motter, Mark A.; Logan, Michael J.; French, Michael L.; Guerreiro, Nelson M.

2006-01-01

The NASA Flying Controls Testbed (FLiC) is a relatively small and inexpensive unmanned aerial vehicle developed specifically to test highly experimental flight control approaches. The most recent version of the FLiC is configured with 16 independent aileron segments, supports the implementation of C-coded experimental controllers, and is capable of fully autonomous flight from takeoff roll to landing, including flight test maneuvers. The test vehicle is basically a modified Army target drone, AN/FQM-117B, developed as part of a collaboration between the Aviation Applied Technology Directorate (AATD) at Fort Eustis, Virginia and NASA Langley Research Center. Several vehicles have been constructed and collectively have flown over 600 successful test flights, including a fully autonomous demonstration at the Association of Unmanned Vehicle Systems International (AUVSI) UAV Demo 2005. Simulations based on wind tunnel data are being used to further develop advanced controllers for implementation and flight test.

Vortex wake, downwash distribution, aerodynamic performance and wingbeat kinematics in slow-flying pied flycatchers.

Science.gov (United States)

Muijres, Florian T; Bowlin, Melissa S; Johansson, L Christoffer; Hedenström, Anders

2012-02-07

Many small passerines regularly fly slowly when catching prey, flying in cluttered environments or landing on a perch or nest. While flying slowly, passerines generate most of the flight forces during the downstroke, and have a 'feathered upstroke' during which they make their wing inactive by retracting it close to the body and by spreading the primary wing feathers. How this flight mode relates aerodynamically to the cruising flight and so-called 'normal hovering' as used in hummingbirds is not yet known. Here, we present time-resolved fluid dynamics data in combination with wingbeat kinematics data for three pied flycatchers flying across a range of speeds from near hovering to their calculated minimum power speed. Flycatchers are adapted to low speed flight, which they habitually use when catching insects on the wing. From the wake dynamics data, we constructed average wingbeat wakes and determined the time-resolved flight forces, the time-resolved downwash distributions and the resulting lift-to-drag ratios, span efficiencies and flap efficiencies. During the downstroke, slow-flying flycatchers generate a single-vortex loop wake, which is much more similar to that generated by birds at cruising flight speeds than it is to the double loop vortex wake in hovering hummingbirds. This wake structure results in a relatively high downwash behind the body, which can be explained by the relatively active tail in flycatchers. As a result of this, slow-flying flycatchers have a span efficiency which is similar to that of the birds in cruising flight and which can be assumed to be higher than in hovering hummingbirds. During the upstroke, the wings of slowly flying flycatchers generated no significant forces, but the body-tail configuration added 23 per cent to weight support. This is strikingly similar to the 25 per cent weight support generated by the wing upstroke in hovering hummingbirds. Thus, for slow-flying passerines, the upstroke cannot be regarded as inactive

77 FR 69572 - Special Conditions: Embraer S.A., Model EMB-550 Airplanes; Flight Envelope Protection: High Speed...

Science.gov (United States)

2012-11-20

... electronic flight control system which contains fly-by-wire control laws, including envelope protections, for... airplane incorporates an overspeed protection system in the normal mode. This mode prevents the pilot from... contain appropriate standards for high speed protection systems. Discussion As further discussed...

78 FR 11562 - Special Conditions: Embraer S.A., Model EMB-550 Airplanes; Flight Envelope Protection: High Speed...

Science.gov (United States)

2013-02-19

... electronic flight control system which contains fly-by-wire control laws, including envelope protections, for... airplane incorporates an overspeed protection system in the normal mode. This mode prevents the pilot from... contain appropriate standards for high speed protection systems. Discussion As further discussed...

Environmental and genetic influences on flight metabolic rate in the honey bee, Apis mellifera.

Science.gov (United States)

Harrison, Jon F; Fewell, Jennifer H

2002-10-01

Flying honey bees demonstrate highly variable metabolic rates. The lowest reported values (approximately 0.3 Wg(-1)) occur in tethered bees generating the minimum lift to support their body weight, free-flying 2-day old bees, winter bees, or bees flying at high air temperatures (45 degrees C). The highest values (approximately 0.8 Wg(-1)) occur in foragers that are heavily loaded or flying in low-density air. In different studies, flight metabolic rate has increased, decreased, or remained constant with air temperature. Current research collectively suggests that this variation occurs because flight metabolic rates decrease at thorax temperatures above or below 38 degrees C. At 30 degrees C, approximately 30% of colonial energy is spent during typical foraging, so variation in flight metabolic rate can strongly affect colony-level energy balance. Higher air temperatures tend to increase colonial net gain rates, efficiencies and honey storage rates due to lower metabolic rates during flight and in the hive. Variation in flight metabolism has a clear genetic basis. Different genetic strains of honey bees often differ in flight metabolic rate, and these differences in flight physiology can be correlated with foraging effort, suggesting a possible pathway for selection effects on flight metabolism.

Physics-Based Virtual Fly-Outs of Projectiles on Supercomputers

National Research Council Canada - National Science Library

Sahu, Jubaraj

2006-01-01

...) have been successfully fully coupled on high performance computing (HPC) platforms for Virtual Fly-Outs of guided munitions identical to actual free flight tests in the aerodynamic experimental facilities...

X-36 in Flight over Mojave Desert during 5th Flight

Science.gov (United States)

1997-01-01

The unusual lines of the X-36 Tailless Fighter Agility Research Aircraft contrast sharply with the desert floor as the remotely-piloted aircraft flies over the Mojave Desert on a June 1997 research flight. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of

Norwegian airline passengers are not more afraid of flying after the terror act of September 11. The flight anxiety, however, is significantly attributed to acts of terrorism.

Science.gov (United States)

Ekeberg, Oivind; Fauske, Berit; Berg-Hansen, Bente

2014-10-01

The aim of this paper is to study: (1) the prevalence of flight anxiety among Norwegian airline passengers; (2) situations that may be of concern during flights and situations not related to flying; (3) whether passengers feel more afraid after the terror act of September 11, 2001; and (4) whether passengers were more afraid in 2002 than in 1986.A questionnaire was distributed during domestic flights in Norway in 1986 and 2002. To asses flight anxiety, a six point scale was used, from 0 = not afraid at all, to 5 = always very afraid, and sometimes avoid flying because of that. A 10-cm visual analogue scale (VAS) was used to measure the degree of anxiety. There were 50.8% who were not afraid at all. There were 12 women (5.2%) and one man (0.4%) with flight phobia. However, 22 (4.5%) had cancelled flights because of anxiety during the last two years. Situations that caused most concern during flights were turbulence and fear of terrorism and highjacking. After September 11, 48% were not more afraid, 38% a little more, 10% moderately, 3% rather much and 2% very much. The passengers, however, were not more afraid of flying in 2002 than in 1986. About 3% of Norwegian airline passengers have a flight phobia. Women are significantly more concerned than men. The impact of the terror act September 11, 2001 was rather moderate. The level of flight anxiety among Norwegian airline passengers was not significantly different in 2002 and 1986. © 2014 Oslo University Hospital. Scandinavian Journal of Psychology published by Scandinavian Psychological Associations and John Wiley & Sons Ltd.

High Altitude Balloon Flight Path Prediction and Site Selection Based On Computer Simulations

Science.gov (United States)

Linford, Joel

2010-10-01

Interested in the upper atmosphere, Weber State University Physics department has developed a High Altitude Reconnaissance Balloon for Outreach and Research team, also known as HARBOR. HARBOR enables Weber State University to take a variety of measurements from ground level to altitudes as high as 100,000 feet. The flight paths of these balloons can extend as long as 100 miles from the launch zone, making the choice of where and when to fly critical. To ensure the ability to recover the packages in a reasonable amount of time, days and times are carefully selected using computer simulations limiting flight tracks to approximately 40 miles from the launch zone. The computer simulations take atmospheric data collected by National Oceanic and Atmospheric Administration (NOAA) to plot what flights might have looked like in the past, and to predict future flights. Using these simulations a launch zone has been selected in Duchesne Utah, which has hosted eight successful flights over the course of the last three years, all of which have been recovered. Several secondary launch zones in western Wyoming, Southern Idaho, and Northern Utah are also being considered.

A digital fly-by-wire technology development program using an F-8C test aircraft

Science.gov (United States)

Jarvis, C. R.

1974-01-01

A digital fly-by-wire flight control system has been installed in an F-8C test airplane and has undergone extensive ground and flight testing as part of an overall program to develop digital fly-by-wire technology. This is the first airplane to fly with a digital fly-by-wire system as its primary means of control and with no mechanical reversion capability. Forty-two test flights were made for a total flight time of 57 hours. Six pilots participated in the evaluation. This paper presents an overview of the digital fly-by-wire program and discusses some of the flight-test results.

Recording and Analysis of Tsetse Flight Responses in Three Dimensions

Energy Technology Data Exchange (ETDEWEB)

Guerin, P M; Gurba, A; Harraca, V; Perret, J -L [Institute of Biology, University of Neuchatel, Rue Emile-Argand 11, Case Postale 158, 2009 Neuchatel (Switzerland); Casera, S; Donnet, S [Institute of Informatics, University of Neuchatel, Rue Emile-Argand 11, Case Postale 158, 2009 Neuchatel (Switzerland)

2012-07-15

Recording and analysing three dimensional (3D) motions of tsetse flies in flight are technically challenging due to their speed of flight. However, video recording of tsetse fly flight responses has already been made in both wind tunnels and the field. The aim of our research was to study the way tsetse flies exploit host odours and visual targets during host searching. Such knowledge can help in the development of better trapping devices. We built a wind tunnel where it is possible to control environmental parameters, e.g. temperature, relative humidity and light. The flight of the flies was filmed from above with two high speed Linux-embedded cameras equipped with fish-eye objectives viewing at 60o from one another. The synchronized stereo images were used to reconstruct the trajectory of flies in 3D and in real time. Software permitted adjustment for parameters such as luminosity and size of the tsetse species being tracked. Interpolation permitted us to calculate flight coordinates and to measure modifications of flight parameters such as acceleration, velocity, rectitude, angular velocity and curvature according to the experimental conditions. Using this system we filmed the responses of Glossina brevipalpis Newstead obtained from a colony at the IAEA Entomology Unit, Seibersdorf, Austria to human breath presented with and without a visual target. Flights lasting up to 150 s duration and covering up to 153 m were recorded. G. brevipalpis flights to human breath were characterized by wide undulations along the course. When a visual target was placed in the plume of breath, flights of G. brevipalpis were more tightly controlled, i.e. slower and more directed. This showed that after multiple generations in a laboratory colony G. brevipalpis was still capable of complex behaviours during bloodmeal searching. (author)

Wing and body kinematics of forward flight in drone-flies.

Science.gov (United States)

Meng, Xue Guang; Sun, Mao

2016-08-15

Here, we present a detailed analysis of the wing and body kinematics in drone-flies in free flight over a range of speeds from hovering to about 8.5 m s(-1). The kinematics was measured by high-speed video techniques. As the speed increased, the body angle decreased and the stroke plane angle increased; the wingbeat frequency changed little; the stroke amplitude first decreased and then increased; the ratio of the downstroke duration to the upstroke duration increased; the mean positional angle increased at lower speeds but changed little at speeds above 3 m s(-1). At a speed above about 1.5 m s(-1), wing rotation at supination was delayed and that at pronation was advanced, and consequently the wing rotations were mostly performed in the upstroke. In the downstroke, the relative velocity of the wing increased and the effective angle of attack decreased with speed; in the upstroke, they both decreased with speed at lower speeds, and at higher speeds, the relative velocity became larger but the effective angle of attack became very small. As speed increased, the increasing inclination of the stroke plane ensured that the effective angle of attack in the upstroke would not become negative, and that the wing was in suitable orientations for vertical-force and thrust production.

FlyAR: augmented reality supported micro aerial vehicle navigation.

Science.gov (United States)

Zollmann, Stefanie; Hoppe, Christof; Langlotz, Tobias; Reitmayr, Gerhard

2014-04-01

Micro aerial vehicles equipped with high-resolution cameras can be used to create aerial reconstructions of an area of interest. In that context automatic flight path planning and autonomous flying is often applied but so far cannot fully replace the human in the loop, supervising the flight on-site to assure that there are no collisions with obstacles. Unfortunately, this workflow yields several issues, such as the need to mentally transfer the aerial vehicle’s position between 2D map positions and the physical environment, and the complicated depth perception of objects flying in the distance. Augmented Reality can address these issues by bringing the flight planning process on-site and visualizing the spatial relationship between the planned or current positions of the vehicle and the physical environment. In this paper, we present Augmented Reality supported navigation and flight planning of micro aerial vehicles by augmenting the user’s view with relevant information for flight planning and live feedback for flight supervision. Furthermore, we introduce additional depth hints supporting the user in understanding the spatial relationship of virtual waypoints in the physical world and investigate the effect of these visualization techniques on the spatial understanding.

Comparison of flying qualities derived from in-flight and ground-based simulators for a jet-transport airplane for the approach and landing pilot tasks

Science.gov (United States)

Grantham, William D.

1989-01-01

The primary objective was to provide information to the flight controls/flying qualities engineer that will assist him in determining the incremental flying qualities and/or pilot-performance differences that may be expected between results obtained via ground-based simulation (and, in particular, the six-degree-of-freedom Langley Visual/Motion Simulator (VMS)) and flight tests. Pilot opinion and performance parameters derived from a ground-based simulator and an in-flight simulator are compared for a jet-transport airplane having 32 different longitudinal dynamic response characteristics. The primary pilot tasks were the approach and landing tasks with emphasis on the landing-flare task. The results indicate that, in general, flying qualities results obtained from the ground-based simulator may be considered conservative-especially when the pilot task requires tight pilot control as during the landing flare. The one exception to this, according to the present study, was that the pilots were more tolerant of large time delays in the airplane response on the ground-based simulator. The results also indicated that the ground-based simulator (particularly the Langley VMS) is not adequate for assessing pilot/vehicle performance capabilities (i.e., the sink rate performance for the landing-flare task when the pilot has little depth/height perception from the outside scene presentation).

An overview of NASA's digital fly-by-wire technology development program

Science.gov (United States)

Jarvis, C. R.

1976-01-01

The feasibility of using digital fly by wire systems to control aircraft was demonstrated by developing and flight testing a single channel system, which used Apollo hardware, in an F-8C test airplane. This is the first airplane to fly with a digital fly by wire system as its primary means of control and with no mechanical reversion capability. The development and flight test of a triplex digital fly by wire system, which will serve as an experimental prototype for future operational digital fly by wire systems, are underway.

Flying at no mechanical energy cost: disclosing the secret of wandering albatrosses.

Directory of Open Access Journals (Sweden)

Gottfried Sachs

Full Text Available Albatrosses do something that no other birds are able to do: fly thousands of kilometres at no mechanical cost. This is possible because they use dynamic soaring, a flight mode that enables them to gain the energy required for flying from wind. Until now, the physical mechanisms of the energy gain in terms of the energy transfer from the wind to the bird were mostly unknown. Here we show that the energy gain is achieved by a dynamic flight manoeuvre consisting of a continually repeated up-down curve with optimal adjustment to the wind. We determined the energy obtained from the wind by analysing the measured trajectories of free flying birds using a new GPS-signal tracking method yielding a high precision. Our results reveal an evolutionary adaptation to an extreme environment, and may support recent biologically inspired research on robotic aircraft that might utilize albatrosses' flight technique for engineless propulsion.

SCC with high volume of fly ash content

Directory of Open Access Journals (Sweden)

Bakhrakh Anton

2017-01-01

Full Text Available Self-compacting concrete is a very perspective building material. It provides great benefits during the construction of heavily reinforced buildings. SCC has outstanding properties such as high flowability, dense structure and high strength due to specific quality of aggregates, fillers, their proportion in mix, use of polycarboxylate-based superplasticizers. Main disadvantages of SCC are high price and the difficulty of obtaining a proper mix. Use of fillers, such as fly ash type F, is a way to make SCC cheaper by replacing part of cement. Fly ash also provides some technological and operating advantages. In this paper the influence of high volume (60% from cement fly ash type F on the properties of concrete mixture and hardened concrete is investigated. The result of the work shows the possibility of reduction the cost of SCC using ordinary fillers and high amount of fly ash. The investigated SCC has low speed of hardening (7-day compressive strength at the range of 41.8 MPa and high volume of entrained air content (3.5%.

X-36 in Flight near Edge of Rogers Dry Lake during 5th Flight

Science.gov (United States)

1997-01-01

This photo shows the X-36 Tailless Fighter Agility Research Aircraft passing over the edge of Rogers Dry Lake as the remotely-piloted aircraft flies over Edwards Air Force Base on a June 1997 research flight. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of

Independently controlled wing stroke patterns in the fruit fly Drosophila melanogaster.

Directory of Open Access Journals (Sweden)

Soma Chakraborty

Full Text Available Flies achieve supreme flight maneuverability through a small set of miniscule steering muscles attached to the wing base. The fast flight maneuvers arise from precisely timed activation of the steering muscles and the resulting subtle modulation of the wing stroke. In addition, slower modulation of wing kinematics arises from changes in the activity of indirect flight muscles in the thorax. We investigated if these modulations can be described as a superposition of a limited number of elementary deformations of the wing stroke that are under independent physiological control. Using a high-speed computer vision system, we recorded the wing motion of tethered flying fruit flies for up to 12,000 consecutive wing strokes at a sampling rate of 6250 Hz. We then decomposed the joint motion pattern of both wings into components that had the minimal mutual information (a measure of statistical dependence. In 100 flight segments measured from 10 individual flies, we identified 7 distinct types of frequently occurring least-dependent components, each defining a kinematic pattern (a specific deformation of the wing stroke and the sequence of its activation from cycle to cycle. Two of these stroke deformations can be associated with the control of yaw torque and total flight force, respectively. A third deformation involves a change in the downstroke-to-upstroke duration ratio, which is expected to alter the pitch torque. A fourth kinematic pattern consists in the alteration of stroke amplitude with a period of 2 wingbeat cycles, extending for dozens of cycles. Our analysis indicates that these four elementary kinematic patterns can be activated mutually independently, and occur both in isolation and in linear superposition. The results strengthen the available evidence for independent control of yaw torque, pitch torque, and total flight force. Our computational method facilitates systematic identification of novel patterns in large kinematic datasets.

Independently controlled wing stroke patterns in the fruit fly Drosophila melanogaster.

Science.gov (United States)

Chakraborty, Soma; Bartussek, Jan; Fry, Steven N; Zapotocky, Martin

2015-01-01

Flies achieve supreme flight maneuverability through a small set of miniscule steering muscles attached to the wing base. The fast flight maneuvers arise from precisely timed activation of the steering muscles and the resulting subtle modulation of the wing stroke. In addition, slower modulation of wing kinematics arises from changes in the activity of indirect flight muscles in the thorax. We investigated if these modulations can be described as a superposition of a limited number of elementary deformations of the wing stroke that are under independent physiological control. Using a high-speed computer vision system, we recorded the wing motion of tethered flying fruit flies for up to 12,000 consecutive wing strokes at a sampling rate of 6250 Hz. We then decomposed the joint motion pattern of both wings into components that had the minimal mutual information (a measure of statistical dependence). In 100 flight segments measured from 10 individual flies, we identified 7 distinct types of frequently occurring least-dependent components, each defining a kinematic pattern (a specific deformation of the wing stroke and the sequence of its activation from cycle to cycle). Two of these stroke deformations can be associated with the control of yaw torque and total flight force, respectively. A third deformation involves a change in the downstroke-to-upstroke duration ratio, which is expected to alter the pitch torque. A fourth kinematic pattern consists in the alteration of stroke amplitude with a period of 2 wingbeat cycles, extending for dozens of cycles. Our analysis indicates that these four elementary kinematic patterns can be activated mutually independently, and occur both in isolation and in linear superposition. The results strengthen the available evidence for independent control of yaw torque, pitch torque, and total flight force. Our computational method facilitates systematic identification of novel patterns in large kinematic datasets.

In-Flight Validation of a Pilot Rating Scale for Evaluating Failure Transients in Electronic Flight Control Systems

Science.gov (United States)

Kalinowski, Kevin F.; Tucker, George E.; Moralez, Ernesto, III

2006-01-01

Engineering development and qualification of a Research Flight Control System (RFCS) for the Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL) JUH-60A has motivated the development of a pilot rating scale for evaluating failure transients in fly-by-wire flight control systems. The RASCAL RFCS includes a highly-reliable, dual-channel Servo Control Unit (SCU) to command and monitor the performance of the fly-by-wire actuators and protect against the effects of erroneous commands from the flexible, but single-thread Flight Control Computer. During the design phase of the RFCS, two piloted simulations were conducted on the Ames Research Center Vertical Motion Simulator (VMS) to help define the required performance characteristics of the safety monitoring algorithms in the SCU. Simulated failures, including hard-over and slow-over commands, were injected into the command path, and the aircraft response and safety monitor performance were evaluated. A subjective Failure/Recovery Rating (F/RR) scale was developed as a means of quantifying the effects of the injected failures on the aircraft state and the degree of pilot effort required to safely recover the aircraft. A brief evaluation of the rating scale was also conducted on the Army/NASA CH-47B variable stability helicopter to confirm that the rating scale was likely to be equally applicable to in-flight evaluations. Following the initial research flight qualification of the RFCS in 2002, a flight test effort was begun to validate the performance of the safety monitors and to validate their design for the safe conduct of research flight testing. Simulated failures were injected into the SCU, and the F/RR scale was applied to assess the results. The results validate the performance of the monitors, and indicate that the Failure/Recovery Rating scale is a very useful tool for evaluating failure transients in fly-by-wire flight control systems.

The relationship between manual handling performance and recent flying experience in air transport pilots.

Science.gov (United States)

Ebbatson, Matt; Harris, Don; Huddlestone, John; Sears, Rodney

2010-02-01

Modern jet transport aircraft are typically flown using the on-board automation by the pilot programming commands into the auto-flight systems. Anecdotal evidence exists suggesting that pilots of highly automated aircraft experience manual flying skills decay as a result of a lack of opportunity to practise hand-flying during line operations. The ability of a pilot to revert to basic manual control is essential, for example, in cases where the aircraft's automatic capability is diminished or when reconfiguring the automatics is an ineffective use of crew capacity. However, there is a paucity of objective data to substantiate this perceived threat to flight safety. Furthermore, traditional performance measurement techniques may lack the ability to identify subtle but significant differences in pilots' manual handling ability in large transport aircraft. This study examines the relationship between pilot manual handling performance and their recent flying experience using both traditional flight path tracking measures and frequency-based control strategy measures. Significant relationships are identified between pilots' very recent flying experience and their manual control strategy. Statement of Relevance: The study demonstrates a novel application of frequency analysis, which produces a broader and more sensitive analysis of pilot performance than has been offered in previous research. Additionally, the relationships that are found to exist between recent flying experience and manual flying performance will help to guide future pilot assessment and training.

Mechanical Constraints on Flight at High Elevation Decrease Maneuvering Performance of Hummingbirds.

Science.gov (United States)

Segre, Paolo S; Dakin, Roslyn; Read, Tyson J G; Straw, Andrew D; Altshuler, Douglas L

2016-12-19

High-elevation habitats offer ecological advantages including reduced competition, predation, and parasitism [1]. However, flying organisms at high elevation also face physiological challenges due to lower air density and oxygen availability [2]. These constraints are expected to affect the flight maneuvers that are required to compete with rivals, capture prey, and evade threats [3-5]. To test how individual maneuvering performance is affected by elevation, we measured the free-flight maneuvers of male Anna's hummingbirds in a large chamber translocated to a high-elevation site and then measured their performance at low elevation. We used a multi-camera tracking system to identify thousands of maneuvers based on body position and orientation [6]. At high elevation, the birds' translational velocities, accelerations, and rotational velocities were reduced, and they used less demanding turns. To determine how mechanical and metabolic constraints independently affect performance, we performed a second experiment to evaluate flight maneuvers in an airtight chamber infused with either normoxic heliox, to lower air density, or nitrogen, to lower oxygen availability. The hypodense treatment caused the birds to reduce their accelerations and rotational velocities, whereas the hypoxic treatment had no significant effect on maneuvering performance. Collectively, these experiments reveal how aerial maneuvering performance changes with elevation, demonstrating that as birds move up in elevation, air density constrains their maneuverability prior to any influence of oxygen availability. Our results support the hypothesis that changes in competitive ability at high elevations are the result of mechanical limits to flight performance [7]. Copyright © 2016 Elsevier Ltd. All rights reserved.

Life-critical digital flight control systems

Science.gov (United States)

Mcwha, James

1990-01-01

Digital autopilot systems were first used on commercial airplanes in the late 1970s. The A-320 airplane was the first air transport airplane with a fly-by-wire primary flight control system. On the 767-X (777) airplane Boeing will install all fly-by-wire flight controls. Activities related to safety, industry status and program phases are discussed.

Flight time and flight age in the sweet potato weevil, Cylas formicarius (Fabricius)(Coleoptera: Brentidae)

International Nuclear Information System (INIS)

Shimizu, T.; Moriya, S.

1996-01-01

We examined daily flight patterns and the correlation between adult age and flight in Cylas formicarius in the laboratory at 25 ± 1 ℃ under a 14L10D photoregime by a simple method of counting the number of adults flying out of a cup. The flight activity of males peaked just after the onset of darkness and gradually decreased toward the onset of light. Only a small proportion of them flew during the photophase. More than 90% of male adults flow at least once within 2 weeks after exodus from the sweet potato tuber. The proportion of males flying per day increased to a maximum 1 week after the exodus, and about 10% of them flow even 30 days after the exodus. On the other hand, flight activity of females was low and the proportion of females flying at least once was about 25%. Females flow from 7 to 24 days after the exodus

Flight performance of western sandpipers, Calidris mauri, remains uncompromised when mounting an acute phase immune response.

Science.gov (United States)

Nebel, Silke; Buehler, Deborah M; MacMillan, Alexander; Guglielmo, Christopher G

2013-07-15

Migratory birds have been implicated in the spread of some zoonotic diseases, but how well infected individuals can fly remains poorly understood. We used western sandpipers, Calidris mauri, to experimentally test whether flight is affected when long-distance migrants are mounting an immune response and whether migrants maintain immune defences during a flight in a wind tunnel. We measured five indicators of innate immunity in 'flown-healthy' birds (flying in a wind tunnel without mounting an immune response), 'flown-sick' birds (flying while mounting an acute phase response, which is part of induced innate immunity), and a non-flying control group ('not-flown'). Voluntary flight duration did not differ between flown-healthy and flown-sick birds, indicating that mounting an acute phase response to simulated infection did not hamper an individual's ability to fly for up to 3 h. However, in comparison to not-flown birds, bacterial killing ability of plasma was significantly reduced after flight in flown-sick birds. In flown-healthy birds, voluntary flight duration was positively correlated with bacterial killing ability and baseline haptoglobin concentration of the blood plasma measured 1-3 weeks before experimental flights, suggesting that high quality birds had strong immune systems and greater flight capacity. Our findings indicate that flight performance is not diminished by prior immune challenge, but that flight while mounting an acute phase response negatively affects other aspects of immune function. These findings have important implications for our understanding of the transmission of avian diseases, as they suggest that birds can still migrate while fighting an infection.

A Cognitive and Virtual Reality Treatment Program for the Fear of Flying.

Science.gov (United States)

Ferrand, Margot; Ruffault, Alexis; Tytelman, Xavier; Flahault, Cécile; Négovanska, Vélina

2015-08-01

Passenger air transport has considerably increased in the past 50 yr. It is estimated that between 7 and 40% of the population of industrialized countries is currently afraid of flying. Programs treating the fear of flying have been developed to meet this problem. This study measures the effectiveness of one of these programs by focusing on flight-related anxiety before the program and after the first flight following the intervention. There were 157 individuals recruited to participate in a 1-d intervention aiming at treating the fear of flying, and using both cognitive behavioral techniques and virtual reality. Anxiety was measured with the Flight Anxiety Situations (FAS) and the Flight Anxiety Modality (FAM) questionnaires. Statistical analyses were conducted on 145 subjects (69.7% female; ages from 14 to 64) after the exclusion of individuals with missing data. The results showed a decrease in flight-related anxiety for each subscale of the two questionnaires: the somatic (d=2.44) and cognitive anxiety (d=1.47) subscales of the FAM, and the general flight anxiety (d=3.20), the anticipatory flight anxiety (d=1.74), and the in-flight anxiety (d=1.04) subscales of the FAS. The effectiveness of the treatment program using both cognitive behavioral techniques and virtual reality strategies for fear of flying reduced flight-related anxiety in the subjects in our study. Our results show that subjects demonstrated lower anxiety levels after the first flight following the program than before the intervention.

Aging Enhances Indirect Flight Muscle Fiber Performance yet Decreases Flight Ability in Drosophila

Energy Technology Data Exchange (ETDEWEB)

Miller, Mark S.; Lekkas, Panagiotis; Braddock, Joan M.; Farman, Gerrie P.; Ballif, Bryan A.; Irving, Thomas C.; Maughan, David W.; Vigoreaux, Jim O. (IIT); (Vermont)

2008-10-02

We investigated the effects of aging on Drosophila melanogaster indirect flight muscle from the whole organism to the actomyosin cross-bridge. Median-aged (49-day-old) flies were flight impaired, had normal myofilament number and packing, barely longer sarcomeres, and slight mitochondrial deterioration compared with young (3-day-old) flies. Old (56-day-old) flies were unable to beat their wings, had deteriorated ultrastructure with severe mitochondrial damage, and their skinned fibers failed to activate with calcium. Small-amplitude sinusoidal length perturbation analysis showed median-aged indirect flight muscle fibers developed greater than twice the isometric force and power output of young fibers, yet cross-bridge kinetics were similar. Large increases in elastic and viscous moduli amplitude under active, passive, and rigor conditions suggest that median-aged fibers become stiffer longitudinally. Small-angle x-ray diffraction indicates that myosin heads move increasingly toward the thin filament with age, accounting for the increased transverse stiffness via cross-bridge formation. We propose that the observed protein composition changes in the connecting filaments, which anchor the thick filaments to the Z-disk, produce compensatory increases in longitudinal stiffness, isometric tension, power and actomyosin interaction in aging indirect flight muscle. We also speculate that a lack of MgATP due to damaged mitochondria accounts for the decreased flight performance.

Time-Accurate Calculations of Free-Flight Aerodynamics of Maneuvering Projectiles

National Research Council Canada - National Science Library

Sahu, Jubaraj

2007-01-01

...) have been successfully fully coupled on high performance computing (HPC) platforms for "Virtual Fly-Outs" of munitions similar to actual free flight tests in the aerodynamic experimental facilities...

OBTAINING A PERMIT-TO-FLY FOR A HALE-UAV IN BELGIUM

Directory of Open Access Journals (Sweden)

J. Everaerts

2012-09-01

Full Text Available Ever since 2000, VITO has been working on the Pegasus project. This involves a solar High Altitude Long Endurance Unmanned Aerial Vehicle (HALE-UAV as a stratospheric platform for Earth Observation. This aircraft, called Mercator, is designed to fly for prolonged duration at altitudes up to 20 km. The technology has been proven by the aircraft’s manufacturer, QinetiQ (UK by a series of test flights over the past years, culminating in a world record flight in duration of over 14 days duration. All test flights, however, were conducted in test ranges, where other air traffic does not pose a concern. Pegasus aims to demonstrate the viability of stratospheric Earth Observation in Belgium, as a proof of concept for other areas around the world. The Belgian air space is completely different from a test range. More than 1 million aircraft movements take place over Belgium and Luxembourg every year, with routes to Amsterdam, Paris, Frankfurt, and London. Although Pegasus will usually be flying above this dense traffic, it does interfere with it during ascent and landing, and needs to be monitored during the cruise phase for safety reasons. Air traffic management in Belgium is a shared responsibility of Air Navigation Service Providers (ANSPs Belgocontrol (civil, ATCC (military and Eurocontrol MUAC (high altitude. In 2010, VITO applied for a permit-to-fly for a test flight of one day duration. Although the Belgian Civil Aviation Authority (CAA had issued a regulation on UAVs in 2007, it was the first application for a permit to fly in controlled airspace. The Belgian CAA decided to use it as a test for the procedures as well. A prerequisite for flying in controlled airspace was that the aircraft has to carry a mode-S transponder and navigation lights. During first half of 2010, the ANSPs collaborated on a Temporary Operations Instruction and studied the safety impact of this flight on their operations. As an outcome, they decided that the Pegasus

Radiation dose to the global flying population

International Nuclear Information System (INIS)

Alvarez, Luis E; Eastham, Sebastian D; Barrett, Steven R H

2016-01-01

Civil airliner passengers and crew are exposed to elevated levels of radiation relative to being at sea level. Previous studies have assessed the radiation dose received in particular cases or for cohort studies. Here we present the first estimate of the total radiation dose received by the worldwide civilian flying population. We simulated flights globally from 2000 to 2013 using schedule data, applying a radiation propagation code to estimate the dose associated with each flight. Passengers flying in Europe and North America exceed the International Commission on Radiological Protection annual dose limits at an annual average of 510 or 420 flight hours per year, respectively. However, this falls to 160 or 120 h on specific routes under maximum exposure conditions. (paper)

Flying Fast and High: Operational Flight Planning for Maximum Data Return for Airborne Snow Observatory Mountain Surveys

Science.gov (United States)

Berisford, D. F.; Painter, T. H.; Richardson, M.; Wallach, A.; Deems, J. S.; Bormann, K. J.

2017-12-01

The Airborne Snow Observatory (ASO - http://aso.jpl.nasa.gov) uses an airborne laser scanner to map snow depth, and imaging spectroscopy to map snow albedo in order to estimate snow water equivalent and melt rate over mountainous, hydrologic basin-scale areas. Optimization of planned flight lines requires the balancing of many competing factors, including flying altitude and speed, bank angle limitation, laser pulse rate and power level, flightline orientation relative to terrain, surface optical properties, and data output requirements. These variables generally distill down to cost vs. higher resolution data. The large terrain elevation variation encountered in mountainous terrain introduces the challenge of narrow swath widths over the ridgetops, which drive tight flightline spacing and possible dropouts over the valleys due to maximum laser range. Many of the basins flown by ASO exceed 3,000m of elevation relief, exacerbating this problem. Additionally, sun angle may drive flightline orientations for higher-quality spectrometer data, which may change depending on time of day. Here we present data from several ASO missions, both operational and experimental, showing the lidar performance and accuracy limitations for a variety of operating parameters. We also discuss flightline planning strategies to maximize data density return per dollar, and a brief analysis on the effect of short turn times/steep bank angles on GPS position accuracy.

Hovering and intermittent flight in birds

International Nuclear Information System (INIS)

Tobalske, Bret W

2010-01-01

Two styles of bird locomotion, hovering and intermittent flight, have great potential to inform future development of autonomous flying vehicles. Hummingbirds are the smallest flying vertebrates, and they are the only birds that can sustain hovering. Their ability to hover is due to their small size, high wingbeat frequency, relatively large margin of mass-specific power available for flight and a suite of anatomical features that include proportionally massive major flight muscles (pectoralis and supracoracoideus) and wing anatomy that enables them to leave their wings extended yet turned over (supinated) during upstroke so that they can generate lift to support their weight. Hummingbirds generate three times more lift during downstroke compared with upstroke, with the disparity due to wing twist during upstroke. Much like insects, hummingbirds exploit unsteady mechanisms during hovering including delayed stall during wing translation that is manifest as a leading-edge vortex (LEV) on the wing and rotational circulation at the end of each half stroke. Intermittent flight is common in small- and medium-sized birds and consists of pauses during which the wings are flexed (bound) or extended (glide). Flap-bounding appears to be an energy-saving style when flying relatively fast, with the production of lift by the body and tail critical to this saving. Flap-gliding is thought to be less costly than continuous flapping during flight at most speeds. Some species are known to shift from flap-gliding at slow speeds to flap-bounding at fast speeds, but there is an upper size limit for the ability to bound (∼0.3 kg) and small birds with rounded wings do not use intermittent glides.

Hovering and intermittent flight in birds

Energy Technology Data Exchange (ETDEWEB)

Tobalske, Bret W, E-mail: bret.tobalske@mso.umt.ed [Field Research Station at Fort Missoula, Division of Biological Sciences, University of Montana, Missoula, MT 59812 (United States)

2010-12-15

Two styles of bird locomotion, hovering and intermittent flight, have great potential to inform future development of autonomous flying vehicles. Hummingbirds are the smallest flying vertebrates, and they are the only birds that can sustain hovering. Their ability to hover is due to their small size, high wingbeat frequency, relatively large margin of mass-specific power available for flight and a suite of anatomical features that include proportionally massive major flight muscles (pectoralis and supracoracoideus) and wing anatomy that enables them to leave their wings extended yet turned over (supinated) during upstroke so that they can generate lift to support their weight. Hummingbirds generate three times more lift during downstroke compared with upstroke, with the disparity due to wing twist during upstroke. Much like insects, hummingbirds exploit unsteady mechanisms during hovering including delayed stall during wing translation that is manifest as a leading-edge vortex (LEV) on the wing and rotational circulation at the end of each half stroke. Intermittent flight is common in small- and medium-sized birds and consists of pauses during which the wings are flexed (bound) or extended (glide). Flap-bounding appears to be an energy-saving style when flying relatively fast, with the production of lift by the body and tail critical to this saving. Flap-gliding is thought to be less costly than continuous flapping during flight at most speeds. Some species are known to shift from flap-gliding at slow speeds to flap-bounding at fast speeds, but there is an upper size limit for the ability to bound ({approx}0.3 kg) and small birds with rounded wings do not use intermittent glides.

An Experimental Study of High Strength-High Volume Fly Ash Concrete for Sustainable Construction Industry

Science.gov (United States)

Kate, Gunavant K.; Thakare, Sunil B., Dr.

2017-08-01

Concrete is the most widely used building material in the construction of infrastructures such as buildings, bridges, highways, dams, and many other facilities. This paper reports the development, the basic idea, the main properties of high strength-high volume fly ash with application in concrete associated with the development and implementation of Sustainable Properties of High Volume Fly Ash Concrete (HVFAC) Mixtures and Early Age Shrinkage and mechanical properties of concrete for 7,28,56 and 90days. Another alternative to make environment-friendly concrete is the development of high strength-high-volume fly ash concrete which is an synthesized from materials of geological origin or by-product materials such as fly ash which is rich in silicon and aluminum. In this paper 6 concrete mixtures were produced to evaluate the effect of key parameters on the mechanical properties of concrete and its behavior. The study key parameters are; binder material content, cement replacement ratios, and the steel fibers used to High Volume Fly Ash mixtures for increasing performance of concrete.

Cost-Effectiveness of Flight Simulators for Military Training. Volume 1. Use and Effectiveness of Flight Simulators

Science.gov (United States)

1977-08-01

Training Division DCS for Personnel LCOL Ralph H. Lauder Aviation Systems Division DCS, RDA CAPT James LeBlanc Aviation Manpower and Training...Since. a commercial flight brings in money to the airlines, their pilots are encouraged to fly up to the limit supported by the market. A military...by 17 percent in FY 1981. Thus, while flight simulators may save money by reducing flying hours, it is also necessary to demonstrate that they are

Self compacting concrete incorporating high-volumes of fly ash

Energy Technology Data Exchange (ETDEWEB)

Bouzoubaa, N. [Natural Resources Canada, Ottawa, ON (Canada). International Centre for Sustainable Development of Cement and Concrete; Lachemi, M. [Ryerson Polytechnic Univ., Toronto, ON (Canada). Dept. of Civil Engineering

2004-07-01

Self-compacting concrete (SCC) is now widely used in reinforced concrete structures. Fine materials such as fly ash ensure that the concrete has the necessary properties of high fluidity and cohesiveness. An experimental study was conducted in which 9 SCC mixtures and one control concrete were produced in order to evaluate SCC made with high-volumes of fly ash. The content of the cementitious materials remained constant at 400 kg/cubic metre, but the ratio of water to cementitious material ranged from 0.35 to 0.45. The viscosity and stability of the fresh concrete was determined for self-compacting mixtures of 40, 50 and 60 per cent Class F fly ash. The compressive strength and drying shrinkage were also determined for the hardened concretes. Results showed that the SCCs developed a 28-day compressive strength ranging from 26 to 48 MPa. It was concluded that high-volumes of Class F fly ash could offer the following advantages to an SCC: reduced construction time and labour cost; eliminate the need for vibration; reduce noise pollution; improve the filling capacity of highly congested structural members; and, ensure good structural performance. 19 refs., 8 tabs., 2 figs.

Wind and Wake Sensing with UAV Formation Flight: System Development and Flight Testing

Science.gov (United States)

Larrabee, Trenton Jameson

Wind turbulence including atmospheric turbulence and wake turbulence have been widely investigated; however, only recently it become possible to use Unmanned Aerial Vehicles (UAVs) as a validation tool for research in this area. Wind can be a major contributing factor of adverse weather for aircraft. More importantly, it is an even greater risk towards UAVs because of their small size and weight. Being able to estimate wind fields and gusts can potentially provide substantial benefits for both unmanned and manned aviation. Possible applications include gust suppression for improving handling qualities, a better warning system for high wind encounters, and enhanced control for small UAVs during flight. On the other hand, the existence of wind can be advantageous since it can lead to fuel savings and longer duration flights through dynamic soaring or thermal soaring. Wakes are an effect of the lift distribution across an aircraft's wing or tail. Wakes can cause substantial disturbances when multiple aircraft are moving through the same airspace. In fact, the perils from an aircraft flying through the wake of another aircraft is a leading cause of the delay between takeoff times at airports. Similar to wind, though, wakes can be useful for energy harvesting and increasing an aircraft's endurance when flying in formation which can be a great advantage to UAVs because they are often limited in flight time due to small payload capacity. Formation flight can most often be seen in manned aircraft but can be adopted for use with unmanned systems. Autonomous flight is needed for flying in the "sweet spot" of the generated wakes for energy harvesting as well as for thermal soaring during long duration flights. For the research presented here formation flight was implemented for the study of wake sensing and gust alleviation. The major contributions of this research are in the areas of a novel technique to estimate wind using an Unscented Kalman filter and experimental wake

Nocturnal insects use optic flow for flight control

OpenAIRE

Baird, Emily; Kreiss, Eva; Wcislo, William; Warrant, Eric; Dacke, Marie

2011-01-01

To avoid collisions when navigating through cluttered environments, flying insects must control their flight so that their sensory systems have time to detect obstacles and avoid them. To do this, day-active insects rely primarily on the pattern of apparent motion generated on the retina during flight (optic flow). However, many flying insects are active at night, when obtaining reliable visual information for flight control presents much more of a challenge. To assess whether nocturnal flyin...

Flying spin qualities testing of airplane

Directory of Open Access Journals (Sweden)

Kostić Čedomir J.

2015-01-01

Full Text Available In this paper is presented the theoretical analysis of origins and characteristics of spinning motion. There are precise explanation of every stage spin flight and basic meaning of notion. Personated equation of motion in spin and equitation of motion airplane in settled spin motion, analysis of them and general recommendation for pilots for recovering from spins. Introduced in valid military and civil specifications flight test demonstration requirements for departure resistance and flying stall and spin qualities testing of airplane. Special attention was given on predicting departure, stall and spin susceptibility and theoretical analysis in the name of magnify flight testing security. There are explanation of test equipment and methodology of flying qualities testing of airplanes. Like a support of this theme are described method and results of flight stall and spin qualities testing of airplane G-4(N-62 super see-gull with precise recommendation for pilots for recovering from spins, from TOC SLI VS (Technical testing center, department for fight testing Air Force of Serbia.

Durability properties of high volume fly ash self compacting concretes

Energy Technology Data Exchange (ETDEWEB)

P. Dinakar; K.G. Babu; Manu Santhanam [Indian Institute of Technology, Chennai (India). Building Technology Division

2008-11-15

This paper presents an experimental study on the durability properties of self compacting concretes (SCCs) with high volume replacements of fly ash. Eight fly ash self compacting concretes of various strength grades were designed at desired fly ash percentages of 0, 10, 30, 50, 70 and 85%, in comparison with five different mixtures of normal vibrated concretes (NCs) at equivalent strength grades. The durability properties were studied through the measurement of permeable voids, water absorption, acid attack and chloride permeation. The results indicated that the SCCs showed higher permeable voids and water absorption than the vibrated normal concretes of the same strength grades. However, in acid attack and chloride diffusion studies the high volume fly ash SCCs had significantly lower weight losses and chloride ion diffusion.

Aerodynamics of bird flight

Directory of Open Access Journals (Sweden)

Dvořák Rudolf

2016-01-01

Full Text Available Unlike airplanes birds must have either flapping or oscillating wings (the hummingbird. Only such wings can produce both lift and thrust – two sine qua non attributes of flying.The bird wings have several possibilities how to obtain the same functions as airplane wings. All are realized by the system of flight feathers. Birds have also the capabilities of adjusting the shape of the wing according to what the immediate flight situation demands, as well as of responding almost immediately to conditions the flow environment dictates, such as wind gusts, object avoidance, target tracking, etc. In bird aerodynamics also the tail plays an important role. To fly, wings impart downward momentum to the surrounding air and obtain lift by reaction. How this is achieved under various flight situations (cruise flight, hovering, landing, etc., and what the role is of the wing-generated vortices in producing lift and thrust is discussed.The issue of studying bird flight experimentally from in vivo or in vitro experiments is also briefly discussed.

Visualization of Projectile Flying at High Speed in Dusty Atmosphere

Science.gov (United States)

Masaki, Chihiro; Watanabe, Yasumasa; Suzuki, Kojiro

2017-10-01

Considering a spacecraft that encounters particle-laden environment, such as dust particles flying up over the regolith by the jet of the landing thruster, high-speed flight of a projectile in such environment was experimentally simulated by using the ballistic range. At high-speed collision of particles on the projectile surface, they may be reflected with cracking into smaller pieces. On the other hand, the projectile surface will be damaged by the collision. To obtain the fundamental characteristics of such complicated phenomena, a projectile was launched at the velocity up to 400 m/s and the collective behaviour of particles around projectile was observed by the high-speed camera. To eliminate the effect of the gas-particle interaction and to focus on only the effect of the interaction between the particles and the projectile's surface, the test chamber pressure was evacuated down to 30 Pa. The particles about 400μm diameter were scattered and formed a sheet of particles in the test chamber by using two-dimensional funnel with a narrow slit. The projectile was launched into the particle sheet in the tangential direction, and the high-speed camera captured both projectile and particle motions. From the movie, the interaction between the projectile and particle sheet was clarified.

Closed-Loop System Identification Experience for Flight Control Law and Flying Qualities Evaluation of a High Performance Fighter Aircraft

Science.gov (United States)

Murphy, Patrick C.

1999-01-01

This paper highlights some of the results and issues associated with estimating models to evaluate control law design methods and design criteria for advanced high performance aircraft. Experimental fighter aircraft such as the NASA High Alpha Research Vehicle (HARV) have the capability to maneuver at very high angles of attack where nonlinear aerodynamics often predominate. HARV is an experimental F/A-18, configured with thrust vectoring and conformal actuated nose strakes. Identifying closed-loop models for this type of aircraft can be made difficult by nonlinearities and high-order characteristics of the system. In this paper only lateral-directional axes are considered since the lateral-directional control law was specifically designed to produce classical airplane responses normally expected with low-order, rigid-body systems. Evaluation of the control design methodology was made using low-order equivalent systems determined from flight and simulation. This allowed comparison of the closed-loop rigid-body dynamics achieved in flight with that designed in simulation. In flight, the On Board Excitation System was used to apply optimal inputs to lateral stick and pedals at five angles of attack: 5, 20, 30, 45, and 60 degrees. Data analysis and closed-loop model identification were done using frequency domain maximum likelihood. The structure of the identified models was a linear state-space model reflecting classical 4th-order airplane dynamics. Input time delays associated with the high-order controller and aircraft system were accounted for in data preprocessing. A comparison of flight estimated models with small perturbation linear design models highlighted nonlinearities in the system and indicated that the estimated closed-loop rigid-body dynamics were sensitive to input amplitudes at 20 and 30 degrees angle of attack.

NASA-FAA helicopter Microwave Landing System curved path flight test

Science.gov (United States)

Swenson, H. N.; Hamlin, J. R.; Wilson, G. W.

1984-01-01

An ongoing series of joint NASA/FAA helicopter Microwave Landing System (MLS) flight tests was conducted at Ames Research Center. This paper deals with tests done from the spring through the fall of 1983. This flight test investigated and developed solutions to the problem of manually flying curved-path and steep glide slope approaches into the terminal area using the MLS and flight director guidance. An MLS-equipped Bell UH-1H helicopter flown by NASA test pilots was used to develop approaches and procedures for flying these approaches. The approaches took the form of Straight-in, U-turn, and S-turn flightpaths with glide slopes of 6 deg, 9 deg, and 12 deg. These procedures were evaluated by 18 pilots from various elements of the helicopter community, flying a total of 221 hooded instrument approaches. Flying these curved path and steep glide slopes was found to be operationally acceptable with flight director guidance using the MLS.

Nocturnal insects use optic flow for flight control.

Science.gov (United States)

Baird, Emily; Kreiss, Eva; Wcislo, William; Warrant, Eric; Dacke, Marie

2011-08-23

To avoid collisions when navigating through cluttered environments, flying insects must control their flight so that their sensory systems have time to detect obstacles and avoid them. To do this, day-active insects rely primarily on the pattern of apparent motion generated on the retina during flight (optic flow). However, many flying insects are active at night, when obtaining reliable visual information for flight control presents much more of a challenge. To assess whether nocturnal flying insects also rely on optic flow cues to control flight in dim light, we recorded flights of the nocturnal neotropical sweat bee, Megalopta genalis, flying along an experimental tunnel when: (i) the visual texture on each wall generated strong horizontal (front-to-back) optic flow cues, (ii) the texture on only one wall generated these cues, and (iii) horizontal optic flow cues were removed from both walls. We find that Megalopta increase their groundspeed when horizontal motion cues in the tunnel are reduced (conditions (ii) and (iii)). However, differences in the amount of horizontal optic flow on each wall of the tunnel (condition (ii)) do not affect the centred position of the bee within the flight tunnel. To better understand the behavioural response of Megalopta, we repeated the experiments on day-active bumble-bees (Bombus terrestris). Overall, our findings demonstrate that despite the limitations imposed by dim light, Megalopta-like their day-active relatives-rely heavily on vision to control flight, but that they use visual cues in a different manner from diurnal insects. This journal is © 2011 The Royal Society

Alertness management in two-person long-haul flight operations

Science.gov (United States)

Rosekind, M. R.; Gander, P. H.

1992-01-01

Long-haul flight operations involve cumulative sleep loss, circadian disruption, and extended and irregular duty schedules. These factors reduce pilot alertness and performance on the flightdeck. Conceptually and operationally, alertness management in flight operations can be divided into preventive strategies and operational countermeasures. Preventive strategies are utilized prior to a duty period to mitigate or reduce the effects of sleep loss, circadian disruption and fatigue during subsequent flight operations. Operational countermeasures are used during operations as acute techniques for maintaining performance and alertness. Results from previous NASA Ames field studies document the sleep loss and circadian disruption in three-person long-haul flying and illustrate the application of preventive strategies and operational countermeasures. One strategy that can be used in both a preventive and operational manner is strategic napping. The application and effectiveness of strategic napping in long-haul operations will be discussed. Finally, long-haul flying in two-person highly automated aircraft capable of extended range operations will create new challenges to maintaining pilot alertness and performance. Alertness management issues in this flight environment will be explored.

Flying Drosophilamelanogaster maintain arbitrary but stable headings relative to the angle of polarized light.

Science.gov (United States)

Warren, Timothy L; Weir, Peter T; Dickinson, Michael H

2018-05-11

Animals must use external cues to maintain a straight course over long distances. In this study, we investigated how the fruit fly Drosophila melanogaster selects and maintains a flight heading relative to the axis of linearly polarized light, a visual cue produced by the atmospheric scattering of sunlight. To track flies' headings over extended periods, we used a flight simulator that coupled the angular velocity of dorsally presented polarized light to the stroke amplitude difference of the animals' wings. In the simulator, most flies actively maintained a stable heading relative to the axis of polarized light for the duration of 15 min flights. We found that individuals selected arbitrary, unpredictable headings relative to the polarization axis, which demonstrates that D . melanogaster can perform proportional navigation using a polarized light pattern. When flies flew in two consecutive bouts separated by a 5 min gap, the two flight headings were correlated, suggesting individuals retain a memory of their chosen heading. We found that adding a polarized light pattern to a light intensity gradient enhanced flies' orientation ability, suggesting D . melanogaster use a combination of cues to navigate. For both polarized light and intensity cues, flies' capacity to maintain a stable heading gradually increased over several minutes from the onset of flight. Our findings are consistent with a model in which each individual initially orients haphazardly but then settles on a heading which is maintained via a self-reinforcing process. This may be a general dispersal strategy for animals with no target destination. © 2018. Published by The Company of Biologists Ltd.

A Study on the Evaluation of Field Application of High-Fluidity Concrete Containing High Volume Fly Ash

Directory of Open Access Journals (Sweden)

Yun-Wang Choi

2015-01-01

Full Text Available In the recent concrete industry, high-fluidity concrete is being widely used for the pouring of dense reinforced concrete. Normally, in the case of high-fluidity concrete, it includes high binder contents, so it is necessary to replace part of the cement through admixtures such as fly ash to procure economic feasibility and durability. This study shows the mechanical properties and field applicability of high-fluidity concrete using mass of fly ash as alternative materials of cement. The high-fluidity concrete mixed with 50% fly ash was measured to manufacture concrete that applies low water/binder ratio to measure the mechanical characteristics as compressive strength and elastic modulus. Also, in order to evaluate the field applicability, high-fluidity concrete containing high volume fly ash was evaluated for fluidity, compressive strength, heat of hydration, and drying shrinkage of concrete.

X-36 during First Flight

Science.gov (United States)

1997-01-01

The remotely-piloted X-36 Tailless Fighter Agility Research Aircraft climbs out from Rogers Dry Lake at the Dryden Flight Research Center on its first flight in May 1997. The aircraft flew for five minutes and reached an altitude of approximately 4,900 feet. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19

14 CFR 121.483 - Flight time limitations: Two pilots and one additional flight crewmember.

Science.gov (United States)

2010-01-01

... crewmember. (a) No certificate holder conducting flag operations may schedule a pilot to fly, in an airplane... 12 hours during any 24 consecutive hours. (b) If a pilot has flown 20 or more hours during any 48... consecutive hours of rest during any seven consecutive days. (c) No pilot may fly as a flight crewmember more...

Flightless mutants in the melon fly and oriental fruit fly (Diptera: Tephritidae) and their possible role in the sterile insect release method

International Nuclear Information System (INIS)

McCombs, S.D.; Saul, S.H.

1992-01-01

Two new mutants that affect adult wing morphology and render the flies incapable of flight.sbd.bubble wing (bw) in the melon fly, Bactrocera cucurbitae (Coquillett), and small wing (sw) in the oriental fruit fly, Bactrocera dorsalis (Hendel).sbd.are described. Both mutants have variable expression and are caused by autosomal, recessive genes. We discuss the possible role of these alleles in constructing genetic sex sorting systems to improve the effectiveness and efficiency of the sterile insect release method

Radiation exposure and high-altitude flight. NCRP Commentary No. 12

International Nuclear Information System (INIS)

1995-01-01

Enhanced air crew and public radiation exposure while flying at current altitudes and speeds has not been adequately addressed. However, the commercial aircraft industry continues to expand with greater numbers of passengers and more air crews year by year. With the expected expansions in high-altitude flight in the next two decades there will be many more people exposed to higher levels of ionizing radiation than currently. The equivalent dose rates at the higher altitudes are of the order of two to three times those received at current aircraft altitudes, but are not known very well, partly because of limitations in the knowledge of the component radiations, especially the high-energy neutron component. The risks are also more uncertain than for low-LET exposures on the ground because of uncertainty in an average W R to use for high-LET radiations. Exposures of current air crew are presently comparable with the average exposures of other radiation workers on the ground (EPA, 1995). Substantially higher exposures must be expected at high altitudes to air crew (perhaps approaching or possibly exceeding the current limit for workers on the ground). Higher exposures to sensitive groups of the population such as the fetuses carried by pregnant women are of special concern. Therefore, steps must be taken to improve our knowledge base with respect to dose levels and risks at these high altitudes. Following acquisition of this knowledge, modifications in radiation protection practices with respect to air crew and passengers will need to be considered and recommended to assure that adequate radiation protection is provided with respect to high-altitude flight

Attracting the attention of a fly

OpenAIRE

Sareen, Preeti; Wolf, Reinhard; Heisenberg, Martin

2011-01-01

Organisms with complex visual systems rarely respond to just the sum of all visual stimuli impinging on their eyes. Often, they restrict their responses to stimuli in a temporarily selected region of the visual field (selective visual attention). Here, we investigate visual attention in the fly Drosophila during tethered flight at a torque meter. Flies can actively shift their attention; however, their attention can be guided to a certain location by external cues. Using visual cues, we can d...

X-36 Tailless Fighter Agility Research Aircraft in flight

Science.gov (United States)

1997-01-01

The lack of a vertical tail on the X-36 technology demonstrator is evident as the remotely piloted aircraft flies a low-altitude research flight above Rogers Dry Lake at Edwards Air Force Base in the California desert on October 30, 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three

Schlieren photography on freely flying hawkmoth.

Science.gov (United States)

Liu, Yun; Roll, Jesse; Van Kooten, Stephen; Deng, Xinyan

2018-05-01

The aerodynamic force on flying insects results from the vortical flow structures that vary both spatially and temporally throughout flight. Due to these complexities and the inherent difficulties in studying flying insects in a natural setting, a complete picture of the vortical flow has been difficult to obtain experimentally. In this paper, Schlieren , a widely used technique for highspeed flow visualization, was adapted to capture the vortex structures around freely flying hawkmoth ( Manduca ). Flow features such as leading-edge vortex, trailing-edge vortex, as well as the full vortex system in the wake were visualized directly. Quantification of the flow from the Schlieren images was then obtained by applying a physics-based optical flow method, extending the potential applications of the method to further studies of flying insects. © 2018 The Author(s).

WAYS OF ACQUIRING FLYING PHOBIA.

Science.gov (United States)

Schindler, Bettina; Vriends, Noortje; Margraf, Jürgen; Stieglitz, Rolf-Dieter

2016-02-01

The few studies that have explored how flying phobia is acquired have produced contradictory results. We hypothesized that classical conditioning plays a role in acquiring flying phobia and investigated if vicarious (model) learning, informational learning through media, and experiencing stressful life events at the time of onset of phobia also play a role. Thirty patients with flying phobia and thirty healthy controls matched on age, sex, and education were interviewed with the Mini-DIPS, the short German version of the Anxiety Disorders Interview Schedule (DSM-IV diagnostic criteria) and the Fear-of-Flying History Interview. Fifty Percent of patients with flying phobia and 53% of healthy controls reported frightening events in the air. There was no significant difference between the two samples. Thus there were not more classical conditioning events for patients with flying phobia. There also was no significant difference between the two samples for vicarious (model) learning: 37% of flying phobia patients and 23% of healthy controls felt influenced by model learning. The influence of informational learning through media was significantly higher for the clinical sample (70%) than for the control group (37%). Patients with flying phobia experienced significantly more stressful life events in the period of their frightening flight experience (60%) than healthy controls (19%). Frightening experiences while flying are quite common, but not everybody develops a flying phobia. Stressful life events and other factors might enhance conditionability. Informational learning through negative media reports probably reinforces the development of flying phobia. Clinical implications are discussed. © 2015 Wiley Periodicals, Inc.

To Fly in the Sky.

Science.gov (United States)

Brodie, Carolyn S.

1995-01-01

Suggests activities for students that focus on airplanes, famous pilots, and travel. Provides a list of suggested titles with the following topics: history of flight and airplanes; airplanes and flying information; paper and model airplanes; Charles Lindbergh; Amelia Earhart; the Wright Brothers; videos; and picture books. (AEF)

Orion Powered Flight Guidance Burn Options for Near Term Exploration

Science.gov (United States)

Fill, Tom; Goodman, John; Robinson, Shane

2018-01-01

NASA's Orion exploration spacecraft will fly more demanding mission profiles than previous NASA human flight spacecraft. Missions currently under development are destined for cislunar space. The EM-1 mission will fly unmanned to a Distant Retrograde Orbit (DRO) around the Moon. EM-2 will fly astronauts on a mission to the lunar vicinity. To fly these missions, Orion requires powered flight guidance that is more sophisticated than the orbital guidance flown on Apollo and the Space Shuttle. Orion's powered flight guidance software contains five burn guidance options. These five options are integrated into an architecture based on a proven shuttle heritage design, with a simple closed-loop guidance strategy. The architecture provides modularity, simplicity, versatility, and adaptability to future, yet-to-be-defined, exploration mission profiles. This paper provides a summary of the executive guidance architecture and details the five burn options to support both the nominal and abort profiles for the EM-1 and EM-2 missions.

X-36 Taking off During First Flight

Science.gov (United States)

1997-01-01

The X-36 remotely piloted aircraft lifts off on its first flight, May 17, 1997, at NASA's Dryden Flight Research Center, Edwards, California. The aircraft flew for five minutes and reached an altitude of approximately 4,900 feet. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet

In-flight simulation of high agility through active control: Taming complexity by design

Science.gov (United States)

Padfield, Gareth D.; Bradley, Roy

1993-01-01

The motivation for research into helicopter agility stems from the realization that marked improvements relative to current operational types are possible, yet there is a dearth of useful criteria for flying qualities at high performance levels. Several research laboratories are currently investing resources in developing second generation airborne rotorcraft simulators. The UK's focus has been the exploitation of agility through active control technology (ACT); this paper reviews the results of studies conducted to date. The conflict between safety and performance in flight research is highlighted and the various forms of safety net to protect against system failures are described. The role of the safety pilot, and the use of actuator and flight envelope limiting are discussed. It is argued that the deep complexity of a research ACT system can only be tamed through a requirement specification assembled using design principles and cast in an operational simulation form. Work along these lines conducted at DRA is described, including the use of the Jackson System Development method and associated Ada simulation.

To walk or to fly? How birds choose among foraging modes

NARCIS (Netherlands)

Bautista, LM; Tinbergen, J; Kacelnik, A; Bautista, Luis M.; Southwood, Richard

2001-01-01

We test the predictive value of the main energetic currencies used in foraging theory using starlings that choose between two foraging modes (walking versus flying). Walking is low-cost, low-yield, whereas flying is the opposite. We fixed experimentally, at 11 different values, the amount of flight

High-Resolution Remotely Sensed Small Target Detection by Imitating Fly Visual Perception Mechanism

Directory of Open Access Journals (Sweden)

Fengchen Huang

2012-01-01

Full Text Available The difficulty and limitation of small target detection methods for high-resolution remote sensing data have been a recent research hot spot. Inspired by the information capture and processing theory of fly visual system, this paper endeavors to construct a characterized model of information perception and make use of the advantages of fast and accurate small target detection under complex varied nature environment. The proposed model forms a theoretical basis of small target detection for high-resolution remote sensing data. After the comparison of prevailing simulation mechanism behind fly visual systems, we propose a fly-imitated visual system method of information processing for high-resolution remote sensing data. A small target detector and corresponding detection algorithm are designed by simulating the mechanism of information acquisition, compression, and fusion of fly visual system and the function of pool cell and the character of nonlinear self-adaption. Experiments verify the feasibility and rationality of the proposed small target detection model and fly-imitated visual perception method.

High-resolution remotely sensed small target detection by imitating fly visual perception mechanism.

Science.gov (United States)

Huang, Fengchen; Xu, Lizhong; Li, Min; Tang, Min

2012-01-01

The difficulty and limitation of small target detection methods for high-resolution remote sensing data have been a recent research hot spot. Inspired by the information capture and processing theory of fly visual system, this paper endeavors to construct a characterized model of information perception and make use of the advantages of fast and accurate small target detection under complex varied nature environment. The proposed model forms a theoretical basis of small target detection for high-resolution remote sensing data. After the comparison of prevailing simulation mechanism behind fly visual systems, we propose a fly-imitated visual system method of information processing for high-resolution remote sensing data. A small target detector and corresponding detection algorithm are designed by simulating the mechanism of information acquisition, compression, and fusion of fly visual system and the function of pool cell and the character of nonlinear self-adaption. Experiments verify the feasibility and rationality of the proposed small target detection model and fly-imitated visual perception method.

Bicycles, Airplanes and Peter Pans: Flying Scenes in Steven Spielberg's Films

Directory of Open Access Journals (Sweden)

Emilio Audissino

2014-10-01

Full Text Available In Steven Spielberg's cinema the flight is a recurring theme. Flying scenes can be sorted into two classes: those involving a realistic flight – by aircraft – and those involving a magical flight – by supernatural powers. The realistic flight is influenced by the war stories of Spielberg's father – a radio man in U.S. Air-force during WWII – and it is featured in such films as Empire of the Sun (1987, Always (1989, and 1941 (1979. The magical flight is influenced by James M. Barries' character Peter Pan (Peter and Wendy, 1911, which is quoted directly in E.T. the Extraterrestrial (1982 and, above all, in Hook (1991, which is a sequel to Barrie's story. These two types of flying scenes are analysed as to their meanings, compared to the models that influenced them, and surveyed as to their evolution across Spielberg's films. A central case study is the episode The Mission from Amazing Stories (1985, in which the realistic and the magical flights overlap.

Theseus in Flight

Science.gov (United States)

1996-01-01

The twin pusher propeller-driven engines of the Theseus research aircraft can be clearly seen in this photo, taken during a 1996 research flight at NASA's Dryden Flight Research Center, Edwards, California. The Theseus aircraft, built and operated by Aurora Flight Sciences Corporation, Manassas, Virginia, was a unique aircraft flown at NASA's Dryden Flight Research Center, Edwards, California, under a cooperative agreement between NASA and Aurora. Dryden hosted the Theseus program, providing hangar space and range safety for flight testing. Aurora Flight Sciences was responsible for the actual flight testing, vehicle flight safety, and operation of the aircraft. The Theseus remotely piloted aircraft flew its maiden flight on May 24, 1996, at Dryden. During its sixth flight on November 12, 1996, Theseus experienced an in-flight structural failure that resulted in the loss of the aircraft. As of the beginning of the year 2000, Aurora had not rebuilt the aircraft. Theseus was built for NASA under an innovative, $4.9 million fixed-price contract by Aurora Flight Sciences Corporation and its partners, West Virginia University, Morgantown, West Virginia, and Fairmont State College, Fairmont, West Virginia. The twin-engine, unpiloted vehicle had a 140-foot wingspan, and was constructed largely of composite materials. Powered by two 80-horsepower, turbocharged piston engines that drove twin 9-foot-diameter propellers, Theseus was designed to fly autonomously at high altitudes, with takeoff and landing under the active control of a ground-based pilot in a ground control station 'cockpit.' With the potential ability to carry 700 pounds of science instruments to altitudes above 60,000 feet for durations of greater than 24 hours, Theseus was intended to support research in areas such as stratospheric ozone depletion and the atmospheric effects of future high-speed civil transport aircraft engines. Instruments carried aboard Theseus also would be able to validate satellite

Aerodynamics, sensing and control of insect-scale flapping-wing flight

Science.gov (United States)

Shyy, Wei; Kang, Chang-kwon; Chirarattananon, Pakpong; Ravi, Sridhar; Liu, Hao

2016-01-01

There are nearly a million known species of flying insects and 13 000 species of flying warm-blooded vertebrates, including mammals, birds and bats. While in flight, their wings not only move forward relative to the air, they also flap up and down, plunge and sweep, so that both lift and thrust can be generated and balanced, accommodate uncertain surrounding environment, with superior flight stability and dynamics with highly varied speeds and missions. As the size of a flyer is reduced, the wing-to-body mass ratio tends to decrease as well. Furthermore, these flyers use integrated system consisting of wings to generate aerodynamic forces, muscles to move the wings, and sensing and control systems to guide and manoeuvre. In this article, recent advances in insect-scale flapping-wing aerodynamics, flexible wing structures, unsteady flight environment, sensing, stability and control are reviewed with perspective offered. In particular, the special features of the low Reynolds number flyers associated with small sizes, thin and light structures, slow flight with comparable wind gust speeds, bioinspired fabrication of wing structures, neuron-based sensing and adaptive control are highlighted. PMID:27118897

X-36 in Flight over Mojave Desert

Science.gov (United States)

1997-01-01

The unusual lines of the X-36 technology demonstrator contrast sharply with the desert floor as the remotely piloted aircraft scoots across the California desert at low altitude during a research flight on October 30, 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with

How Insect Flight Steering Muscles Work

OpenAIRE

Walker, Simon M.; Schwyn, Daniel A.; Mokso, Rajmund; Wicklein, Martina; Müller, Tonya; Doube, Michael; Stampanoni, Marco; Krapp, Holger G.; Taylor, Graham K.

2014-01-01

Dipteran flies are amongst the smallest and most agile of flying animals. Their wings are driven indirectly by large power muscles, which cause cyclical deformations of the thorax that are amplified through the intricate wing hinge. Asymmetric flight manoeuvres are controlled by 13 pairs of steering muscles acting directly on the wing articulations. Collectively the steering muscles account for

Pathfinder-Plus on flight in Hawaii

Science.gov (United States)

1998-01-01

Pathfinder-Plus on a flight over Hawaii in 1998. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4 days

Pathfinder-Plus on flight over Hawaii

Science.gov (United States)

1998-01-01

Pathfinder-Plus on flight over Hawaii. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4 days above 50

Formation Flight Control System for In-Flight Sweet Spot Estimation

NARCIS (Netherlands)

Brodecki, M.; Subbarao, K.; Chu, Q.P.

2013-01-01

A formation flight control system has been designed that addresses the unique environment encountered by aircraft flying in formation and in the upwash of the leading aircraft. In order to test the control system a simulation environment has been created that adequately represents the aerodynamic

Rheology and setting of high volume fly ash mixtures

Energy Technology Data Exchange (ETDEWEB)

Dale P. Bentz; Chiara F. Ferraris [National Institute of Standards and Technology, Gaithersburg, MD (United States). Building and Fire Research Laboratory

2010-04-15

While high volume fly ash (HVFA) concretes can be designed and produced to meet 28-d strength requirements and often even exceed the durability performance of conventional concretes, a persistent problem is the potentially long delay in setting time that produces concurrently long delays in finishing the concrete in the field. Previous isothermal calorimetry studies on two different powder additions, namely calcium hydroxide and a rapid set cement, have shown that these powders can mitigate excessive retardation of the hydration reactions. In this paper, rheological measurements and conventional Vicat setting time studies are conducted to verify that these powder additions do indeed reduce setting times in paste systems based on both ASTM Class C and ASTM Class F fly ashes. The reductions depend on the class of fly ash and suggest that trial mixtures would be a necessity to apply these technologies to each specific fly ash/cement/admixture combination being employed in the field. Potentially, for such screening studies, the rheological measurement of yield stress may provide a faster indication of setting (and finishability) than conventional Vicat needle penetration measurements on pastes.

Orion's Powered Flight Guidance Burn Options for Near Term Exploration Missions

Science.gov (United States)

Fill, Thomas; Goodman, John; Robinson, Shane

2018-01-01

NASA's Orion exploration spacecraft will fly more demanding mission profiles than previous NASA human flight spacecraft. Missions currently under development are destined for cislunar space. The EM-1 mission will fly unmanned to a Distant Retrograde Orbit (DRO) around the Moon. EM-2 will fly astronauts on a mission to the lunar vicinity. To fly these missions, Orion requires powered flight guidance that is more sophisticated than the orbital guidance flown on Apollo and the Space Shuttle. Orion's powered flight guidance software contains five burn guidance options. These five options are integrated into an architecture based on a proven shuttle heritage design, with a simple closed-loop guidance strategy. The architecture provides modularity, simplicity, versatility, and adaptability to future, yet-to-be-defined, exploration mission profiles. This paper provides a summary of the executive guidance architecture and details the five burn options to support both the nominal and abort profiles for the EM-1 and EM-2 missions.

Constructal Theory and Aeroelastic Design of Flexible Flying Wing Aircraft

Directory of Open Access Journals (Sweden)

Pezhman Mardanpour

2017-07-01

Full Text Available The aeroelastic behavior of high-aspect-ratio very flexible flying wing is highly affected by the geometric nonlinearities of the aircraft structure. This paper reviews the findings on how these nonlinearities influence the structural and flight dynamics, and it shows that the aeroelastic flight envelope could significantly be extended with proper choices of design parameters such as engine placement. Moreover, in order to investigate the physics behind the effects of design parameters, constructal theory of design is reviewed. The constructal theory advances the philosophy of design as science, it states that the better structural design emerges when stress flow strangulation is avoided. Furthermore, it shows that airplanes, through their evolution, have obeyed theoretical allometric rules that unite their designs.

The Effects of Design Strength, Fly Ash Content and Curing Method on Compressive Strength of High Volume Fly Ash Concrete: A Design of Experimental

OpenAIRE

Solikin Mochamad; Setiawan Budi

2017-01-01

High volume fly ash concrete becomes one of alternatives to produce green concrete as it uses waste material and significantly reduces the utilization of Portland cement in concrete production. Although using less cement, its compressive strength is comparable to ordinary Portland cement (hereafter OPC) and the its durability increases significantly. This paper reports investigation on the effect of design strength, fly ash content and curing method on compressive strength of High Volume Fly ...

The Effects of Design Strength, Fly Ash Content and Curing Method on Compressive Strength of High Volume Fly Ash Concrete: A Design of Experimental

Directory of Open Access Journals (Sweden)

Solikin Mochamad

2017-01-01

Full Text Available High volume fly ash concrete becomes one of alternatives to produce green concrete as it uses waste material and significantly reduces the utilization of Portland cement in concrete production. Although using less cement, its compressive strength is comparable to ordinary Portland cement (hereafter OPC and the its durability increases significantly. This paper reports investigation on the effect of design strength, fly ash content and curing method on compressive strength of High Volume Fly Ash Concrete. The experiment and data analysis were prepared using minitab, a statistic software for design of experimental. The specimens were concrete cylinder with diameter of 15 cm and height of 30 cm, tested for its compressive strength at 56 days. The result of the research demonstrates that high volume fly ash concrete can produce comparable compressive strength which meets the strength of OPC design strength especially for high strength concrete. In addition, the best mix proportion to achieve the design strength is the combination of high strength concrete and 50% content of fly ash. Moreover, the use of spraying method for curing method of concrete on site is still recommended as it would not significantly reduce the compressive strength result.

FT 3 Flight Test Cards for Export

Science.gov (United States)

Marston, Michael L.

2015-01-01

These flight test cards will be made available to stakeholders who participated in FT3. NASA entered into the relationship with our stakeholders, including the FAA, to develop requirements that will lead to routine flights of unmanned aircraft systems flying in the national airspace system.

Smart wing rotation and trailing-edge vortices enable high frequency mosquito flight

Science.gov (United States)

Bomphrey, Richard J.; Nakata, Toshiyuki; Phillips, Nathan; Walker, Simon M.

2017-03-01

Mosquitoes exhibit unusual wing kinematics; their long, slender wings flap at remarkably high frequencies for their size (>800 Hz)and with lower stroke amplitudes than any other insect group. This shifts weight support away from the translation-dominated, aerodynamic mechanisms used by most insects, as well as by helicopters and aeroplanes, towards poorly understood rotational mechanisms that occur when pitching at the end of each half-stroke. Here we report free-flight mosquito wing kinematics, solve the full Navier-Stokes equations using computational fluid dynamics with overset grids, and validate our results with in vivo flow measurements. We show that, although mosquitoes use familiar separated flow patterns, much of the aerodynamic force that supports their weight is generated in a manner unlike any previously described for a flying animal. There are three key features: leading-edge vortices (a well-known mechanism that appears to be almost ubiquitous in insect flight), trailing-edge vortices caused by a form of wake capture at stroke reversal, and rotational drag. The two new elements are largely independent of the wing velocity, instead relying on rapid changes in the pitch angle (wing rotation) at the end of each half-stroke, and they are therefore relatively immune to the shallow flapping amplitude. Moreover, these mechanisms are particularly well suited to high aspect ratio mosquito wings.

Scaling of soaring seabirds and implications for flight abilities of giant pterosaurs.

Directory of Open Access Journals (Sweden)

Katsufumi Sato

Full Text Available The flight ability of animals is restricted by the scaling effects imposed by physical and physiological factors. In comparisons of the power available from muscle and the mechanical power required to fly, it is predicted that the margin between the powers should decrease with body size and that flying animals have a maximum body size. However, predicting the absolute value of this upper limit has proven difficult because wing morphology and flight styles varies among species. Albatrosses and petrels have long, narrow, aerodynamically efficient wings and are considered soaring birds. Here, using animal-borne accelerometers, we show that soaring seabirds have two modes of flapping frequencies under natural conditions: vigorous flapping during takeoff and sporadic flapping during cruising flight. In these species, high and low flapping frequencies were found to scale with body mass (mass(-0.30 and mass(-0.18 in a manner similar to the predictions from biomechanical flight models (mass(-1/3 and mass(-1/6. These scaling relationships predicted that the maximum limits on the body size of soaring animals are a body mass of 41 kg and a wingspan of 5.1 m. Albatross-like animals larger than the limit will not be able to flap fast enough to stay aloft under unfavourable wind conditions. Our result therefore casts doubt on the flying ability of large, extinct pterosaurs. The largest extant soarer, the wandering albatross, weighs about 12 kg, which might be a pragmatic limit to maintain a safety margin for sustainable flight and to survive in a variable environment.

Adaptive-Repetitive Visual-Servo Control of Low-Flying Aerial Robots via Uncalibrated High-Flying Cameras

Science.gov (United States)

Guo, Dejun; Bourne, Joseph R.; Wang, Hesheng; Yim, Woosoon; Leang, Kam K.

2017-08-01

This paper presents the design and implementation of an adaptive-repetitive visual-servo control system for a moving high-flying vehicle (HFV) with an uncalibrated camera to monitor, track, and precisely control the movements of a low-flying vehicle (LFV) or mobile ground robot. Applications of this control strategy include the use of high-flying unmanned aerial vehicles (UAVs) with computer vision for monitoring, controlling, and coordinating the movements of lower altitude agents in areas, for example, where GPS signals may be unreliable or nonexistent. When deployed, a remote operator of the HFV defines the desired trajectory for the LFV in the HFV's camera frame. Due to the circular motion of the HFV, the resulting motion trajectory of the LFV in the image frame can be periodic in time, thus an adaptive-repetitive control system is exploited for regulation and/or trajectory tracking. The adaptive control law is able to handle uncertainties in the camera's intrinsic and extrinsic parameters. The design and stability analysis of the closed-loop control system is presented, where Lyapunov stability is shown. Simulation and experimental results are presented to demonstrate the effectiveness of the method for controlling the movement of a low-flying quadcopter, demonstrating the capabilities of the visual-servo control system for localization (i.e.,, motion capturing) and trajectory tracking control. In fact, results show that the LFV can be commanded to hover in place as well as track a user-defined flower-shaped closed trajectory, while the HFV and camera system circulates above with constant angular velocity. On average, the proposed adaptive-repetitive visual-servo control system reduces the average RMS tracking error by over 77% in the image plane and over 71% in the world frame compared to using just the adaptive visual-servo control law.

Radiation exposure on flights; Strahlenexposition beim Fliegen. Ein Fall fuer den Strahlenschutz

Energy Technology Data Exchange (ETDEWEB)

Blettner, Maria [Mainz Univ. (Germany). Inst. fuer Medizinische Biometrie, Epidemiologie und Informatik (IMBEI); Boehm, Theresia; Eberbach, Frieder [Vereinigung Cockpit e.V. Main Airport Center (MAC), Frankfurt (Germany). AG Strahlenschutz; Bottollier-Depois, Jean-Francois [Institut de Radioprotection et de Surete Nucleaire (IRSN), Fontenay-aux-Roses (France); Clairand, Isabelle; Huet, Christelle [Institut de Radioprotection et de Surete Nucleaire (IRSN), Fontenay-aux-Roses (France). Ionizing Radiation Dosimetry Lab.; Frasch, Gerhard [Bundesamt fuer Strahlenschutz, Oberschleissheim/Neuherberg (Germany). Beruflicher Strahlenschutz und Strahlenschutzregister; Hammer, Ga el P. [Laboratoire National de Sante E.P., Dudelange (Luxembourg). Registre Morphologique des Tumeurs; Mares, Vladimir; Ruehm, Werner [Helmholtz Zentrum Muenchen Deutsches Forschungszentrum fuer Gesundheit und Umwelt GmbH, Neuherberg (Germany); Voelkle, Hansruedi [Fribourg Univ. (Switzerland). Physikdept.

2014-09-01

Extend and effects of radiation doses occuring during flights are treated under various aspects. Part of them are, in the first line, radiation exposure of the flying staff and the results of epidemiologic studies regarding the health consequences, as well as aspects of practical radiation protection for the flying staff. Computer programs for dose calculation on flights round off the theme. (orig.)

Silent and Efficient Supersonic Bi-Directional Flying Wing

Data.gov (United States)

National Aeronautics and Space Administration — We propose a Phase I study for a novel concept of a supersonic bi-directional (SBiDir) flying wing (FW) that has the potential to revolutionize supersonic flight...

High precision relative position sensing system for formation flying spacecraft

Data.gov (United States)

National Aeronautics and Space Administration — We propose to develop and test an optical sensing system that provides high precision relative position sensing for formation flying spacecraft.  A high precision...

The dynamics of parabolic flight: Flight characteristics and passenger percepts

Science.gov (United States)

Karmali, Faisal; Shelhamer, Mark

2008-09-01

Flying a parabolic trajectory in an aircraft is one of the few ways to create freefall on Earth, which is important for astronaut training and scientific research. Here we review the physics underlying parabolic flight, explain the resulting flight dynamics, and describe several counterintuitive findings, which we corroborate using experimental data. Typically, the aircraft flies parabolic arcs that produce approximately 25 s of freefall (0 g) followed by 40 s of enhanced force (1.8 g), repeated 30-60 times. Although passengers perceive gravity to be zero, in actuality acceleration, and not gravity, has changed, and thus we caution against the terms "microgravity" and "zero gravity." Despite the aircraft trajectory including large (45°) pitch-up and pitch-down attitudes, the occupants experience a net force perpendicular to the floor of the aircraft. This is because the aircraft generates appropriate lift and thrust to produce the desired vertical and longitudinal accelerations, respectively, although we measured moderate (0.2 g) aft-ward accelerations during certain parts of these trajectories. Aircraft pitch rotation (average 3°/s) is barely detectable by the vestibular system, but could influence some physics experiments. Investigators should consider such details in the planning, analysis, and interpretation of parabolic-flight experiments.

Pathfinder-Plus on a flight in Hawaii

Science.gov (United States)

1998-01-01

Pathfinder-Plus on a flight in 1998 over Hawaiian waters. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least

Pathfinder-Plus on flight over Hawaiian Islands

Science.gov (United States)

1998-01-01

Pathfinder-Plus on flight over Hawaiian Islands in 1998. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4

Adaptive evolution of mitochondrial energy metabolism genes associated with increased energy demand in flying insects.

Science.gov (United States)

Yang, Yunxia; Xu, Shixia; Xu, Junxiao; Guo, Yan; Yang, Guang

2014-01-01

Insects are unique among invertebrates for their ability to fly, which raises intriguing questions about how energy metabolism in insects evolved and changed along with flight. Although physiological studies indicated that energy consumption differs between flying and non-flying insects, the evolution of molecular energy metabolism mechanisms in insects remains largely unexplored. Considering that about 95% of adenosine triphosphate (ATP) is supplied by mitochondria via oxidative phosphorylation, we examined 13 mitochondrial protein-encoding genes to test whether adaptive evolution of energy metabolism-related genes occurred in insects. The analyses demonstrated that mitochondrial DNA protein-encoding genes are subject to positive selection from the last common ancestor of Pterygota, which evolved primitive flight ability. Positive selection was also found in insects with flight ability, whereas no significant sign of selection was found in flightless insects where the wings had degenerated. In addition, significant positive selection was also identified in the last common ancestor of Neoptera, which changed its flight mode from direct to indirect. Interestingly, detection of more positively selected genes in indirect flight rather than direct flight insects suggested a stronger selective pressure in insects having higher energy consumption. In conclusion, mitochondrial protein-encoding genes involved in energy metabolism were targets of adaptive evolution in response to increased energy demands that arose during the evolution of flight ability in insects.

Theseus Landing Following Maiden Flight

Science.gov (United States)

1996-01-01

The Theseus prototype research aircraft shows off its high aspect-ratio wing as it comes in for a landing on Rogers Dry Lake after its first test flight from NASA's Dryden Flight Research Center, Edwards, California, on May 24, 1996. The Theseus aircraft, built and operated by Aurora Flight Sciences Corporation, Manassas, Virginia, was a unique aircraft flown at NASA's Dryden Flight Research Center, Edwards, California, under a cooperative agreement between NASA and Aurora. Dryden hosted the Theseus program, providing hangar space and range safety for flight testing. Aurora Flight Sciences was responsible for the actual flight testing, vehicle flight safety, and operation of the aircraft. The Theseus remotely piloted aircraft flew its maiden flight on May 24, 1996, at Dryden. During its sixth flight on November 12, 1996, Theseus experienced an in-flight structural failure that resulted in the loss of the aircraft. As of the beginning of the year 2000, Aurora had not rebuilt the aircraft. Theseus was built for NASA under an innovative, $4.9 million fixed-price contract by Aurora Flight Sciences Corporation and its partners, West Virginia University, Morgantown, West Virginia, and Fairmont State College, Fairmont, West Virginia. The twin-engine, unpiloted vehicle had a 140-foot wingspan, and was constructed largely of composite materials. Powered by two 80-horsepower, turbocharged piston engines that drove twin 9-foot-diameter propellers, Theseus was designed to fly autonomously at high altitudes, with takeoff and landing under the active control of a ground-based pilot in a ground control station 'cockpit.' With the potential ability to carry 700 pounds of science instruments to altitudes above 60,000 feet for durations of greater than 24 hours, Theseus was intended to support research in areas such as stratospheric ozone depletion and the atmospheric effects of future high-speed civil transport aircraft engines. Instruments carried aboard Theseus also would be able

The Comparison Of In-Flight Pitot Static Calibration Method By Using Radio Altimeter As Reference with GPS and Tower Fly By Methods On CN235-100 MPA

Science.gov (United States)

Derajat; Hariowibowo, Hindawan

2018-04-01

The new proposed In-Flight Pitot Static Calibration Method has been carried out during Development and Qualification of CN235-100 MPA (Military Patrol Aircraft). This method is expected to reduce flight hours, less human resources required, no additional special equipment, simple analysis calculation and finally by using this method it is expected to automatically minimized operational cost. At The Indonesian Aerospace (IAe) Flight Test Center Division, the development and updating of new flight test technique and data analysis method as specially for flight physics test subject are still continued to be developed as long as it safety for flight and give additional value for the industrial side. More than 30 years, Flight Test Data Engineers at The Flight Test center Division work together with the Air Crew (Test Pilots, Co-Pilots, and Flight Test Engineers) to execute the flight test activity with standard procedure for both the existance or development test techniques and test data analysis. In this paper the approximation of mathematical model, data reduction and flight test technique of The In-Flight Pitot Static Calibration by using Radio Altimeter as reference will be described and the test results had been compared with another methods ie. By using Global Position System (GPS) and the traditional method (Tower Fly By Method) which were used previously during this Flight Test Program (Ref. [10]). The flight test data case are using CN235-100 MPA flight test data during development and Qualification Flight Test Program at Cazaux Airport, France, in June-November 2009 (Ref. [2]).

Simulation of the Physics of Flight

Science.gov (United States)

Lane, W. Brian

2013-01-01

Computer simulations continue to prove to be a valuable tool in physics education. Based on the needs of an Aviation Physics course, we developed the PHYSics of FLIght Simulator (PhysFliS), which numerically solves Newton's second law for an airplane in flight based on standard aerodynamics relationships. The simulation can be used to pique…

Flying Drosophila orient to sky polarization.

Science.gov (United States)

Weir, Peter T; Dickinson, Michael H

2012-01-10

Insects maintain a constant bearing across a wide range of spatial scales. Monarch butterflies and locusts traverse continents [1, 2], and foraging bees and ants travel hundreds of meters to return to their nests [1, 3, 4], whereas many other insects fly straight for only a few centimeters before changing direction. Despite this variation in spatial scale, the brain region thought to underlie long-distance navigation is remarkably conserved [5, 6], suggesting that the use of a celestial compass is a general and perhaps ancient capability of insects. Laboratory studies of Drosophila have identified a local search mode in which short, straight segments are interspersed with rapid turns [7, 8]. However, this flight mode is inconsistent with measured gene flow between geographically separated populations [9-11], and individual Drosophila can travel 10 km across desert terrain in a single night [9, 12, 13]-a feat that would be impossible without prolonged periods of straight flight. To directly examine orientation behavior under outdoor conditions, we built a portable flight arena in which a fly viewed the natural sky through a liquid crystal device that could experimentally rotate the polarization angle. Our findings indicate that Drosophila actively orient using the sky's natural polarization pattern. Copyright © 2012 Elsevier Ltd. All rights reserved.

Enclosure enhancement of flight performance

KAUST Repository

Ghommem, Mehdi; Garcia, Daniel; Calo, Victor M.

2014-01-01

We use a potential flow solver to investigate the aerodynamic aspects of flapping flights in enclosed spaces. The enclosure effects are simulated by the method of images. Our study complements previous aerodynamic analyses which considered only the near-ground flight. The present results show that flying in the proximity of an enclosure affects the aerodynamic performance of flapping wings in terms of lift and thrust generation and power consumption. It leads to higher flight efficiency and more than 5% increase of the generation of lift and thrust.

Enclosure enhancement of flight performance

KAUST Repository

Ghommem, Mehdi

2014-08-19

We use a potential flow solver to investigate the aerodynamic aspects of flapping flights in enclosed spaces. The enclosure effects are simulated by the method of images. Our study complements previous aerodynamic analyses which considered only the near-ground flight. The present results show that flying in the proximity of an enclosure affects the aerodynamic performance of flapping wings in terms of lift and thrust generation and power consumption. It leads to higher flight efficiency and more than 5% increase of the generation of lift and thrust.

Closing Symposium of the German Research Initiative ComFliTe

CERN Document Server

Radespiel, Rolf; Burg, Jan; Sørensen, Kaare

2013-01-01

This book reports on the German research initiative ComFliTe (Computational Flight Testing), the main goal of which was to enhance the capabilities of and tools for numerical simulation in flight physics to support future aircraft design and development. The initiative was coordinated by the German Aerospace Center (DLR) and promoted collaboration between the aircraft industry and academia. Activities focused on improving physical modeling for separated flows, developing advanced numerical algorithms for series computations and sensitivity predictions, as well as surrogate and reduced order modeling for aero data production and developing robust fluid-, structure- and flight mechanics coupling procedures. Further topics included more efficient handling of aircraft control surfaces and improving simulation methods for maneuvers, such as gust encounter. The important results of this three-year initiative were presented during the ComFliTe closing symposium, which took place at the DLR in Braunschweig, Germany, ...

A Distributed Flight Software Design for Satellite Formation Flying Control

National Research Council Canada - National Science Library

Mueller, Joseph B; Brito, Margarita

2003-01-01

.... Princeton Satellite Systems developed the Formation Flying Module (FFM) for TechSat 21 to provide autonomous reconfiguration, formation keeping,and collision avoidance capabilities to the three-satellite cluster...

F-14 in banked flight

Science.gov (United States)

1979-01-01

NASA 991, an F-14 Navy Tomcat designated the F-14 (1X), is seen here in banked flight over the desert on a research flight at NASA's Dryden Flight Research Center, Edwards, California. The F-14 was used at Dryden between 1979 and 1985 in extensive high-angle-of-attack and spin-control-and-recovery tests. The NASA/Navy program, which included 212 total flights, acheived considerable improvement in the F-14 high-angle-of-attack flying qualities, improved departure and spin resistance, and contributed to substantial improvements in reducing 'wing rock,' (i.e., tilting from one side to another), at high angles of attack. The Navy had been experiencing inadvertant spin entries caused by the F-14's aileron rudder interconnect. The NASA/Navy/Grumman team developed and tested 4 different configurations of the aileron rudder interconnect to address the spin problem. These problems prompted the Navy to ask the manufacturer, Grumman, and NASA to investigate the issue. NASA 991 had numerous special additions for high-angle-of-attack and spin-recovery research. These included a battery-powered auxiliary power unit, a flight test nose boom, and a special spin recovery system, consisting of forward mounted, hydraulically actuated canards and an emergency spin chute. NASA's F-14 was first flown by NASA research pilots, but was later flown by Grumman, and by Navy test pilots from Patuxent River Naval Air Station (NAS). The Navy test flights with the spin research vehicle constituted the first program that incorporated air combat maneuvering in its test flights at Dryden. The Navy brought F-14s from Point Mugu and Miramar NAS in San Diego to test the new spin control laws in combat situations. Although the new control laws proved valuable, the Navy did not incorporate them into production F-14s until the F-14D, nearly 15 years later.

X-36 Being Prepared on Lakebed for First Flight

Science.gov (United States)

1997-01-01

Lit by the rays of the morning sunrise on Rogers Dry Lake, adjacent to NASA's Dryden Flight Research Center, Edwards, California, technicians prepare the remotely-piloted X-36 Tailless Fighter Agility Research Aircraft for its first flight in May 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet

Mechanization of and experience with a triplex fly-by-wire backup control system

Science.gov (United States)

Lock, W. P.; Petersen, W. R.; Whitman, G. B.

1976-01-01

A redundant three axis analog control system was designed and developed to back up a digital fly by wire control system for an F-8C airplane. The mechanization and operational experience with the backup control system, the problems involved in synchronizing it with the primary system, and the reliability of the system are discussed. The backup control system was dissimilar to the primary system, and it provided satisfactory handling through the flight envelope evaluated. Limited flight tests of a variety of control tasks showed that control was also satisfactory when the backup control system was controlled by a minimum displacement (force) side stick. The operational reliability of the F-8 digital fly by wire control system was satisfactory, with no unintentional downmodes to the backup control system in flight. The ground and flight reliability of the system's components is discussed.

Heat dissipation during hovering and forward flight in hummingbirds.

Science.gov (United States)

Powers, Donald R; Tobalske, Bret W; Wilson, J Keaton; Woods, H Arthur; Corder, Keely R

2015-12-01

Flying animals generate large amounts of heat, which must be dissipated to avoid overheating. In birds, heat dissipation is complicated by feathers, which cover most body surfaces and retard heat loss. To understand how birds manage heat budgets during flight, it is critical to know how heat moves from the skin to the external environment. Hummingbirds are instructive because they fly at speeds from 0 to more than 12 m s(-1), during which they transit from radiative to convective heat loss. We used infrared thermography and particle image velocimetry to test the effects of flight speed on heat loss from specific body regions in flying calliope hummingbirds (Selasphorus calliope). We measured heat flux in a carcass with and without plumage to test the effectiveness of the insulation layer. In flying hummingbirds, the highest thermal gradients occurred in key heat dissipation areas (HDAs) around the eyes, axial region and feet. Eye and axial surface temperatures were 8°C or more above air temperature, and remained relatively constant across speeds suggesting physiological regulation of skin surface temperature. During hovering, birds dangled their feet, which enhanced radiative heat loss. In addition, during hovering, near-body induced airflows from the wings were low except around the feet (approx. 2.5 m s(-1)), which probably enhanced convective heat loss. Axial HDA and maximum surface temperature exhibited a shallow U-shaped pattern across speeds, revealing a localized relationship with power production in flight in the HDA closest to the primary flight muscles. We conclude that hummingbirds actively alter routes of heat dissipation as a function of flight speed.

Computers Take Flight: A History of NASA's Pioneering Digital Fly-By-Wire Project

Science.gov (United States)

Tomayko, James E.

2000-01-01

An overview of the NASA F-8 Fly-by Wire project is presented. The project made two significant contributions to the new technology: (1) a solid design base of techniques that work and those that do not, and (2) credible evidence of good flying qualities and the ability of such a system to tolerate real faults and to continue operation without degradation. In 1972 the F-8C aircraft used in the program became he first digital fly-by-wire aircraft to operate without a mechanical backup system.

The Cryogenic Test Bed experiments: Cryogenic heat pipe flight experiment CRYOHP (STS-53). Cryogenic two phase flight experiment CRYOTP (STS-62). Cryogenic flexible diode flight experiment CRYOFD

Science.gov (United States)

Thienel, Lee; Stouffer, Chuck

1995-09-01

This paper presents an overview of the Cryogenic Test Bed (CTB) experiments including experiment results, integration techniques used, and lessons learned during integration, test and flight phases of the Cryogenic Heat Pipe Flight Experiment (STS-53) and the Cryogenic Two Phase Flight Experiment (OAST-2, STS-62). We will also discuss the Cryogenic Flexible Diode Heat Pipe (CRYOFD) experiment which will fly in the 1996/97 time frame and the fourth flight of the CTB which will fly in the 1997/98 time frame. The two missions tested two oxygen axially grooved heat pipes, a nitrogen fibrous wick heat pipe and a 2-methylpentane phase change material thermal storage unit. Techniques were found for solving problems with vibration from the cryo-collers transmitted through the compressors and the cold heads, and mounting the heat pipe without introducing parasitic heat leaks. A thermally conductive interface material was selected that would meet the requirements and perform over the temperature range of 55 to 300 K. Problems are discussed with the bi-metallic thermostats used for heater circuit protection and the S-Glass suspension straps originally used to secure the BETSU PCM in the CRYOTP mission. Flight results will be compared to 1-g test results and differences will be discussed.

14 CFR 91.151 - Fuel requirements for flight in VFR conditions.

Science.gov (United States)

2010-01-01

... begin a flight in an airplane under VFR conditions unless (considering wind and forecast weather conditions) there is enough fuel to fly to the first point of intended landing and, assuming normal cruising speed— (1) During the day, to fly after that for at least 30 minutes; or (2) At night, to fly after that...

The Function and Organization of the Motor System Controlling Flight Maneuvers in Flies.

Science.gov (United States)

Lindsay, Theodore; Sustar, Anne; Dickinson, Michael

2017-02-06

Animals face the daunting task of controlling their limbs using a small set of highly constrained actuators. This problem is particularly demanding for insects such as Drosophila, which must adjust wing motion for both quick voluntary maneuvers and slow compensatory reflexes using only a dozen pairs of muscles. To identify strategies by which animals execute precise actions using sparse motor networks, we imaged the activity of a complete ensemble of wing control muscles in intact, flying flies. Our experiments uncovered a remarkably efficient logic in which each of the four skeletal elements at the base of the wing are equipped with both large phasically active muscles capable of executing large changes and smaller tonically active muscles specialized for continuous fine-scaled adjustments. Based on the responses to a broad panel of visual motion stimuli, we have developed a model by which the motor array regulates aerodynamically functional features of wing motion. VIDEO ABSTRACT. Copyright © 2017 Elsevier Ltd. All rights reserved.

Enclosure enhancement of flight performance

Directory of Open Access Journals (Sweden)

Mehdi Ghommem

2014-01-01

Full Text Available We use a potential flow solver to investigate the aerodynamic aspects of flapping flights in enclosed spaces. The enclosure effects are simulated by the method of images. Our study complements previous aerodynamic analyses which considered only the near-ground flight. The present results show that flying in the proximity of an enclosure affects the aerodynamic performance of flapping wings in terms of lift and thrust generation and power consumption. It leads to higher flight efficiency and more than 5% increase of the generation of lift and thrust.

Perseus in Flight

Science.gov (United States)

1991-01-01

The Perseus proof-of-concept vehicle flies over Rogers Dry Lake at the Dryden Flight Research Center, Edwards, California, to test basic design concepts for the remotely-piloted, high-altitude vehicle. Perseus B is a remotely piloted aircraft developed as a design-performance testbed under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project. Perseus is one of several flight vehicles involved in the ERAST project. A piston engine, propeller-powered aircraft, Perseus was designed and built by Aurora Flight Sciences Corporation, Manassas, Virginia. The objectives of Perseus B's ERAST flight tests have been to reach and maintain horizontal flight above altitudes of 60,000 feet and demonstrate the capability to fly missions lasting from 8 to 24 hours, depending on payload and altitude requirements. The Perseus B aircraft established an unofficial altitude record for a single-engine, propeller-driven, remotely piloted aircraft on June 27, 1998. It reached an altitude of 60,280 feet. In 1999, several modifications were made to the Perseus aircraft including engine, avionics, and flight-control-system improvements. These improvements were evaluated in a series of operational readiness and test missions at the Dryden Flight Research Center, Edwards, California. Perseus is a high-wing monoplane with a conventional tail design. Its narrow, straight, high-aspect-ratio wing is mounted atop the fuselage. The aircraft is pusher-designed with the propeller mounted in the rear. This design allows for interchangeable scientific-instrument payloads to be placed in the forward fuselage. The design also allows for unobstructed airflow to the sensors and other devices mounted in the payload compartment. The Perseus B that underwent test and development in 1999 was the third generation of the Perseus design, which began with the Perseus Proof-Of-Concept aircraft. Perseus was initially developed as part of NASA's Small High-Altitude Science Aircraft (SHASA

Unsteady bio-fluid dynamics in flying and swimming

Science.gov (United States)

Liu, Hao; Kolomenskiy, Dmitry; Nakata, Toshiyuki; Li, Gen

2017-08-01

Flying and swimming in nature present sophisticated and exciting ventures in biomimetics, which seeks sustainable solutions and solves practical problems by emulating nature's time-tested patterns, functions, and strategies. Bio-fluids in insect and bird flight, as well as in fish swimming are highly dynamic and unsteady; however, they have been studied mostly with a focus on the phenomena associated with a body or wings moving in a steady flow. Characterized by unsteady wing flapping and body undulation, fluid-structure interactions, flexible wings and bodies, turbulent environments, and complex maneuver, bio-fluid dynamics normally have challenges associated with low Reynolds number regime and high unsteadiness in modeling and analysis of flow physics. In this article, we review and highlight recent advances in unsteady bio-fluid dynamics in terms of leading-edge vortices, passive mechanisms in flexible wings and hinges, flapping flight in unsteady environments, and micro-structured aerodynamics in flapping flight, as well as undulatory swimming, flapping-fin hydrodynamics, body-fin interaction, C-start and maneuvering, swimming in turbulence, collective swimming, and micro-structured hydrodynamics in swimming. We further give a perspective outlook on future challenges and tasks of several key issues of the field.

Disposal of low-level radioactive waste using high-calcium fly ash. Final report

International Nuclear Information System (INIS)

Cogburn, C.O.; Hodgson, L.M.; Ragland, R.C.

1986-04-01

The feasibility of using calcium-rich fly ash from coal-fired power plants in the disposal of low-level radioactive waste was examined. The proposed areas of use were: (1) fly-ash cement as a trench lining material; (2) fly ash as a backfill material; and (3) fly ash as a liquid waste solidifier. The physical properties of fly-ash cement were determined to be adequate for trench liner construction, with compressive strengths attaining greater than 3000 psi. Hydraulic conductivities were determined to be less than that for clay mineral deposits, and were on the order of 10 -7 cm/sec, with some observed values as low as 10 -9 cm/sec. Removal of radioisotopes from acidified solutions by fly ash was good for all elements tested except cesium. The removal of cesium by fly ash was similar to that of montmorillonite clay. The corrosive effects on metals in fly ash environments was determined to be slight, if not non-existent. Coatings at the fly-ash/metal interfaces were observed which appeared to inhibit or diminish corrosion. The study has indicated that high-calcium fly ash appears to offer considerable potential for improved retention of low-level radioactive wastes in shallow land disposal sites. Further tests are needed to determine optimum methods of use. 8 refs., 4 figs., 7 tabs

Perseus A High Altitude Remotely Piloted Aircraft being Towed in Flight

Science.gov (United States)

1994-01-01

Perseus A, a remotely piloted, high-altitude research vehicle designed by Aurora Flight Sciences Corp., takes off from Rogers Dry Lake at the Dryden Flight Research Center, Edwards, California. The Perseus was towed into the air by a ground vehicle. At about 700 ft. the aircraft was released and the engine turned the propeller to take the plane to its desired altitude. Perseus B is a remotely piloted aircraft developed as a design-performance testbed under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project. Perseus is one of several flight vehicles involved in the ERAST project. A piston engine, propeller-powered aircraft, Perseus was designed and built by Aurora Flight Sciences Corporation, Manassas, Virginia. The objectives of Perseus B's ERAST flight tests have been to reach and maintain horizontal flight above altitudes of 60,000 feet and demonstrate the capability to fly missions lasting from 8 to 24 hours, depending on payload and altitude requirements. The Perseus B aircraft established an unofficial altitude record for a single-engine, propeller-driven, remotely piloted aircraft on June 27, 1998. It reached an altitude of 60,280 feet. In 1999, several modifications were made to the Perseus aircraft including engine, avionics, and flight-control-system improvements. These improvements were evaluated in a series of operational readiness and test missions at the Dryden Flight Research Center, Edwards, California. Perseus is a high-wing monoplane with a conventional tail design. Its narrow, straight, high-aspect-ratio wing is mounted atop the fuselage. The aircraft is pusher-designed with the propeller mounted in the rear. This design allows for interchangeable scientific-instrument payloads to be placed in the forward fuselage. The design also allows for unobstructed airflow to the sensors and other devices mounted in the payload compartment. The Perseus B that underwent test and development in 1999 was the third generation of the

Optic flow stabilizes flight in ruby-throated hummingbirds.

Science.gov (United States)

Ros, Ivo G; Biewener, Andrew A

2016-08-15

Flying birds rely on visual cues for retinal image stabilization by negating rotation-induced optic flow, the motion of the visual panorama across the retina, through corrective eye and head movements. In combination with vestibular and proprioceptive feedback, birds may also use visual cues to stabilize their body during flight. Here, we test whether artificially induced wide-field motion generated through projected visual patterns elicits maneuvers in body orientation and flight position, in addition to stabilizing vision. To test this hypothesis, we present hummingbirds flying freely within a 1.2 m cylindrical visual arena with a virtual surround rotated at different speeds about its vertical axis. The birds responded robustly to these visual perturbations by rotating their heads and bodies with the moving visual surround, and by adjusting their flight trajectories, following the surround. Thus, similar to insects, hummingbirds appear to use optic flow cues to control flight maneuvers as well as to stabilize their visual inputs. © 2016. Published by The Company of Biologists Ltd.

A role for acoustic distortion in novel rapid frequency modulation behaviour in free-flying male mosquitoes.

Science.gov (United States)

Simões, Patrício M V; Ingham, Robert A; Gibson, Gabriella; Russell, Ian J

2016-07-01

We describe a new stereotypical acoustic behaviour by male mosquitoes in response to the fundamental frequency of female flight tones during mating sequences. This male-specific free-flight behaviour consists of phonotactic flight beginning with a steep increase in wing-beat frequency (WBF) followed by rapid frequency modulation (RFM) of WBF in the lead up to copula formation. Male RFM behaviour involves remarkably fast changes in WBF and can be elicited without acoustic feedback or physical presence of the female. RFM features are highly consistent, even in response to artificial tones that do not carry the multi-harmonic components of natural female flight tones. Comparison between audiograms of the robust RFM behaviour and the electrical responses of the auditory Johnston's organ (JO) reveals that the male JO is tuned not to the female WBF per se but, remarkably, to the difference between the male and female WBFs. This difference is generated in the JO responses as a result of intermodulation distortion products (DPs) caused by non-linear interaction between male-female flight tones in the vibrations of the antenna. We propose that male mosquitoes rely on their own flight tones in making use of DPs to acoustically detect, locate and orientate towards flying females. We argue that the previously documented flight-tone harmonic convergence of flying male and female mosquitoes could be a consequence of WBF adjustments so that DPs generated through flight-tone interaction fall within the optimal frequency ranges for JO detection. © 2016. Published by The Company of Biologists Ltd.

Photogrammetry and ballistic analysis of a high-flying projectile in the STS-124 space shuttle launch

Science.gov (United States)

Metzger, Philip T.; Lane, John E.; Carilli, Robert A.; Long, Jason M.; Shawn, Kathy L.

2010-07-01

A method combining photogrammetry with ballistic analysis is demonstrated to identify flying debris in a rocket launch environment. Debris traveling near the STS-124 Space Shuttle was captured on cameras viewing the launch pad within the first few seconds after launch. One particular piece of debris caught the attention of investigators studying the release of flame trench fire bricks because its high trajectory could indicate a flight risk to the Space Shuttle. Digitized images from two pad perimeter high-speed 16-mm film cameras were processed using photogrammetry software based on a multi-parameter optimization technique. Reference points in the image were found from 3D CAD models of the launch pad and from surveyed points on the pad. The three-dimensional reference points were matched to the equivalent two-dimensional camera projections by optimizing the camera model parameters using a gradient search optimization technique. Using this method of solving the triangulation problem, the xyz position of the object's path relative to the reference point coordinate system was found for every set of synchronized images. This trajectory was then compared to a predicted trajectory while performing regression analysis on the ballistic coefficient and other parameters. This identified, with a high degree of confidence, the object's material density and thus its probable origin within the launch pad environment. Future extensions of this methodology may make it possible to diagnose the underlying causes of debris-releasing events in near-real time, thus improving flight safety.

Stabilisation of clayey soils with high calcium fly ash and cement

Energy Technology Data Exchange (ETDEWEB)

S. Kolias; V. Kasselouri-Rigopoulou; A. Karahalios [National Technical University of Athens, Athens (Greece)

2005-02-01

The effectiveness of using high calcium fly ash and cement in stabilising fine-grained clayey soils (CL,CH) was investigated in the laboratory. Strength tests in uniaxial compression, in indirect (splitting) tension and flexure were carried out on samples to which various percentages of fly ash and cement had been added. Modulus of elasticity was determined at 90 days with different types of load application and 90-day soaked CBR values are also reported. Pavement structures incorporating subgrades improved by in situ stabilisation with fly ash and cement were analyzed for construction traffic and for operating traffic. These pavements are compared with conventional flexible pavements without improved subgrades and the results clearly show the technical benefits of stabilising clayey soils with fly ash and cement. In addition TG-SDTA and XRD tests were carried out on certain samples in order to study the hydraulic compounds, which were formed.

Behavioural system identification of visual flight speed control in Drosophila melanogaster.

Science.gov (United States)

Rohrseitz, Nicola; Fry, Steven N

2011-02-06

Behavioural control in many animals involves complex mechanisms with intricate sensory-motor feedback loops. Modelling allows functional aspects to be captured without relying on a description of the underlying complex, and often unknown, mechanisms. A wide range of engineering techniques are available for modelling, but their ability to describe time-continuous processes is rarely exploited to describe sensory-motor control mechanisms in biological systems. We performed a system identification of visual flight speed control in the fruitfly Drosophila, based on an extensive dataset of open-loop responses previously measured under free flight conditions. We identified a second-order under-damped control model with just six free parameters that well describes both the transient and steady-state characteristics of the open-loop data. We then used the identified control model to predict flight speed responses after a visual perturbation under closed-loop conditions and validated the model with behavioural measurements performed in free-flying flies under the same closed-loop conditions. Our system identification of the fruitfly's flight speed response uncovers the high-level control strategy of a fundamental flight control reflex without depending on assumptions about the underlying physiological mechanisms. The results are relevant for future investigations of the underlying neuromotor processing mechanisms, as well as for the design of biomimetic robots, such as micro-air vehicles.

Flight simulation program for high altitude long endurance unmanned vehicle; Kokodo mujinki no hiko simulation program

Energy Technology Data Exchange (ETDEWEB)

Suzuki, H.; Hashidate, M. [National Aerospace Laboratory, Tokyo (Japan)

1995-11-01

An altitude of about 20 km has the atmospheric density too dilute for common aircraft, and the air resistance too great for satellites. Attention has been drawn in recent years on a high-altitude long-endurance unmanned vehicle that flies at this altitude for a long period of time to serve as a wave relaying base and perform traffic control. Therefore, a development was made on a flight simulation program to evaluate and discuss the guidance and control laws for the high-altitude unmanned vehicle. Equations of motion were derived for three-dimensional six freedom and three-dimensional three freedom. Aerodynamic characteristics of an unmanned vehicle having a Rectenna wing were estimated, and formulation was made according to the past research results on data of winds that the unmanned vehicle is anticipated to encounter at an altitude of 20 km. Noticing the inside of a horizontal plane, a proposal was given on a guidance law that follows a given path. A flight simulation was carried out to have attained a prospect that the unmanned vehicle may be enclosed in a limited space even if the vehicle is encountered with a relatively strong wind. 18 refs., 20 figs., 1 tab.

Metabolism during flight in two species of bats, Phyllostomus hastatus and Pteropus gouldii.

Science.gov (United States)

Thomas, S P

1975-08-01

The energetic cost of flight in a wind-tunnel was measured at various combinations of speed and flight angle from two species of bats whose body masses differ by almost an order of magnitude. The highest mean metabolic rate per unit body mass measured from P. hastatus (mean body mass, 0.093 kg) was 130.4 Wkg-1, and that for P. gouldii (mean body mass, 0.78 kg) was 69.6 Wkg-1. These highest metabolic rates, recorded from flying bats, are essentially the same as those predicted for flying birds of the same body masses, but are from 2.5 to 3.0 times greater than the highest metabolic rates of which similar-size exercising terrestrial mammals appear capable. The lowest mean rate of energy utilization per unit body mass P. hastatus required to sustain level flight was 94.2 Wkg-1 and that for P. gouldii was 53.4 Wkg-1. These data from flying bats together with comparable data for flying birds all fall along a straight line when plotted on double logarithmic coordinates as a function of body mass. Such data show that even the lowest metabolic requirements of bats and birds during level flight are about twice the highest metabolic capabilities of similar-size terrestrial mammals. Flying bats share with flying birds the ability to move substantially greater distance per unit energy consumed than walking or running mammals. Calculations show that P. hastatus requires only one-sixth the energy to cover a given distance as does the same-size terrestrial mammal, while P. gouldii requires one-fourth the energy of the same-size terrestrial mammal. An empirically derived equation is presented which enables one to make estimates of the metabolic rates of bats and birds during level flight in nature from body mass data alone. Metabolic data obtained in this study are compared with predictions calculated from an avian flight theory.

Flight Muscle Development in the Males of Glossina Pallidipes Reared for the Sterile Insect Technique

Energy Technology Data Exchange (ETDEWEB)

Ciampor, F Jr; Palosova, Z; Mancosova, L; Takac, P [Institute of Zoology, Slovak Academy of Sciences, Bratislava, SK-845 06 (Slovakia)

2012-07-15

The project's main goal was to study the influence of laboratory conditions on the development of flight muscles and the ability to fly in males of Glossina pallidipes Austen. Flight muscles can serve as an important criterion in the quality control of mass reared tsetse flies. All experiments were performed in the research and training facility in Bratislava which provided the flies. The experiments were generally performed by comparing different age groups and groups with different flight activity. To acquire data, several approaches were employed, i.e. classical measurements (residual dry weight, thoracic surface) as well as other alternatives - flight mill, electron microscopy and immunohistochemistry - to visualize and analyse muscle development. The results clearly identified differences in age groups. Slight changes in the development of flight muscles regarding different chances to fly were also detected, but these were not sufficiently significant to decrease the quality of males produced in mass rearing facilities. No distinct trends (rising or declining of amount of metabolites) in the groups studied were detected. The differences were in the amount of analysed metabolic components and the structure of the flight muscles. Our results suggest that, similar to other Glossina species, in G. pallidipes males the first days after emergence are crucial for successful muscle development. On the other hand, rearing in cages does not negatively influence the quality of males with respect to their ability to fly and actively search for females in the wild after release. We also compared the mating behaviour of irradiated and non-irradiated males. We initiated the development of a functional walk-in field cage in which to rear a small colony of G. pallidipes under semi-natural conditions. Our work suggested that outside climatic conditions and suitable cage components, e.g. food source, limit the successful realization of using such a cage for rearing tsetse flies

Towards an Improved Pilot-Vehicle Interface for Highly Automated Aircraft: Evaluation of the Haptic Flight Control System

Science.gov (United States)

Schutte, Paul; Goodrich, Kenneth; Williams, Ralph

2012-01-01

The control automation and interaction paradigm (e.g., manual, autopilot, flight management system) used on virtually all large highly automated aircraft has long been an exemplar of breakdowns in human factors and human-centered design. An alternative paradigm is the Haptic Flight Control System (HFCS) that is part of NASA Langley Research Center s Naturalistic Flight Deck Concept. The HFCS uses only stick and throttle for easily and intuitively controlling the actual flight of the aircraft without losing any of the efficiency and operational benefits of the current paradigm. Initial prototypes of the HFCS are being evaluated and this paper describes one such evaluation. In this evaluation we examined claims regarding improved situation awareness, appropriate workload, graceful degradation, and improved pilot acceptance. Twenty-four instrument-rated pilots were instructed to plan and fly four different flights in a fictitious airspace using a moderate fidelity desktop simulation. Three different flight control paradigms were tested: Manual control, Full Automation control, and a simplified version of the HFCS. Dependent variables included both subjective (questionnaire) and objective (SAGAT) measures of situation awareness, workload (NASA-TLX), secondary task performance, time to recognize automation failures, and pilot preference (questionnaire). The results showed a statistically significant advantage for the HFCS in a number of measures. Results that were not statistically significant still favored the HFCS. The results suggest that the HFCS does offer an attractive and viable alternative to the tactical components of today s FMS/autopilot control system. The paper describes further studies that are planned to continue to evaluate the HFCS.

From damselflies to pterosaurs: how burst and sustainable flight performance scale with size.

Science.gov (United States)

Marden, J H

1994-04-01

Recent empirical data for short-burst lift and power production of flying animals indicate that mass-specific lift and power output scale independently (lift) or slightly positively (power) with increasing size. These results contradict previous theory, as well as simple observation, which argues for degradation of flight performance with increasing size. Here, empirical measures of lift and power during short-burst exertion are combined with empirically based estimates of maximum muscle power output in order to predict how burst and sustainable performance scale with body size. The resulting model is used to estimate performance of the largest extant flying birds and insects, along with the largest flying animals known from fossils. These estimates indicate that burst flight performance capacities of even the largest extinct fliers (estimated mass 250 kg) would allow takeoff from the ground; however, limitations on sustainable power output should constrain capacity for continuous flight at body sizes exceeding 0.003-1.0 kg, depending on relative wing length and flight muscle mass.

Pathfinder-Plus takes off on flight in Hawaii

Science.gov (United States)

1998-01-01

Pathfinder-Plus on a flight over Hawaii in 1998. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4 days

RESULTS OF THE FIRST MI-171A2 FLYING LABORATORY TEST PHASE

OpenAIRE

V. A. Ivchin; K. Y. Samsonov

2014-01-01

The present publication describes the results of the first stage of the flying laboratory (Mi-171 helicopter) flight tests performed at Mil Moscow Helicopter Plant, JSC facilities. Main rotor components with blades made of polymer composite materials and X-type tail rotor were tested on the Mi-171 № 14987, flying laboratory, under Mi-171A Helicopter Retrofit Program.

Gemini flies! unmanned flights and the first manned mission

CERN Document Server

Shayler, David J

2018-01-01

In May 1961, President John F. Kennedy committed the United States to landing a man on the moon before the end of the decade. With just a handful of years to pull it off, NASA authorized the Project Gemini space program, which gathered vital knowledge needed to achieve the nation’s goal. This book introduces the crucial three-step test program employed by the Gemini system, covering:  The short unmanned orbital flight of Gemini 1 that tested the compatibility of launch vehicle, spacecraft and ground systems.  The unmanned suborbital flight of Gemini 2 to establish the integrity of the reentry system and protective heat shield.  The three-orbit manned evaluation flight of Gemini 3, christened ‘Molly Brown’ by her crew. A mission recalled orbit by orbit, using mission transcripts, post-flight reports and the astronauts’ own account of their historic journey. The missions of Project Gemini was the pivotal steppingstone between Project Mercury and the Apollo Program. Following the success of its fi...

USAF Test Pilot School. Flying Qualities Textbook, Volume 2, Part 1

Science.gov (United States)

1986-04-01

Qualities Flight Testing, Performance and Flying Qaulities Branch, Flight Test Engneerd ision, 6510th Test Wing, Air Force Flight Mayst Ce1ter, Edwards...For these aircraft, the program manager may re*uire a mil spec written specifically for the aircraft and control system involwd. 5.20.2 _EL k,Tt...OR MANAGED IN CONTEXT OF MISSION, WITH AVAILABLE PILOT ATTENTION. S UNCONTROLLABLE CONTROL WILL BE LOST DURING SOME PORTION OF MISSION. ACCEPTABLE

Studies of Sterile Irradiation Effects on the White-striped Fruit Fly

International Nuclear Information System (INIS)

Limohpasmanee, Wanitch; Tannarin, Thodsapol; Khongratarpon, Titima; Segsarnviriya, Suchada

2011-06-01

Full text: In general, sterile irradiation can affect vigor and mating competitiveness of the fruit flies. The objective of the experiments was to study the effects of sterile irradiation on the white-striped oriental fruit fly, Bactrocera dorsalis (Hendel), developed for sterile fly detection. A day before adult emergence, the pupae were irradiated at the dose of 90 Grays. No effects on adult emergence and flight ability were observed. However, it induced complete sterility in both sexes. Also, it decreased male mating competitiveness significantly, while increasing sexual competitiveness significantly

Theseus First Flight - May 24, 1996

Science.gov (United States)

1996-01-01

The Theseus prototype research aircraft shows off its high aspect-ratio wing as it lifts off from Rogers Dry Lake during its first test flight from NASA's Dryden Flight Research Center, Edwards, California, on May 24, 1996. The Theseus aircraft, built and operated by Aurora Flight Sciences Corporation, Manassas, Virginia, was a unique aircraft flown at NASA's Dryden Flight Research Center, Edwards, California, under a cooperative agreement between NASA and Aurora. Dryden hosted the Theseus program, providing hangar space and range safety for flight testing. Aurora Flight Sciences was responsible for the actual flight testing, vehicle flight safety, and operation of the aircraft. The Theseus remotely piloted aircraft flew its maiden flight on May 24, 1996, at Dryden. During its sixth flight on November 12, 1996, Theseus experienced an in-flight structural failure that resulted in the loss of the aircraft. As of the beginning of the year 2000, Aurora had not rebuilt the aircraft. Theseus was built for NASA under an innovative, $4.9 million fixed-price contract by Aurora Flight Sciences Corporation and its partners, West Virginia University, Morgantown, West Virginia, and Fairmont State College, Fairmont, West Virginia. The twin-engine, unpiloted vehicle had a 140-foot wingspan, and was constructed largely of composite materials. Powered by two 80-horsepower, turbocharged piston engines that drove twin 9-foot-diameter propellers, Theseus was designed to fly autonomously at high altitudes, with takeoff and landing under the active control of a ground-based pilot in a ground control station 'cockpit.' With the potential ability to carry 700 pounds of science instruments to altitudes above 60,000 feet for durations of greater than 24 hours, Theseus was intended to support research in areas such as stratospheric ozone depletion and the atmospheric effects of future high-speed civil transport aircraft engines. Instruments carried aboard Theseus also would be able to

Neuroanatomy of flying reptiles and implications for flight, posture and behaviour.

Science.gov (United States)

Witmer, Lawrence M; Chatterjee, Sankar; Franzosa, Jonathan; Rowe, Timothy

2003-10-30

Comparison of birds and pterosaurs, the two archosaurian flyers, sheds light on adaptation to an aerial lifestyle. The neurological basis of control holds particular interest in that flight demands on sensory integration, equilibrium, and muscular coordination are acute. Here we compare the brain and vestibular apparatus in two pterosaurs based on high-resolution computed tomographic (CT) scans from which we constructed digital endocasts. Although general neural organization resembles birds, pterosaurs had smaller brains relative to body mass than do birds. This difference probably has more to do with phylogeny than flight, in that birds evolved from nonavian theropods that had already established trends for greater encephalization. Orientation of the osseous labyrinth relative to the long axis of the skull was different in these two pterosaur species, suggesting very different head postures and reflecting differing behaviours. Their enlarged semicircular canals reflect a highly refined organ of equilibrium, which is concordant with pterosaurs being visually based, aerial predators. Their enormous cerebellar floccular lobes may suggest neural integration of extensive sensory information from the wing, further enhancing eye- and neck-based reflex mechanisms for stabilizing gaze.

DLR HABLEG- High Altitude Balloon Launched Experimental Glider

Science.gov (United States)

Wlach, S.; Schwarzbauch, M.; Laiacker, M.

2015-09-01

The group Flying Robots at the DLR Institute of Robotics and Mechatronics in Oberpfaffenhofen conducts research on solar powered high altitude aircrafts. Due to the high altitude and the almost infinite mission duration, these platforms are also denoted as High Altitude Pseudo-Satellites (HAPS). This paper highlights some aspects of the design, building, integration and testing of a flying experimental platform for high altitudes. This unmanned aircraft, with a wingspan of 3 m and a mass of less than 10 kg, is meant to be launched as a glider from a high altitude balloon in 20 km altitude and shall investigate technologies for future large HAPS platforms. The aerodynamic requirements for high altitude flight included the development of a launch method allowing for a safe transition to horizontal flight from free-fall with low control authority. Due to the harsh environmental conditions in the stratosphere, the integration of electronic components in the airframe is a major effort. For regulatory reasons a reliable and situation dependent flight termination system had to be implemented. In May 2015 a flight campaign was conducted. The mission was a full success demonstrating that stratospheric research flights are feasible with rather small aircrafts.

THE MODULATED SOUNDS MADE BY THE TSETSE FLY ...

African Journals Online (AJOL)

Tsetse flies produce modulated sounds, variously described as singing, buzzing, squeaking or pinging. The calls are closely related to the vital functions of the community namely hunting, feeding, mating and larviposition. The ecological significance of this faculty, therefore, needs further investigation. The flight sounds ...

Formation Design Strategy for SCOPE High-Elliptic Formation Flying Mission

Science.gov (United States)

Tsuda, Yuichi

2007-01-01

The new formation design strategy using simulated annealing (SA) optimization is presented. The SA algorithm is useful to survey a whole solution space of optimum formation, taking into account realistic constraints composed of continuous and discrete functions. It is revealed that this method is not only applicable for circular orbit, but also for high-elliptic orbit formation flying. The developed algorithm is first tested with a simple cart-wheel motion example, and then applied to the formation design for SCOPE. SCOPE is the next generation geomagnetotail observation mission planned in JAXA, utilizing a formation flying techonology in a high elliptic orbit. A distinctive and useful heuristics is found by investigating SA results, showing the effectiveness of the proposed design process.

RESULTS OF THE FIRST MI-171A2 FLYING LABORATORY TEST PHASE

Directory of Open Access Journals (Sweden)

V. A. Ivchin

2014-01-01

Full Text Available The present publication describes the results of the first stage of the flying laboratory (Mi-171 helicopter flight tests performed at Mil Moscow Helicopter Plant, JSC facilities. Main rotor components with blades made of polymer composite materials and X-type tail rotor were tested on the Mi-171 № 14987, flying laboratory, under Mi-171A Helicopter Retrofit Program.

The analysis of the flying wing in morphing concept

Directory of Open Access Journals (Sweden)

Ionică CÎRCIU

2013-06-01

Full Text Available The combination between the flying wing morphing concept and the use of modern command and control system offers exponential advantages having a leverage effect in the economy and research. The flying wing architecture has the advantage of low cost against efficiency, the morphing of this concept defining the new characteristic frontiers and aerodynamic performances which derive immediately. On designing an unmanned aerial vehicle for a various range of missions, its lifting surface needs to display optimal geometrical features, so that the UAV may maintain the induced drag and the moment coefficient at reasonable levels. The command and control of the lifting surfaces in morphing concept offer characteristics and in-flight performances at a superior level. The limits of the system depend on the reliability of the execution elements and the grade of accuracy for the control laws which are implemented in the calculation module. The paper aims at presenting an analysis regarding the robotic air systems of flying wing type through the aerodynamic analysis and with the help of specific software instruments. The performances and flight qualities depend directly on the geometry of the lifting surface of the aerial vehicle.

Porosity of Self-Compacting Concrete (SCC) incorporating high volume fly ash

Science.gov (United States)

Kristiawan, S. A.; Sunarmasto; Murti, G. Y.

2017-02-01

Degradation of concrete could be triggered by the presence of aggressive agents from the environment into the body of concrete. The penetration of these agents is influenced by the pore characteristics of the concrete. Incorporating a pozzolanic material such as fly ash could modify the pore characteristic of the concrete. This research aims to investigate the influence of incorporating fly ash at high volume level on the porosity of Self-Compacting Concrete (SCC). Laboratory investigations were carried out following the ASTM C642 for measuring density and volume of permeable pores (voids) of the SCC with varying fly ash contents (50-70% by weight of total binder). In addition, a measurement of permeable voids by saturation method was carried out to obtain an additional volume of voids that could not be measured by the immersion and boiling method of ASTM C642. The results show that the influence of fly ash content on the porosity appears to be dependent on age of SCC. At age less than 56 d, fly ash tends to cause an increase of voids but at 90 d of age it reduces the pores. The additional pores that can be penetrated by vacuum saturation method counts about 50% of the total voids.

Intelligent Simulation-Based Tutor for Flight Training

National Research Council Canada - National Science Library

Remolina, Emilio; Ramachandran, Sowmya; Fu, Daniel; Stottler, Richard; Howse, William R

2004-01-01

.... However, flight training is still limited by the availability of instructor pilots. The adage "practice makes perfect" is nowhere truer than in the learning of psychomotor skills such as flying...

76 FR 14795 - Special Conditions: Gulfstream Model GVI Airplane; Electronic Flight Control System Mode...

Science.gov (United States)

2011-03-18

... electronic flight control system. The applicable airworthiness regulations do not contain adequate or...). Novel or Unusual Design Features The GVI will have a fly-by-wire electronic flight control system. This system provides an electronic interface between the pilot's flight controls and the flight control...

Design of a high altitude long endurance flying-wing solar-powered unmanned air vehicle

Science.gov (United States)

Alsahlani, A. A.; Johnston, L. J.; Atcliffe, P. A.

2017-06-01

The low-Reynolds number environment of high-altitude §ight places severe demands on the aerodynamic design and stability and control of a high altitude, long endurance (HALE) unmanned air vehicle (UAV). The aerodynamic efficiency of a §ying-wing configuration makes it an attractive design option for such an application and is investigated in the present work. The proposed configuration has a high-aspect ratio, swept-wing planform, the wing sweep being necessary to provide an adequate moment arm for outboard longitudinal and lateral control surfaces. A design optimization framework is developed under a MATLAB environment, combining aerodynamic, structural, and stability analysis. Low-order analysis tools are employed to facilitate efficient computations, which is important when there are multiple optimization loops for the various engineering analyses. In particular, a vortex-lattice method is used to compute the wing planform aerodynamics, coupled to a twodimensional (2D) panel method to derive aerofoil sectional characteristics. Integral boundary-layer methods are coupled to the panel method in order to predict §ow separation boundaries during the design iterations. A quasi-analytical method is adapted for application to flyingwing con¦gurations to predict the wing weight and a linear finite-beam element approach is used for structural analysis of the wing-box. Stability is a particular concern in the low-density environment of high-altitude flight for flying-wing aircraft and so provision of adequate directional stability and control power forms part of the optimization process. At present, a modified Genetic Algorithm is used in all of the optimization loops. Each of the low-order engineering analysis tools is validated using higher-order methods to provide con¦dence in the use of these computationally-efficient tools in the present design-optimization framework. This paper includes the results of employing the present optimization tools in the design of a

Vector soup: high-throughput identification of Neotropical phlebotomine sand flies using metabarcoding.

Science.gov (United States)

Kocher, Arthur; Gantier, Jean-Charles; Gaborit, Pascal; Zinger, Lucie; Holota, Helene; Valiere, Sophie; Dusfour, Isabelle; Girod, Romain; Bañuls, Anne-Laure; Murienne, Jerome

2017-03-01

Phlebotomine sand flies are haematophagous dipterans of primary medical importance. They represent the only proven vectors of leishmaniasis worldwide and are involved in the transmission of various other pathogens. Studying the ecology of sand flies is crucial to understand the epidemiology of leishmaniasis and further control this disease. A major limitation in this regard is that traditional morphological-based methods for sand fly species identifications are time-consuming and require taxonomic expertise. DNA metabarcoding holds great promise in overcoming this issue by allowing the identification of multiple species from a single bulk sample. Here, we assessed the reliability of a short insect metabarcode located in the mitochondrial 16S rRNA for the identification of Neotropical sand flies, and constructed a reference database for 40 species found in French Guiana. Then, we conducted a metabarcoding experiment on sand flies mixtures of known content and showed that the method allows an accurate identification of specimens in pools. Finally, we applied metabarcoding to field samples caught in a 1-ha forest plot in French Guiana. Besides providing reliable molecular data for species-level assignations of phlebotomine sand flies, our study proves the efficiency of metabarcoding based on the mitochondrial 16S rRNA for studying sand fly diversity from bulk samples. The application of this high-throughput identification procedure to field samples can provide great opportunities for vector monitoring and eco-epidemiological studies. © 2016 John Wiley & Sons Ltd.

Pathfinder-Plus on flight over Hawaiian island N'ihau

Science.gov (United States)

1998-01-01

Pathfinder-Plus on a flight over the Hawaiian island of N'ihau in 1998. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non

Pathfinder-Plus on flight near Hawaiian island N'ihau

Science.gov (United States)

1998-01-01

Pathfinder-Plus on a flight with the Hawaiian island of N'ihau in the background. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and

Flight is the key to postprandial blood glucose balance in the fruit bats Eonycteris spelaea and Cynopterus sphinx.

Science.gov (United States)

Peng, Xingwen; He, Xiangyang; Liu, Qi; Sun, Yunxiao; Liu, Hui; Zhang, Qin; Liang, Jie; Peng, Zhen; Liu, Zhixiao; Zhang, Libiao

2017-11-01

Excessive sugar consumption could lead to high blood glucose levels that are harmful to mammalian health and life. Despite consuming large amounts of sugar-rich food, fruit bats have a longer lifespan, raising the question of how these bats overcome potential hyperglycemia. We investigated the change of blood glucose level in nectar-feeding bats ( Eonycteris spelaea ) and fruit-eating bats ( Cynopterus sphinx ) via adjusting their sugar intake and time of flight. We found that the maximum blood glucose level of C. sphinx was higher than 24 mmol/L that is considered to be pathological in other mammals. After C. sphinx bats spent approximately 75% of their time to fly, their blood glucose levels dropped markedly, and the blood glucose of E. spelaea fell to the fast levels after they spent 70% time of fly. Thus, the level of blood glucose elevated with the quantity of sugar intake but declined with the time of flight. Our results indicate that high-intensive flight is a key regulator for blood glucose homeostasis during foraging. High-intensive flight may confer benefits to the fruit bats in foraging success and behavioral interactions and increases the efficiency of pollen and seed disposal mediated by bats.

High filler concrete using fly ash. Chloride penetration and microstructure

NARCIS (Netherlands)

Valcke, S.L.A.; Polder, R.B.; Nijland, T.G.; Leegwater, G.A.; Visser, J.H.M.; Bigaj-van Vliet, A.J.

2012-01-01

Most high filler concrete studies are based on relatively high contents of powder (cement + filler) (>400 kg m-3). This paper aims to increase the total fly ash content relative to the clinker content, while simultaneously minimizing the total powder content in the concrete to values lower than 300

High filler concrete using fly ash : Chloride penetration and microstructure

NARCIS (Netherlands)

Valcke, S.L.A.; Polder, R.B.; Nijland, T.G.; Leegwater, G.A.; Visser, J.H.M.; Bigaj-van Vliet, A.J.

2012-01-01

Most high filler concrete studies are based on relatively high contents of powder (cement + filler) (>400 kg m-3). This paper aims to increase the total fly ash content relative to the clinker content, while simultaneously minimizing the total powder content in the concrete to values lower than 300

Control-oriented reduced order modeling of dipteran flapping flight

Science.gov (United States)

Faruque, Imraan

Flying insects achieve flight stabilization and control in a manner that requires only small, specialized neural structures to perform the essential components of sensing and feedback, achieving unparalleled levels of robust aerobatic flight on limited computational resources. An engineering mechanism to replicate these control strategies could provide a dramatic increase in the mobility of small scale aerial robotics, but a formal investigation has not yet yielded tools that both quantitatively and intuitively explain flapping wing flight as an "input-output" relationship. This work uses experimental and simulated measurements of insect flight to create reduced order flight dynamics models. The framework presented here creates models that are relevant for the study of control properties. The work begins with automated measurement of insect wing motions in free flight, which are then used to calculate flight forces via an empirically-derived aerodynamics model. When paired with rigid body dynamics and experimentally measured state feedback, both the bare airframe and closed loop systems may be analyzed using frequency domain system identification. Flight dynamics models describing maneuvering about hover and cruise conditions are presented for example fruit flies (Drosophila melanogaster) and blowflies (Calliphorids). The results show that biologically measured feedback paths are appropriate for flight stabilization and sexual dimorphism is only a minor factor in flight dynamics. A method of ranking kinematic control inputs to maximize maneuverability is also presented, showing that the volume of reachable configurations in state space can be dramatically increased due to appropriate choice of kinematic inputs.

Theseus on Take-off for First Flight

Science.gov (United States)

1996-01-01

The Theseus prototype research aircraft takes off for its first test flight from NASA's Dryden Flight Research Center, Edwards, California, on May 24, 1996. The Theseus aircraft, built and operated by Aurora Flight Sciences Corporation, Manassas, Virginia, was a unique aircraft flown at NASA's Dryden Flight Research Center, Edwards, California, under a cooperative agreement between NASA and Aurora. Dryden hosted the Theseus program, providing hangar space and range safety for flight testing. Aurora Flight Sciences was responsible for the actual flight testing, vehicle flight safety, and operation of the aircraft. The Theseus remotely piloted aircraft flew its maiden flight on May 24, 1996, at Dryden. During its sixth flight on November 12, 1996, Theseus experienced an in-flight structural failure that resulted in the loss of the aircraft. As of the beginning of the year 2000, Aurora had not rebuilt the aircraft. Theseus was built for NASA under an innovative, $4.9 million fixed-price contract by Aurora Flight Sciences Corporation and its partners, West Virginia University, Morgantown, West Virginia, and Fairmont State College, Fairmont, West Virginia. The twin-engine, unpiloted vehicle had a 140-foot wingspan, and was constructed largely of composite materials. Powered by two 80-horsepower, turbocharged piston engines that drove twin 9-foot-diameter propellers, Theseus was designed to fly autonomously at high altitudes, with takeoff and landing under the active control of a ground-based pilot in a ground control station 'cockpit.' With the potential ability to carry 700 pounds of science instruments to altitudes above 60,000 feet for durations of greater than 24 hours, Theseus was intended to support research in areas such as stratospheric ozone depletion and the atmospheric effects of future high-speed civil transport aircraft engines. Instruments carried aboard Theseus also would be able to validate satellite-based global environmental change measurements. Dryden

Daedalus - Last Dryden flight

Science.gov (United States)

1988-01-01

autopilot that could be used on high altitude or human powered aircraft, and determining the power required to fly the Daedalus aircraft. The research flights began in late December 1987 with a shake-down of the Light Eagle instrumentation and data transfer links. The first flight of the Daedalus 87 also occurred during this time. On February 7, 1988, the Daedalus 87 aircraft crashed on Rogers Dry Lakebed. The Daedalus 88, which later set the world record, was then shipped from MIT to replace the 87's research flights, and for general checkout procedures. Due to the accident, flight testing was extended four weeks and thus ended in mid-March 1988 after having achieved the major goals of the program; exploring the dynamics of low Reynolds number aircraft, and investigating the aeroelastic behavior of lightweight aircraft. The information obtained from this program had direct applications to the later design of many high-altitude, long endurance aircraft.

Computer aided in-flight radiation scanning

International Nuclear Information System (INIS)

Schmitzer, C.; Kloesch, W.

1989-01-01

The equipment consists of a radiation detecting instrument, a flight prospection probe and a portable PC. It is aimed at detection of ground radiation sources from a flying airplane, e.g. in case of radiation accident. 3 figs

14 CFR 121.503 - Flight time limitations: Pilots: airplanes.

Science.gov (United States)

2010-01-01

... Operations § 121.503 Flight time limitations: Pilots: airplanes. (a) A certificate holder conducting supplemental operations may schedule a pilot to fly in an airplane for eight hours or less during any 24... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Flight time limitations: Pilots: airplanes...

An algorithm for enhanced formation flying of satellites in low earth orbit

Science.gov (United States)

Folta, David C.; Quinn, David A.

1998-01-01

With scientific objectives for Earth observation programs becoming more ambitious and spacecraft becoming more autonomous, the need for innovative technical approaches on the feasibility of achieving and maintaining formations of spacecraft has come to the forefront. The trend to develop small low-cost spacecraft has led many scientists to recognize the advantage of flying several spacecraft in formation to achieve the correlated instrument measurements formerly possible only by flying many instruments on a single large platform. Yet, formation flying imposes additional complications on orbit maintenance, especially when each spacecraft has its own orbit requirements. However, advances in automation and technology proposed by the Goddard Space Flight Center (GSFC) allow more of the burden in maneuver planning and execution to be placed onboard the spacecraft, mitigating some of the associated operational concerns. The purpose of this paper is to present GSFC's Guidance, Navigation, and Control Center's (GNCC) algorithm for Formation Flying of the low earth orbiting spacecraft that is part of the New Millennium Program (NMP). This system will be implemented as a close-loop flight code onboard the NMP Earth Orbiter-1 (EO-1) spacecraft. Results of this development can be used to determine the appropriateness of formation flying for a particular case as well as operational impacts. Simulation results using this algorithm integrated in an autonomous `fuzzy logic' control system called AutoCon™ are presented.

A pilot's assessment of helicopter handling-quality factors common to both agility and instrument flying tasks

Science.gov (United States)

Gerdes, R. M.

1980-01-01

A series of simulation and flight investigations were undertaken to evaluate helicopter flying qualities and the effects of control system augmentation for nap-of-the-Earth (NOE) agility and instrument flying tasks. Handling quality factors common to both tasks were identified. Precise attitude control was determined to be a key requirement for successful accomplishment of both tasks. Factors that degraded attitude controllability were improper levels of control sensitivity and damping, and rotor system cross coupling due to helicopter angular rate and collective pitch input. Application of rate command, attitude command, and control input decouple augmentation schemes enhanced attitude control and significantly improved handling qualities for both tasks. The NOE agility and instrument flying handling quality considerations, pilot rating philosophy, and supplemental flight evaluations are also discussed.

Multisensory integration for odor tracking by flying Drosophila: Behavior, circuits and speculation.

Science.gov (United States)

Duistermars, Brian J; Frye, Mark A

2010-01-01

Many see fruit flies as an annoyance, invading our homes with a nagging persistence and efficiency. Yet from a scientific perspective, these tiny animals are a wonder of multisensory integration, capable of tracking fragmented odor plumes amidst turbulent winds and constantly varying visual conditions. The peripheral olfactory, mechanosensory, and visual systems of the fruit fly, Drosophila melanogaster, have been studied in great detail;1-4 however, the mechanisms by which fly brains integrate information from multiple sensory modalities to facilitate robust odor tracking remain elusive. Our studies on olfactory orientation by flying flies reveal that these animals do not simply follow their "nose"; rather, fruit flies require mechanosensory and visual input to track odors in flight.5,6 Collectively, these results shed light on the neural circuits involved in odor localization by fruit flies in the wild and illuminate the elegant complexity underlying a behavior to which the annoyed and amazed are familiar.

Laboratory Investigations on Mechanical Properties of High Volume Fly Ash Concrete and Composite Sections

OpenAIRE

Aravindkumar B. Harwalkar; S. S. Awanti

2013-01-01

Use of fly ash as a supplementary cementing material in large volumes can bring both technological and economic benefits for concrete industry. In this investigation mix proportions for high volume fly ash concrete were determined at cement replacement levels of 50%, 55%, 60% and 65% with low calcium fly ash. Flexural and compressive strengths of different mixes were measured at ages of 7, 28 and 90 days. Flexural strength of composite section prepared from pavement quali...

Flapping Tail Membrane in Bats Produces Potentially Important Thrust during Horizontal Takeoffs and Very Slow Flight

Science.gov (United States)

Adams, Rick A.; Snode, Emily R.; Shaw, Jason B.

2012-01-01

Historically, studies concerning bat flight have focused primarily on the wings. By analyzing high-speed video taken on 48 individuals of five species of vespertilionid bats, we show that the capacity to flap the tail-membrane (uropatagium) in order to generate thrust and lift during takeoffs and minimal-speed flight (ecomorphology. The extensive fanning motion of the tail membrane by vespertilionid bats has not been reported for other flying vertebrates. PMID:22393378

Direct Evidence for Vision-based Control of Flight Speed in Budgerigars.

Science.gov (United States)

Schiffner, Ingo; Srinivasan, Mandyam V

2015-06-05

We have investigated whether, and, if so, how birds use vision to regulate the speed of their flight. Budgerigars, Melopsittacus undulatus, were filmed in 3-D using high-speed video cameras as they flew along a 25 m tunnel in which stationary or moving vertically oriented black and white stripes were projected on the side walls. We found that the birds increased their flight speed when the stripes were moved in the birds' flight direction, but decreased it only marginally when the stripes were moved in the opposite direction. The results provide the first direct evidence that Budgerigars use cues based on optic flow, to regulate their flight speed. However, unlike the situation in flying insects, it appears that the control of flight speed in Budgerigars is direction-specific. It does not rely solely on cues derived from optic flow, but may also be determined by energy constraints.

Flight safety measurements of UAVs in congested airspace

Directory of Open Access Journals (Sweden)

Xiang Jinwu

2016-10-01

Full Text Available Describing spatial safety status is crucial for high-density air traffic involving multiple unmanned aerial vehicles (UAVs in a complex environment. A probabilistic approach is proposed to measure safety situation in congested airspace. The occupancy distribution of the airspace is represented with conflict probability between spatial positions and UAV. The concept of a safety envelope related to flight performance and response time is presented first instead of the conventional fixed-size protected zones around aircraft. Consequently, the conflict probability is performance-dependent, and effects of various UAVs on safety can be distinguished. The uncertainty of a UAV future position is explicitly accounted for as Brownian motion. An analytic approximate algorithm for the conflict probability is developed to decrease the computational consumption. The relationship between safety and flight performance are discussed for different response times and prediction intervals. To illustrate the applications of the approach, an experiment of three UAVs in formation flight is performed. In addition, an example of trajectory planning is simulated for one UAV flying over airspace where five UAVs exist. The validation of the approach shows its potential in guaranteeing flight safety in highly dynamic environment.

Preliminary Flight Results of a Fly-by-throttle Emergency Flight Control System on an F-15 Airplane

Science.gov (United States)

Burcham, Frank W., Jr.; Maine, Trindel A.; Fullerton, C. Gordon; Wells, Edward A.

1993-01-01

A multi-engine aircraft, with some or all of the flight control system inoperative, may use engine thrust for control. NASA Dryden has conducted a study of the capability and techniques for this emergency flight control method for the F-15 airplane. With an augmented control system, engine thrust, along with appropriate feedback parameters, is used to control flightpath and bank angle. Extensive simulation studies were followed by flight tests. The principles of throttles only control, the F-15 airplane, the augmented system, and the flight results including actual landings with throttles-only control are discussed.

Design of a Haptic Feedback System for Flight Envelope Protection

NARCIS (Netherlands)

Van Baelen, D.; Ellerbroek, J.; van Paassen, M.M.; Mulder, M.

2018-01-01

Current Airbus aircraft use a fly-by-wire control device: a passive spring-damper system which generates, without any force feedback, an electrical signal to the flight control computer. Additionally, a hard flight envelope protection system is used which can limit the inputs of the pilot when

A system look at electromechanical actuation for primary flight control

NARCIS (Netherlands)

Lomonova, E.A.

1997-01-01

An overview is presented of the emergence of the ALL Electric flight control system (FCS) or power-by-wire (PBW) concept. The concept of fly-by-power refers to the actuator using electrical rather than hydraulic power. The development of the primary flight control Electromechanical Actuators (EMAs)

Some results of the effect of space flight factors on Drosophila melanogaster

International Nuclear Information System (INIS)

Filatova, L.P.; Vaulina, E.N.

1983-01-01

Chromosomal effects of space flight factors were investigated in Drosophila melanogaster flown aboard the Salyut 6 orbital station. Drosophila males heterozygous for four linked traits were exposed to space flight conditions for periods of eight days, and the progeny when the males were mated with homozygous recessive females were compared with those from control flies exposed to the same vibration and acceleration environment, and the progeny of laboratory controls. Increases in recombination and nondisjunction frequencies were observed in the flies exposed to the space environment, with recombinant flies also found in the F1 generation of the vibration and acceleration controls. Results suggest that it is the action of heavy particles that accounts for the major portion of the genetic effects observed. 17 references

A Simple Flight Mill for the Study of Tethered Flight in Insects.

Science.gov (United States)

Attisano, Alfredo; Murphy, James T; Vickers, Andrew; Moore, Patricia J

2015-12-10

Flight in insects can be long-range migratory flights, intermediate-range dispersal flights, or short-range host-seeking flights. Previous studies have shown that flight mills are valuable tools for the experimental study of insect flight behavior, allowing researchers to examine how factors such as age, host plants, or population source can influence an insects' propensity to disperse. Flight mills allow researchers to measure components of flight such as speed and distance flown. Lack of detailed information about how to build such a device can make their construction appear to be prohibitively complex. We present a simple and relatively inexpensive flight mill for the study of tethered flight in insects. Experimental insects can be tethered with non-toxic adhesives and revolve around an axis by means of a very low friction magnetic bearing. The mill is designed for the study of flight in controlled conditions as it can be used inside an incubator or environmental chamber. The strongest points are the very simple electronic circuitry, the design that allows sixteen insects to fly simultaneously allowing the collection and analysis of a large number of samples in a short time and the potential to use the device in a very limited workspace. This design is extremely flexible, and we have adjusted the mill to accommodate different species of insects of various sizes.

Role of Meteorology in Flights of a Solar-Powered Airplane

Science.gov (United States)

Donohue, Casey

2004-01-01

In the summer of 2001, the Helios prototype solar-powered uninhabited aerial vehicle (UAV) [a lightweight, remotely piloted airplane] was deployed to the Pacific Missile Range Facility (PMRF), at Kauai, Hawaii, in an attempt to fly to altitudes above 100,000 ft (30.48 km). The goal of flying a UAV to such high altitudes has been designated a level-I milestone of the NASA Environmental Research Aircraft and Sensor Technology (ERAST) program. In support of this goal, meteorologists from NASA Dryden Flight Research Center were sent to PMRF, as part of the flight crew, to provide current and forecast weather information to the pilots, mission directors, and planners. Information of this kind is needed to optimize flight conditions for peak aircraft performance and to enable avoidance of weather conditions that could adversely affect safety. In general, the primary weather data of concern for ground and flight operations are wind speeds (see Figure 1). Because of its long wing span [247 ft (.75 m)] and low weight [1,500 to 1,600 lb (about 680 to 726 kg)], the Helios airplane is sensitive to wind speeds exceeding 7 kn (3.6 m/s) at the surface. Also, clouds are of concern because they can block sunlight needed to energize an array of solar photovoltaic cells that provide power to the airplane. Vertical wind shear is very closely monitored in order to prevent damage or loss of control due to turbulence.

Navigation and flight director guidance for the NASA/FAA helicopter MLS curved approach flight test program

Science.gov (United States)

Phatak, A. V.; Lee, M. G.

1985-01-01

The navigation and flight director guidance systems implemented in the NASA/FAA helicopter microwave landing system (MLS) curved approach flight test program is described. Flight test were conducted at the U.S. Navy's Crows Landing facility, using the NASA Ames UH-lH helicopter equipped with the V/STOLAND avionics system. The purpose of these tests was to investigate the feasibility of flying complex, curved and descending approaches to a landing using MLS flight director guidance. A description of the navigation aids used, the avionics system, cockpit instrumentation and on-board navigation equipment used for the flight test is provided. Three generic reference flight paths were developed and flown during the test. They were as follows: U-Turn, S-turn and Straight-In flight profiles. These profiles and their geometries are described in detail. A 3-cue flight director was implemented on the helicopter. A description of the formulation and implementation of the flight director laws is also presented. Performance data and analysis is presented for one pilot conducting the flight director approaches.

Speciation of zinc in secondary fly ashes of municipal solid waste at high temperatures

Energy Technology Data Exchange (ETDEWEB)

Yu, Meijuan; Chu, Wangsheng; Chen, Dongliang [Chinese Academy of Sciences, Beijing (China). Inst. of High Energy Physics; Tian, Shulei [Tsinghua Univ., Beijing (China). Dept. of Environmental Science and Engineering; Wang, Qi [Chinese Research Academy of Environmental Science, Beijing (China); Wu, Ziyu [Chinese Academy of Sciences, Beijing (China). Inst. of High Energy Physics; Univ. of Science and Technology of China, Hefei (China). National Synchrotron Radiation Lab.; Chinese Academy of Sciences, Beijing (China). Theoretical Physics Center for Science Facilities

2009-07-15

The evaporation aerosols produced during the vitrification process of municipal solid waste incinerators (MSWI) fly ash represent a potential environmental risk owing to their high content of heavy metals. In this research, high-temperature heating processes were carried out on fly ashes collected from bag houses in a Chinese MSWI plant and the secondary fly ashes (SFA) were separately collected at three high temperatures (1273 K, 1423 K and 1523 K) below the melting range. Elemental analysis showed that high contents of both zinc and chlorine were present in these SFA samples and, according to the standard of the heavy metals industrial grade of ore, SFAs can be re-used as metallurgical raw materials or rich ore. Moreover, as shown by XAS analysis and for different high temperatures, zinc environments in the three SFA samples were characterized by the same local structure of the zinc chloride. As a consequence, a zinc recycling procedure can be easily designed based on the configuration information. (orig.)

Speciation of zinc in secondary fly ashes of municipal solid waste at high temperatures

International Nuclear Information System (INIS)

Yu, Meijuan; Chu, Wangsheng; Chen, Dongliang; Wu, Ziyu; Univ. of Science and Technology of China, Hefei; Chinese Academy of Sciences, Beijing

2009-01-01

The evaporation aerosols produced during the vitrification process of municipal solid waste incinerators (MSWI) fly ash represent a potential environmental risk owing to their high content of heavy metals. In this research, high-temperature heating processes were carried out on fly ashes collected from bag houses in a Chinese MSWI plant and the secondary fly ashes (SFA) were separately collected at three high temperatures (1273 K, 1423 K and 1523 K) below the melting range. Elemental analysis showed that high contents of both zinc and chlorine were present in these SFA samples and, according to the standard of the heavy metals industrial grade of ore, SFAs can be re-used as metallurgical raw materials or rich ore. Moreover, as shown by XAS analysis and for different high temperatures, zinc environments in the three SFA samples were characterized by the same local structure of the zinc chloride. As a consequence, a zinc recycling procedure can be easily designed based on the configuration information. (orig.)

Autogenic-feedback training improves pilot performance during emergency flying conditions

Science.gov (United States)

Kellar, Michael A.; Folen, Raymond A.; Cowings, Patricia S.; Toscano, William B.; Hisert, Glen L.

1994-01-01

Studies have shown that autonomous mode behavior is one cause of aircraft fatalities due to pilot error. In such cases, the pilot is in a high state of psychological and physiological arousal and tends to focus on one problem, while ignoring more critical information. This study examined the effect of training in physiological self-recognition and regulation, as a means of improving crew cockpit performance. Seventeen pilots were assigned to the treatment and control groups matched for accumulated flight hours. The treatment group comprised three pilots of HC-130 Hercules aircraft and four HH-65 Dolphin helicopter pilots; the control group comprised three pilots of HC-130's and six Dolphin helicopter pilots. During an initial flight, physiological data were recorded for each crew member and individual crew performance was rated by an instructor pilot. Eight crewmembers were then taught to regulate their own physiological response levels using Autogenic-Feedback Training (AFT). The remaining subjects received no training. During a second flight, treatment subjects showed significant improvement in performance, while controls did not improve. The results indicate that AFT management of high states of physiological arousal may improve pilot performance during emergency flying conditions.

Pathfinder-Plus on a flight over Hawaiian island N'ihau

Science.gov (United States)

1998-01-01

Pathfinder-Plus on a flight over the Hawaiian island of N'ihau in 1998. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non

Solar array flight dynamic experiment

Science.gov (United States)

Schock, Richard W.

1987-01-01

The purpose of the Solar Array Flight Dynamic Experiment (SAFDE) is to demonstrate the feasibility of on-orbit measurement and ground processing of large space structures' dynamic characteristics. Test definition or verification provides the dynamic characteristic accuracy required for control systems use. An illumination/measurement system was developed to fly on space shuttle flight STS-41D. The system was designed to dynamically evaluate a large solar array called the Solar Array Flight Experiment (SAFE) that had been scheduled for this flight. The SAFDE system consisted of a set of laser diode illuminators, retroreflective targets, an intelligent star tracker receiver and the associated equipment to power, condition, and record the results. In six tests on STS-41D, data was successfully acquired from 18 retroreflector targets and ground processed, post flight, to define the solar array's dynamic characteristic. The flight experiment proved the viability of on-orbit test definition of large space structures dynamic characteristics. Future large space structures controllability should be greatly enhanced by this capability.

Chilled packing systems for fruit flies (Diptera: Tephritidae) in the sterile insect technique

International Nuclear Information System (INIS)

Hernandez, Emilio; Escobar, Arseny; Bravo, Bigail; Montoya, Pablo; Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentacion

2010-01-01

We evaluated three packing systems (PARC boxes, 'GT' screen towers and 'MX' screen towers) for the emergence and sexual maturation of sterile fruit flies, at three adult fl y densities (1, 1.2 and 1.3 fly/cm 2) and three food types. At the lowest density, results showed no significant differences in the longevity and flight ability of adult Anastrepha ludens (Loew) and Anastrepha obliqua Macquart among the three packing systems. Higher densities resulted in a decrease in these parameters. In the evaluation of the three food types, no significant differences were found either on longevity or flight ability of A. ludens. However, the greatest longevity for both sexes A. obliqua was obtained with commercial powdered Mb and the mix of sugar, protein and corn starch on paper (SPCP) food types. The highest value for flight ability in A. obliqua males was obtained with powdered Mb and SPCP food types, and for females with Mb powdered food. Our data indicated that GT and MX screen tower packing systems are an alternative to the PARC boxes, since they were suitable for adult fl y sexual maturation without any harm to their longevity or flight ability. The tested foods were equivalent in both fruit fl y species, with the exception of the agar type for A. obliqua, which yielded the lowest biological parameters evaluated. Our results contribute to the application of new methods for the packing and release of sterile flies in large-scale programs. (author)

Resistance to Corrosion of Reinforcement of High Volume Fly Ash Concrete

International Nuclear Information System (INIS)

Kwon, S. O.; Bae, S. H.; Lee, H. J.; Lee, K. M.; Jung, S. H.

2014-01-01

Due to the increasing of interest about the eco-friendly concrete, it is increased to use concretes containing by-products of industry such as fly ash(FA), ground granulated blast furnace slag(GGBFS), silica fume(SF), and etc. Especially, these are well known for improving the resistances to reinforcement corrosion in concrete and decreasing chloride ion penetration. The purpose of this experimental research is to evaluate the resistance against corrosion of reinforcement of high volume fly ash(HVFA) concrete which is replaced with high volume fly ash for cement volume. For this purpose, the concrete test specimens were made for various strength level and replacement ratio of FA, and then the compressive strength and diffusion coefficient for chloride ion of them were measured for 28, 91, and 182 days, respectively. Also, corrosion monitoring by half cell potential method was carried out for the made lollypop concrete test specimens to detect the time of corrosion initiation for reinforcement in concrete. As a result, it was observed from the test results that the compressive strength of HVFA concrete was decreased with increasing replacement ratio of FA but long-term resistances against reinforcement corrosion and chloride ion penetration of that were increased

Envelope Protection for In-Flight Ice Contamination

Science.gov (United States)

Gingras, David R.; Barnhart, Billy P.; Ranaudo, Richard J.; Ratvasky, Thomas P.; Morelli, Eugene A.

2010-01-01

Fatal loss-of-control (LOC) accidents have been directly related to in-flight airframe icing. The prototype system presented in this paper directly addresses the need for real-time onboard envelope protection in icing conditions. The combinations of a-priori information and realtime aerodynamic estimations are shown to provide sufficient input for determining safe limits of the flight envelope during in-flight icing encounters. The Icing Contamination Envelope Protection (ICEPro) system has been designed and implemented to identify degradations in airplane performance and flying qualities resulting from ice contamination and provide safe flight-envelope cues to the pilot. Components of ICEPro are described and results from preliminary tests are presented.

Understanding the Sun-Earth Libration Point Orbit Formation Flying Challenges For WFIRST and Starshade

Science.gov (United States)

Webster, Cassandra M.; Folta, David C.

2017-01-01

In order to fly an occulter in formation with a telescope at the Sun-Earth L2 (SEL2) Libration Point, one must have a detailed understanding of the dy-namics that govern the restricted three body system. For initial purposes, a linear approximation is satisfactory, but operations will require a high-fidelity modeling tool along with strategic targeting methods in order to be successful. This paper focuses on the challenging dynamics of the transfer trajectories to achieve the relative positioning of two spacecraft to fly in formation at SEL2, in our case, the Wide-Field Infrared Survey Telescope (WFIRST) and a proposed Starshade. By modeling the formation transfers using a high fidelity tool, an accurate V approximation can be made to as-sist with the development of the subsystem design required for a WFIRST and Starshade formation flight mission.

The ASAC Flight Segment and Network Cost Models

Science.gov (United States)

Kaplan, Bruce J.; Lee, David A.; Retina, Nusrat; Wingrove, Earl R., III; Malone, Brett; Hall, Stephen G.; Houser, Scott A.

1997-01-01

To assist NASA in identifying research art, with the greatest potential for improving the air transportation system, two models were developed as part of its Aviation System Analysis Capability (ASAC). The ASAC Flight Segment Cost Model (FSCM) is used to predict aircraft trajectories, resource consumption, and variable operating costs for one or more flight segments. The Network Cost Model can either summarize the costs for a network of flight segments processed by the FSCM or can be used to independently estimate the variable operating costs of flying a fleet of equipment given the number of departures and average flight stage lengths.

The aerodynamic cost of flight in the short-tailed fruit bat (Carollia perspicillata): comparing theory with measurement.

Science.gov (United States)

von Busse, Rhea; Waldman, Rye M; Swartz, Sharon M; Voigt, Christian C; Breuer, Kenneth S

2014-06-06

Aerodynamic theory has long been used to predict the power required for animal flight, but widely used models contain many simplifications. It has been difficult to ascertain how closely biological reality matches model predictions, largely because of the technical challenges of accurately measuring the power expended when an animal flies. We designed a study to measure flight speed-dependent aerodynamic power directly from the kinetic energy contained in the wake of bats flying in a wind tunnel. We compared these measurements with two theoretical predictions that have been used for several decades in diverse fields of vertebrate biology and to metabolic measurements from a previous study using the same individuals. A high-accuracy displaced laser sheet stereo particle image velocimetry experimental design measured the wake velocities in the Trefftz plane behind four bats flying over a range of speeds (3-7 m s(-1)). We computed the aerodynamic power contained in the wake using a novel interpolation method and compared these results with the power predicted by Pennycuick's and Rayner's models. The measured aerodynamic power falls between the two theoretical predictions, demonstrating that the models effectively predict the appropriate range of flight power, but the models do not accurately predict minimum power or maximum range speeds. Mechanical efficiency--the ratio of aerodynamic power output to metabolic power input--varied from 5.9% to 9.8% for the same individuals, changing with flight speed.

Observation of sandhill cranes' (Grus canadensis) flight behavior in heavy fog

Science.gov (United States)

Kirsch, Eileen M.; Wellik, Mike J.; Suarez, Manuel J.; Diehl, Robert H.; Lutes, Jim; Woyczik, Wendy; Krapfl, Jon; Sojda, Richard S.

2015-01-01

The behaviors of birds flying in low visibility conditions remain poorly understood. We had the opportunity to monitor Sandhill Cranes (Grus canadensis) flying in heavy fog with very low visibility during a comprehensive landscape use study of refuging cranes in the Horicon Marsh in southeastern Wisconsin. As part of the study, we recorded flight patterns of cranes with a portable marine radar at various locations and times of day, and visually counted cranes as they departed the roost in the morning. We compared flight patterns during a fog event with those recorded during clear conditions. In good visibility, cranes usually departed the night roost shortly after sunrise and flew in relatively straight paths toward foraging areas. In fog, cranes departed the roost later in the day, did not venture far from the roost, engaged in significantly more circling flight, and returned to the roost site rather than proceeding to foraging areas. We also noted that compared to mornings with good visibility, cranes flying in fog called more frequently than usual. The only time in this 2-year study that observers heard young of the year calling was during the fog event. The observed behavior of cranes circling and lingering in an area while flying in poor visibility conditions suggests that such situations may increase chances of colliding with natural or anthropogenic obstacles in the vicinity.

Mechanically activated fly ash as a high performance binder for civil engineering

International Nuclear Information System (INIS)

Rieger, D; Kullová, L; Čekalová, M; Novotný, P; Pola, M

2017-01-01

This study is aimed for investigation of fly ash binder with suitable properties for civil engineering needs. The fly ash from Czech brown coal power plant Prunerov II was used and mechanically activated to achieve suitable particle size for alkaline activation of hardening process. This process is driven by dissolution of aluminosilicate content of fly ash and by subsequent development of inorganic polymeric network called geopolymer. Hardening kinetics at 25 and 30 °C were measured by strain controlled small amplitude oscillatory rheometry with strain of 0.01 % and microstructure of hardened binder was evaluated by scanning electron microscopy. Strength development of hardened binder was investigated according to compressional and flexural strength for a period of 180 days. Our investigation finds out, that mechanically activated fly ash can be comparable to metakaolin geopolymers, according to setting time and mechanical parameters even at room temperature curing. Moreover, on the bases of long time strength development, achieved compressional strength of 134.5 after 180 days is comparable to performance of high grade Portland cement concretes. (paper)

Dispersion of fruit flies (Diptera: Tephritidae) at high and low densities and consequences of mismatching dispersions of wild and sterile flies

International Nuclear Information System (INIS)

Meats, A.

2007-01-01

Both wild and released (sterile) Bactrocera tryoni (Froggatt) (Diptera: Tephritidae) and wild Bactrocera papayae (Drew and Hancock) in Australia had patchy distributions and comparisons with predictions of the negative binomial model indicated that the degree of clumping was sometimes very high, particularly at low densities during eradication. An increase of mean recapture rate of sterile B. tryoni on either of 2 trap arrays was not accompanied by a reduction in its coefficient of variation and when recapture rates were high, the percentage of traps catching zero decreased only slightly with increase in recapture rate, indicating that it is not practicable to decrease the heterogeneity of dispersion of sterile flies by increasing the number released. There was often a mismatch between the dispersion patterns of the wild and sterile flies, and the implications of this for the efficiency of the sterile insect technique (SIT) were investigated with a simulation study with the observed degrees of mismatch obtained from the monitoring data and assuming the overall ratio of sterile to wild flies to be 100:1. The simulation indicated that mismatches could result in the imposed rate of increase of wild flies being up to 3.5 times higher than that intended (i.e., 0.35 instead of 0.1). The effect of a mismatch always reduces the efficiency of SIT. The reason for this asymmetry is discussed and a comparison made with host-parasitoid and other systems. A release strategy to counter this effect is suggested. (author) [es

Effects of flight speed upon muscle activity in hummingbirds.

Science.gov (United States)

Tobalske, Bret W; Biewener, Andrew A; Warrick, Douglas R; Hedrick, Tyson L; Powers, Donald R

2010-07-15

Hummingbirds have the smallest body size and highest wingbeat frequencies of all flying vertebrates, so they represent one endpoint for evaluating the effects of body size on sustained muscle function and flight performance. Other bird species vary neuromuscular recruitment and contractile behavior to accomplish flight over a wide range of speeds, typically exhibiting a U-shaped curve with maxima at the slowest and fastest flight speeds. To test whether the high wingbeat frequencies and aerodynamically active upstroke of hummingbirds lead to different patterns, we flew rufous hummingbirds (Selasphorus rufus, 3 g body mass, 42 Hz wingbeat frequency) in a variable-speed wind tunnel (0-10 m s(-1)). We measured neuromuscular activity in the pectoralis (PECT) and supracoracoideus (SUPRA) muscles using electromyography (EMG, N=4 birds), and we measured changes in PECT length using sonomicrometry (N=1). Differing markedly from the pattern in other birds, PECT deactivation occurred before the start of downstroke and the SUPRA was deactivated before the start of upstroke. The relative amplitude of EMG signal in the PECT and SUPRA varied according to a U-shaped curve with flight speed; additionally, the onset of SUPRA activity became relatively later in the wingbeat at intermediate flight speeds (4 and 6 m s(-1)). Variation in the relative amplitude of EMG was comparable with that observed in other birds but the timing of muscle activity was different. These data indicate the high wingbeat frequency of hummingbirds limits the time available for flight muscle relaxation before the next half stroke of a wingbeat. Unlike in a previous study that reported single-twitch EMG signals in the PECT of hovering hummingbirds, across all flight speeds we observed 2.9+/-0.8 spikes per contraction in the PECT and 3.8+/-0.8 spikes per contraction in the SUPRA. Muscle strain in the PECT was 10.8+/-0.5%, the lowest reported for a flying bird, and average strain rate was 7.4+/-0.2 muscle

Comparison of Anastrepha ludens (Diptera: Tephritidae) Bisexual and Genetic Sexing (Tapachula-7) Strains: Effect of Hypoxia, Fly Density, Chilling Period, and Food Type on Fly Quality.

Science.gov (United States)

Arredondo, José; Ruiz, Lía; Hernández, Emilio; Montoya, Pablo; Díaz-Fleischer, Francisco

2016-04-01

The use of genetic sexing strain (GSS) insects in the sterile insect technique (SIT) makes necessary the revision of quality parameters of some stressful steps used during the packing process for aerial release because of possible differences in tolerance between fly strains. Here, we determined the effect of three periods of hypoxia (12, 24, and 36 h at pupal stage), three cage densities (1.0, 1.3, and 1.5 flies/cm2), two different foods (protein/sugar (1/24) and Mubarqui), and three chilling times (20 min [control], 90, and 180 min) on the quality parameters of flies of two Anastrepha ludens (Loew) strains (bisexual and GSS Tapachula-7). In general, the response to stressful conditions of both fly strains was qualitatively equivalent but quantitatively different, as flies of both strains responded equally to the stressful factors; however, flies of Tapachula-7 exhibited lower quality parameters than the control flies. Thus, hypoxia affected the flying ability but not the emergence or longevity of flies. The food type affected the adult weight; protein/sugar produced heavier flies that also survived longer and had a greater mating propensity. Flies under the lowest density were better fliers that those at the other two densities. Increasing chilling time reduced flight ability but not longevity or mating propensity. The implications of these findings for the use of A. ludens GSS in SIT programs are discussed herein.

The Legacy of Space Shuttle Flight Software

Science.gov (United States)

Hickey, Christopher J.; Loveall, James B.; Orr, James K.; Klausman, Andrew L.

2011-01-01

The initial goals of the Space Shuttle Program required that the avionics and software systems blaze new trails in advancing avionics system technology. Many of the requirements placed on avionics and software were accomplished for the first time on this program. Examples include comprehensive digital fly-by-wire technology, use of a digital databus for flight critical functions, fail operational/fail safe requirements, complex automated redundancy management, and the use of a high-order software language for flight software development. In order to meet the operational and safety goals of the program, the Space Shuttle software had to be extremely high quality, reliable, robust, reconfigurable and maintainable. To achieve this, the software development team evolved a software process focused on continuous process improvement and defect elimination that consistently produced highly predictable and top quality results, providing software managers the confidence needed to sign each Certificate of Flight Readiness (COFR). This process, which has been appraised at Capability Maturity Model (CMM)/Capability Maturity Model Integration (CMMI) Level 5, has resulted in one of the lowest software defect rates in the industry. This paper will present an overview of the evolution of the Primary Avionics Software System (PASS) project and processes over thirty years, an argument for strong statistical control of software processes with examples, an overview of the success story for identifying and driving out errors before flight, a case study of the few significant software issues and how they were either identified before flight or slipped through the process onto a flight vehicle, and identification of the valuable lessons learned over the life of the project.

Comparison of acoustic properties of tethered flight sounds for wild, mass-reared, and irradiated melon flies, Dacus cucurbitae COQUILLETT (Diptera: Tephritidae)

International Nuclear Information System (INIS)

Kanmiya, Kenkichi; Nakagawa, Kohjin; Tanaka, Akira; Kamiwada, Hidemi.

1987-01-01

Acoustic properties of tethered flight sounds produced by the male melon fly, Dacus cucurbitae COQUILLETT in wild (W-), mass-reared (M-), and irradiated (I-) strains were analyzed. Properties included fundamental frequency (FFQ), peak power density of FFQ (PPD), overall root mean square value (ORMS), total harmonic RMS (THRMS), total harmonic distortion (THDIST), bandwidth of FFQ (BWFF), and the number of harmonics and wing-strokes. M- and I-strains developed FFQ 3 days earlier than the W-strain. The W-strain had a greater variance in the mean, and overall lower values for FFQ, PPD, and ORMS than M- and I-strains. The fluctuation of acoustic properties of wild strain with aging was markedly different from that of the laboratory strains. The fact that values of these parameters for laboratory strains developed at earlier adult age and continued relatively high may by due to selection effects. No significant differences were observed between laboratory strains resulting from effect of irradiation. There were, however, significant differences among the 6 parameters in 8 age groups which were recognized for 12 cases between W- and I-, 8 between W- and M-, and 4 between M- and I-strains. (author)

High volume fly ash RCC for dams - I : mixture optimization and mechanical properties

Energy Technology Data Exchange (ETDEWEB)

Jacobsen, S. [PEAB Construction Co., Oslo (Norway); Lahus, O. [Norwegian Building Research Inst., Oslo (Norway)

2001-07-01

Roller compacted concretes (RCC) were developed for the Norwegian Skjerka hydropower project. RCCs were developed to have a high-volume fly ash content to address environmental issues, including the reduction of carbon dioxide emissions associated with dam construction. They also makes good use of waste product and conserve natural resources. This study examined a series of mixtures to determine the appropriateness of using RCC as a competing alternative to the traditional rock fill dam proposed for the Skjerka hydropower project. The main advantage of RCC is speed, allowing a relatively large dam to be constructed in just one summer season, saving financial costs and providing early return on the investment. In addition, fly ash can be used in the structure, using clean and renewable energy. Several procedures to proportion RCC mixtures were proposed, including the optimal paste volume method which is based on the assumption that an optimal RCC should have just enough paste to fill the space between particles when the granular skeleton has reached its maximum density under compaction. With this assumption, RCC tests began in 1998 in the laboratories of the Norwegian Building Research Institute. An ordinary portland cement was used and combined with ordinary low lime fly ash. Both coarse and fine aggregate were used. The tests determined the optimum paste-mortar ratio, the content of coarse aggregates and the production of specimens for test on hardened and fresh concrete. The study showed that the compressive strength of RCC increased with increasing cement/(cement + fly ash) ratio. The permeability coefficient decreased with increasing cement-content and increasing cement/(cement + fly ash) ratio due to the slow pozzolanic reaction of fly ash making a more open pore structure. It was concluded that an optimized mixture can result in a high performance RCC in terms of fresh and hardened concrete properties. 15 refs., 5 tabs., 11 figs.

Combined treatment of SO2 and high resistivity fly ash using a pulse energized electron reactor

International Nuclear Information System (INIS)

Mizuno, A.; Clements, J.S.; Davis, R.H.

1984-01-01

The combined removal of SO 2 and high resistivity fly ash has been demonstrated in a pulse energized electron reactor (PEER). The PEER system which was originally developed for the removal of SO 2 utilizes a positive pulse streamer corona discharge in a non-uniform field geometry. In performance tests on SO 2 , more than 90% was removed with an advantageously small power requirement. Combined treatment performance was demonstrated by introducing high resistivity fly ash into the test gas and the PEER is significantly more efficient than a conventional electrostatic precipitator operated with a dc voltage. Observations show that the PEER agglomerates the fly ash and further that the SO 2 removal efficiency is improved by the presence of fly ash. The electrode configuration and performance results make retrofit consideration attractive

Backward flight in hummingbirds employs unique kinematic adjustments and entails low metabolic cost.

Science.gov (United States)

Sapir, Nir; Dudley, Robert

2012-10-15

Backward flight is a frequently used transient flight behavior among members of the species-rich hummingbird family (Trochilidae) when retreating from flowers, and is known from a variety of other avian and hexapod taxa, but the biomechanics of this intriguing locomotor mode have not been described. We measured rates of oxygen uptake (V(O2)) and flight kinematics of Anna's hummingbirds, Calypte anna (Lesson), within a wind tunnel using mask respirometry and high-speed videography, respectively, during backward, forward and hovering flight. We unexpectedly found that in sustained backward flight is similar to that in forward flight at equivalent airspeed, and is about 20% lower than hovering V(O2). For a bird that was measured throughout a range of backward airspeeds up to a speed of 4.5 m s(-1), the power curve resembled that of forward flight at equivalent airspeeds. Backward flight was facilitated by steep body angles coupled with substantial head flexion, and was also characterized by a higher wingbeat frequency, a flat stroke plane angle relative to horizontal, a high stroke plane angle relative to the longitudinal body axis, a high ratio of maximum:minimum wing positional angle, and a high upstroke:downstroke duration ratio. Because of the convergent evolution of hummingbird and some hexapod flight styles, flying insects may employ similar kinematics while engaged in backward flight, for example during station keeping or load lifting. We propose that backward flight behavior in retreat from flowers, together with other anatomical, physiological, morphological and behavioral adaptations, enables hummingbirds to maintain strictly aerial nectarivory.

Dynamics of human flight on skis: improvements in safety and fairness in ski jumping.

Science.gov (United States)

Müller, W; Platzer, D; Schmölzer, B

1996-08-01

This study of ski jumping includes three areas of research: Wind tunnel measurements with world class athletes in various flight positions, field measurements during the World Championships in Ski Flying 1994 in Planica (Slovenia) and a highly reliable mapping of ski jumping to a computable simulation model. The results explain the effects of equipment, flight style changes, the reason for the enhanced tumbling risk and high gust sensitivity observed. Consequences can be drawn for changes to the FIS regulations, the design of jumping hills and training methods. The internationally induced anorexia of the athletes could be prohibited by a new ski length regulation. Women jumpers could become a real competitive threat.

Quality of the oriental fruit fly, bactrocera dorsalis (Hendel) after sifting pupae by mechanical sifter

International Nuclear Information System (INIS)

Sutantawong, M.; Uthaisarn, K.

1996-01-01

Quality of fruit fly, bactrocera dorsalis (Hendel) in mass production is important for controlling pest populations by means of the sterile insect technique. The experiment was to study the quality of fruit fly after sifting pupae by mechanical sifter. Laboratory-reared pupae, held at 26 ± 1 degree C were sifted at intensity of 18 rpm in a rotary sifting device at 1, 2, 3, 4, 5, 6, 7 and 8 days of age. The quality of fruit flies were determined on adult eclosion and flight capability. The results showed that there were no significantly different (P < 0.05) in adult eclosion between control with sifted pupae at 1 to 8 days of age. However, there were significantly different (P < 0.05) in flight capability between control and sifted pupae at 1, 5, 6, 7, 8 days of age with sifted pupae at 2, 3, 4 days of age

77 FR 57039 - Special Conditions: Embraer S.A., Model EMB-550 Airplane; Electronic Flight Control System...

Science.gov (United States)

2012-09-17

... Flight Control System: Control Surface Awareness and Mode Annunciation AGENCY: Federal Aviation... a fly-by-wire electronic flight control system and no direct coupling from the flightdeck controller... nuisance alerting. This special condition also addresses flight control system mode annunciation. It...

Theseus Waits on Lakebed for First Flight

Science.gov (United States)

1996-01-01

The Theseus prototype remotely-piloted aircraft (RPA) waits on the lakebed before its first test flight from NASA's Dryden Flight Research Center, Edwards, California, on May 24, 1996. The Theseus aircraft, built and operated by Aurora Flight Sciences Corporation, Manassas, Virginia, was a unique aircraft flown at NASA's Dryden Flight Research Center, Edwards, California, under a cooperative agreement between NASA and Aurora. Dryden hosted the Theseus program, providing hangar space and range safety for flight testing. Aurora Flight Sciences was responsible for the actual flight testing, vehicle flight safety, and operation of the aircraft. The Theseus remotely piloted aircraft flew its maiden flight on May 24, 1996, at Dryden. During its sixth flight on November 12, 1996, Theseus experienced an in-flight structural failure that resulted in the loss of the aircraft. As of the beginning of the year 2000, Aurora had not rebuilt the aircraft. Theseus was built for NASA under an innovative, $4.9 million fixed-price contract by Aurora Flight Sciences Corporation and its partners, West Virginia University, Morgantown, West Virginia, and Fairmont State College, Fairmont, West Virginia. The twin-engine, unpiloted vehicle had a 140-foot wingspan, and was constructed largely of composite materials. Powered by two 80-horsepower, turbocharged piston engines that drove twin 9-foot-diameter propellers, Theseus was designed to fly autonomously at high altitudes, with takeoff and landing under the active control of a ground-based pilot in a ground control station 'cockpit.' With the potential ability to carry 700 pounds of science instruments to altitudes above 60,000 feet for durations of greater than 24 hours, Theseus was intended to support research in areas such as stratospheric ozone depletion and the atmospheric effects of future high-speed civil transport aircraft engines. Instruments carried aboard Theseus also would be able to validate satellite-based global environmental

Methodology for Evaluating the Simulator Flight Performance of Pilots

National Research Council Canada - National Science Library

Smith, Jennifer

2004-01-01

The type of research that investigates operational tasks such as flying an aircraft or flight simulator is extremely useful to the Air Force's operational community because the results apply directly...

Human Factors Topics in Flight Simulation: An Annotated Bibliography

Science.gov (United States)

1976-01-01

A flight simulator study of missile control performance as a function of concurrent workload. AGARD CP-146, 1974. HUMAN PERFORMANCE. CREELMAN , J.A...aircraft flight simulators. Aviation Psychological Research Centre, Western European Association for Aviation Psychology , Brussels, Belgium. 1973...training fighter pilots. AIAA 72-161, 1972. TRAINING. FRISBY, C.B. Field research in flying training. Occupational Psychology , 1947, 21, 24-33

Influence of Utilization of High-Volumes of Class F Fly Ash on the Abrasion Resistance of Concrete

Directory of Open Access Journals (Sweden)

William PRINCE

2007-01-01

Full Text Available Utilization of large volumes of fly ash in various concrete applications is a becoming a more general practice in an efforts towards using large quantities of fly ash. Around the world, Class C or Class F or both as available have been used in high volumes in cement-based materials. In India, majority of fly generated is of Class F type as per ASTM C 618. Yearly fly ash generation in India is approximately 95 million tonnes. Out of which around 15-20% is utilized in cement production and cement/concrete related activities. In order to increase its percentage utilization, an investigation was carried out to use it in concrete.In this paper, abrasion resistance of high volume fly ash (HVFA concretes made with 35, 45, 55, and 65% of cement replacement was evaluated in terms of its relation with compressive strength. Comparison was made between ordinary Portland cement and fly ash concrete. Test results indicated that abrasion resistance of concrete having cement replacement up to 35 percent was comparable to the normal concrete mix with out fly ash. Beyond 35% cement replacement, fly ash concretes exhibited slightly lower resistance to abrasion relative to non-fly ash concretes. Test results further indicated that abrasion resistance of concrete is closely related with compressive strength, and had a very good correlation between abrasion resistance and compressive strength (R2 value between 0.9018 and 0.9859 depending upon age.

Abolishment of Spontaneous Flight Turns in Visually Responsive Drosophila.

Science.gov (United States)

Ferris, Bennett Drew; Green, Jonathan; Maimon, Gaby

2018-01-22

Animals react rapidly to external stimuli, such as an approaching predator, but in other circumstances, they seem to act spontaneously, without any obvious external trigger. How do the neural processes mediating the execution of reflexive and spontaneous actions differ? We studied this question in tethered, flying Drosophila. We found that silencing a large but genetically defined set of non-motor neurons virtually eliminates spontaneous flight turns while preserving the tethered flies' ability to perform two types of visually evoked turns, demonstrating that, at least in flies, these two modes of action are almost completely dissociable. Copyright © 2017 Elsevier Ltd. All rights reserved.

Analysis of rocket flight stability based on optical image measurement

Science.gov (United States)

Cui, Shuhua; Liu, Junhu; Shen, Si; Wang, Min; Liu, Jun

2018-02-01

Based on the abundant optical image measurement data from the optical measurement information, this paper puts forward the method of evaluating the rocket flight stability performance by using the measurement data of the characteristics of the carrier rocket in imaging. On the basis of the method of measuring the characteristics of the carrier rocket, the attitude parameters of the rocket body in the coordinate system are calculated by using the measurements data of multiple high-speed television sets, and then the parameters are transferred to the rocket body attack angle and it is assessed whether the rocket has a good flight stability flying with a small attack angle. The measurement method and the mathematical algorithm steps through the data processing test, where you can intuitively observe the rocket flight stability state, and also can visually identify the guidance system or failure analysis.

Chilled packing systems for fruit flies (Diptera: Tephritidae) in the sterile insect technique

Energy Technology Data Exchange (ETDEWEB)

Hernandez, Emilio; Escobar, Arseny; Bravo, Bigail; Montoya, Pablo [Instituto Interamericano de Cooperacion para la Agricultura (IICA), Chiapas (Mexico); Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentacion (SAGARPA), Mexico, D.F. (Mexico). Programa Moscafrut

2010-07-15

We evaluated three packing systems (PARC boxes, 'GT' screen towers and 'MX' screen towers) for the emergence and sexual maturation of sterile fruit flies, at three adult fl y densities (1, 1.2 and 1.3 fly/cm 2) and three food types. At the lowest density, results showed no significant differences in the longevity and flight ability of adult Anastrepha ludens (Loew) and Anastrepha obliqua Macquart among the three packing systems. Higher densities resulted in a decrease in these parameters. In the evaluation of the three food types, no significant differences were found either on longevity or flight ability of A. ludens. However, the greatest longevity for both sexes A. obliqua was obtained with commercial powdered Mb and the mix of sugar, protein and corn starch on paper (SPCP) food types. The highest value for flight ability in A. obliqua males was obtained with powdered Mb and SPCP food types, and for females with Mb powdered food. Our data indicated that GT and MX screen tower packing systems are an alternative to the PARC boxes, since they were suitable for adult fl y sexual maturation without any harm to their longevity or flight ability. The tested foods were equivalent in both fruit fl y species, with the exception of the agar type for A. obliqua, which yielded the lowest biological parameters evaluated. Our results contribute to the application of new methods for the packing and release of sterile flies in large-scale programs. (author)

78 FR 75284 - Special Conditions: Bombardier Inc., Models BD-500-1A10 and BD-500-1A11 Series Airplanes; Flight...

Science.gov (United States)

2013-12-11

... electronic flight control system that contains fly-by-wire control laws, including envelope protections, for... issue a finding of regulatory adequacy under Sec. 611 of Public Law 92-574, the ``Noise Control Act of... electronic flight control system that contains fly-by-wire control laws, including envelope protections, for...

Flight demonstration of aircraft fuselage and bulkhead monitoring using optical fiber distributed sensing system

Science.gov (United States)

Wada, Daichi; Igawa, Hirotaka; Tamayama, Masato; Kasai, Tokio; Arizono, Hitoshi; Murayama, Hideaki; Shiotsubo, Katsuya

2018-02-01

We have developed an optical fiber distributed sensing system based on optical frequency domain reflectometry (OFDR) that uses long-length fiber Bragg gratings (FBGs). This technique obtains strain data not as a point data from an FBG but as a distributed profile within the FBG. This system can measure the strain distribution profile with an adjustable high spatial resolution of the mm or sub-mm order in real-time. In this study, we applied this OFDR-FBG technique to a flying test bed that is a mid-sized jet passenger aircraft. We conducted flight tests and monitored the structural responses of a fuselage stringer and the bulkhead of the flying test bed during flights. The strain distribution variations were successfully monitored for various events including taxiing, takeoff, landing and several other maneuvers. The monitoring was effective not only for measuring the strain amplitude applied to the individual structural parts but also for understanding the characteristics of the structural responses in accordance with the flight maneuvers. We studied the correlations between various maneuvers and strains to explore the relationship between the operation and condition of aircraft.

Preliminary flight test results of a fly-by-throttle emergency flight control system on an F-15 airplane

Science.gov (United States)

Burcham, Frank W., Jr.; Maine, Trindel A.; Fullerton, C. G.; Wells, Edward A.

1993-01-01

A multi-engine aircraft, with some or all of the flight control system inoperative, may use engine thrust for control. NASA Dryden has conducted a study of the capability and techniques for this emergency flight control method for the F-15 airplane. With an augmented control system, engine thrust, along with appropriate feedback parameters, is used to control flightpath and bank angle. Extensive simulation studies have been followed by flight tests. This paper discusses the principles of throttles-only control, the F-15 airplane, the augmented system, and the flight results including landing approaches with throttles-only control to within 10 ft of the ground.

Lightning effects on the NASA F-8 digital fly-by-wire airplane

Science.gov (United States)

Plumer, J. A.

1975-01-01

An investigation was conducted to evaluate the possible electromagnetic effects of lightning on a fly-by-wire flight control system which had been developed for an F8 aircraft. A brief description is presented of the flight control system. The test and measurement technique used in the investigation is discussed. The results of the investigation are considered, taking into account the vulnerability of individual system components to lightning induced voltages.

How lizards fly: A novel type of wing in animals.

Science.gov (United States)

Dehling, J Maximilian

2017-01-01

Flying lizards of the genus Draco are renowned for their gliding ability, using an aerofoil formed by winglike patagial membranes and supported by elongated thoracic ribs. It remains unknown, however, how these lizards manoeuvre during flight. Here, I present the results of a study on the aerial behaviour of Dussumier's Flying Lizard (Draco dussumieri) and show that Draco attaches the forelimbs to the leading edge of the patagium while airborne, forming a hitherto unknown type of composite wing. The attachment of the forelimbs to the patagium suggests that that aerofoil is controlled through movements of the forelimbs. One major advantage for the lizards is that the forelimbs retain their complete range of movement and functionality for climbing and running when not used as a part of the wing. These findings not only shed a new light on the flight of Draco but also have implications for the interpretation of gliding performance in fossil species.

Recyclability of Concrete Pavement Incorporating High Volume of Fly Ash

Science.gov (United States)

Yoshitake, Isamu; Ishida, Takeo; Fukumoto, Sunao

2015-01-01

Recyclable concrete pavement was made from fly ash and crushed limestone sand and gravel as aggregates so that the concrete pavement could be recycled to raw materials for cement production. With the aim to use as much fly ash as possible for the sustainable development of society, while achieving adequate strength development, pavement concrete having a cement-replacement ratio of 40% by mass was experimentally investigated, focusing on the strength development at an early age. Limestone powder was added to improve the early strength; flexural strength at two days reached 3.5 MPa, the minimum strength for traffic service in Japan. The matured fly ash concrete made with a cement content of 200 kg/m3 achieved a flexural strength almost equal to that of the control concrete without fly ash. Additionally, Portland cement made from the tested fly ash concrete was tested to confirm recyclability, with the cement quality meeting the Japanese classification of ordinary Portland cement. Limestone-based recyclable fly ash concrete pavement is, thus, a preferred material in terms of sustainability. PMID:28793518

Recyclability of Concrete Pavement Incorporating High Volume of Fly Ash.

Science.gov (United States)

Yoshitake, Isamu; Ishida, Takeo; Fukumoto, Sunao

2015-08-21

Recyclable concrete pavement was made from fly ash and crushed limestone sand and gravel as aggregates so that the concrete pavement could be recycled to raw materials for cement production. With the aim to use as much fly ash as possible for the sustainable development of society, while achieving adequate strength development, pavement concrete having a cement-replacement ratio of 40% by mass was experimentally investigated, focusing on the strength development at an early age. Limestone powder was added to improve the early strength; flexural strength at two days reached 3.5 MPa, the minimum strength for traffic service in Japan. The matured fly ash concrete made with a cement content of 200 kg/m3 achieved a flexural strength almost equal to that of the control concrete without fly ash. Additionally, Portland cement made from the tested fly ash concrete was tested to confirm recyclability, with the cement quality meeting the Japanese classification of ordinary Portland cement. Limestone-based recyclable fly ash concrete pavement is, thus, a preferred material in terms of sustainability.

Basal metabolic rate declines during long-distance migratory flight in great knots

NARCIS (Netherlands)

Battley, PF; Dekinga, A; Dietz, MW; Piersma, T; Tang, SX; Hulsman, K; Battley, Phil F.; Tang, Sixian

2001-01-01

Great Knots (Calidris tenuirostris) make one of the longest migratory flights in the avian world, flying almost 5500 km from Australia to China during northward migration. We measured basal metabolic rate (BMR) and body composition in birds before and after this flight and found that BMR decreased

The flight of the Rufus hummingbird

Science.gov (United States)

Bocanegra-Evans, Humberto; Pena, Jeremy; Hightower, Scott; Tobalske, Bret; Allen, James

2007-11-01

This paper will present preliminary experimental data for the flow field around a robotic model hummingbird ``flying'' in the New Mexico State large water channel. The Rufus hummingbird, which fly's with a wing beat frequency of 45Hz, in the Reynolds number range of 8,000 and a Strouhal number of 0.3 is mimicked by a two degree of freedom mechanical model operating in a large water channel. Phase locked PIV data and flow visualization results for hovering and relatively slow forward flight will be presented. Non-intrusive techniques will be used to estimate the hummingbirds lift and drag.

78 FR 11553 - Special Conditions: Embraer S.A., Model EMB-550 Airplane; Electronic Flight Control System...

Science.gov (United States)

2013-02-19

...; Electronic Flight Control System: Control Surface Awareness and Mode Annunciation AGENCY: Federal Aviation...) associated with the control surface awareness and mode annunciation of the electronic flight control system... a fly-by-wire electronic flight control system and no direct coupling from the flightdeck controller...

The repellency of lemongrass oil against stable flies, tested using video tracking

Science.gov (United States)

Baldacchino, Frédéric; Tramut, Coline; Salem, Ali; Liénard, Emmanuel; Delétré, Emilie; Franc, Michel; Martin, Thibaud; Duvallet, Gérard; Jay-Robert, Pierre

2013-01-01

Lemongrass oil (Cymbopogon citratus) is an effective repellent against mosquitoes (Diptera: Culicidae) and house flies (Diptera: Muscidae). In this study, its effectiveness was assessed on stable flies (Diptera: Muscidae) in laboratory conditions. First, we demonstrated that lemongrass oil is an active substance for antennal olfactory receptor cells of Stomoxys calcitrans as indicated by a significant increase in the electroantennogram responses to increasing doses of lemongrass oil. Feeding-choice tests in a flight cage with stable flies having access to two blood-soaked sanitary pads, one of which was treated with lemongrass oil, showed that stable flies (n = 24) spent significantly more time in the untreated zone (median value = 218.4 s) than in the treated zone (median value = 63.7 s). No stable flies fed on the treated pad, whereas nine fed on the untreated pad. These results suggest that lemongrass oil could be used as an effective repellent against stable flies. Additional studies to confirm its spatial repellent and feeding deterrent effects are warranted. PMID:23759542

To Fly or Not to Fly: Teaching Advanced Secondary School Students about Principles of Flight in Biological Systems

Science.gov (United States)

Pietsch, Renée B.; Bohland, Cynthia L.; Schmale, David G., III.

2015-01-01

Biological flight mechanics is typically taught in graduate level college classes rather than in secondary school classes. We developed an interdisciplinary unit for advanced upper-level secondary school students (ages 15-18) to teach the principles of flight and applications to biological systems. This unit capitalised on the tremendous…

Flight calls and orientation

DEFF Research Database (Denmark)

Larsen, Ole Næsbye; Andersen, Bent Bach; Kropp, Wibke

2008-01-01

flight calls was simulated by sequential computer controlled activation of five loudspeakers placed in a linear array perpendicular to the bird's migration course. The bird responded to this stimulation by changing its migratory course in the direction of that of the ‘flying conspecifics' but after about......  In a pilot experiment a European Robin, Erithacus rubecula, expressing migratory restlessness with a stable orientation, was video filmed in the dark with an infrared camera and its directional migratory activity was recorded. The flight overhead of migrating conspecifics uttering nocturnal...... 30 minutes it drifted back to its original migration course. The results suggest that songbirds migrating alone at night can use the flight calls from conspecifics as additional cues for orientation and that they may compare this information with other cues to decide what course to keep....

CFD Analysis of UAV Flying Wing

Directory of Open Access Journals (Sweden)

Vasile PRISACARIU

2016-09-01

Full Text Available Numerical methods for solving equations describing the evolution of 3D fluid experienced a significant development closely related to the progress of information systems. Today, especially in the field of fluid mechanics, numerical simulations allow the study of gas-thermodynamic confirmed by experimental techniques in wind tunnel conditions and actual flight tests for modeling complex aircraft. The article shows a case of numerical analysis of the lifting surface on the UAV type flying wing.

Actogram analysis of free-flying migratory birds

DEFF Research Database (Denmark)

Bäckman, Johan; Andersson, Arne; Pedersen, Lykke

2017-01-01

The use of accelerometers has become an important part of biologging techniques for large-sized birds with accelerometer data providing information about flight mode, wing-beat pattern, behaviour and energy expenditure. Such data show that birds using much energy-saving soaring/gliding flight like...... frigatebirds and swifts can stay airborne without landing for several months. Successful accelerometer studies have recently been conducted also for free-flying small songbirds during their entire annual cycle. Here we review the principles and possibilities for accelerometer studies in bird migration. We use...... of the life cycle. Accelerometer recording of the annual activity patterns of individual birds will open up a new dimension in bird migration research....

14 CFR 121.481 - Flight time limitations: One or two pilot crews.

Science.gov (United States)

2010-01-01

... operations may schedule a pilot to fly in an airplane that has a crew of one or two pilots for eight hours or... certificate holder conducting flag operations schedules a pilot to fly more than eight hours during any 24... of flight duty. This rest period must be at least twice the number of hours flown since the preceding...

The aerodynamic cost of flight in bats--comparing theory with measurement

Science.gov (United States)

von Busse, Rhea; Waldman, Rye M.; Swartz, Sharon M.; Breuer, Kenneth S.

2012-11-01

Aerodynamic theory has long been used to predict the aerodynamic power required for animal flight. However, even though the actuator disk model does not account for the flapping motion of a wing, it is used for lack of any better model. The question remains: how close are these predictions to reality? We designed a study to compare predicted aerodynamic power to measured power from the kinetic energy contained in the wake shed behind a bat flying in a wind tunnel. A high-accuracy displaced light-sheet stereo PIV system was used in the Trefftz plane to capture the wake behind four bats flown over a range of flight speeds (1-6m/s). The total power in the wake was computed from the wake vorticity and these estimates were compared with the power predicted using Pennycuick's model for bird flight as well as estimates derived from measurements of the metabolic cost of flight, previously acquired from the same individuals.

Fifty Years of Flight Research: An Annotated Bibliography of Technical Publications of NASA Dryden Flight Research Center, 1946-1996

Science.gov (United States)

Fisher, David F.

1999-01-01

Titles, authors, report numbers, and abstracts are given for more than 2200 unclassified and unrestricted technical reports and papers published from September 1946 to December 1996 by NASA Dryden Flight Research Center and its predecessor organizations. These technical reports and papers describe and give the results of 50 years of flight research performed by the NACA and NASA, from the X-1 and other early X-airplanes, to the X-15, Space Shuttle, X-29 Forward Swept Wing, and X-31 aircraft. Some of the other research airplanes tested were the D-558, phase 1 and 2; M-2, HL-10 and X-24 lifting bodies; Digital Fly-By-Wire and Supercritical Wing F-8; XB-70; YF-12; AFTI F-111 TACT and MAW; F-15 HiDEC; F-18 High Alpha Research Vehicle, and F-18 Systems Research Aircraft. The citations of reports and papers are listed in chronological order, with author and aircraft indices. In addition, in the appendices, citations of 233 contractor reports, more than 200 UCLA Flight System Research Center reports and 25 video tapes are included.

Realistic 3D Terrain Roaming and Real-Time Flight Simulation

Science.gov (United States)

Que, Xiang; Liu, Gang; He, Zhenwen; Qi, Guang

2014-12-01

This paper presents an integrate method, which can provide access to current status and the dynamic visible scanning topography, to enhance the interactive during the terrain roaming and real-time flight simulation. A digital elevation model and digital ortho-photo map data integrated algorithm is proposed as the base algorithm for our approach to build a realistic 3D terrain scene. A new technique with help of render to texture and head of display for generating the navigation pane is used. In the flight simulating, in order to eliminate flying "jump", we employs the multidimensional linear interpolation method to adjust the camera parameters dynamically and steadily. Meanwhile, based on the principle of scanning laser imaging, we draw pseudo color figures by scanning topography in different directions according to the real-time flying status. Simulation results demonstrate that the proposed algorithm is prospective for applications and the method can improve the effect and enhance dynamic interaction during the real-time flight.

Vision in Flies: Measuring the Attention Span.

Directory of Open Access Journals (Sweden)

Sebastian Koenig

Full Text Available A visual stimulus at a particular location of the visual field may elicit a behavior while at the same time equally salient stimuli in other parts do not. This property of visual systems is known as selective visual attention (SVA. The animal is said to have a focus of attention (FoA which it has shifted to a particular location. Visual attention normally involves an attention span at the location to which the FoA has been shifted. Here the attention span is measured in Drosophila. The fly is tethered and hence has its eyes fixed in space. It can shift its FoA internally. This shift is revealed using two simultaneous test stimuli with characteristic responses at their particular locations. In tethered flight a wild type fly keeps its FoA at a certain location for up to 4s. Flies with a mutation in the radish gene, that has been suggested to be involved in attention-like mechanisms, display a reduced attention span of only 1s.

Vision in Flies: Measuring the Attention Span.

Science.gov (United States)

Koenig, Sebastian; Wolf, Reinhard; Heisenberg, Martin

2016-01-01

A visual stimulus at a particular location of the visual field may elicit a behavior while at the same time equally salient stimuli in other parts do not. This property of visual systems is known as selective visual attention (SVA). The animal is said to have a focus of attention (FoA) which it has shifted to a particular location. Visual attention normally involves an attention span at the location to which the FoA has been shifted. Here the attention span is measured in Drosophila. The fly is tethered and hence has its eyes fixed in space. It can shift its FoA internally. This shift is revealed using two simultaneous test stimuli with characteristic responses at their particular locations. In tethered flight a wild type fly keeps its FoA at a certain location for up to 4s. Flies with a mutation in the radish gene, that has been suggested to be involved in attention-like mechanisms, display a reduced attention span of only 1s.

Fly ash carbon passivation

Science.gov (United States)

La Count, Robert B; Baltrus, John P; Kern, Douglas G

2013-05-14

A thermal method to passivate the carbon and/or other components in fly ash significantly decreases adsorption. The passivated carbon remains in the fly ash. Heating the fly ash to about 500 and 800 degrees C. under inert gas conditions sharply decreases the amount of surfactant adsorbed by the fly ash recovered after thermal treatment despite the fact that the carbon content remains in the fly ash. Using oxygen and inert gas mixtures, the present invention shows that a thermal treatment to about 500 degrees C. also sharply decreases the surfactant adsorption of the recovered fly ash even though most of the carbon remains intact. Also, thermal treatment to about 800 degrees C. under these same oxidative conditions shows a sharp decrease in surfactant adsorption of the recovered fly ash due to the fact that the carbon has been removed. This experiment simulates the various "carbon burnout" methods and is not a claim in this method. The present invention provides a thermal method of deactivating high carbon fly ash toward adsorption of AEAs while retaining the fly ash carbon. The fly ash can be used, for example, as a partial Portland cement replacement in air-entrained concrete, in conductive and other concretes, and for other applications.

Forward flight of swallowtail butterfly with simple flapping motion

Energy Technology Data Exchange (ETDEWEB)

Tanaka, Hiroto [School of Engineering and Applied Sciences, Harvard University, 60 Oxford Street, Cambridge, MA 02138 (United States); Shimoyama, Isao, E-mail: isao@i.u-tokyo.ac.j [Department of Mechano-Informatics, Graduate School of Information Science and Technology, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656 (Japan)

2010-06-15

Unlike other flying insects, the wing motion of swallowtail butterflies is basically limited to flapping because their fore wings partly overlap their hind wings, structurally restricting the feathering needed for active control of aerodynamic force. Hence, it can be hypothesized that the flight of swallowtail butterflies is realized with simple flapping, requiring little feedback control of the feathering angle. To verify this hypothesis, we fabricated an artificial butterfly mimicking the wing motion and wing shape of a swallowtail butterfly and analyzed its flights using images taken with a high-speed video camera. The results demonstrated that stable forward flight could be realized without active feathering or feedback control of the wing motion. During the flights, the artificial butterfly's body moved up and down passively in synchronization with the flapping, and the artificial butterfly followed an undulating flight trajectory like an actual swallowtail butterfly. Without feedback control of the wing motion, the body movement is directly affected by change of aerodynamic force due to the wing deformation; the degree of deformation was determined by the wing venation. Unlike a veinless wing, a mimic wing with veins generated a much higher lift coefficient during the flapping flight than in a steady flow due to the large body motion.

Forward flight of swallowtail butterfly with simple flapping motion

International Nuclear Information System (INIS)

Tanaka, Hiroto; Shimoyama, Isao

2010-01-01

Unlike other flying insects, the wing motion of swallowtail butterflies is basically limited to flapping because their fore wings partly overlap their hind wings, structurally restricting the feathering needed for active control of aerodynamic force. Hence, it can be hypothesized that the flight of swallowtail butterflies is realized with simple flapping, requiring little feedback control of the feathering angle. To verify this hypothesis, we fabricated an artificial butterfly mimicking the wing motion and wing shape of a swallowtail butterfly and analyzed its flights using images taken with a high-speed video camera. The results demonstrated that stable forward flight could be realized without active feathering or feedback control of the wing motion. During the flights, the artificial butterfly's body moved up and down passively in synchronization with the flapping, and the artificial butterfly followed an undulating flight trajectory like an actual swallowtail butterfly. Without feedback control of the wing motion, the body movement is directly affected by change of aerodynamic force due to the wing deformation; the degree of deformation was determined by the wing venation. Unlike a veinless wing, a mimic wing with veins generated a much higher lift coefficient during the flapping flight than in a steady flow due to the large body motion.

Coevolution between flight morphology, vertical stratification and sexual dimorphism: what can we learn from tropical butterflies?

Science.gov (United States)

Graça, M B; Pequeno, P A C L; Franklin, E; Morais, J W

2017-10-01

Occurrence patterns are partly shaped by the affinity of species with habitat conditions. For winged organisms, flight-related attributes are vital for ecological performance. However, due to the different reproductive roles of each sex, we expect divergence in flight energy budget, and consequently different selection responses between sexes. We used tropical frugivorous butterflies as models to investigate coevolution between flight morphology, sex dimorphism and vertical stratification. We studied 94 species of Amazonian fruit-feeding butterflies sampled in seven sites across 3341 ha. We used wing-thorax ratio as a proxy for flight capacity and hierarchical Bayesian modelling to estimate stratum preference. We detected a strong phylogenetic signal in wing-thorax ratio in both sexes. Stouter fast-flying species preferred the canopy, whereas more slender slow-flying species preferred the understorey. However, this relationship was stronger in females than in males, suggesting that female phenotype associates more intimately with habitat conditions. Within species, males were stouter than females and sexual dimorphism was sharper in understorey species. Because trait-habitat relationships were independent from phylogeny, the matching between flight morphology and stratum preference is more likely to reflect adaptive radiation than shared ancestry. This study sheds light on the impact of flight and sexual dimorphism on the evolution and ecological adaptation of flying organisms. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

14 CFR 121.485 - Flight time limitations: Three or more pilots and an additional flight crewmember.

Science.gov (United States)

2010-01-01

... his base and who is a pilot on an airplane that has a crew of three or more pilots and an additional flight crewmember. It shall also provide adequate sleeping quarters on the airplane whenever a pilot is scheduled to fly more than 12 hours during any 24 consecutive hours. (b) The certificate holder conducting...

Simbol-X Formation Flight and Image Reconstruction

Science.gov (United States)

Civitani, M.; Djalal, S.; Le Duigou, J. M.; La Marle, O.; Chipaux, R.

2009-05-01

Simbol-X is the first operational mission relying on two satellites flying in formation. The dynamics of the telescope, due to the formation flight concept, raises a variety of problematic, like image reconstruction, that can be better evaluated via a simulation tools. We present here the first results obtained with Simulos, simulation tool aimed to study the relative spacecrafts navigation and the weight of the different parameters in image reconstruction and telescope performance evaluation. The simulation relies on attitude and formation flight sensors models, formation flight dynamics and control, mirror model and focal plane model, while the image reconstruction is based on the Line of Sight (LOS) concept.

Comparative behaviour of lab.-cultured and wild-type Dacus oleae flies in the field

International Nuclear Information System (INIS)

Prokopy, R.J.; Haniotakis, G.E.; Economopoulos, A.P.

1975-01-01

Under field conditions, the authors compared the responses of lab.-type (ca. 85 generations under artificial conditions) and wild-type Dacus oleae flies to host plant colour and odour, host fruit colour and shape, small rectangles of different colours and shades, and McPhail-type traps of different colours baited with different odours. Except for the lab.-type flies being relatively more attracted toward red fruit models and small red rectangles and relatively less attracted toward yellow fruit models and small yellow rectangles than the wild type, the qualitative nature of the responses of the two fly types toward the various experimental treatments was essentially the same. Quantitatively, however, consistently smaller percentages of the released lab.-type than the released wild-type flies were recaptured, suggesting that the mobility, flight pattern, or vigour of the two types of flies may be different. (author)

Flight test results for the Daedalus and Light Eagle human powered aircraft

Science.gov (United States)

Sullivan, R. Bryan; Zerweckh, Siegfried H.

1988-01-01

The results of the flight test program of the Daedalus and Light Eagle human powered aircraft in the winter of 1987/88 are given. The results from experiments exploring the Light Eagle's rigid body and structural dynamics are presented. The interactions of these dynamics with the autopilot design are investigated. Estimates of the power required to fly the Daedalus aircraft are detailed. The system of sensors, signal conditioning boards, and data acquisition equipment used to record the flight data is also described. In order to investigate the dynamics of the aircraft, flight test maneuvers were developed to yield maximum data quality from the point of view of estimating lateral and longitudinal stability derivatives. From this data, structural flexibility and unsteady aerodynamics have been modeled in an ad hoc manner and are used to augment the equations of motion with flexibility effects. Results of maneuvers that were flown are compared with the predictions from the flexibility model. To extend the ad hoc flexibility model, a fully flexible aeroelastic model has been developed. The model is unusual in the approximate equality of many structural natural frequencies and the importance of unsteady aerodynamic effects. the Gossamer Albatross. It is hypothesized that this inverse ground effect is caused by turbulence in the Earth's boundary layer. The diameters of the largest boundary layer eddies (which represent most of the turbulent kinetic energy) are proportional to altitude; thus, closer to the ground, the energy in the boundary layer becomes concentrated in eddies of smaller and smaller diameter. Eventually the eddies become sufficiently small (approximately 0.5 cm) that they trip the laminar boundary layer on the wing. As a result, a greater percentage of the wing area is covered with turbulent flow. Consequently the aircraft's drag and the pow er required both increase as the aircraft flies closer to the ground. The results of the flight test program are

Prediction of the Chloride Resistance of Concrete Modified with High Calcium Fly Ash Using Machine Learning.

Science.gov (United States)

Marks, Michał; Glinicki, Michał A; Gibas, Karolina

2015-12-11

The aim of the study was to generate rules for the prediction of the chloride resistance of concrete modified with high calcium fly ash using machine learning methods. The rapid chloride permeability test, according to the Nordtest Method Build 492, was used for determining the chloride ions' penetration in concrete containing high calcium fly ash (HCFA) for partial replacement of Portland cement. The results of the performed tests were used as the training set to generate rules describing the relation between material composition and the chloride resistance. Multiple methods for rule generation were applied and compared. The rules generated by algorithm J48 from the Weka workbench provided the means for adequate classification of plain concretes and concretes modified with high calcium fly ash as materials of good, acceptable or unacceptable resistance to chloride penetration.

The importance of being top-heavy: Intrinsic stability of flapping flight

Science.gov (United States)

Ristroph, Leif; Liu, Bin; Zhang, Jun

2011-11-01

We explore the stability of flapping flight in a model system that consists of a pyramid-shaped object that freely hovers in a vertically oscillating airflow. Such a ``bug'' not only generates sufficient aerodynamic force to keep aloft but also robustly maintains balance during free-flight. Flow visualization reveals that both weight support and intrinsic stability result from the periodic shedding of dipolar vortices. Counter-intuitively, the observed pattern of vortex shedding suggests that stability requires a high center-of-mass, which we verify by comparing the performance of top- and bottom-heavy bugs. Finally, we visit a zoo of other flapping flyers, including Mary Poppins' umbrella, a flying saucer or UFO, and Da Vinci's helicopter.

An Indispensable Ingredient: Flight Research and Aircraft Design

Science.gov (United States)

Gorn, Michael H.

2003-01-01

Flight research-the art of flying actual vehicles in the atmosphere in order to collect data about their behavior-has played a historic and decisive role in the design of aircraft. Naturally, wind tunnel experiments, computational fluid dynamics, and mathematical analyses all informed the judgments of the individuals who conceived of new aircraft. But flight research has offered moments of realization found in no other method. Engineer Dale Reed and research pilot Milt Thompson experienced one such epiphany on March 1, 1963, at the National Aeronautics and Space Administration s Dryden Flight Research Center in Edwards, California. On that date, Thompson sat in the cockpit of a small, simple, gumdrop-shaped aircraft known as the M2-F1, lashed by a long towline to a late-model Pontiac Catalina. As the Pontiac raced across Rogers Dry Lake, it eventually gained enough speed to make the M2-F1 airborne. Thompson braced himself for the world s first flight in a vehicle of its kind, called a lifting body because of its high lift-to-drag ratio. Reed later recounted what he saw:

Activity and migratory flights of individual free-flying songbirds throughout the annual cycle

DEFF Research Database (Denmark)

Bäckman, Johan; Andersson, Arne; Alerstam, Thomas

2017-01-01

the sampling events. Activity levels were stored on an hourly basis throughout the annual cycle, allowing periods of resting/sleep, continuous flight and intermediate activity (foraging, breeding) to be distinguished. Measurements from a light sensor were stored from preprogrammed key stationary periods during...... the year to provide control information about geographic location. Successful results, including annual actogram, were obtained for a red-backed shrike Lanius collurio carrying out its annual loop migration between northern Europe and southern Africa. The shrike completed its annual migration by performing...... > 66 (max. 73) nocturnal migratory flights (29 flights in autumn and > 37, max. 44, in spring) adding up to a total of > 434 (max. 495) flight hours. Migratory flights lasted on average 6.6 h with maximum 15.9 h. These flights were aggregated into eight travel episodes (periods of 4-11 nights when...

Flight initiation and maintenance deficits in flies with genetically altered biogenic amine levels

OpenAIRE

Brembs, Björn; Christiansen, F.; Pflüger, J.; Duch, C.

2007-01-01

Insect flight is one of the fastest, most intense and most energy-demanding motor behaviors. It is modulated on multiple levels by the biogenic amine octopamine. Within the CNS, octopamine acts directly on the flight central pattern generator, and it affects motivational states. In the periphery, octopamine sensitizes sensory receptors, alters muscle contraction kinetics, and enhances flight muscle glycolysis. This study addresses the roles for octopamine and its precursor tyramine in flight ...

Tryptophan metabolism in tsetse flies and the consequences of its derangement

Directory of Open Access Journals (Sweden)

R. H. Gooding

1987-01-01

Full Text Available Literature comparing salmon and wild type Glossina morsitans morsitans and that comparing tan and wild type Glossina palpalis palpalis is reviewed. New information is presented on behaviour and biochemistry of salmon and wild type G. m. morsitans. The eye color mutants result from two lesions in the tryptophan to xanthommatin pathway: lack of tryptophan oxygenase in G. m morsitans and failure to produce or retain xanthommatin in eyes (but not in testes of G. p. palpalis. The salmon allele in G. m. morsitans is pleiotropic and profoundly affects many aspects of fly biology including longevity, reproductive capacity, vision, vectorial capacity and duration of flight, but not circadian rhythms. The tan allele in G. p. palpalis has little effect upon the biology of flies under laboratory conditions, except that tan flies appear less active than normal. Adult tsetse flies metabolize tryptophan to kynurenine which is excreted; fluctuations in activities of the enzymes producing kynurenine suggest this pathway is under metabolic control.

Adaptive Augmenting Control Flight Characterization Experiment on an F/A-18

Science.gov (United States)

VanZwieten, Tannen S.; Gilligan, Eric T.; Wall, John H.; Orr, Jeb S.; Miller, Christopher J.; Hanson, Curtis E.

2014-01-01

The NASA Marshall Space Flight Center (MSFC) Flight Mechanics and Analysis Division developed an Adaptive Augmenting Control (AAC) algorithm for launch vehicles that improves robustness and performance by adapting an otherwise welltuned classical control algorithm to unexpected environments or variations in vehicle dynamics. This AAC algorithm is currently part of the baseline design for the SLS Flight Control System (FCS), but prior to this series of research flights it was the only component of the autopilot design that had not been flight tested. The Space Launch System (SLS) flight software prototype, including the adaptive component, was recently tested on a piloted aircraft at Dryden Flight Research Center (DFRC) which has the capability to achieve a high level of dynamic similarity to a launch vehicle. Scenarios for the flight test campaign were designed specifically to evaluate the AAC algorithm to ensure that it is able to achieve the expected performance improvements with no adverse impacts in nominal or nearnominal scenarios. Having completed the recent series of flight characterization experiments on DFRC's F/A-18, the AAC algorithm's capability, robustness, and reproducibility, have been successfully demonstrated. Thus, the entire SLS control architecture has been successfully flight tested in a relevant environment. This has increased NASA's confidence that the autopilot design is ready to fly on the SLS Block I vehicle and will exceed the performance of previous architectures.

Trajectory Evaluation of Rotor-Flying Robots Using Accurate Inverse Computation Based on Algorithm Differentiation

Directory of Open Access Journals (Sweden)

Yuqing He

2014-01-01

Full Text Available Autonomous maneuvering flight control of rotor-flying robots (RFR is a challenging problem due to the highly complicated structure of its model and significant uncertainties regarding many aspects of the field. As a consequence, it is difficult in many cases to decide whether or not a flight maneuver trajectory is feasible. It is necessary to conduct an analysis of the flight maneuvering ability of an RFR prior to test flight. Our aim in this paper is to use a numerical method called algorithm differentiation (AD to solve this problem. The basic idea is to compute the internal state (i.e., attitude angles and angular rates and input profiles based on predetermined maneuvering trajectory information denoted by the outputs (i.e., positions and yaw angle and their higher-order derivatives. For this purpose, we first present a model of the RFR system and show that it is flat. We then cast the procedure for obtaining the required state/input based on the desired outputs as a static optimization problem, which is solved using AD and a derivative based optimization algorithm. Finally, we test our proposed method using a flight maneuver trajectory to verify its performance.

X-1A in flight with flight data superimposed

Science.gov (United States)

1953-01-01

for heat transfer research while the X-1C was intended as a high-speed armament systems test bed. All of these aircraft like the original X-1s, were launched from a Boeing B-29 or Boeing B-50 'mothership' to take maximum advantage of their limited flying time with a rocket engine. Most launches were made from the JTB-29A (45-21800). The other launch aircraft was EB-50A (46-006). X-1A The Bell X-1A was similar to the Bell X-1, except for having turbo-driven fuel pumps (instead of a system using nitrogen under pressure), a new cockpit canopy, longer fuselage and increased fuel capacity. The X-1A arrived at Edwards Air Force Base, California on January 7, 1953, with the first glide flight being successfully completed by Bell pilot, Jean 'Skip' Ziegler. The airplane also made five powered flights with Ziegler at the controls. The USAF was attempting a Mach 2 flight and USAF test pilot Charles 'Chuck' Yeager was eager. He reached speed of Mach 2.435, at a altitude of 75,000 feet on December 12, 1953, a speed record at the time. But all was not well, the aircraft encountered an inertial coupling phenomenon and went out of control. Once the X-1A had entered the denser atmosphere (35,000 feet) it slowly stabilized and Yeager was able to return to Edwards. The aircraft had experienced high-speed roll-coupling, something aerodynamicists had predicted, but this was the first actual encounter. On August 26, 1954, Major Arthur Murray, USAF test pilot flew the X-1A to an altitude record of 90,440 feet. NACA High-Speed Flight Station received the aircraft in September 1954 and returned it to Bell for the installation of an ejection seat. NACA test pilot Joseph Walker made a familiarization flight on July 20, 1955 followed by another scheduled flight on August 8, 1955. Shortly before launch the X-1A suffered an explosion. The extent of the damage prohibited landing the crippled aircraft. The X-1A was jettisoned into the desert, exploding and burning on impact. Walker and the B-29

Multiple losses of flight and recent speciation in steamer ducks

Science.gov (United States)

Fulton, Tara L.; Letts, Brandon; Shapiro, Beth

2012-01-01

Steamer ducks (Tachyeres) comprise four species, three of which are flightless. The flightless species are believed to have diverged from a flying common ancestor during the Late Pleistocene; however, their taxonomy remains contentious. Of particular interest is the previously unstudied population of flying steamer ducks in the Falkland Islands. We present the first genetic data from this insular population, and illustrate that the flying and flightless steamer ducks on the Falkland Islands are genetically indistinguishable, in contrast to their traditional classification as separate species. The three species that reside in continental South America form a genetically distinct lineage from the Falkland Island ducks. The Falkland steamer ducks diverged from their continental relatives 2.2–0.6 million years ago, coincident with a probable land bridge connecting the Falkland Islands to the mainland. The three continental species share a common ancestor approximately 15 000 years ago, possibly owing to isolation during a recent glacial advance. The continental steamer duck species are not reciprocally monophyletic, but show some amount of genetic differentiation between them. Each lineage of Tachyeres represents a different stage between flight and flightlessness. Their phylogenetic relationships suggest multiple losses of flight and/or long-term persistence of mixed-flight capability. As such, steamer ducks may provide a model system to study the evolution of flightlessness. PMID:22319122

Homing pigeons externally exposed to Deepwater Horizon crude oil change flight performance and behavior.

Science.gov (United States)

Perez, Cristina R; Moye, John K; Cacela, Dave; Dean, Karen M; Pritsos, Chris A

2017-11-01

The Deepwater Horizon oil spill was the largest in U.S. history, contaminating thousands of miles of coastal habitat and affecting the lives of many avian species. The Gulf of Mexico is a critical bird migration route area and migrants that were oiled but did not suffer mortality as a direct result of the spill faced unpredictable fates. This study utilized homing pigeons as a surrogate species for migratory birds to investigate the effects a single low level external oiling event has on the flight performance and behavior of birds flying repeated 161 km flights. Data from GPS data loggers showed that lightly oiled pigeons changed their flight paths, increased their flight durations by 2.6 fold, increased their flight distances by 28 km and subsequently decreased their route efficiencies. Oiled birds also exhibited reduced rate of weight gain between flights. Our data suggest that contaminated birds surviving the oil spill may have experienced flight impairment and reduced refueling abilities, likely reducing overall migration speed. Our findings contribute new information on how oil spills affect avian species, as the effects of oil on the flight behavior of long distance free-flying birds have not been previously described. Copyright © 2017 Elsevier Ltd. All rights reserved.

Space Shuttle Boundary Layer Transition Flight Experiment Ground Testing Overview

Science.gov (United States)

Berger, Karen T.; Anderson, Brian P.; Campbell, Charles H.

2014-01-01

In support of the Boundary Layer Transition (BLT) Flight Experiment (FE) Project in which a manufactured protuberance tile was installed on the port wing of Space Shuttle Orbiter Discovery for STS-119, STS- 128, STS-131 and STS-133 as well as Space Shuttle Orbiter Endeavour for STS-134, a significant ground test campaign was completed. The primary goals of the test campaign were to provide ground test data to support the planning and safety certification efforts required to fly the flight experiment as well as validation for the collected flight data. These test included Arcjet testing of the tile protuberance, aerothermal testing to determine the boundary layer transition behavior and resultant surface heating and planar laser induced fluorescence (PLIF) testing in order to gain a better understanding of the flow field characteristics associated with the flight experiment. This paper provides an overview of the BLT FE Project ground testing. High-level overviews of the facilities, models, test techniques and data are presented, along with a summary of the insights gained from each test.

Foraging in an unsteady world: bumblebee flight performance in field-realistic turbulence.

Science.gov (United States)

Crall, J D; Chang, J J; Oppenheimer, R L; Combes, S A

2017-02-06

Natural environments are characterized by variable wind that can pose significant challenges for flying animals and robots. However, our understanding of the flow conditions that animals experience outdoors and how these impact flight performance remains limited. Here, we combine laboratory and field experiments to characterize wind conditions encountered by foraging bumblebees in outdoor environments and test the effects of these conditions on flight. We used radio-frequency tags to track foraging activity of uniquely identified bumblebee ( Bombus impatiens ) workers, while simultaneously recording local wind flows. Despite being subjected to a wide range of speeds and turbulence intensities, we find that bees do not avoid foraging in windy conditions. We then examined the impacts of turbulence on bumblebee flight in a wind tunnel. Rolling instabilities increased in turbulence, but only at higher wind speeds. Bees displayed higher mean wingbeat frequency and stroke amplitude in these conditions, as well as increased asymmetry in stroke amplitude-suggesting that bees employ an array of active responses to enable flight in turbulence, which may increase the energetic cost of flight. Our results provide the first direct evidence that moderate, environmentally relevant turbulence affects insect flight performance, and suggest that flying insects use diverse mechanisms to cope with these instabilities.

Manual Manipulation of Engine Throttles for Emergency Flight Control

Science.gov (United States)

Burcham, Frank W., Jr.; Fullerton, C. Gordon; Maine, Trindel A.

2004-01-01

If normal aircraft flight controls are lost, emergency flight control may be attempted using only engines thrust. Collective thrust is used to control flightpath, and differential thrust is used to control bank angle. Flight test and simulation results on many airplanes have shown that pilot manipulation of throttles is usually adequate to maintain up-and-away flight, but is most often not capable of providing safe landings. There are techniques that will improve control and increase the chances of a survivable landing. This paper reviews the principles of throttles-only control (TOC), a history of accidents or incidents in which some or all flight controls were lost, manual TOC results for a wide range of airplanes from simulation and flight, and suggested techniques for flying with throttles only and making a survivable landing.

Development and Flight Test of an Augmented Thrust-Only Flight Control System on an MD-11 Transport Airplane

Science.gov (United States)

Burcham, Frank W., Jr.; Maine, Trindel A.; Burken, John J.; Pappas, Drew

1996-01-01

An emergency flight control system using only engine thrust, called Propulsion-Controlled Aircraft (PCA), has been developed and flight tested on an MD-11 airplane. In this thrust-only control system, pilot flight path and track commands and aircraft feedback parameters are used to control the throttles. The PCA system was installed on the MD-11 airplane using software modifications to existing computers. Flight test results show that the PCA system can be used to fly to an airport and safely land a transport airplane with an inoperative flight control system. In up-and-away operation, the PCA system served as an acceptable autopilot capable of extended flight over a range of speeds and altitudes. The PCA approaches, go-arounds, and three landings without the use of any non-nal flight controls have been demonstrated, including instrument landing system-coupled hands-off landings. The PCA operation was used to recover from an upset condition. In addition, PCA was tested at altitude with all three hydraulic systems turned off. This paper reviews the principles of throttles-only flight control; describes the MD-11 airplane and systems; and discusses PCA system development, operation, flight testing, and pilot comments.

An Alternative Flight Software Paradigm: Applying Multivariate Logistic Regression to Sense Trigger Conditions using Inaccurate or Scarce Information

Science.gov (United States)

Smith, Kelly; Gay, Robert; Stachowiak, Susan

2013-01-01

In late 2014, NASA will fly the Orion capsule on a Delta IV-Heavy rocket for the Exploration Flight Test-1 (EFT-1) mission. For EFT-1, the Orion capsule will be flying with a new GPS receiver and new navigation software. Given the experimental nature of the flight, the flight software must be robust to the loss of GPS measurements. Once the high-speed entry is complete, the drogue parachutes must be deployed within the proper conditions to stabilize the vehicle prior to deploying the main parachutes. When GPS is available in nominal operations, the vehicle will deploy the drogue parachutes based on an altitude trigger. However, when GPS is unavailable, the navigated altitude errors become excessively large, driving the need for a backup barometric altimeter to improve altitude knowledge. In order to increase overall robustness, the vehicle also has an alternate method of triggering the parachute deployment sequence based on planet-relative velocity if both the GPS and the barometric altimeter fail. However, this backup trigger results in large altitude errors relative to the targeted altitude. Motivated by this challenge, this paper demonstrates how logistic regression may be employed to semi-automatically generate robust triggers based on statistical analysis. Logistic regression is used as a ground processor pre-flight to develop a statistical classifier. The classifier would then be implemented in flight software and executed in real-time. This technique offers improved performance even in the face of highly inaccurate measurements. Although the logistic regression-based trigger approach will not be implemented within EFT-1 flight software, the methodology can be carried forward for future missions and vehicles

UAS Flight Planning Tool for Atmospheric Energy Extraction, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Aircraft have been flying point to point missions for the past 100 years. Each flight, the fuel energy is burned based upon an assumed time requirement to transport...

CHALLENGES IN FLYING QUADROTOR UNMANNED AERIAL VEHICLE FOR 3D INDOOR RECONSTRUCTION

Directory of Open Access Journals (Sweden)

J. Yan

2017-09-01

Full Text Available Three-dimensional modelling plays a vital role in indoor 3D tracking, navigation, guidance and emergency evacuation. Reconstruction of indoor 3D models is still problematic, in part, because indoor spaces provide challenges less-documented than their outdoor counterparts. Challenges include obstacles curtailing image and point cloud capture, restricted accessibility and a wide array of indoor objects, each with unique semantics. Reconstruction of indoor environments can be achieved through a photogrammetric approach, e.g. by using image frames, aligned using recurring corresponding image points (CIP to build coloured point clouds. Our experiments were conducted by flying a QUAV in three indoor environments and later reconstructing 3D models which were analysed under different conditions. Point clouds and meshes were created using Agisoft PhotoScan Professional. We concentrated on flight paths from two vantage points: 1 safety and security while flying indoors and 2 data collection needed for reconstruction of 3D models. We surmised that the main challenges in providing safe flight paths are related to the physical configuration of indoor environments, privacy issues, the presence of people and light conditions. We observed that the quality of recorded video used for 3D reconstruction has a high dependency on surface materials, wall textures and object types being reconstructed. Our results show that 3D indoor reconstruction predicated on video capture using a QUAV is indeed feasible, but close attention should be paid to flight paths and conditions ultimately influencing the quality of 3D models. Moreover, it should be decided in advance which objects need to be reconstructed, e.g. bare rooms or detailed furniture.

Challenges in Flying Quadrotor Unmanned Aerial Vehicle for 3d Indoor Reconstruction

Science.gov (United States)

Yan, J.; Grasso, N.; Zlatanova, S.; Braggaar, R. C.; Marx, D. B.

2017-09-01

Three-dimensional modelling plays a vital role in indoor 3D tracking, navigation, guidance and emergency evacuation. Reconstruction of indoor 3D models is still problematic, in part, because indoor spaces provide challenges less-documented than their outdoor counterparts. Challenges include obstacles curtailing image and point cloud capture, restricted accessibility and a wide array of indoor objects, each with unique semantics. Reconstruction of indoor environments can be achieved through a photogrammetric approach, e.g. by using image frames, aligned using recurring corresponding image points (CIP) to build coloured point clouds. Our experiments were conducted by flying a QUAV in three indoor environments and later reconstructing 3D models which were analysed under different conditions. Point clouds and meshes were created using Agisoft PhotoScan Professional. We concentrated on flight paths from two vantage points: 1) safety and security while flying indoors and 2) data collection needed for reconstruction of 3D models. We surmised that the main challenges in providing safe flight paths are related to the physical configuration of indoor environments, privacy issues, the presence of people and light conditions. We observed that the quality of recorded video used for 3D reconstruction has a high dependency on surface materials, wall textures and object types being reconstructed. Our results show that 3D indoor reconstruction predicated on video capture using a QUAV is indeed feasible, but close attention should be paid to flight paths and conditions ultimately influencing the quality of 3D models. Moreover, it should be decided in advance which objects need to be reconstructed, e.g. bare rooms or detailed furniture.

Flying starlings, PET and the evolution of volant dinosaurs.

Science.gov (United States)

Gold, Maria Eugenia Leone; Schulz, Daniela; Budassi, Michael; Gignac, Paul M; Vaska, Paul; Norell, Mark A

2016-04-04

Birds have evolved behavioral and morphological adaptations for powered flight. Many aspects of this transition are unknown, including the neuroanatomical changes that made flight possible [1]. To understand how the avian brain drives this complex behavior, we utilized positron emission tomography (PET) scanning and the tracer (18)F-fluorodeoxyglucose (FDG) to document regional metabolic activity in the brain associated with a variety of locomotor behaviors. FDG studies are typically employed in rats [2] though the technology has been applied to birds [3]. We examined whole-brain function in European Starlings (Sturnus vulgaris), trained to fly in a wind tunnel while metabolizing the tracer. Drawing on predictions from early anatomical studies [4], we hypothesized increased metabolic activity in the Wulst and functionally related visual brain regions during flight. We found that flight behaviors correlated positively with entopallia and Wulst activity, but negatively with thalamic activity. Copyright © 2016 Elsevier Ltd. All rights reserved.

A general method for closed-loop inverse simulation of helicopter maneuver flight

Directory of Open Access Journals (Sweden)

Wei WU

2017-12-01

Full Text Available Maneuverability is a key factor to determine whether a helicopter could finish certain flight missions successfully or not. Inverse simulation is commonly used to calculate the pilot controls of a helicopter to complete a certain kind of maneuver flight and to assess its maneuverability. A general method for inverse simulation of maneuver flight for helicopters with the flight control system online is developed in this paper. A general mathematical describing function is established to provide mathematical descriptions of different kinds of maneuvers. A comprehensive control solver based on the optimal linear quadratic regulator theory is developed to calculate the pilot controls of different maneuvers. The coupling problem between pilot controls and flight control system outputs is well solved by taking the flight control system model into the control solver. Inverse simulation of three different kinds of maneuvers with different agility requirements defined in the ADS-33E-PRF is implemented based on the developed method for a UH-60 helicopter. The results show that the method developed in this paper can solve the closed-loop inverse simulation problem of helicopter maneuver flight with high reliability as well as efficiency. Keywords: Closed-loop, Flying quality, Helicopters, Inverse simulation, Maneuver flight

New Methodology for Optimal Flight Control using Differential Evolution Algorithms applied on the Cessna Citation X Business Aircraft – Part 2. Validation on Aircraft Research Flight Level D Simulator

Directory of Open Access Journals (Sweden)

Yamina BOUGHARI

2017-06-01

Full Text Available In this paper the Cessna Citation X clearance criteria were evaluated for a new Flight Controller. The Flight Control Law were optimized and designed for the Cessna Citation X flight envelope by combining the Deferential Evolution algorithm, the Linear Quadratic Regulator method, and the Proportional Integral controller during a previous research presented in part 1. The optimal controllers were used to reach satisfactory aircraft’s dynamic and safe flight operations with respect to the augmentation systems’ handling qualities, and design requirements. Furthermore the number of controllers used to control the aircraft in its flight envelope was optimized using the Linear Fractional Representations features. To validate the controller over the whole aircraft flight envelope, the linear stability, eigenvalue, and handling qualities criteria in addition of the nonlinear analysis criteria were investigated during this research to assess the business aircraft for flight control clearance and certification. The optimized gains provide a very good stability margins as the eigenvalue analysis shows that the aircraft has a high stability, and a very good flying qualities of the linear aircraft models are ensured in its entire flight envelope, its robustness is demonstrated with respect to uncertainties due to its mass and center of gravity variations.

An Alternative Flight Software Trigger Paradigm: Applying Multivariate Logistic Regression to Sense Trigger Conditions Using Inaccurate or Scarce Information

Science.gov (United States)

Smith, Kelly M.; Gay, Robert S.; Stachowiak, Susan J.

2013-01-01

In late 2014, NASA will fly the Orion capsule on a Delta IV-Heavy rocket for the Exploration Flight Test-1 (EFT-1) mission. For EFT-1, the Orion capsule will be flying with a new GPS receiver and new navigation software. Given the experimental nature of the flight, the flight software must be robust to the loss of GPS measurements. Once the high-speed entry is complete, the drogue parachutes must be deployed within the proper conditions to stabilize the vehicle prior to deploying the main parachutes. When GPS is available in nominal operations, the vehicle will deploy the drogue parachutes based on an altitude trigger. However, when GPS is unavailable, the navigated altitude errors become excessively large, driving the need for a backup barometric altimeter to improve altitude knowledge. In order to increase overall robustness, the vehicle also has an alternate method of triggering the parachute deployment sequence based on planet-relative velocity if both the GPS and the barometric altimeter fail. However, this backup trigger results in large altitude errors relative to the targeted altitude. Motivated by this challenge, this paper demonstrates how logistic regression may be employed to semi-automatically generate robust triggers based on statistical analysis. Logistic regression is used as a ground processor pre-flight to develop a statistical classifier. The classifier would then be implemented in flight software and executed in real-time. This technique offers improved performance even in the face of highly inaccurate measurements. Although the logistic regression-based trigger approach will not be implemented within EFT-1 flight software, the methodology can be carried forward for future missions and vehicles.

Passengers waste production during flights.

Science.gov (United States)

Tofalli, Niki; Loizia, Pantelitsa; Zorpas, Antonis A

2017-12-20

We assume that during flights the amount of waste that is produced is limited. However, daily, approximately 8000 commercial airplanes fly above Europe's airspace while at the same time, more than 17,000 commercial flights exist in the entire world. Using primary data from airlines, which use the Larnaca's International Airport (LIA) in Cyprus, we have tried to understand why wastes are produced during a typical flight such as food waste, paper, and plastics, as well as how passengers affect the production of those wastes. The compositional analysis took place on 27 flights of 4 different airlines which used LIA as final destination. The evaluation indicated that the passenger's habits and ethics, and the policy of each airline produced different kinds of waste during the flights and especially food waste (FW). Furthermore, it was observed that the only waste management strategy that exists in place in the airport is the collection and the transportation of all those wastes from aircrafts and from the airport in the central unit for further treatment. Hence, this research indicated extremely difficulties to implement any specific waste minimization, or prevention practice or other sorting methods during the flights due to the limited time of the most flights (less than 3 h), the limited available space within the aircrafts, and the strictly safety roles that exist during the flights.

Combining control input with flight path data to evaluate pilot performance in transport aircraft.

Science.gov (United States)

Ebbatson, Matt; Harris, Don; Huddlestone, John; Sears, Rodney

2008-11-01

When deriving an objective assessment of piloting performance from flight data records, it is common to employ metrics which purely evaluate errors in flight path parameters. The adequacy of pilot performance is evaluated from the flight path of the aircraft. However, in large jet transport aircraft these measures may be insensitive and require supplementing with frequency-based measures of control input parameters. Flight path and control input data were collected from pilots undertaking a jet transport aircraft conversion course during a series of symmetric and asymmetric approaches in a flight simulator. The flight path data were analyzed for deviations around the optimum flight path while flying an instrument landing approach. Manipulation of the flight controls was subject to analysis using a series of power spectral density measures. The flight path metrics showed no significant differences in performance between the symmetric and asymmetric approaches. However, control input frequency domain measures revealed that the pilots employed highly different control strategies in the pitch and yaw axes. The results demonstrate that to evaluate pilot performance fully in large aircraft, it is necessary to employ performance metrics targeted at both the outer control loop (flight path) and the inner control loop (flight control) parameters in parallel, evaluating both the product and process of a pilot's performance.

Synanthropic flies of Asir Province, southwest of Saudi Arabia

Directory of Open Access Journals (Sweden)

M.A. Kenawy

2014-12-01

Full Text Available A survey of synanthropic flies was carried out in 11 slaughter houses in 8 localities representing different altitudes in Asir. Flies were sampled twice a month from December 2008 to November 2009 by Final Flight Fly Traps. A total of 11,737 flies consisting of 19 species, belonging to 7 families were collected, of which those of family Muscidae predominated (94.88% followed by Calliphoridae (3.12%, Sarcophagidae (1.22% and Fanniidae (0.55%. The other 5 families (Piophilidae, Oestridae, Phoridae, Ulidiidae and Lonchaeidae totally represented 0.79%. Of the identified species, Musca domestica was predominant (94.26% followed by Lucilia sericata (1.51%, Sarcophaga carnaria (1.01%, Chrysomya albiceps (0.67%, Fannia canicularis (0.55%, Chrysomya marginalis (0.54%, Muscina stabulans (0.52%, Calliphora vicina (0.39%, Wohlfahrtia nuba (0.14%, Megaselia scalaris (0.08%, Lonchaea sp. (0.06, Bercaea cruentata (0.05, Ophyra sp. and Oestrus ovis (0.04% each, Atherigona sp., Piophila casie and Physiphora demandala (0.03% each and Parasarcophaga ruficornis (0.01. Flies altogether were more common (16 spp., 84.21% and abundant (36.45 fly/trap in highlands than in the other altitude levels. The highlands were found with the maximum Simpson (1-D=0.18 and Shannon (H=0.49, P<0.001 diversity indices. Likewise, the highest density of M. domestica was in the highlands (P<0.05. Regression analysis confirmed that house fly density was directly related to the altitude level (P<0.05. In all altitude levels, housefly was active during the whole year with higher activities during months of low and moderate temperatures (spring, autumn and winter seasons. Analysis revealed that fly density had inverse relation with temperature.

Reactions of Air Transport Flight Crews to Displays of Weather During Simulated Flight

Science.gov (United States)

Bliss, James P.; Fallon, Corey; Bustamante, Ernesto; Bailey, William R., III; Anderson, Brittany

2005-01-01

Display of information in the cockpit has long been a challenge for aircraft designers. Given the limited space in which to present information, designers have had to be extremely selective about the types and amount of flight related information to present to pilots. The general goal of cockpit display design and implementation is to ensure that displays present information that is timely, useful, and helpful. This suggests that displays should facilitate the management of perceived workload, and should allow maximal situation awareness. The formatting of current and projected weather displays represents a unique challenge. As technologies have been developed to increase the variety and capabilities of weather information available to flight crews, factors such as conflicting weather representations and increased decision importance have increased the likelihood for errors. However, if formatted optimally, it is possible that next generation weather displays could allow for clearer indications of weather trends such as developing or decaying weather patterns. Important issues to address include the integration of weather information sources, flight crew trust of displayed weather information, and the teamed reactivity of flight crews to displays of weather. Past studies of weather display reactivity and formatting have not adequately addressed these issues; in part because experimental stimuli have not approximated the complexity of modern weather displays, and in part because they have not used realistic experimental tasks or participants. The goal of the research reported here was to investigate the influence of onboard and NEXRAD agreement, range to the simulated potential weather event, and the pilot flying on flight crew deviation decisions, perceived workload, and perceived situation awareness. Fifteen pilot-copilot teams were required to fly a simulated route while reacting to weather events presented in two graphical formats on a separate visual display

Integrated Design of a Long-Haul Commercial Aircraft Optimized for Formation Flying

NARCIS (Netherlands)

Dijkers, H.P.A.; Van Nunen, R.; Bos, D.A.; Gutleb, T.L.M.; Herinckx, L.E.; Radfar, H.; Van Rompuy, E.; Sayin, S.E.; De Wit, J.; Beelaerts van Blokland, W.W.A.

2011-01-01

The airline industry is under continuous pressure to reduce emissions and costs. This paper investigates the feasibility for commercial airlines to use formation flight to reduce emissions and fuel burn. To fly in formation, an aircraft needs to benefit from the wake vortices of the preceding

In-flight Meals, Passengers- Level of Satisfaction and Re-flying Intention

OpenAIRE

Mohd Zahari; M. S; Salleh; N. K.; Kamaruddin; M. S. Y; Kutut; M. Z.

2011-01-01

Service quality has become a centerpiece for airline companies in vying with one another and keeps their image in the minds of passengers. Many airlines have pushed service quality through service personalization which includes both ground and on board especially from the viewpoint of retaining satisfied passengers and attracting new ones. Besides those, in-flight meals/food service is another important aspect of the airline operation. The in flight meals/food services now are seen as part of...

Individual differences in strategic flight management and scheduling

Science.gov (United States)

Wickens, Christopher D.; Raby, Mireille

1991-01-01

A group of 30 instrument-rated pilots was made to fly simulator approaches to three airports under conditions of low, medium, and high workload conditions. An analysis is presently conducted of the difference in discrete task scheduling between the group of 10 highest and 10 lowest performing pilots in the sample; this categorization was based on the mean of various flight-profile measures. The two groups were found to differ from each other only in terms of the time when specific events were conducted, and of the optimality of scheduling for certain high-priority tasks. These results are assessed in view of the relative independence of task-management skills from aircraft-control skills.

Full Scale Advanced Systems Testbed (FAST): Capabilities and Recent Flight Research

Science.gov (United States)

Miller, Christopher

2014-01-01

At the NASA Armstrong Flight Research Center research is being conducted into flight control technologies that will enable the next generation of air and space vehicles. The Full Scale Advanced Systems Testbed (FAST) aircraft provides a laboratory for flight exploration of these technologies. In recent years novel but simple adaptive architectures for aircraft and rockets have been researched along with control technologies for improving aircraft fuel efficiency and control structural interaction. This presentation outlines the FAST capabilities and provides a snapshot of the research accomplishments to date. Flight experimentation allows a researcher to substantiate or invalidate their assumptions and intuition about a new technology or innovative approach Data early in a development cycle is invaluable for determining which technology barriers are real and which ones are imagined Data for a technology at a low TRL can be used to steer and focus the exploration and fuel rapid advances based on real world lessons learned It is important to identify technologies that are mature enough to benefit from flight research data and not be tempted to wait until we have solved all the potential issues prior to getting some data Sometimes a stagnated technology just needs a little real world data to get it going One trick to getting data for low TRL technologies is finding an environment where it is okay to take risks, where occasional failure is an expected outcome Learning how things fail is often as valuable as showing that they work FAST has been architected to facilitate this type of testing for control system technologies, specifically novel algorithms and sensors Rapid prototyping with a quick turnaround in a fly-fix-fly paradigm Sometimes it's easier and cheaper to just go fly it than to analyze the problem to death The goal is to find and test control technologies that would benefit from flight data and find solutions to the real barriers to innovation. The FAST

Oceanic Flights and Airspace: Improving Efficiency by Trajectory-Based Operations

Science.gov (United States)

Fernandes, Alicia Borgman; Rebollo, Juan; Koch, Michael

2016-01-01

Oceanic operations suffer from multiple inefficiencies, including pre-departure planning that does not adequately consider uncertainty in the proposed trajectory, restrictions on the routes that a flight operator can choose for an oceanic crossing, time-consuming processes and procedures for amending en route trajectories, and difficulties exchanging data between Flight Information Regions (FIRs). These inefficiencies cause aircraft to fly suboptimal trajectories, burning fuel and time that could be conserved. A concept to support integration of existing and emerging capabilities and concepts is needed to transition to an airspace system that employs Trajectory Based Operations (TBO) to improve efficiency and safety in oceanic operations. This paper describes such a concept and the results of preliminary activities to evaluate the concept, including a stakeholder feedback activity, user needs analysis, and high level benefits analysis.

Airborne electromagnetic data levelling using principal component analysis based on flight line difference

Science.gov (United States)

Zhang, Qiong; Peng, Cong; Lu, Yiming; Wang, Hao; Zhu, Kaiguang

2018-04-01

A novel technique is developed to level airborne geophysical data using principal component analysis based on flight line difference. In the paper, flight line difference is introduced to enhance the features of levelling error for airborne electromagnetic (AEM) data and improve the correlation between pseudo tie lines. Thus we conduct levelling to the flight line difference data instead of to the original AEM data directly. Pseudo tie lines are selected distributively cross profile direction, avoiding the anomalous regions. Since the levelling errors of selective pseudo tie lines show high correlations, principal component analysis is applied to extract the local levelling errors by low-order principal components reconstruction. Furthermore, we can obtain the levelling errors of original AEM data through inverse difference after spatial interpolation. This levelling method does not need to fly tie lines and design the levelling fitting function. The effectiveness of this method is demonstrated by the levelling results of survey data, comparing with the results from tie-line levelling and flight-line correlation levelling.

Six Decades of Flight Research: An Annotated Bibliography of Technical Publications of NASA Dryden Flight Research Center, 1946-2006

Science.gov (United States)

Fisher, David F.

2007-01-01

Titles, authors, report numbers, and abstracts are given for nearly 2900 unclassified and unrestricted technical reports and papers published from September 1946 to December 2006 by the NASA Dryden Flight Research Center and its predecessor organizations. These technical reports and papers describe and give the results of 60 years of flight research performed by the NACA and NASA, from the X-1 and other early X-airplanes, to the X-15, Space Shuttle, X-29 Forward Swept Wing, X-31, and X-43 aircraft. Some of the other research airplanes tested were the D-558, phase 1 and 2; M-2, HL-10 and X-24 lifting bodies; Digital Fly-By-Wire and Supercritical Wing F-8; XB-70; YF-12; AFTI F-111 TACT and MAW; F-15 HiDEC; F-18 High Alpha Research Vehicle, F-18 Systems Research Aircraft and the NASA Landing Systems Research aircraft. The citations of reports and papers are listed in chronological order, with author and aircraft indices. In addition, in the appendices, citations of 270 contractor reports, more than 200 UCLA Flight System Research Center reports, nearly 200 Tech Briefs, 30 Dryden Historical Publications, and over 30 videotapes are included.

In vivo time-resolved microtomography reveals the mechanics of the blowfly flight motor.

Directory of Open Access Journals (Sweden)

Simon M Walker

2014-03-01

Full Text Available Dipteran flies are amongst the smallest and most agile of flying animals. Their wings are driven indirectly by large power muscles, which cause cyclical deformations of the thorax that are amplified through the intricate wing hinge. Asymmetric flight manoeuvres are controlled by 13 pairs of steering muscles acting directly on the wing articulations. Collectively the steering muscles account for <3% of total flight muscle mass, raising the question of how they can modulate the vastly greater output of the power muscles during manoeuvres. Here we present the results of a synchrotron-based study performing micrometre-resolution, time-resolved microtomography on the 145 Hz wingbeat of blowflies. These data represent the first four-dimensional visualizations of an organism's internal movements on sub-millisecond and micrometre scales. This technique allows us to visualize and measure the three-dimensional movements of five of the largest steering muscles, and to place these in the context of the deforming thoracic mechanism that the muscles actuate. Our visualizations show that the steering muscles operate through a diverse range of nonlinear mechanisms, revealing several unexpected features that could not have been identified using any other technique. The tendons of some steering muscles buckle on every wingbeat to accommodate high amplitude movements of the wing hinge. Other steering muscles absorb kinetic energy from an oscillating control linkage, which rotates at low wingbeat amplitude but translates at high wingbeat amplitude. Kinetic energy is distributed differently in these two modes of oscillation, which may play a role in asymmetric power management during flight control. Structural flexibility is known to be important to the aerodynamic efficiency of insect wings, and to the function of their indirect power muscles. We show that it is integral also to the operation of the steering muscles, and so to the functional flexibility of the

In vivo time-resolved microtomography reveals the mechanics of the blowfly flight motor.

Science.gov (United States)

Walker, Simon M; Schwyn, Daniel A; Mokso, Rajmund; Wicklein, Martina; Müller, Tonya; Doube, Michael; Stampanoni, Marco; Krapp, Holger G; Taylor, Graham K

2014-03-01

Dipteran flies are amongst the smallest and most agile of flying animals. Their wings are driven indirectly by large power muscles, which cause cyclical deformations of the thorax that are amplified through the intricate wing hinge. Asymmetric flight manoeuvres are controlled by 13 pairs of steering muscles acting directly on the wing articulations. Collectively the steering muscles account for flight muscle mass, raising the question of how they can modulate the vastly greater output of the power muscles during manoeuvres. Here we present the results of a synchrotron-based study performing micrometre-resolution, time-resolved microtomography on the 145 Hz wingbeat of blowflies. These data represent the first four-dimensional visualizations of an organism's internal movements on sub-millisecond and micrometre scales. This technique allows us to visualize and measure the three-dimensional movements of five of the largest steering muscles, and to place these in the context of the deforming thoracic mechanism that the muscles actuate. Our visualizations show that the steering muscles operate through a diverse range of nonlinear mechanisms, revealing several unexpected features that could not have been identified using any other technique. The tendons of some steering muscles buckle on every wingbeat to accommodate high amplitude movements of the wing hinge. Other steering muscles absorb kinetic energy from an oscillating control linkage, which rotates at low wingbeat amplitude but translates at high wingbeat amplitude. Kinetic energy is distributed differently in these two modes of oscillation, which may play a role in asymmetric power management during flight control. Structural flexibility is known to be important to the aerodynamic efficiency of insect wings, and to the function of their indirect power muscles. We show that it is integral also to the operation of the steering muscles, and so to the functional flexibility of the insect flight motor.

Rotational accelerations stabilize leading edge vortices on revolving fly wings.

Science.gov (United States)

Lentink, David; Dickinson, Michael H

2009-08-01

The aerodynamic performance of hovering insects is largely explained by the presence of a stably attached leading edge vortex (LEV) on top of their wings. Although LEVs have been visualized on real, physically modeled, and simulated insects, the physical mechanisms responsible for their stability are poorly understood. To gain fundamental insight into LEV stability on flapping fly wings we expressed the Navier-Stokes equations in a rotating frame of reference attached to the wing's surface. Using these equations we show that LEV dynamics on flapping wings are governed by three terms: angular, centripetal and Coriolis acceleration. Our analysis for hovering conditions shows that angular acceleration is proportional to the inverse of dimensionless stroke amplitude, whereas Coriolis and centripetal acceleration are proportional to the inverse of the Rossby number. Using a dynamically scaled robot model of a flapping fruit fly wing to systematically vary these dimensionless numbers, we determined which of the three accelerations mediate LEV stability. Our force measurements and flow visualizations indicate that the LEV is stabilized by the ;quasi-steady' centripetal and Coriolis accelerations that are present at low Rossby number and result from the propeller-like sweep of the wing. In contrast, the unsteady angular acceleration that results from the back and forth motion of a flapping wing does not appear to play a role in the stable attachment of the LEV. Angular acceleration is, however, critical for LEV integrity as we found it can mediate LEV spiral bursting, a high Reynolds number effect. Our analysis and experiments further suggest that the mechanism responsible for LEV stability is not dependent on Reynolds number, at least over the range most relevant for insect flight (100wind turbines at much higher Reynolds numbers suggest that even large flying animals could potentially exploit LEV-based force augmentation during slow hovering flight, take-offs or landing

Certification and safety aspects relating to the transport of passengers on high altitude balloons in Europe

Science.gov (United States)

Schoenmaker, Annelie

2014-07-01

High-altitude balloons typically fly between 25 and 50 km in altitude, which, while below the Karman line of 100 km, is yet far above the altitudes typically flown by aircraft. For example, the highest-flying commercial aircraft - the Concorde - had a maximum cruising altitude of only 18 km. zero2infinity, a Spanish company, is currently developing a pressurized pod named “bloon” which will be capable of lifting six people, including two pilot crew members and four paying passengers, to an altitude of 36 km through the use of high-altitude balloons. The boundary between Airspace and Outer Space has never been legally defined, mostly because of the lack of activities taking place between the altitude where airplanes fly and the lowest orbiting spacecraft. High-altitude balloons do fly at these in-between altitudes and the prospect of commercializing access to these parts of the stratosphere poses some questions in a new light. Given the relatively low altitude at which they fly, it may well be that these types of balloons would be considered to operate exclusively within air space. However, given the technology involved in crewed high altitude balloon flights, which is more similar to spacecraft engineering than to traditional hot-air or gas ballooning, it is necessary to evaluate the various legal regimes, codes, and regulations that would apply to such flights, especially regarding licenses and liabilities. For high altitude balloon flights commencing in Europe, the European Aviation Safety Agency (EASA) would very likely be the competent certification or licensing agency for these flights, although there would likely be input from various national aviation authorities as well. However, because the European Commission (EC) has not yet issued regulations regarding commercial spaceflight, particularly the use of high altitude balloons, new rules and regulations governing such flights may still need to be drafted and promulgated. With the development of

Flight test trajectory control analysis

Science.gov (United States)

Walker, R.; Gupta, N.

1983-01-01

Recent extensions to optimal control theory applied to meaningful linear models with sufficiently flexible software tools provide powerful techniques for designing flight test trajectory controllers (FTTCs). This report describes the principal steps for systematic development of flight trajectory controllers, which can be summarized as planning, modeling, designing, and validating a trajectory controller. The techniques have been kept as general as possible and should apply to a wide range of problems where quantities must be computed and displayed to a pilot to improve pilot effectiveness and to reduce workload and fatigue. To illustrate the approach, a detailed trajectory guidance law is developed and demonstrated for the F-15 aircraft flying the zoom-and-pushover maneuver.

Requirements and feasibility study of flight demonstration of Active Controls Technology (ACT) on the NASA 515 airplane

Science.gov (United States)

Gordon, C. K.

1975-01-01

A preliminary design study was conducted to evaluate the suitability of the NASA 515 airplane as a flight demonstration vehicle, and to develop plans, schedules, and budget costs for fly-by-wire/active controls technology flight validation in the NASA 515 airplane. The preliminary design and planning were accomplished for two phases of flight validation.

Upper-stratospheric glider flights for low-g experimentation

Science.gov (United States)

Loesch, Adam

Near Space Corporation's fully-operational High Altitude Shuttle System (HASS) consists of a glider carried to 100,000ft by a high altitude balloon. Originally intended to safely return sensitive instrumentation from altitude back to Earth, the glider provides the opportunity to fly ultra-smooth "parabolas" for low-g experimentation. This work models the dynamic behavior of the glider using aerodynamic parameters of a scaled F-4 Phantom to determine the optimal flight path during descent. Low-g parabola and pull-up pairs are flown until the altitude drops below 18km, approaching the maximum altitude of controlled airspace. With this model, it was found that eleven low-g parabolas can be flown to yield 137 seconds of total test time at an average RMS g-loading of 4.9x10 -2. By changing the weighting factor of the merit function, a tradeoff can be made to increase total test time at the expense of increasing g-loading, or vice-versa. A preliminary design exercise for an improved glider is conducted based on lessons learned from the scaled F-4 flight results.

Increased frequency of chromosome translocations in airline pilots with long-term flying experience.

Science.gov (United States)

Yong, L C; Sigurdson, A J; Ward, E M; Waters, M A; Whelan, E A; Petersen, M R; Bhatti, P; Ramsey, M J; Ron, E; Tucker, J D

2009-01-01

Chromosome translocations are an established biomarker of cumulative exposure to external ionising radiation. Airline pilots are exposed to cosmic ionising radiation, but few flight crew studies have examined translocations in relation to flight experience. We determined the frequency of translocations in the peripheral blood lymphocytes of 83 airline pilots and 50 comparison subjects (mean age 47 and 46 years, respectively). Translocations were scored in an average of 1039 cell equivalents (CE) per subject using fluorescence in situ hybridisation (FISH) whole chromosome painting and expressed per 100 CE. Negative binomial regression models were used to assess the relationship between translocation frequency and exposure status and flight years, adjusting for age, diagnostic x ray procedures, and military flying. There was no significant difference in the adjusted mean translocation frequency of pilots and comparison subjects (0.37 (SE 0.04) vs 0.38 (SE 0.06) translocations/100 CE, respectively). However, among pilots, the adjusted translocation frequency was significantly associated with flight years (p = 0.01) with rate ratios of 1.06 (95% CI 1.01 to 1.11) and 1.81 (95% CI 1.16 to 2.82) for a 1- and 10-year incremental increase in flight years, respectively. The adjusted rate ratio for pilots in the highest compared to the lowest quartile of flight years was 2.59 (95% CI 1.26 to 5.33). Our data suggests that pilots with long-term flying experience may be exposed to biologically significant doses of ionising radiation. Epidemiological studies with longer follow-up of larger cohorts of pilots with a wide range of radiation exposure levels are needed to clarify the relationship between cosmic radiation exposure and cancer risk.

Statistical evaluation of the mechanical properties of high-volume class F fly ash concretes

KAUST Repository

Yoon, Seyoon

2014-03-01

High-Volume Fly Ash (HVFA) concretes are seen by many as a feasible solution for sustainable, low embodied carbon construction. At the moment, fly ash is classified as a waste by-product, primarily of thermal power stations. In this paper the authors experimentally and statistically investigated the effects of mix-design factors on the mechanical properties of high-volume class F fly ash concretes. A total of 240 and 32 samples were produced and tested in the laboratory to measure compressive strength and Young\\'s modulus respectively. Applicability of the CEB-FIP (Comite Euro-international du Béton - Fédération Internationale de la Précontrainte) and ACI (American Concrete Institute) Building Model Code (Thomas, 2010; ACI Committee 209, 1982) [1,2] to the experimentally-derived mechanical property data for HVFA concretes was established. Furthermore, using multiple linear regression analysis, Mean Squared Residuals (MSRs) were obtained to determine whether a weight- or volume-based mix proportion is better to predict the mechanical properties of HVFA concrete. The significance levels of the design factors, which indicate how significantly the factors affect the HVFA concrete\\'s mechanical properties, were determined using analysis of variance (ANOVA) tests. The results show that a weight-based mix proportion is a slightly better predictor of mechanical properties than volume-based one. The significance level of fly ash substitution rate was higher than that of w/b ratio initially but reduced over time. © 2014 Elsevier Ltd. All rights reserved.

Aurora Flight Sciences' Perseus B Remotely Piloted Aircraft in Flight

Science.gov (United States)

1998-01-01

A long, slender wing and a pusher propeller at the rear characterize the Perseus B remotely piloted research aircraft, seen here during a test flight in June 1998. Perseus B is a remotely piloted aircraft developed as a design-performance testbed under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project. Perseus is one of several flight vehicles involved in the ERAST project. A piston engine, propeller-powered aircraft, Perseus was designed and built by Aurora Flight Sciences Corporation, Manassas, Virginia. The objectives of Perseus B's ERAST flight tests have been to reach and maintain horizontal flight above altitudes of 60,000 feet and demonstrate the capability to fly missions lasting from 8 to 24 hours, depending on payload and altitude requirements. The Perseus B aircraft established an unofficial altitude record for a single-engine, propeller-driven, remotely piloted aircraft on June 27, 1998. It reached an altitude of 60,280 feet. In 1999, several modifications were made to the Perseus aircraft including engine, avionics, and flight-control-system improvements. These improvements were evaluated in a series of operational readiness and test missions at the Dryden Flight Research Center, Edwards, California. Perseus is a high-wing monoplane with a conventional tail design. Its narrow, straight, high-aspect-ratio wing is mounted atop the fuselage. The aircraft is pusher-designed with the propeller mounted in the rear. This design allows for interchangeable scientific-instrument payloads to be placed in the forward fuselage. The design also allows for unobstructed airflow to the sensors and other devices mounted in the payload compartment. The Perseus B that underwent test and development in 1999 was the third generation of the Perseus design, which began with the Perseus Proof-Of-Concept aircraft. Perseus was initially developed as part of NASA's Small High-Altitude Science Aircraft (SHASA) program, which later evolved into the ERAST

75 FR 77569 - Special Conditions: Gulfstream Model GVI Airplane; Electronic Flight Control System Mode...

Science.gov (United States)

2010-12-13

... Some failures of this system may lead to a degraded operating mode that does not merit a classic ``failure warning'' but in which flight envelope protection is lost and the flight crew must fly the... surfaces for both normal and failure states, and it generates the actual surface commands that provide for...

Ge extraction from gasification fly ash

Energy Technology Data Exchange (ETDEWEB)

Oriol Font; Xavier Querol; Angel Lopez-Soler; Jose M. Chimenos; Ana I. Fernandez; Silvia Burgos; Francisco Garcia Pena [Institute of Earth Sciences ' Jaume Almera' , Barcelona (Spain)

2005-08-01

Water-soluble germanium species (GeS{sub 2}, GeS and hexagonal-GeO{sub 2}) are generated during coal gasification and retained in fly ash. This fact together with the high market value of this element and the relatively high contents in the fly ashes of the Puertollano Integrated Gasification in Combined Cycle (IGCC) plant directed our research towards the development of an extraction process for this element. Major objectives of this research was to find a low cost and environmentally suitable process. Several water based extraction tests were carried out using different Puertollano IGCC fly ash samples, under different temperatures, water/fly ash ratios, and extraction times. High Ge extraction yields (up to 84%) were obtained at room temperature (25{sup o}C) but also high proportions of other trace elements (impurities) were simultaneously extracted. Increasing the extraction temperature to 50, 90 and 150{sup o}C, Ge extraction yields were kept at similar levels, while reducing the content of impurities, the water/fly ash ratio and extraction time. The experimental data point out the influence of chloride, calcium and sulphide dissolutions on the Ge extraction. 16 refs., 9 figs., 6 tabs.

Flight test of a resident backup software system

Science.gov (United States)

Deets, Dwain A.; Lock, Wilton P.; Megna, Vincent A.

1987-01-01

A new fault-tolerant system software concept employing the primary digital computers as host for the backup software portion has been implemented and flight tested in the F-8 digital fly-by-wire airplane. The system was implemented in such a way that essentially no transients occurred in transferring from primary to backup software. This was accomplished without a significant increase in the complexity of the backup software. The primary digital system was frame synchronized, which provided several advantages in implementing the resident backup software system. Since the time of the flight tests, two other flight vehicle programs have made a commitment to incorporate resident backup software similar in nature to the system described here.

USAF Flight Surgeon Survey: Aircrew Mental Health Referrals and Satisfaction with Local Mental Health Providers Response

Science.gov (United States)

2008-05-01

Autogenic training exercise; A treatment for airsickness in military pilots. International Journal of Aviation Psychology, 2005; 15(4): 395-412...flying during training , humanitarian, and operational missions can be extremely taxing. Flight surgeons often observe or hear of changes in the...health care is to ease and resolve the emotional or behavioral difficulties of an aviator while attempting to preserve a highly trained USAF asset

Flight Control of the High Altitude Wind Power System

NARCIS (Netherlands)

Podgaets, A.R.; Ockels, W.J.

2007-01-01

Closed loop Laddermill flight control problem is considered in this paper. Laddermill is a high altitude kites system for energy production. The kites have been simulated as rigid bodies and the cable as a thin elastic line. Euler angles and cable speed are controls. Flight control is written as a

Pathfinder-Plus on flight over Hawaiian Islands, with N'ihau and Lehua in the background

Science.gov (United States)

1998-01-01

Pathfinder-Plus on flight over Hawaiian Islands, with N'ihau and Lehua in the background. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet

Enhanced thrust and speed revealed in the forward flight of a butterfly with transient body translation.

Science.gov (United States)

Fei, Yueh-Han John; Yang, Jing-Tang

2015-09-01

A butterfly with broad wings, flapping at a small frequency, flies an erratic trajectory at an inconstant speed. A large variation of speed within a cycle is observed in the forward flight of a butterfly. A self-propulsion model to simulate a butterfly is thus created to investigate the transient translation of the body; the results, which are in accordance with experimental data, show that the shape of the variation of the flight speed is similar to a sinusoidal wave with a maximum (J=0.89) at the beginning of the downstroke, and a decrease to a minimum (J=0.17) during a transition from downstroke to upstroke; the difference between the extrema of the flight speed is enormous in a flapping cycle. At a high speed, a clapping motion of the butterfly wings decreases the generation of drag. At a small speed, a butterfly is able to capture the induced wakes generated in a downstroke, and effectively generates a thrust at the beginning of an upstroke. The wing motion of a butterfly skillfully interacts with its speed so as to enable an increased speed with the same motion. Considering a butterfly to fly in a constant inflow leads to either an underestimate of its speed or an overestimate of its generated lift, which yields an inaccurate interpretation of the insect's flight. Our results reveal the effect of transient translation on a butterfly in forward flight, which is especially important for an insect with a small flapping frequency.

Enhanced thrust and speed revealed in the forward flight of a butterfly with transient body translation

Science.gov (United States)

Fei, Yueh-Han John; Yang, Jing-Tang

2015-09-01

A butterfly with broad wings, flapping at a small frequency, flies an erratic trajectory at an inconstant speed. A large variation of speed within a cycle is observed in the forward flight of a butterfly. A self-propulsion model to simulate a butterfly is thus created to investigate the transient translation of the body; the results, which are in accordance with experimental data, show that the shape of the variation of the flight speed is similar to a sinusoidal wave with a maximum (J =0.89 ) at the beginning of the downstroke, and a decrease to a minimum (J =0.17 ) during a transition from downstroke to upstroke; the difference between the extrema of the flight speed is enormous in a flapping cycle. At a high speed, a clapping motion of the butterfly wings decreases the generation of drag. At a small speed, a butterfly is able to capture the induced wakes generated in a downstroke, and effectively generates a thrust at the beginning of an upstroke. The wing motion of a butterfly skillfully interacts with its speed so as to enable an increased speed with the same motion. Considering a butterfly to fly in a constant inflow leads to either an underestimate of its speed or an overestimate of its generated lift, which yields an inaccurate interpretation of the insect's flight. Our results reveal the effect of transient translation on a butterfly in forward flight, which is especially important for an insect with a small flapping frequency.

Dynamical continuous time random Lévy flights

Science.gov (United States)

Liu, Jian; Chen, Xiaosong

2016-03-01

The Lévy flights' diffusive behavior is studied within the framework of the dynamical continuous time random walk (DCTRW) method, while the nonlinear friction is introduced in each step. Through the DCTRW method, Lévy random walker in each step flies by obeying the Newton's Second Law while the nonlinear friction f(v) = - γ0v - γ2v3 being considered instead of Stokes friction. It is shown that after introducing the nonlinear friction, the superdiffusive Lévy flights converges, behaves localization phenomenon with long time limit, but for the Lévy index μ = 2 case, it is still Brownian motion.

Flight test guidelines for homebuilt and experimental aircraft

CSIR Research Space (South Africa)

White, WJ

2013-04-01

Full Text Available experience totalling approximately 7,000 flying hours on forty-five different variants of military aircraft, nearly all in the flight-test environment. He holds a Commercial Pilot’s Licence with a Class I test pilot rating. During his twenty-eight years... of military flight-testing, he was involved in the fixed wing fighter programmes and weapons development testing and amongst others, he was the project test pilot on the Cheetah C, the Mirage IIIRZ/Atar 09K50 engine integration and the Mirage F1 fitted...

The First Flight Decision for New Human Spacecraft Vehicles - A General Approach

Science.gov (United States)

Schaible, Dawn M.; Sumrall, John Phillip

2011-01-01

Determining when it is safe to fly a crew on a launch vehicle/spacecraft for the first time, especially when the test flight is a part of the overall system certification process, has long been a challenge for program decision makers. The decision on first flight is ultimately the judgment of the program and agency management in conjunction with the design and operations team. To aid in this decision process, a NASA team undertook the task to develop a generic framework for evaluating whether any given program or commercial provider has sufficiently complete and balanced plans in place to allow crewmembers to safely fly on human spaceflight systems for the first time. It was the team s goal to establish a generic framework that could easily be applied to any new system, although the system design and intended mission would require specific assessment. Historical data shows that there are multiple approaches that have been successful in first flight with crew. These approaches have always been tailored to the specific system design, mission objectives, and launch environment. Because specific approaches may vary significantly between different system designs and situations, prescriptive instructions or thorough checklists cannot be provided ahead of time. There are, however, certain general approaches that should be applied in thinking through the decision for first flight. This paper addresses some of the most important factors to consider when developing a new system or evaluating an existing system for whether or not it is safe to fly humans to/from space. In the simplest terms, it is time to fly crew for the first time when it is safe to do so and the benefit of the crewed flight is greater than the residual risk. This is rarely a straight-forward decision. The paper describes the need for experience, sound judgment, close involvement of the technical and management teams, and established decision processes. In addition, the underlying level of confidence the

Solar-powered Gossamer Penguin in flight

Science.gov (United States)

1979-01-01

determine the power required to fly the airplane, optimize the airframe/propulsion system, and train the pilot. He made the first flights on April 7, 1980, and made a brief solar-powered flight on May 18. The official project pilot was Janice Brown, a Bakersfield school teacher who weighed in at slightly under 100 pounds and was a charter pilot with commercial, instrument, and glider ratings. She checked out in the plane at Shafter and made about 40 flights under battery and solar power there. Wind direction, turbulence, convection, temperature and radiation at Shafter in mid-summer proved to be less than ideal for Gossamer Penguin because takeoffs required no crosswind and increases in temperature reduced the power output from the solar cells. Consequently, the project moved to Dryden in late July, although conditions there also were not ideal. Nevertheless, Janice finished the testing, and on August 7, 1980, she flew a public demonstration of the aircraft at Dryden in which it went roughly 1.95 miles in 14 minutes and 21 seconds. This was significant as the first sustained flight of an aircraft relying solely on direct solar power rather than batteries. It provided the designers with practical experience for developing a more advanced, solar-powered aircraft, since the Gossamer Penguin was fragile and had limited controllability. This necessitated its flying early in the day when there were minimal wind and turbulence levels, but the angle of the sun was also low, requiring a panel for the solar cells that could be tilted toward the sun. Using the specific conclusions derived from their experience with Gossamer Penguin, the AeroVironment engineers designed Solar Challenger, a piloted, solar-powered aircraft strong enough to handle both long and high flights when encountering normal turbulence.

A field investigation of flight anxiety: Evidence of gender differences in consumer behaviors among Las Vegas passengers

Directory of Open Access Journals (Sweden)

Lindsey A Harvell

2016-02-01

Full Text Available Purpose: This study examines how anxious the Las Vegas public is through a case study of one local international airport. Design/Methodology/Approach: This study examines gender differences in consumer behaviors among the flying public inside Las Vegas McCarran International Airport in a field experiment theoretically grounded in Terror Management Theory. Findings and Originality/Value: Because airports are replete with reminders of human mortality, it is not a surprise that death awareness and flight anxiety may be closely related. The flying public that is anxious to fly presents an interesting public relations situation for airports. Therefore, this study examines how anxious the Las Vegas public is through a case study of one local international airport. Results show that flight anxiety does provoke the same kind of existential defenses that traditional death awareness does. This study also suggests that men and women do not react to flight anxiety in a uniform way, they are different in their reactions in seeking to gamble, eating unhealthy food, and an increased desire for electronic entertainment.

Perseus Post-flight

Science.gov (United States)

1991-01-01

Crew members check out the Perseus proof-of-concept vehicle on Rogers Dry Lake, adjacent to the Dryden Flight Research Center, Edwards, California, after a test flight in 1991. Perseus B is a remotely piloted aircraft developed as a design-performance testbed under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project. Perseus is one of several flight vehicles involved in the ERAST project. A piston engine, propeller-powered aircraft, Perseus was designed and built by Aurora Flight Sciences Corporation, Manassas, Virginia. The objectives of Perseus B's ERAST flight tests have been to reach and maintain horizontal flight above altitudes of 60,000 feet and demonstrate the capability to fly missions lasting from 8 to 24 hours, depending on payload and altitude requirements. The Perseus B aircraft established an unofficial altitude record for a single-engine, propeller-driven, remotely piloted aircraft on June 27, 1998. It reached an altitude of 60,280 feet. In 1999, several modifications were made to the Perseus aircraft including engine, avionics, and flight-control-system improvements. These improvements were evaluated in a series of operational readiness and test missions at the Dryden Flight Research Center, Edwards, California. Perseus is a high-wing monoplane with a conventional tail design. Its narrow, straight, high-aspect-ratio wing is mounted atop the fuselage. The aircraft is pusher-designed with the propeller mounted in the rear. This design allows for interchangeable scientific-instrument payloads to be placed in the forward fuselage. The design also allows for unobstructed airflow to the sensors and other devices mounted in the payload compartment. The Perseus B that underwent test and development in 1999 was the third generation of the Perseus design, which began with the Perseus Proof-Of-Concept aircraft. Perseus was initially developed as part of NASA's Small High-Altitude Science Aircraft (SHASA) program, which later evolved

Comparing future options for human space flight

Science.gov (United States)

Sherwood, Brent

2011-09-01

The paper analyzes the "value proposition" for government-funded human space flight, a vexing question that persistently dogs efforts to justify its $10 10/year expense in the US. The original Mercury/Gemini/Apollo value proposition is not valid today. Neither was it the value proposition actually promoted by von Braun, which the post-Apollo 80% of human space flight history has persistently attempted to fulfill. Divergent potential objectives for human space flight are captured in four strategic options— Explore Mars; accelerate Space Passenger Travel; enable Space Power for Earth; and Settle the Moon—which are then analyzed for their purpose, societal myth, legacy benefits, core needs, and result as measured by the number and type of humans they would fly in space. This simple framework is proposed as a way to support productive dialog with public and other stakeholders, to determine a sustainable value proposition for human space flight.

A controlled study of virtual reality exposure therapy for the fear of flying.

Science.gov (United States)

Rothbaum, B O; Hodges, L; Smith, S; Lee, J H; Price, L

2000-12-01

Fear of flying (FOF) affects an estimated 10-25% of the population. Patients with FOF (N = 49) were randomly assigned to virtual reality exposure (VRE) therapy, standard exposure (SE) therapy, or a wait-list (WL) control. Treatment consisted of 8 sessions over 6 weeks, with 4 sessions of anxiety management training followed by either exposure to a virtual airplane (VRE) or exposure to an actual airplane at the airport (SE). A posttreatment flight on a commercial airline measured participants' willingness to fly and anxiety during flight immediately after treatment. The results indicated that VRE and SE were both superior to WL, with no differences between VRE and SE. The gains observed in treatment were maintained at a 6-month follow up. By 6 months posttreatment, 93% of VRE participants and 93% of SE participants had flown. VRE therapy and SE therapy for treatment of FOF were unequivocally supported in this controlled study.

Review: Potential Strength of Fly Ash-Based Geopolymer Paste with Substitution of Local Waste Materials with High-Temperature Effect

Science.gov (United States)

Subekti, S.; Bayuaji, R.; Darmawan, M. S.; Husin, N. A.; Wibowo, B.; Anugraha, B.; Irawan, S.; Dibiantara, D.

2017-11-01

This research provided an overview of the potential fly ash based geopolymer paste for application in building construction. Geopolymer paste with various variations of fly ash substitution with local waste material and high-temperature influence exploited with the fresh and hardened condition. The local waste material which utilized for this study were sandblasting waste, carbide waste, shell powder, bagasse ash, rice husk and bottom ash. The findings of this study indicated that fly-based geopolymer paste with local waste material substitution which had high-temperature influence ash showed a similar nature of OPC binders potentially used in civil engineering applications.

Using Cementitious Materials Such as Fly Ash to Replace a Part of Cement in Producing High Strength Concrete in Hot Weather

Science.gov (United States)

Turuallo, Gidion; Mallisa, Harun

2018-03-01

The use of waste materials in concrete gave many advantages to prove the properties of concrete such as its workability, strength and durability; as well to support sustaianable development programs. Fly ash was a waste material produced from coal combustion. This research was conducted to find out the effect of fly ash as a part replacement of cement to produce high strength concrete. The fly ash, which was used in this research, was taken from PLTU Mpanau Palu, Central Sulawesi. The water-binder ratio used in this research was 0.3 selected from trial mixes done before. The results of this research showed that the strength of fly ash concretes were higher than concrete with PCC only. The replacement of cement with fly ash concrete could be up to 20% to produce high strength concrete.

Optimum Wing Shape of Highly Flexible Morphing Aircraft for Improved Flight Performance

Science.gov (United States)

Su, Weihua; Swei, Sean Shan-Min; Zhu, Guoming G.

2016-01-01

In this paper, optimum wing bending and torsion deformations are explored for a mission adaptive, highly flexible morphing aircraft. The complete highly flexible aircraft is modeled using a strain-based geometrically nonlinear beam formulation, coupled with unsteady aerodynamics and six-degrees-of-freedom rigid-body motions. Since there are no conventional discrete control surfaces for trimming the flexible aircraft, the design space for searching the optimum wing geometries is enlarged. To achieve high performance flight, the wing geometry is best tailored according to the specific flight mission needs. In this study, the steady level flight and the coordinated turn flight are considered, and the optimum wing deformations with the minimum drag at these flight conditions are searched by utilizing a modal-based optimization procedure, subject to the trim and other constraints. The numerical study verifies the feasibility of the modal-based optimization approach, and shows the resulting optimum wing configuration and its sensitivity under different flight profiles.

How birds direct impulse to minimize the energetic cost of foraging flight

Science.gov (United States)

Chin, Diana; Lentink, David

2017-11-01

Foraging arboreal birds frequently hop and fly between branches by extending long-jumps with a few wingbeats. Their legs transfer impulse to the branch during takeoff and landing, and their wings transfer impulse to the air to support their bodyweight during flight. To determine the mechanical energy tradeoffs of this bimodal locomotion, we studied how Pacific parrotlets transfer impulse during voluntary perch-to-perch flights. We tested five foraging flight variations by varying the inclination and distance between instrumented perches inside a novel aerodynamic force platform. This setup enables direct, time-resolved in vivo measurements of both leg and wing forces, which we combined with high-speed kinematics to develop a new bimodal long-jump and flight model. The model demonstrates how parrotlets direct their leg impulse to minimize the mechanical energy needed for each flight, and further shows how even a single proto-wingbeat would have significantly lengthened the long-jump of foraging arboreal dinosaurs. By directing jumps and flapping their wings, both extant and ancestral birds could thus improve foraging effectiveness. Similarly, bimodal robots could also employ these locomotion strategies to traverse cluttered environments more effectively.

CALET: a stopover at CERN before flying to space

CERN Multimedia

Antonella Del Rosso

2015-01-01

CALET is an electron telescope that will be flying to the ISS this year. Calibration tests are currently being completed on a replica of the instrument at CERN’s H8 beam line. The final payload will then be transported on board a Japanese transfer vehicle and docked on the JEM-EF platform to take data and explore the high-energy cosmos.   The CALET calorimeter is preparing for installation in the flight module that will bring it to its final destination on the ISS. The CALorimetric Electron Telescope (CALET) is a detector designed by a Japanese-led international collaboration to identify cosmic electrons, nuclei and gamma-rays and to provide high-resolution measurements of their energy. Using two calorimetric instruments and a particle identification system, CALET will perform high-precision measurements of the electron energy spectrum from 1 GeV to 20 TeV. “By detecting electrons with an energy above 1 TeV, CALET might be able to identify the astronomical sources from whi...

Treatment of fly ash for use in concrete

Science.gov (United States)

Boxley, Chett; Akash, Akash; Zhao, Qiang

2013-01-08

A process for treating fly ash to render it highly usable as a concrete additive. A quantity of fly ash is obtained that contains carbon and which is considered unusable fly ash for concrete based upon foam index testing. The fly ash is mixed with an activator solution sufficient to initiate a geopolymerization reaction and for a geopolymerized fly ash. The geopolymerized fly ash is granulated. The geopolymerized fly ash is considered usable fly ash for concrete according to foam index testing. The geopolymerized fly ash may have a foam index less than 35% of the foam index of the untreated fly ash, and in some cases less than 10% of the foam index of the untreated fly ash. The activator solution may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof.

Flight Test of a Propulsion-Based Emergency Control System on the MD-11 Airplane with Emphasis on the Lateral Axis

Science.gov (United States)

Burken, John J.; Burcham, Frank W., Jr.; Maine, Trindel A.; Feather, John; Goldthorpe, Steven; Kahler, Jeffrey A.

1996-01-01

A large, civilian, multi-engine transport MD-11 airplane control system was recently modified to perform as an emergency backup controller using engine thrust only. The emergency backup system, referred to as the propulsion-controlled aircraft (PCA) system, would be used if a major primary flight control system fails. To allow for longitudinal and lateral-directional control, the PCA system requires at least two engines and is implemented through software modifications. A flight-test program was conducted to evaluate the PCA system high-altitude flying characteristics and to demonstrate its capacity to perform safe landings. The cruise flight conditions, several low approaches and one landing without any aerodynamic flight control surface movement, were demonstrated. This paper presents results that show satisfactory performance of the PCA system in the longitudinal axis. Test results indicate that the lateral-directional axis of the system performed well at high attitude but was sluggish and prone to thermal upsets during landing approaches. Flight-test experiences and test techniques are also discussed with emphasis on the lateral-directional axis because of the difficulties encountered in flight test.

Investigation of Inner Loop Flight Control Strategies for High-Speed Research

Science.gov (United States)

Newman, Brett; Kassem, Ayman

1999-01-01

This report describes the activities and findings conducted under contract NAS1-19858 with NASA Langley Research Center. Subject matter is the investigation of suitable flight control design methodologies and solutions for large, flexible high-speed vehicles. Specifically, methodologies are to address the inner control loops used for stabilization and augmentation of a highly coupled airframe system possibly involving rigid-body motion, structural vibrations, unsteady aerodynamics, and actuator dynamics. Techniques considered in this body of work are primarily conventional-based, and the vehicle of interest is the High-Speed Civil Transport (HSCT). Major findings include 1) current aeroelastic vehicle modeling procedures require further emphasis and refinement, 2) traditional and nontraditional inner loop flight control strategies employing a single feedback loop do not appear sufficient for highly flexible HSCT class vehicles, 3) inner loop flight control systems will, in all likelihood, require multiple interacting feedback loops, and 4) Ref. H HSCT configuration presents major challenges to designing acceptable closed-loop flight dynamics.

Remotely Piloted Vehicles for Experimental Flight Control Testing

Science.gov (United States)

Motter, Mark A.; High, James W.

2009-01-01

A successful flight test and training campaign of the NASA Flying Controls Testbed was conducted at Naval Outlying Field, Webster Field, MD during 2008. Both the prop and jet-powered versions of the subscale, remotely piloted testbeds were used to test representative experimental flight controllers. These testbeds were developed by the Subsonic Fixed Wing Project s emphasis on new flight test techniques. The Subsonic Fixed Wing Project is under the Fundamental Aeronautics Program of NASA's Aeronautics Research Mission Directorate (ARMD). The purpose of these testbeds is to quickly and inexpensively evaluate advanced concepts and experimental flight controls, with applications to adaptive control, system identification, novel control effectors, correlation of subscale flight tests with wind tunnel results, and autonomous operations. Flight tests and operator training were conducted during four separate series of tests during April, May, June and August 2008. Experimental controllers were engaged and disengaged during fully autonomous flight in the designated test area. Flaps and landing gear were deployed by commands from the ground control station as unanticipated disturbances. The flight tests were performed NASA personnel with support from the Maritime Unmanned Development and Operations (MUDO) team of the Naval Air Warfare Center, Aircraft Division

Alertness management in flight operations - Strategic napping

Science.gov (United States)

Rosekind, Mark R.; Gander, Philippa H.; Dinges, David F.

1991-01-01

Strategic napping in two different flight operation environments is considered to illustrate its application as a fatigue countermeasure. Data obtained from commercial short-haul and long-haul operations demonstrated the utility and current practices of strategic napping. A preplanned cockpit nap acted as an acute 'safety valve' for the sleep loss, circadian disruption, and fatigue that occurs in long-haul flying.

Touching for attention: How flight instructors support a pilot wearing a view-limiting device

DEFF Research Database (Denmark)

Nevile, Maurice Richard; Tuccio, William A.

2018-01-01

We use video recordings from pilot training flights to show how instructors support attention of a student wearing ‘foggles’, a view-limiting device designed to train pilots to fly by reference only to the cockpit flight instruments. The instructors touch cockpit displays with a pointing finger...... demonstrates a technique for controlling descent. The data examples are taken from a corpus of almost 100 hours of video recordings of actual in-flight instruction. We consider how our analyses can inform flight instructor training and improve instructor effectiveness, for example by revealing possible...

Development and Flight Test of an Emergency Flight Control System Using Only Engine Thrust on an MD-11 Transport Airplane

Science.gov (United States)

Burcham, Frank W., Jr.; Burken, John J.; Maine, Trindel A.; Fullerton, C. Gordon

1997-01-01

An emergency flight control system that uses only engine thrust, called the propulsion-controlled aircraft (PCA) system, was developed and flight tested on an MD-11 airplane. The PCA system is a thrust-only control system, which augments pilot flightpath and track commands with aircraft feedback parameters to control engine thrust. The PCA system was implemented on the MD-11 airplane using only software modifications to existing computers. Results of a 25-hr flight test show that the PCA system can be used to fly to an airport and safely land a transport airplane with an inoperative flight control system. In up-and-away operation, the PCA system served as an acceptable autopilot capable of extended flight over a range of speeds, altitudes, and configurations. PCA approaches, go-arounds, and three landings without the use of any normal flight controls were demonstrated, including ILS-coupled hands-off landings. PCA operation was used to recover from an upset condition. The PCA system was also tested at altitude with all three hydraulic systems turned off. This paper reviews the principles of throttles-only flight control, a history of accidents or incidents in which some or all flight controls were lost, the MD-11 airplane and its systems, PCA system development, operation, flight testing, and pilot comments.

Aircraft Configuration and Flight Crew Compliance with Procedures While Conducting Flight Deck Based Interval Management (FIM) Operations

Science.gov (United States)

Shay, Rick; Swieringa, Kurt A.; Baxley, Brian T.

2012-01-01

Flight deck based Interval Management (FIM) applications using ADS-B are being developed to improve both the safety and capacity of the National Airspace System (NAS). FIM is expected to improve the safety and efficiency of the NAS by giving pilots the technology and procedures to precisely achieve an interval behind the preceding aircraft by a specific point. Concurrently but independently, Optimized Profile Descents (OPD) are being developed to help reduce fuel consumption and noise, however, the range of speeds available when flying an OPD results in a decrease in the delivery precision of aircraft to the runway. This requires the addition of a spacing buffer between aircraft, reducing system throughput. FIM addresses this problem by providing pilots with speed guidance to achieve a precise interval behind another aircraft, even while flying optimized descents. The Interval Management with Spacing to Parallel Dependent Runways (IMSPiDR) human-in-the-loop experiment employed 24 commercial pilots to explore the use of FIM equipment to conduct spacing operations behind two aircraft arriving to parallel runways, while flying an OPD during high-density operations. This paper describes the impact of variations in pilot operations; in particular configuring the aircraft, their compliance with FIM operating procedures, and their response to changes of the FIM speed. An example of the displayed FIM speeds used incorrectly by a pilot is also discussed. Finally, this paper examines the relationship between achieving airline operational goals for individual aircraft and the need for ATC to deliver aircraft to the runway with greater precision. The results show that aircraft can fly an OPD and conduct FIM operations to dependent parallel runways, enabling operational goals to be achieved efficiently while maintaining system throughput.

RHAGOLETIS COMPLETA (DIPTERA; TEPHRITIDAE DISTRIBUTION, FLIGHT DYNAMICS AND INFLUENCE ON WALNUT KERNEL QUALITY IN THE CONTINENTAL CROATIA

Directory of Open Access Journals (Sweden)

Božena Barić

2015-06-01

Full Text Available Walnut husk fly (WHF, Rhagoletis completa Cresson 1929 is an invasive species spreading quickly and damaging walnuts in Croatia and neighbouring countries. We researched distribution of this pest in the continental part of Croatia, flight dynamics in Međimurje County and its influence on quality of walnut kernels. CSALOMON®PALz traps were used for monitoring the spread and flight dynamics of R. completa. Weight and the protein content of kernels and the presence of mycotoxin contamination were measured. Walnut husk fly was found in six counties (Istria County: pest reconfirmation, Zagreb County, The City of Zagreb, Varaždin County, Međimurje County and Koprivnica-Križevci County. The presence of the fly was not confirmed on one site in Koprivnica-Križevci County (locality Ferdinandovac and in the eastern part of Croatia (Vukovar-Srijem County: Vinkovci locality. The flight dynamics showed rapid increase in number of adults only a year after the introduction into new area. The weight of infested kernels was 5.81% lower compared to not infested. Protein content was 14.04% in infested kernels and 17.31% in not infested kernels. There was no difference in mycotoxins levels. Additional researches on mycotoxin levels in stored nuts, ovipositional preferences of walnut husk fly and protection measures against this pest are suggested.

Assessment of fly ash-aided phytostabilisation of highly contaminated soils after an 8-year field trial

International Nuclear Information System (INIS)

Pourrut, Bertrand; Lopareva-Pohu, Alena; Pruvot, Christelle; Garcon, Guillaume; Verdin, Anthony; Waterlot, Christophe; Bidar, Geraldine; Shirali, Pirouz

2011-01-01

Aided phytostabilisation is a cost-efficient technique to manage metal-contaminated areas, particularly in the presence of extensive pollution. Plant establishment and survival in highly metal-contaminated soils are crucial for phytostabilisation success, as metal toxicity for plants is widely reported. A relevant phytostabilisation solution must limit metal transfer through the food chain. Therefore, this study aimed at evaluating the long-term efficiency of aided phytostabilisation on former agricultural soils highly contaminated by cadmium, lead, and zinc. The influence of afforestation and fly ash amendments on reducing metal phytoavailability was investigated as were their effects on plant development. Before being planted with a tree mix, the site was divided into three plots: a reference plot with no amendment, a plot amended with silico-aluminous fly ash and one with sulfo-calcic fly ash. Unlike Salix alba and Quercus robur, Alnus glutinosa, Acer pseudoplatanus and Robinia pseudoacacia grew well on the site and accumulated, overall, quite low concentrations of metals in their leaves and young twigs. This suggests that these three species have an excluder phenotype for Cd, Zn and Pb. After 8 years, metal availability to A. glutinosa, A. pseudoplatanus and R. pseudoacacia, and translocation to their above-ground parts, strongly decreased in fly ash-amended soils. Such decreases fit well together with the depletion of CaCl 2 -extractable metals in amended soils. Although both fly ashes were effective to decrease Cd, Pb and Zn concentrations in above-ground parts of trees, the sulfo-calcic ash was more efficient.

Assessment of fly ash-aided phytostabilisation of highly contaminated soils after an 8-year field trial

Energy Technology Data Exchange (ETDEWEB)

Pourrut, Bertrand [Universite Lille Nord de France, Lille (France); Groupe ISA, Equipe Sols et Environnement, Laboratoire Genie Civil et geoEnvironnement (LGCgE) Lille Nord de France EA 4515, 48 boulevard Vauban, 59046 Lille Cedex (France); Lopareva-Pohu, Alena [Universite Lille Nord de France, Lille (France); Groupe ISA, Equipe Sols et Environnement, Laboratoire Genie Civil et geoEnvironnement (LGCgE) Lille Nord de France EA 4515, 48 boulevard Vauban, 59046 Lille Cedex (France); Universite du Littoral-Cote d' Opale, Unite de Chimie Environnementale et Interaction sur le Vivant (UCEIV), EA 4492, Maison de la Recherche en Environnement Industriel de Dunkerque 2, avenue Maurice Schumann, 59140 Dunkerque (France); Pruvot, Christelle [Universite Lille Nord de France, Lille (France); Groupe ISA, Equipe Sols et Environnement, Laboratoire Genie Civil et geoEnvironnement (LGCgE) Lille Nord de France EA 4515, 48 boulevard Vauban, 59046 Lille Cedex (France); Garcon, Guillaume; Verdin, Anthony [Universite Lille Nord de France, Lille (France); Universite du Littoral-Cote d' Opale, Unite de Chimie Environnementale et Interaction sur le Vivant (UCEIV), EA 4492, Maison de la Recherche en Environnement Industriel de Dunkerque 2, avenue Maurice Schumann, 59140 Dunkerque (France); Waterlot, Christophe; Bidar, Geraldine [Universite Lille Nord de France, Lille (France); Groupe ISA, Equipe Sols et Environnement, Laboratoire Genie Civil et geoEnvironnement (LGCgE) Lille Nord de France EA 4515, 48 boulevard Vauban, 59046 Lille Cedex (France); Shirali, Pirouz [Universite Lille Nord de France, Lille (France); Universite du Littoral-Cote d' Opale, Unite de Chimie Environnementale et Interaction sur le Vivant (UCEIV), EA 4492, Maison de la Recherche en Environnement Industriel de Dunkerque 2, avenue Maurice Schumann, 59140 Dunkerque (France); and others

2011-10-01

Aided phytostabilisation is a cost-efficient technique to manage metal-contaminated areas, particularly in the presence of extensive pollution. Plant establishment and survival in highly metal-contaminated soils are crucial for phytostabilisation success, as metal toxicity for plants is widely reported. A relevant phytostabilisation solution must limit metal transfer through the food chain. Therefore, this study aimed at evaluating the long-term efficiency of aided phytostabilisation on former agricultural soils highly contaminated by cadmium, lead, and zinc. The influence of afforestation and fly ash amendments on reducing metal phytoavailability was investigated as were their effects on plant development. Before being planted with a tree mix, the site was divided into three plots: a reference plot with no amendment, a plot amended with silico-aluminous fly ash and one with sulfo-calcic fly ash. Unlike Salix alba and Quercus robur, Alnus glutinosa, Acer pseudoplatanus and Robinia pseudoacacia grew well on the site and accumulated, overall, quite low concentrations of metals in their leaves and young twigs. This suggests that these three species have an excluder phenotype for Cd, Zn and Pb. After 8 years, metal availability to A. glutinosa, A. pseudoplatanus and R. pseudoacacia, and translocation to their above-ground parts, strongly decreased in fly ash-amended soils. Such decreases fit well together with the depletion of CaCl{sub 2}-extractable metals in amended soils. Although both fly ashes were effective to decrease Cd, Pb and Zn concentrations in above-ground parts of trees, the sulfo-calcic ash was more efficient.

Adaptive aerostructures : The first decade of flight on uninhabited aerial vehicles

NARCIS (Netherlands)

Barrett, R.

2004-01-01

Although many subscale aircraft regularly fly with adaptive materials in sensors and small components in secondary subsystems, only a handful have flown with adaptive aerostructures as flight critical, enabling components. This paper reviews several families of adaptive aerostructures which have

Optimization of radiation dose within the frame work of the SIT med fly tunisian suppression program

International Nuclear Information System (INIS)

Lachiheb, Abdallah

2008-01-01

The technique of the sterile insect confirmed its effectiveness in the fight against Ce ratite in Tunisia. The principal components of the success of this technique it is the choice of a suitable degree of irradiation. Indeed, this last exploits a dominating role the quality and the reproductive potential of the males intended to release it. The objective of this work was to determine the necessary degree of ionization to produce flies with a development, an emergence and an aptitude for the flight perfect, as well as a competitiveness, a latency time and a tolerable time of coupling and finally a rate of blossoming and an enough low F1 generation to be able to cause damage with the various types of fruits. A first stage consists in the determination of the rate of blossoming of the eggs which result from a coupling between fertile females and males irradiated with different amounts of ionization, a test which revealed a perfect sterilization for the flies irradiated with an amount of 145 Gy, a second test which to aim at the analysis of the F1 generation and which to confirm the results of the first test. But the analyses of quality of these flies irradiated in question, revealed the bad quality of this amount supposed best to be seen the low values recorded compared to the rate of emergence of the flies and their aptitude for the flight thereafter of an analysis of the competitiveness of the various amounts of irradiation, this test revealed the capacity of the irradiated flies with 80 Gy and 90 Gy to form the greatest number of couples that the witness not irradiated and the other irradiated flies sets with coupling and latency times rather tolerable and close to the average. (Author)

The flying classroom - a cost effective integrated approach to learning and teaching flight dynamics

Science.gov (United States)

Bromfield, Michael A.; Belberov, Aleksandar

2017-11-01

In the UK, the Royal Aeronautical Society recommends the inclusion of practical flight exercises for accredited undergraduate aerospace engineering programmes to enhance learning and student experience. The majority of academic institutions teaching aerospace in the UK separate the theory and practice of flight dynamics with students attending a series of lectures supplemented by an intensive one-day flight exercise. Performance and/or handling qualities flight tests are performed in a dedicated aircraft fitted with specialist equipment for the recording and presentation of flight data. This paper describes an innovative approach to better integrate theory and practice and the use of portable Commercial-off-The-Shelf (COTS) technologies to enable a range of standard, unmodified aircraft to be used. The integration of theory and practice has enriched learning and teaching, improved coursework grades and the student experience. The use of COTS and unmodified aircraft has reduced costs and enabled increased student participation.

Self-healing of mechanically-loaded self consolidating concretes with high volumes of fly ash

Energy Technology Data Exchange (ETDEWEB)

Mustafa Sahmaran; Suleyman B. Keskin; Gozde Ozerkan; Ismail O. Yaman [University of Gaziantep, Gaziantep (Turkey). Department of Civil Engineering

2008-11-15

This article discusses the effects of self-healing on self consolidating concretes incorporating high volumes of fly ash (HVFA-SCC) when subjected to continuous water exposure. For this purpose, self consolidating concretes with fly ash replacement ratios of 0%, 35%, and 55% were prepared having a constant water-cementitious material ratio of 0.35. A uniaxial compression load was applied to generate microcracks in concrete where cylindrical specimens were pre-loaded up to 70% and 90% of the ultimate compressive load determined at 28 days. Later, the extent of damage was determined as percentage of loss in mechanical properties and percentage of increase in permeation properties. After pre-loading, concrete specimens were stored in water for a month and the mechanical and permeation properties are monitored at every two weeks. It was observed that HVFA-SCC mixtures initially lost 27% of their strength when pre-loaded up to 90% of their ultimate strength, and after 30 days of water curing that reduction was only 7%, indicating a substantial healing. On the other hand, for SCC specimens without fly ash that were pre-loaded to the same level, the loss in strength was initially 19%, and after a month of moist curing it was only 13%. Similar observations were also made on the permeation properties with greater effects. As the HVFA-SCCs studied have an important amount of unhydrated fly ash available in their microstructure, these observations are attributed to the self-healing of the pre-existing cracks, mainly by hydration of anhydrous fly ash particles on the crack surfaces.

Treatment of fly ash for use in concrete

Science.gov (United States)

Boxley, Chett [Park City, UT

2012-05-15

A process for treating fly ash to render it highly usable as a concrete additive. A quantity of fly ash is obtained that contains carbon and which is considered unusable fly ash for concrete based upon foam index testing. The fly ash is mixed with a quantity of spray dryer ash (SDA) and water to initiate a geopolymerization reaction and form a geopolymerized fly ash. The geopolymerized fly ash is granulated. The geopolymerized fly ash is considered usable fly ash for concrete according to foam index testing. The geopolymerized fly ash may have a foam index less than 40%, and in some cases less than 20%, of the foam index of the untreated fly ash. An optional alkaline activator may be mixed with the fly ash and SDA to facilitate the geopolymerization reaction. The alkaline activator may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof.

Insect Flight: From Newton's Law to Neurons

Science.gov (United States)

Wang, Z. Jane

2016-03-01

Why do animals move the way they do? Bacteria, insects, birds, and fish share with us the necessity to move so as to live. Although each organism follows its own evolutionary course, it also obeys a set of common laws. At the very least, the movement of animals, like that of planets, is governed by Newton's law: All things fall. On Earth, most things fall in air or water, and their motions are thus subject to the laws of hydrodynamics. Through trial and error, animals have found ways to interact with fluid so they can float, drift, swim, sail, glide, soar, and fly. This elementary struggle to escape the fate of falling shapes the development of motors, sensors, and mind. Perhaps we can deduce parts of their neural computations by understanding what animals must do so as not to fall. Here I discuss recent developments along this line of inquiry in the case of insect flight. Asking how often a fly must sense its orientation in order to balance in air has shed new light on the role of motor neurons and steering muscles responsible for flight stability.

Using wide area differential GPS to improve total system error for precision flight operations

Science.gov (United States)

Alter, Keith Warren

Total System Error (TSE) refers to an aircraft's total deviation from the desired flight path. TSE can be divided into Navigational System Error (NSE), the error attributable to the aircraft's navigation system, and Flight Technical Error (FTE), the error attributable to pilot or autopilot control. Improvement in either NSE or FTE reduces TSE and leads to the capability to fly more precise flight trajectories. The Federal Aviation Administration's Wide Area Augmentation System (WAAS) became operational for non-safety critical applications in 2000 and will become operational for safety critical applications in 2002. This navigation service will provide precise 3-D positioning (demonstrated to better than 5 meters horizontal and vertical accuracy) for civil aircraft in the United States. Perhaps more importantly, this navigation system, which provides continuous operation across large regions, enables new flight instrumentation concepts which allow pilots to fly aircraft significantly more precisely, both for straight and curved flight paths. This research investigates the capabilities of some of these new concepts, including the Highway-In-The Sky (HITS) display, which not only improves FTE but also reduces pilot workload when compared to conventional flight instrumentation. Augmentation to the HITS display, including perspective terrain and terrain alerting, improves pilot situational awareness. Flight test results from demonstrations in Juneau, AK, and Lake Tahoe, CA, provide evidence of the overall feasibility of integrated, low-cost flight navigation systems based on these concepts. These systems, requiring no more computational power than current-generation low-end desktop computers, have immediate applicability to general aviation flight from Cessnas to business jets and can support safer and ultimately more economical flight operations. Commercial airlines may also, over time, benefit from these new technologies.

Altitude exposures during commercial flight: a reappraisal.

Science.gov (United States)

Hampson, Neil B; Kregenow, David A; Mahoney, Anne M; Kirtland, Steven H; Horan, Kathleen L; Holm, James R; Gerbino, Anthony J

2013-01-01

Hypobaric hypoxia during commercial air travel has the potential to cause or worsen hypoxemia in individuals with pre-existing cardiopulmonary compromise. Knowledge of cabin altitude pressures aboard contemporary flights is essential to counseling patients accurately about flying safety. The objective of the study was to measure peak cabin altitudes during U.S. domestic commercial flights on a variety of aircraft. A handheld mountaineering altimeter was carried by the investigators in the plane cabin during commercial air travel and peak cabin altitude measured. The values were then compared between aircraft models, aircraft classes, and distances flown. The average peak cabin altitude on 207 flights aboard 17 different aircraft was 6341 +/- 1813 ft (1933 m +/- 553 m), significantly higher than when measured in a similar fashion in 1988. Peak cabin altitude was significantly higher for flights longer than 750 mi (7085 +/- 801 ft) compared to shorter flights (5160 +/- 2290 ft/1573 +/- 698 m). Cabin altitude increased linearly with flight distance for flights up to 750 mi in length, but was independent of flight distance for flights exceeding 750 mi. Peak cabin altitude was less than 5000 ft (1524 m) in 70% of flights shorter than 500 mi. Peak cabin altitudes greater than 8000 ft (2438 m) were measured on approximately 10% of the total flights. Peak cabin altitude on commercial aircraft flights has risen over time. Cabin altitude is lower with flights of shorter distance. Physicians should take these factors into account when determining an individual's need for supplemental oxygen during commercial air travel.

Matching times of leading and following suggest cooperation through direct reciprocity during V-formation flight in ibis.

Science.gov (United States)

Voelkl, Bernhard; Portugal, Steven J; Unsöld, Markus; Usherwood, James R; Wilson, Alan M; Fritz, Johannes

2015-02-17

One conspicuous feature of several larger bird species is their annual migration in V-shaped or echelon formation. When birds are flying in these formations, energy savings can be achieved by using the aerodynamic up-wash produced by the preceding bird. As the leading bird in a formation cannot profit from this up-wash, a social dilemma arises around the question of who is going to fly in front? To investigate how this dilemma is solved, we studied the flight behavior of a flock of juvenile Northern bald ibis (Geronticus eremita) during a human-guided autumn migration. We could show that the amount of time a bird is leading a formation is strongly correlated with the time it can itself profit from flying in the wake of another bird. On the dyadic level, birds match the time they spend in the wake of each other by frequent pairwise switches of the leading position. Taken together, these results suggest that bald ibis cooperate by directly taking turns in leading a formation. On the proximate level, we propose that it is mainly the high number of iterations and the immediacy of reciprocation opportunities that favor direct reciprocation. Finally, we found evidence that the animals' propensity to reciprocate in leading has a substantial influence on the size and cohesion of the flight formations.

Advanced fighter technology integration (AFTI)/F-16 Automated Maneuvering Attack System final flight test results

Science.gov (United States)

Dowden, Donald J.; Bessette, Denis E.

1987-01-01

The AFTI F-16 Automated Maneuvering Attack System has undergone developmental and demonstration flight testing over a total of 347.3 flying hours in 237 sorties. The emphasis of this phase of the flight test program was on the development of automated guidance and control systems for air-to-air and air-to-ground weapons delivery, using a digital flight control system, dual avionics multiplex buses, an advanced FLIR sensor with laser ranger, integrated flight/fire-control software, advanced cockpit display and controls, and modified core Multinational Stage Improvement Program avionics.

Adjustment of muscle function to flight in bats; Komori no kinkino no hiko eno tekio

Energy Technology Data Exchange (ETDEWEB)

Yamashita, M. [Institute of the Space and Astronautical Science,Tokyo (Japan); Choi, I.H.

1999-12-05

This paper outlines the muscle of bats that generates a motive force for flight. The weight of the muscle is less compared with that of birds. The energy required for flight is twice as much as that for running. Conversely, in view of metabolic cost (transporting cost) for moving a unit mass for a unit distance, the transporting cost of bats for flying is one fifth. The acquisition of this flight ability through evolution can be inferred from the fossils of reptiles. Bats, having a stream-lined body shape and a small body mass, are capable of efficient flight. A fast durable flight is possible by having the pectoral muscle constituted of speed muscles of oxidation/glycolysis muscle fiber, a well-developed oxygen transporting system, the arrangement around the capillary of mitochondria and fat grains that are cell organs for producing energy, and a high-density contact between the capillary and the muscle fiber. The muscle functions at low body temperature and imparts adaptability to hibernation with the body temperature lowered. The flight is controlled by the cycle and synchronized with this biological clock, optical cycle and change in temperature. (NEDO)

Early life hormetic treatments decrease irradiation-induced oxidative damage, increase longevity, and enhance sexual performance during old age in the Caribbean fruit fly

International Nuclear Information System (INIS)

López-Martínez, Giancarlo; Hahn, Daniel A.

2014-01-01

Early life events can have dramatic consequences on performance later in life. Exposure to stressors at a young age affects development, the rate of aging, risk of disease, and overall lifespan. In spite of this, mild stress exposure early in life can have beneficial effects on performance later in life. These positive effects of mild stress are referred to as physiological conditioning hormesis. In our current study we used anoxia conditioning hormesis as a pretreatment to reduce oxidative stress and improve organismal performance, lifespan, and healthspan of Caribbean fruit flies. We used gamma irradiation to induce mild oxidative damage in a low-dose experiment, and massive oxidative damage in a separate high-dose experiment, in pharate adult fruit flies just prior to adult emergence. Irradiation-induced oxidative stress leads to reduced adult emergence, flight ability, mating performance, and lifespan. We used a hormetic approach, one hour of exposure to anoxia plus irradiation in anoxia, to lower post-irradiation oxidative damage. We have previously shown that this anoxic-conditioning treatment elevates total antioxidant capacity and lowers post-irradiation oxidative damage to lipids and proteins. In this study, conditioned flies had lower mortality rates and longer lifespan compared to those irradiated without hormetic conditioning. As a metric of healthspan, we tracked mating both at a young age (10 d) and old age (30 d). We found that anoxia-conditioned male flies were more competitive at young ages when compared to unconditioned irradiation stressed male flies, and that the positive effects of anoxic conditioning hormesis on mating success were even more pronounced in older males. Our data shows that physiological conditioning hormesis at a young age, not only improves immediate metrics of organismal performance (emergence, flight, mating), but the beneficial effects also carry into old age by reducing late life oxidative damage and improving lifespan and

Possibilities of utilizing power plant fly ashes

Directory of Open Access Journals (Sweden)

Mezencevová Andrea

2003-09-01

mechanical action. It is known, that performance of fly ash in concrete improves with its increased fineness. Intensive milling of fly ash leads to the increasing fly ash fineness and to the enhancement of its hydration activity. The cement-fly ash composites with 25 wt.% of activated fly ash as cement replacement have exhibited a higher 28-day compressive strength in comparison with a reference concrete sample without fly ash. An unfavorable effect in milling process is the agglomeration of fine particles of fly ash. By high-energy milling of fly ash with addition of surfactants, the ultrafine products can be prepared. Concrete samples containing such fly ash have achieved higher compressive strengths than the reference sample without fly ash or with addition of non-milled fly ash. The considerable physical effect of ultrafine fly ash consists in superior filling of spaces between coarser cement particles and in the favorable influence of hardness of the mixtures at setting.The current research activities in mechanochemistry are oriented to the mechanical activation of poly-component systems. The knowledge in this field indicate that by high-energy milling of fly ash as a poly-component system and following heating of prepared metastable precursors, the cement minerals could be prepared.

Metabolic 'engines' of flight drive genome size reduction in birds.

Science.gov (United States)

Wright, Natalie A; Gregory, T Ryan; Witt, Christopher C

2014-03-22

The tendency for flying organisms to possess small genomes has been interpreted as evidence of natural selection acting on the physical size of the genome. Nonetheless, the flight-genome link and its mechanistic basis have yet to be well established by comparative studies within a volant clade. Is there a particular functional aspect of flight such as brisk metabolism, lift production or maneuverability that impinges on the physical genome? We measured genome sizes, wing dimensions and heart, flight muscle and body masses from a phylogenetically diverse set of bird species. In phylogenetically controlled analyses, we found that genome size was negatively correlated with relative flight muscle size and heart index (i.e. ratio of heart to body mass), but positively correlated with body mass and wing loading. The proportional masses of the flight muscles and heart were the most important parameters explaining variation in genome size in multivariate models. Hence, the metabolic intensity of powered flight appears to have driven genome size reduction in birds.

A new approach for accurate mass assignment on a multi-turn time-of-flight mass spectrometer.

Science.gov (United States)

Hondo, Toshinobu; Jensen, Kirk R; Aoki, Jun; Toyoda, Michisato

2017-12-01

A simple, effective accurate mass assignment procedure for a time-of-flight mass spectrometer is desirable. External mass calibration using a mass calibration standard together with an internal mass reference (lock mass) is a common technique for mass assignment, however, using polynomial fitting can result in mass-dependent errors. By using the multi-turn time-of-flight mass spectrometer infiTOF-UHV, we were able to obtain multiple time-of-flight data from an ion monitored under several different numbers of laps that was then used to calculate a mass calibration equation. We have developed a data acquisition system that simultaneously monitors spectra at several different lap conditions with on-the-fly centroid determination and scan law estimation, which is a function of acceleration voltage, flight path, and instrumental time delay. Less than 0.9 mDa mass errors were observed for assigned mass to charge ratios ( m/z) ranging between 4 and 134 using only 40 Ar + as a reference. It was also observed that estimating the scan law on-the-fly provides excellent mass drift compensation.

First controlled vertical flight of a biologically inspired microrobot

Energy Technology Data Exchange (ETDEWEB)

Perez-Arancibia, Nestor O; Ma, Kevin Y; Greenberg, Jack D; Wood, Robert J [School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138 (United States); Galloway, Kevin C, E-mail: nperez@seas.harvard.edu, E-mail: kevinma@seas.harvard.edu, E-mail: kevin.galloway@wyss.harvard.edu, E-mail: jdgreenb@seas.harvard.edu, E-mail: rjwood@eecs.harvard.edu [Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115 (United States)

2011-09-15

In this paper, we present experimental results on altitude control of a flying microrobot. The problem is approached in two stages. In the first stage, system identification of two relevant subsystems composing the microrobot is performed, using a static flapping experimental setup. In the second stage, the information gathered through the static flapping experiments is employed to design the controller used in vertical flight. The design of the proposed controller relies on the idea of treating an exciting signal as a subsystem of the microrobot. The methods and results presented here are a key step toward achieving total autonomy of bio-inspired flying microrobots.

First controlled vertical flight of a biologically inspired microrobot

International Nuclear Information System (INIS)

Perez-Arancibia, Nestor O; Ma, Kevin Y; Greenberg, Jack D; Wood, Robert J; Galloway, Kevin C

2011-01-01

In this paper, we present experimental results on altitude control of a flying microrobot. The problem is approached in two stages. In the first stage, system identification of two relevant subsystems composing the microrobot is performed, using a static flapping experimental setup. In the second stage, the information gathered through the static flapping experiments is employed to design the controller used in vertical flight. The design of the proposed controller relies on the idea of treating an exciting signal as a subsystem of the microrobot. The methods and results presented here are a key step toward achieving total autonomy of bio-inspired flying microrobots.

Statistical evaluation of the mechanical properties of high-volume class F fly ash concretes

KAUST Repository

Yoon, Seyoon; Monteiro, Paulo J.M.; Macphee, Donald E.; Glasser, Fredrik P.; Imbabi, Mohammed Salah-Eldin

2014-01-01

the authors experimentally and statistically investigated the effects of mix-design factors on the mechanical properties of high-volume class F fly ash concretes. A total of 240 and 32 samples were produced and tested in the laboratory to measure compressive

Development of autonomous controller system of high speed UAV from simulation to ready to fly condition

Science.gov (United States)

Yudhi Irwanto, Herma

2018-02-01

The development of autonomous controller system that is specially used in our high speed UAV, it’s call RKX-200EDF/TJ controlled vehicle needs to be continued as a step to mastery and to developt control system of LAPAN’s satellite launching rocket. The weakness of the existing control system in this high speed UAV needs to be repaired and replaced using the autonomous controller system. Conversion steps for ready-to-fly system involved controlling X tail fin, adjusting auto take off procedure by adding X axis sensor, procedure of way points reading and process of measuring distance and heading to the nearest way point, developing user-friendly ground station, and adding tools for safety landing. The development of this autonomous controller system also covered a real flying test in Pandanwangi, Lumajang in November 2016. Unfortunately, the flying test was not successful because the booster rocket was blown right after burning. However, the system could record the event and demonstrated that the controller system had worked according to plan.

Structural concepts and experimental considerations for a versatile high-speed research airplane

Science.gov (United States)

Jackson, L. R.; Kirkham, F. S.; Weidner, J. P.

1978-01-01

Future aircraft may be hydrogen fueled and fly at hypersonic speeds. The resulting environments will require new structural concepts to satisfy performance goals. Large representative structures will have to be flight tested prior to commitment to a costly vehicle fleet. To perform flight tests, a versatile, economical, high-speed research airplane is defined. Results of this study including experimental considerations for a hypersonic research airplane are reported.

When Computers Fly, It Has to Be Right: Using SPARK for Flight Control of Small Unmanned Aerial Vehicles

National Research Council Canada - National Science Library

Sward, Ricky E; Gerken, Mark; Casey, Dan

2006-01-01

.... For safety critical software programs such as Unmanned Aerial Vehicle flight control software, the risk of software failure demands high assurance that the software will perform its intended function...

Identifying glass compositions in fly ash

Directory of Open Access Journals (Sweden)

Katherine eAughenbaugh

2016-01-01

Full Text Available In this study, four Class F fly ashes were studied with a scanning electron microscope; the glassy phases were identified and their compositions quantified using point compositional analysis with k-means clustering and multispectral image analysis. The results showed that while the bulk oxide contents of the fly ashes were different, the four fly ashes had somewhat similar glassy phase compositions. Aluminosilicate glasses (AS, calcium aluminosilicate glasses (CAS, a mixed glass, and, in one case, a high iron glass were identified in the fly ashes. Quartz and iron crystalline phases were identified in each fly ash as well. The compositions of the three main glasses identified, AS, CAS, and mixed glass, were relatively similar in each ash. The amounts of each glass were varied by fly ash, with the highest calcium fly ash containing the most of calcium-containing glass. Some of the glasses were identified as intermixed in individual particles, particularly the calcium-containing glasses. Finally, the smallest particles in the fly ashes, with the most surface area available to react in alkaline solution, such as when mixed with portland cement or in alkali-activated fly ash, were not different in composition than the large particles, with each of the glasses represented. The method used in the study may be applied to a fly ash of interest for use as a cementing material in order to understand its potential for reactivity.

Bird or bat: comparing airframe design and flight performance

International Nuclear Information System (INIS)

Hedenstroem, Anders; Johansson, L Christoffer; Spedding, Geoffrey R

2009-01-01

Birds and bats have evolved powered flight independently, which makes a comparison of evolutionary 'design' solutions potentially interesting. In this paper we highlight similarities and differences with respect to flight characteristics, including morphology, flight kinematics, aerodynamics, energetics and flight performance. Birds' size range is 0.002-15 kg and bats' size range is 0.002-1.5 kg. The wingbeat kinematics differ between birds and bats, which is mainly due to the different flexing of the wing during the upstroke and constraints by having a wing of feathers and a skin membrane, respectively. Aerodynamically, bats appear to generate a more complex wake than birds. Bats may be more closely adapted for slow maneuvering flight than birds, as required by their aerial hawking foraging habits. The metabolic rate and power required to fly are similar among birds and bats. Both groups share many characteristics associated with flight, such as for example low amounts of DNA in cells, the ability to accumulate fat as fuel for hibernation and migration, and parallel habitat-related wing shape adaptations

Autogenic Feedback Training Exercise and pilot performance: enhanced functioning under search-and-rescue flying conditions

Science.gov (United States)

Cowings, P. S.; Kellar, M. A.; Folen, R. A.; Toscano, W. B.; Burge, J. D.

2001-01-01

Studies have shown that autonomous mode behavior is one cause of aircraft fatalities due to pilot error. In such cases, the pilot is in a high state of psychological and physiological arousal and tends to focus on one problem, while ignoring more critical information. This study examined the effect of training in physiological self-recognition and regulation, as a means of improving crew cockpit performance. Seventeen pilots were assigned to the treatment and control groups matched for accumulated flight hours. The treatment group contained 4 pilots from HC-130 Hercules aircraft and 4 HH-65 Dolphin helicopter pilots; the control group contained 3 pilots of HC-130s and 6 helicopter pilots. During an initial flight, physiological data were recorded on each crewmember and an instructor pilot rated individual crew performance. Eight crewmembers were then taught to regulate their own physiological response levels using Autogenic-Feedback Training Exercise (AFTE). The remaining participants received no training. During a second flight, treatment participants showed significant improvement in performance (rated by the same instructor pilot as in pretests) while controls did not improve. The results indicate that AFTE management of high states of physiological arousal may improve pilot performance during emergency flying conditions.

Identification of high molecular weight nitroaromatic compounds from coal fly ash

International Nuclear Information System (INIS)

Harris, W.R.; Okamoto, D.J.; Chess, E.K.; Wilson, B.W.

1983-01-01

A large sample of stack-collected coal fly ash was extracted with 60:40 nu/nu benzene:methanol to remove as much of the soluble organic material as possible. This solution was concentrated by gentle evaporation, and was then fractionated on a series of high performance liquid chromatography columns to generate samples suitable for probe mass spectrometric analysis. A series of nitrated derivatives of C 21 H 12 polycyclic aromatic hydrocarbon have been tentatively identified by low and high resolution mass spectrometry and gas chromatography. The series includes a mononitro, two dinitro isomers, and a trinitro derivative

Distribution and occurrence of lithium in high-alumina-coal fly ash

DEFF Research Database (Denmark)

Hu, Pengpeng; Hou, Xinjuan; Zhang, Jianbo

2018-01-01

the generalized gradient approximation (GGA) method indicated that Li occurred in Q3(0Al) and Q3(1Al) structures by reacting with Q4(0Al) and Q4(1Al). Based on the experimental and simulation results, we propose extracting Li during the pre-desilication process by dissolving the glass phase.......High-alumina-coal fly ash (HAFA) with a high Li content is regarded as a potential resource for Li production. To support the development of Li recovery technology from HAFA, the distribution and modes of occurrence of Li in HAFA were investigated. HAFA was separated into magnetic particles, glass...

Flight demonstration of new thruster and green propellant technology on the PRISMA satellite

Science.gov (United States)

Anflo, K.; Möllerberg, R.

2009-11-01

The concept of a storable liquid monopropellant blend for space applications based on ammonium dinitramide (ADN) was invented in 1997, within a co-operation between the Swedish Space Corporation (SSC) and the Swedish Defense Research Agency (FOI). The objective was to develop a propellant which has higher performance and is safer than hydrazine. The work has been performed under contract from the Swedish National Space Board and ESA. The progress of the development has been presented in several papers since 2000. ECAPS, a subsidiary of the Swedish Space Corporation was established in 2000 with the aim to develop and market the novel "high performance green propellant" (HPGP) technology for space applications. The new technology is based on several innovations and patents w.r.t. propellant formulation and thruster design, including a high temperature resistant catalyst and thrust chamber. The first flight demonstration of the HPGP propulsion system will be performed on PRISMA. PRISMA is an international technology demonstration program with Swedish Space Corporation as the Prime Contractor. This paper describes the performance, characteristics, design and verification of the HPGP propulsion system for PRISMA. Compatibility issues related to using a new propellant with COTS components is also discussed. The PRISMA mission includes two satellites in LEO orbit were the focus is on rendezvous and formation flying. One of the satellites will act as a "target" and the main spacecraft performs rendezvous and formation flying maneuvers, where the ECAPS HPGP propulsion system will provide delta-V capability. The PRISMA CDR was held in January 2007. Integration of the flight propulsion system is about to be finalized. The flight opportunity on PRISMA represents a unique opportunity to demonstrate the HPGP propulsion system in space, and thus take a significant step towards its use in future space applications. The launch of PRISMA scheduled to 2009.

14 CFR 121.505 - Flight time limitations: Two pilot crews: airplanes.

Science.gov (United States)

2010-01-01

...: airplanes. 121.505 Section 121.505 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Operations § 121.505 Flight time limitations: Two pilot crews: airplanes. (a) If a certificate holder conducting supplemental operations schedules a pilot to fly more than eight hours during any 24 consecutive...

R&D of Novel Materials for Animal Litters Using High Carbon Fly Ash Final Progress Report

Energy Technology Data Exchange (ETDEWEB)

Boxley, Chett J. [Ceramatec, Inc., Salt Lake City, UT (United States); Kadota, Rod [Ceramatec, Inc., Salt Lake City, UT (United States)

2012-10-29

This research program performed by Ceramatec may significantly increase the beneficial utilization of fly ash, and improve the overall performance of high quality animal litter products. Ceramatec has developed a novel high surface area material, which is capable of ammonia adsorption. High surface area zeolites when combined with agglomerated fly ash can significantly reduce the use of naturally mined materials (i.e. clay bentonite) for animal litter manufacture. This not only preserves natural resources and the natural environment, but it also will reduce CO₂ emissions, via the reduced need for heavy mining equipment. This novel animal litter is made with over 85% of recycled materials, thus preventing their disposition to landfills. The novel litter material is similar to traditional clay-like litters, and it is clumpable and has superior odor control properties.

High Temperature Fission Chamber for He- and FLiBe-cooled Reactors

Energy Technology Data Exchange (ETDEWEB)

Bell, Zane W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Giuliano, Dominic R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Holcomb, David Eugene [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lance, Michael J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Miller, Roger G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Warmack, Robert J. Bruce [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wilson, Dane F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Harrison, Mark J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2015-01-01

We have evaluated candidate technologies for in-core fission chambers for high-temperature reactors to monitor power level via measurements of neutron flux from start-up through full power at up to 800°C. This research is important because there are no commercially available instruments capable of operating above 550 °C. Component materials and processes were investigated for fission chambers suitable for operation at 800 °C in reactors cooled by molten fluoride salt (FLiBe) or flowing He, with an emphasis placed on sensitivity (≥ 1 cps/nv), service lifetime (2 years at full power), and resistance to direct immersion in FLiBe. The latter gives the instrument the ability to survive accidents involving breach of a thimble. The device is envisioned to be a two-gap, three-electrode instrument constructed from concentric nickel-plated alumina cylinders and using a noble gas–nitrogen fill-gas. We report the results of measurements and calculations of the response of fill gasses, impurity migration in nickel alloy, brazing of the alumina insulator, and thermodynamic calculations.

Compression Behavior of Confined Columns with High-Volume Fly Ash Concrete

Directory of Open Access Journals (Sweden)

Sung-Won Yoo

2017-01-01

Full Text Available The use of fly ash in ordinary concrete provides practical benefits to concrete structures, such as a gain in long-term strength, reduced hydration heat, improved resistance to chloride, and enhanced workability. However, few studies with high-volume fly ash (HVFA concrete have been conducted that focus on the structural applications such as a column. Thus, there is a need to promote field applications of HVFA concrete as a sustainable construction material. To this end, this study investigated the compressive behavior of reinforced concrete columns that contain HVFA with a 50 percent replacement rate. Six columns were fabricated for this study. The study variables were the HVFA replacement rate, tied steel ratio, and tie steel spacing. The computed ultimate strength by the American Concrete Institute (ACI code conservatively predicted the measured values, and, thus, the existing equation in the ACI code is feasible for confined RC columns that contain HVFA. In addition, an analysis model was calibrated based on the experimental results and is recommended for predicting the stress-strain relationship of confined reinforced concrete columns that contain HVFA.

Fused Reality for Enhanced Flight Test Capabilities

Science.gov (United States)

Bachelder, Ed; Klyde, David

2011-01-01

The feasibility of using Fused Reality-based simulation technology to enhance flight test capabilities has been investigated. In terms of relevancy to piloted evaluation, there remains no substitute for actual flight tests, even when considering the fidelity and effectiveness of modern ground-based simulators. In addition to real-world cueing (vestibular, visual, aural, environmental, etc.), flight tests provide subtle but key intangibles that cannot be duplicated in a ground-based simulator. There is, however, a cost to be paid for the benefits of flight in terms of budget, mission complexity, and safety, including the need for ground and control-room personnel, additional aircraft, etc. A Fused Reality(tm) (FR) Flight system was developed that allows a virtual environment to be integrated with the test aircraft so that tasks such as aerial refueling, formation flying, or approach and landing can be accomplished without additional aircraft resources or the risk of operating in close proximity to the ground or other aircraft. Furthermore, the dynamic motions of the simulated objects can be directly correlated with the responses of the test aircraft. The FR Flight system will allow real-time observation of, and manual interaction with, the cockpit environment that serves as a frame for the virtual out-the-window scene.

Design Criteria for the Future of Flight Controls. Proceedings of the Flight Dynamics Laboratory Flying Qualities and Flight Control Symposium 2-5 March 1982.

Science.gov (United States)

1982-07-01

launch platform . But as a transport, obviously, long duration flights must be accomplished without undue crew fatigue. Underlying all this is an...Modes a weapons platforme throah sore effective flight listed in Figure 1. control design. VII. Sugestd Frthr Research Rfrne There are certain...A KIat KiOW CC~~i at Pilot m1A~ MloU. ftm of a h m ad ftf trn* weD kqr~&~ m Wix a I -n ** Wuma of Am 1 Tbalam, ad axazw Dpi c Fwa PltwsAp ad A

Assessment of fly ash-aided phytostabilisation of highly contaminated soils after an 8-year field trial

Energy Technology Data Exchange (ETDEWEB)

Lopareva-Pohu, Alena [Universite Lille Nord de France, Lille (France); Groupe ISA, Equipe Sols et Environnement, Laboratoire Genie Civil et geoEnvironnement Lille Nord de France EA 4515, 48 boulevard Vauban, 59046 Lille Cedex (France); Universite du Littoral-Cote d' Opale, Unite de Chimie Environnementale et Interactions sur le Vivant (UCEIV), EA4492, Maison de la Recherche en Environnement Industriel de Dunkerque 2, Avenue Maurice Schumann, 59140 Dunkerque (France); Pourrut, Bertrand; Waterlot, Christophe [Universite Lille Nord de France, Lille (France); Groupe ISA, Equipe Sols et Environnement, Laboratoire Genie Civil et geoEnvironnement Lille Nord de France EA 4515, 48 boulevard Vauban, 59046 Lille Cedex (France); Garcon, Guillaume [Universite Lille Nord de France, Lille (France); Universite du Littoral-Cote d' Opale, Unite de Chimie Environnementale et Interactions sur le Vivant (UCEIV), EA4492, Maison de la Recherche en Environnement Industriel de Dunkerque 2, Avenue Maurice Schumann, 59140 Dunkerque (France); Bidar, Geraldine; Pruvot, Christelle [Universite Lille Nord de France, Lille (France); Groupe ISA, Equipe Sols et Environnement, Laboratoire Genie Civil et geoEnvironnement Lille Nord de France EA 4515, 48 boulevard Vauban, 59046 Lille Cedex (France); Shirali, Pirouz [Universite Lille Nord de France, Lille (France); Universite du Littoral-Cote d' Opale, Unite de Chimie Environnementale et Interactions sur le Vivant (UCEIV), EA4492, Maison de la Recherche en Environnement Industriel de Dunkerque 2, Avenue Maurice Schumann, 59140 Dunkerque (France); Douay, Francis, E-mail: f.douay@isa-lille.fr [Universite Lille Nord de France, Lille (France); Groupe ISA, Equipe Sols et Environnement, Laboratoire Genie Civil et geoEnvironnement Lille Nord de France EA 4515, 48 boulevard Vauban, 59046 Lille Cedex (France)

2011-01-01

Sustainable management of large surface areas contaminated with trace elements is a real challenge, since currently applied remediation techniques are too expensive for these areas. Aided phytostabilisation appears to be a cost efficient technique to reduce metal mobility in contaminated soils and contaminated particle spread. In this context, this study aimed at evaluating the long-term efficiency of aided phytostabilisation on former agricultural soils highly contaminated with trace elements. The influence of afforestation and fly ash amendments to reduce metal mobility was investigated. Before being planted with a tree mix, the study site was divided into three plots: a reference plot with no amendment, the second amended with silico-aluminous fly ash and the third with sulfo-calcic fly ash. After eight years, some soil physico-chemical parameters, including cadmium (Cd), lead (Pb) and zinc (Zn) extractability were modified. In particular, pH decreased on the whole site while organic carbon content increased. The alteration of these parameters influencing trace element mobility is explained by afforestation. Over time, concentrations of CaCl{sub 2}-extractable metals increased and were correlated with the soil pH decrease. In the amended soils, extractable Cd, Pb and Zn concentrations were lower than in the reference soil. The results indicated that the two fly ashes buffered natural soil acidification due to vegetation development and limited trace element mobility and thus could limit their bioavailability. For long-term phytostabilisation, special attention should be focused on the soil pH, metal mobility and phytoavailability analysis. - Research Highlights: {yields} Afforestation leads to soil pH decrease and organic carbon content increase. {yields} Fly ashes buffered natural soil acidification. {yields} Fly ashes limited metal mobility.

Assessment of fly ash-aided phytostabilisation of highly contaminated soils after an 8-year field trial

International Nuclear Information System (INIS)

Lopareva-Pohu, Alena; Pourrut, Bertrand; Waterlot, Christophe; Garcon, Guillaume; Bidar, Geraldine; Pruvot, Christelle; Shirali, Pirouz; Douay, Francis

2011-01-01

Sustainable management of large surface areas contaminated with trace elements is a real challenge, since currently applied remediation techniques are too expensive for these areas. Aided phytostabilisation appears to be a cost efficient technique to reduce metal mobility in contaminated soils and contaminated particle spread. In this context, this study aimed at evaluating the long-term efficiency of aided phytostabilisation on former agricultural soils highly contaminated with trace elements. The influence of afforestation and fly ash amendments to reduce metal mobility was investigated. Before being planted with a tree mix, the study site was divided into three plots: a reference plot with no amendment, the second amended with silico-aluminous fly ash and the third with sulfo-calcic fly ash. After eight years, some soil physico-chemical parameters, including cadmium (Cd), lead (Pb) and zinc (Zn) extractability were modified. In particular, pH decreased on the whole site while organic carbon content increased. The alteration of these parameters influencing trace element mobility is explained by afforestation. Over time, concentrations of CaCl 2 -extractable metals increased and were correlated with the soil pH decrease. In the amended soils, extractable Cd, Pb and Zn concentrations were lower than in the reference soil. The results indicated that the two fly ashes buffered natural soil acidification due to vegetation development and limited trace element mobility and thus could limit their bioavailability. For long-term phytostabilisation, special attention should be focused on the soil pH, metal mobility and phytoavailability analysis. - Research Highlights: → Afforestation leads to soil pH decrease and organic carbon content increase. → Fly ashes buffered natural soil acidification. → Fly ashes limited metal mobility.

Fatigue mitigation effects of en-route napping on commercial airline pilots flying international routes

Science.gov (United States)

Baldwin, Jarret Taylor

The introduction of ultra-long range commercial aircraft and the evolution of the commercial airline industry has provided new opportunities for air carriers to fly longer range international route segments while deregulation, industry consolidation, and the constant drive to reduce costs wherever possible has pressured airline managements to seek more productivity from their pilots. At the same time, advancements in the understanding of human physiology have begun to make their way into flight and duty time regulations and airline scheduling practices. In this complex and ever changing operating environment, there remains an essential need to better understand how these developments, and other daily realities facing commercial airline pilots, are affecting their fatigue management strategies as they go about their rituals of getting to and from their homes to work and performing their flight assignments. Indeed, the need for commercial airline pilots to have access to better and more effective fatigue mitigation tools to combat fatigue and insure that they are well rested and at the top of their game when flying long-range international route segments has never been greater. This study examined to what extent the maximum fatigue states prior to napping, as self-accessed by commercial airline pilots flying international route segments, were affected by a number of other common flight assignment related factors. The study also examined to what extent the availability of scheduled en-route rest opportunities, in an onboard crew rest facility, affected the usage of en-route napping as a fatigue mitigation strategy, and to what extent the duration of such naps affected the perceived benefits of such naps as self-accessed by commercial airline pilots flying international route segments. The study utilized an online survey tool to collect data on crew position, prior flight segments flown in the same duty period, augmentation, commuting, pre-flight rest obtained in the

Expected Navigation Flight Performance for the Magnetospheric Multiscale (MMS) Mission

Science.gov (United States)

Olson, Corwin; Wright, Cinnamon; Long, Anne

2012-01-01

The Magnetospheric Multiscale (MMS) mission consists of four formation-flying spacecraft placed in highly eccentric elliptical orbits about the Earth. The primary scientific mission objective is to study magnetic reconnection within the Earth s magnetosphere. The baseline navigation concept is the independent estimation of each spacecraft state using GPS pseudorange measurements (referenced to an onboard Ultra Stable Oscillator) and accelerometer measurements during maneuvers. State estimation for the MMS spacecraft is performed onboard each vehicle using the Goddard Enhanced Onboard Navigation System, which is embedded in the Navigator GPS receiver. This paper describes the latest efforts to characterize expected navigation flight performance using upgraded simulation models derived from recent analyses.

Wake development behind paired wings with tip and root trailing vortices: consequences for animal flight force estimates.

Science.gov (United States)

Horstmann, Jan T; Henningsson, Per; Thomas, Adrian L R; Bomphrey, Richard J

2014-01-01

Recent experiments on flapping flight in animals have shown that a variety of unrelated species shed a wake behind left and right wings consisting of both tip and root vortices. Here we present an investigation using Particle Image Velocimetry (PIV) of the behaviour and interaction of trailing vortices shed by paired, fixed wings that simplify and mimic the wake of a flying animal with a non-lifting body. We measured flow velocities at five positions downstream of two adjacent NACA 0012 aerofoils and systematically varied aspect ratio, the gap between the wings (corresponding to the width of a non-lifting body), angle of attack, and the Reynolds number. The range of aspect ratios and Reynolds number where chosen to be relevant to natural fliers and swimmers, and insect flight in particular. We show that the wake behind the paired wings deformed as a consequence of the induced flow distribution such that the wingtip vortices convected downwards while the root vortices twist around each other. Vortex interaction and wake deformation became more pronounced further downstream of the wing, so the positioning of PIV measurement planes in experiments on flying animals has an important effect on subsequent force estimates due to rotating induced flow vectors. Wake deformation was most severe behind wings with lower aspect ratios and when the distance between the wings was small, suggesting that animals that match this description constitute high-risk groups in terms of measurement error. Our results, therefore, have significant implications for experimental design where wake measurements are used to estimate forces generated in animal flight. In particular, the downstream distance of the measurement plane should be minimised, notwithstanding the animal welfare constraints when measuring the wake behind flying animals.

Wake development behind paired wings with tip and root trailing vortices: consequences for animal flight force estimates.

Directory of Open Access Journals (Sweden)

Jan T Horstmann

Full Text Available Recent experiments on flapping flight in animals have shown that a variety of unrelated species shed a wake behind left and right wings consisting of both tip and root vortices. Here we present an investigation using Particle Image Velocimetry (PIV of the behaviour and interaction of trailing vortices shed by paired, fixed wings that simplify and mimic the wake of a flying animal with a non-lifting body. We measured flow velocities at five positions downstream of two adjacent NACA 0012 aerofoils and systematically varied aspect ratio, the gap between the wings (corresponding to the width of a non-lifting body, angle of attack, and the Reynolds number. The range of aspect ratios and Reynolds number where chosen to be relevant to natural fliers and swimmers, and insect flight in particular. We show that the wake behind the paired wings deformed as a consequence of the induced flow distribution such that the wingtip vortices convected downwards while the root vortices twist around each other. Vortex interaction and wake deformation became more pronounced further downstream of the wing, so the positioning of PIV measurement planes in experiments on flying animals has an important effect on subsequent force estimates due to rotating induced flow vectors. Wake deformation was most severe behind wings with lower aspect ratios and when the distance between the wings was small, suggesting that animals that match this description constitute high-risk groups in terms of measurement error. Our results, therefore, have significant implications for experimental design where wake measurements are used to estimate forces generated in animal flight. In particular, the downstream distance of the measurement plane should be minimised, notwithstanding the animal welfare constraints when measuring the wake behind flying animals.

Evaluation of exposure to cosmic radiation of flight crews of Lithuanian Airlines

International Nuclear Information System (INIS)

Morkunas, G.; Pilkyte, L.; Ereminas, D.

2003-01-01

In Lithuania the average annual effective dose due to cosmic radiation at the sea level is 0.38 mSv. The dose rate caused by cosmic radiation increases with altitude due to the decrease in attenuation of cosmic radiation by atmosphere. Dose rates altitudes of commercial flights are tens times higher than those at the sea level. For this reason people who frequently fly receive higher doses which might even be subject to legal regulations. The European Council Directive (96/29 EURATOM) on basic radiation safety standards requires that doses of air crews members be assessed and appropriate measures taken, depending on the assessment results. The aim of this study was to evaluate potential doses, which can be received by members of air crews of Lithuania Airlines. The assessment was done by performing measurements and calculations. Measurements were performed in flying aircraft by thermoluminescent detectors, Geiger Muller counters and neutron rem counter. Such an approach lead to evaluation of doses due to directly ionizing particles and neutrons. Calculations were done with the help of the code CARI-6M. Such parameters as flight route, solar activity, duration and altitudes of flight were taken into account. Doses received during different flights and in different air crafts were assessed. The results of measurements and calculations were compared and differences discussed. The results were also compared with the data obtained in other similar studies. It was found that the highest doses are received in flights to Paris, London, Amsterdam, and Frankfurt by aircraft B737. A number of flights causing annual doses higher than 1 mSv was estimated. Despite the fact that only European flights are operated by Lithuanian Airlines the dose of 1 mSv may be exceeded under some circumstances. If it happens some radiation protection measures shall be taken. These measures are also discussed. (author)

SIMBOL-X: A Formation Flying Mission on HEO for Exploring the Universe

Science.gov (United States)

Gamet, Philippe; Epenoy, R.; Salcedo, C.

2007-01-01

SIMBOL-X is a high energy new generation telescope covering by a single instrument a continuous energy range starting at classical X-rays and extending to hard X-rays, i.e. from 0.5 to 80 keV. It is using in this field a focalizing payload which until now was used for energy below 10 keV only, via the construction of a telescope distributed on two satellites flying in formation. SIMBOL-X permits a gain of two orders of magnitude in sensibility and spatial resolution in comparison to state of the art hard X-rays instruments. The mirror satellite will be in free flight on a high elliptical orbit and will target the object to observe very precisely, thus focusing the hard X-ray emission thanks to this mirror module. At the focal point area which is situated 20 meters behind the mirror satellite, the detector satellite maintains its position on a forced orbit thanks to a radio link with the mirror satellite and a lateral displacement sensor using a beam emitted onboard the mirror satellite. This configuration is said "formation flying". The location of the detector satellite shall be very finely tuned as it carries the focal plane of this distributed telescope. To provide science measurements, the Simbol-X orbit has been chosen High elliptic (HEO), which means elliptical orbit with a high perigee altitude. Preliminary studies where made with an orbit with an altitude of the perigee of 44000km and altitude of the apogee of 253000km. The orbit was seven days ground track repeated in order to maintain a perigee pass over the Malindi ground station to download scientific telemetry. But as studies went on, difficulties in mass budget, link budget, perigee maintenance and formation flying maintenance were raised. This was mainly due to the vicinity of the Moon and its disturbing effect on the satellites orbits. Alternative orbits have been proposed in order to demonstrate the feasibility of the mission. The problematic of bringing the two satellites from their injection

The case for energy harvesting on wildlife in flight

International Nuclear Information System (INIS)

Shafer, Michael W; MacCurdy, Robert; Garcia, Ephrahim; Shipley, J Ryan; Winkler, David; Guglielmo, Christopher G

2015-01-01

The confluence of advancements in microelectronic components and vibrational energy harvesting has opened the possibility of remote sensor units powered solely from the motion of their hosts. There are numerous applications of such systems, including the development of modern wildlife tracking/data-logging devices. These ‘bio-logging’ devices are typically mass-constrained because they must be carried by an animal. Thus, they have historically traded scientific capability for operational longevity due to restrictions on battery size. Recently, the precipitous decrease in the power requirements of microelectronics has been accompanied by advancements in the area of piezoelectric vibrational energy harvesting. These energy harvesting devices are now capable of powering the type of microelectronic circuits used in bio-logging devices. In this paper we consider the feasibility of employing these vibrational energy harvesters on flying vertebrates for the purpose of powering a bio-logging device. We show that the excess energy available from birds and bats could be harvested without adversely affecting their overall energy budget. We then present acceleration measurements taken on flying birds in a flight tunnel to understand modulation of flapping frequency during steady flight. Finally, we use a recently developed method of estimating the maximum power output from a piezoelectric energy harvester to determine the amount of power that could be practically harvested from a flying bird. The results of this analysis show that the average power output of a piezoelectric energy harvester mounted to a bird or bat could produce more than enough power to run a bio-logging device. We compare the power harvesting capabilities to the energy requirements of an example system and conclude that vibrational energy harvesting on flying birds and bats is viable and warrants further study, including testing. (paper)

A new genus of long-legged flies displaying remarkable wing directional asymmetry

Science.gov (United States)

Justin B. Runyon; Richard L. Hurley

2004-01-01

A previously unknown group of flies is described whose males exhibit directional asymmetry, in that the left wing is larger than, and of a different shape from, the right wing. To our knowledge, wing asymmetry of this degree has not previously been reported in an animal capable of flight. Such consistent asymmetry must result from a left­right axis during development...

Flight behavior of the rhinoceros beetle Trypoxylus dichotomus during electrical nerve stimulation

International Nuclear Information System (INIS)

Truong, Tien Van; Byun, Doyoung; Lavine, Laura Corley; Emlen, Douglas J; Park, Hoon Cheol; Kim, Min Jun

2012-01-01

Neuronal stimulation is an intricate part of understanding insect flight behavior and control insect itself. In this study, we investigated the effects of electrical pulses applied to the brain and basalar muscle of the rhinoceros beetle (Trypoxylus dichotomus). To understand specific neuronal stimulation mechanisms, responses and flight behavior of the beetle, four electrodes were implanted into the two optic lobes, the brain's central complex and the ventral nerve cord in the posterior pronotum. We demonstrated flight initiation, turning and cessation by stimulating the brain. The change undergone by the wing flapping in response to the electrical signal was analyzed from a sequence of images captured by a high-speed camera. Here, we provide evidence to distinguish the important differences between neuronal and muscular flight stimulations in beetles. We found that in the neural potential stimulation, both the hind wing and the elytron were suppressed. Interestingly, the beetle stopped flying whenever a stimulus potential was applied between the pronotum and one side of the optic lobe, or between the ventral nerve cord in the posterior pronotum and the central complex. In-depth experimentation demonstrated the effective of neural stimulation over muscle stimulation for flight control. During electrical stimulation of the optic lobes, the beetle performed unstable flight, resulting in alternating left and right turns. By applying the electrical signal into both the optic lobes and the central complex of the brain, we could precisely control the direction of the beetle flight. This work provides an insight into insect flight behavior for future development of insect-micro air vehicle. (paper)

Flight behavior of the rhinoceros beetle Trypoxylus dichotomus during electrical nerve stimulation.

Science.gov (United States)

Van Truong, Tien; Byun, Doyoung; Lavine, Laura Corley; Emlen, Douglas J; Park, Hoon Cheol; Kim, Min Jun

2012-09-01

Neuronal stimulation is an intricate part of understanding insect flight behavior and control insect itself. In this study, we investigated the effects of electrical pulses applied to the brain and basalar muscle of the rhinoceros beetle (Trypoxylus dichotomus). To understand specific neuronal stimulation mechanisms, responses and flight behavior of the beetle, four electrodes were implanted into the two optic lobes, the brain's central complex and the ventral nerve cord in the posterior pronotum. We demonstrated flight initiation, turning and cessation by stimulating the brain. The change undergone by the wing flapping in response to the electrical signal was analyzed from a sequence of images captured by a high-speed camera. Here, we provide evidence to distinguish the important differences between neuronal and muscular flight stimulations in beetles. We found that in the neural potential stimulation, both the hind wing and the elytron were suppressed. Interestingly, the beetle stopped flying whenever a stimulus potential was applied between the pronotum and one side of the optic lobe, or between the ventral nerve cord in the posterior pronotum and the central complex. In-depth experimentation demonstrated the effective of neural stimulation over muscle stimulation for flight control. During electrical stimulation of the optic lobes, the beetle performed unstable flight, resulting in alternating left and right turns. By applying the electrical signal into both the optic lobes and the central complex of the brain, we could precisely control the direction of the beetle flight. This work provides an insight into insect flight behavior for future development of insect-micro air vehicle.

Efficiency of Lift Production in Flapping and Gliding Flight of Swifts

Science.gov (United States)

Henningsson, Per; Hedenström, Anders; Bomphrey, Richard J.

2014-01-01

Many flying animals use both flapping and gliding flight as part of their routine behaviour. These two kinematic patterns impose conflicting requirements on wing design for aerodynamic efficiency and, in the absence of extreme morphing, wings cannot be optimised for both flight modes. In gliding flight, the wing experiences uniform incident flow and the optimal shape is a high aspect ratio wing with an elliptical planform. In flapping flight, on the other hand, the wing tip travels faster than the root, creating a spanwise velocity gradient. To compensate, the optimal wing shape should taper towards the tip (reducing the local chord) and/or twist from root to tip (reducing local angle of attack). We hypothesised that, if a bird is limited in its ability to morph its wings and adapt its wing shape to suit both flight modes, then a preference towards flapping flight optimization will be expected since this is the most energetically demanding flight mode. We tested this by studying a well-known flap-gliding species, the common swift, by measuring the wakes generated by two birds, one in gliding and one in flapping flight in a wind tunnel. We calculated span efficiency, the efficiency of lift production, and found that the flapping swift had consistently higher span efficiency than the gliding swift. This supports our hypothesis and suggests that even though swifts have been shown previously to increase their lift-to-drag ratio substantially when gliding, the wing morphology is tuned to be more aerodynamically efficient in generating lift during flapping. Since body drag can be assumed to be similar for both flapping and gliding, it follows that the higher total drag in flapping flight compared with gliding flight is primarily a consequence of an increase in wing profile drag due to the flapping motion, exceeding the reduction in induced drag. PMID:24587260

Efficiency of lift production in flapping and gliding flight of swifts.

Directory of Open Access Journals (Sweden)

Per Henningsson

Full Text Available Many flying animals use both flapping and gliding flight as part of their routine behaviour. These two kinematic patterns impose conflicting requirements on wing design for aerodynamic efficiency and, in the absence of extreme morphing, wings cannot be optimised for both flight modes. In gliding flight, the wing experiences uniform incident flow and the optimal shape is a high aspect ratio wing with an elliptical planform. In flapping flight, on the other hand, the wing tip travels faster than the root, creating a spanwise velocity gradient. To compensate, the optimal wing shape should taper towards the tip (reducing the local chord and/or twist from root to tip (reducing local angle of attack. We hypothesised that, if a bird is limited in its ability to morph its wings and adapt its wing shape to suit both flight modes, then a preference towards flapping flight optimization will be expected since this is the most energetically demanding flight mode. We tested this by studying a well-known flap-gliding species, the common swift, by measuring the wakes generated by two birds, one in gliding and one in flapping flight in a wind tunnel. We calculated span efficiency, the efficiency of lift production, and found that the flapping swift had consistently higher span efficiency than the gliding swift. This supports our hypothesis and suggests that even though swifts have been shown previously to increase their lift-to-drag ratio substantially when gliding, the wing morphology is tuned to be more aerodynamically efficient in generating lift during flapping. Since body drag can be assumed to be similar for both flapping and gliding, it follows that the higher total drag in flapping flight compared with gliding flight is primarily a consequence of an increase in wing profile drag due to the flapping motion, exceeding the reduction in induced drag.

The Flight of Birds and Other Animals

Directory of Open Access Journals (Sweden)

Colin J. Pennycuick

2015-09-01

Full Text Available Methods of observing birds in flight now include training them to fly under known conditions in wind tunnels, and fitting free-flying birds with data loggers, that are either retrieved or read remotely via satellite links. The performance that comes to light depends on the known limitations of the materials from which they are made, and the conditions in which the birds live. Bird glide polars can be obtained by training birds to glide in a tilting wind tunnel. Translating these curves to power required from the flight muscles in level flight requires drag coefficients to be measured, which unfortunately does not work with bird bodies, because the flow is always fully detached. The drag of bodies in level flight can be determined by observing wingbeat frequency, and shows CD values around 0.08 in small birds, down to 0.06 in small waders specialised for efficient migration. Lift coefficients are up to 1.6 in gliding, or 1.8 for short, temporary glides. In-flight measurements can be used to calculate power curves for birds in level flight, and this has been applied to migrating geese in detail. These typically achieve lift:drag ratios around 15, including allowances for stops, as against 19 for continuous powered flight. The same calculations, applied to Pacific Black-tailed Godwits which start with fat fractions up to 0.55 at departure, show that such birds not only cross the Pacific to New Zealand, but have enough fuel in hand to reach the South Pole if that were necessary. This performance depends on the “dual fuel” arrangements of these migrants, whereby they use fat as their main fuel, and supplement this by extra fuel from burning the engine (flight muscles, as less power is needed later in the flight. The accuracy of these power curves has never been checked, although provision for stopping the bird, and making these checks at regular intervals during a simulated flight was built into the original design of the Lund wind tunnel. The

Cuticular hydrocarbon analysis of an awake behaving fly using direct analysis in real-time time-of-flight mass spectrometry

OpenAIRE

Yew, Joanne Y.; Cody, Robert B.; Kravitz, Edward A.

2008-01-01

In mammals and insects, pheromones strongly influence social behaviors such as aggression and mate recognition. In Drosophila melanogaster, pheromones in the form of cuticular hydrocarbons play prominent roles in courtship. GC/MS is the primary analytical tool currently used to study Drosophila cuticular hydrocarbons. Although GC/MS is highly reproducible and sensitive, it requires that the fly be placed in a lethal solution of organic solvent, thereby impeding further behavioral studies. We ...

The aerodynamics and control of free flight manoeuvres in Drosophila

Science.gov (United States)

Muijres, Florian T.

2016-01-01

A firm understanding of how fruit flies hover has emerged over the past two decades, and recent work has focused on the aerodynamic, biomechanical and neurobiological mechanisms that enable them to manoeuvre and resist perturbations. In this review, we describe how flies manipulate wing movement to control their body motion during active manoeuvres, and how these actions are regulated by sensory feedback. We also discuss how the application of control theory is providing new insight into the logic and structure of the circuitry that underlies flight stability. This article is part of the themed issue ‘Moving in a moving medium: new perspectives on flight’. PMID:27528778

Computer vision techniques for rotorcraft low altitude flight

Science.gov (United States)

Sridhar, Banavar

1990-01-01

Rotorcraft operating in high-threat environments fly close to the earth's surface to utilize surrounding terrain, vegetation, or manmade objects to minimize the risk of being detected by an enemy. Increasing levels of concealment are achieved by adopting different tactics during low-altitude flight. Rotorcraft employ three tactics during low-altitude flight: low-level, contour, and nap-of-the-earth (NOE). The key feature distinguishing the NOE mode from the other two modes is that the whole rotorcraft, including the main rotor, is below tree-top whenever possible. This leads to the use of lateral maneuvers for avoiding obstacles, which in fact constitutes the means for concealment. The piloting of the rotorcraft is at best a very demanding task and the pilot will need help from onboard automation tools in order to devote more time to mission-related activities. The development of an automation tool which has the potential to detect obstacles in the rotorcraft flight path, warn the crew, and interact with the guidance system to avoid detected obstacles, presents challenging problems. Research is described which applies techniques from computer vision to automation of rotorcraft navigtion. The effort emphasizes the development of a methodology for detecting the ranges to obstacles in the region of interest based on the maximum utilization of passive sensors. The range map derived from the obstacle-detection approach can be used as obstacle data for the obstacle avoidance in an automatic guidance system and as advisory display to the pilot. The lack of suitable flight imagery data presents a problem in the verification of concepts for obstacle detection. This problem is being addressed by the development of an adequate flight database and by preprocessing of currently available flight imagery. The presentation concludes with some comments on future work and how research in this area relates to the guidance of other autonomous vehicles.

Perseus A, Part of the ERAST Program, in Flight

Science.gov (United States)

1993-01-01

The Perseus A remotely-piloted research vehicle flies low over Rogers Dry Lake on its maiden voyage Dec. 21, 1993, at the Dryden Flight Research Center, Edwards, California. The Perseus, designed and built by Aurora Flight Sciences Corp., was towed into the air by a ground vehicle. At about 700 ft. the aircraft was released and the engine turned the propeller to take the plane to its desired altitude. Perseus B is a remotely piloted aircraft developed as a design-performance testbed under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project. Perseus is one of several flight vehicles involved in the ERAST project. A piston engine, propeller-powered aircraft, Perseus was designed and built by Aurora Flight Sciences Corporation, Manassas, Virginia. The objectives of Perseus B's ERAST flight tests have been to reach and maintain horizontal flight above altitudes of 60,000 feet and demonstrate the capability to fly missions lasting from 8 to 24 hours, depending on payload and altitude requirements. The Perseus B aircraft established an unofficial altitude record for a single-engine, propeller-driven, remotely piloted aircraft on June 27, 1998. It reached an altitude of 60,280 feet. In 1999, several modifications were made to the Perseus aircraft including engine, avionics, and flight-control-system improvements. These improvements were evaluated in a series of operational readiness and test missions at the Dryden Flight Research Center, Edwards, California. Perseus is a high-wing monoplane with a conventional tail design. Its narrow, straight, high-aspect-ratio wing is mounted atop the fuselage. The aircraft is pusher-designed with the propeller mounted in the rear. This design allows for interchangeable scientific-instrument payloads to be placed in the forward fuselage. The design also allows for unobstructed airflow to the sensors and other devices mounted in the payload compartment. The Perseus B that underwent test and development in 1999

FliO Regulation of FliP in the Formation of the Salmonella enterica Flagellum

Science.gov (United States)

Barker, Clive S.; Meshcheryakova, Irina V.; Kostyukova, Alla S.; Samatey, Fadel A.

2010-01-01

The type III secretion system of the Salmonella flagellum consists of 6 integral membrane proteins: FlhA, FlhB, FliO, FliP, FliQ, and FliR. However, in some other type III secretion systems, a homologue of FliO is apparently absent, suggesting it has a specialized role. Deleting the fliO gene from the chromosome of a motile strain of Salmonella resulted in a drastic decrease of motility. Incubation of the ΔfliO mutant strain in motility agar, gave rise to pseudorevertants containing extragenic bypass mutations in FliP at positions R143H or F190L. Using membrane topology prediction programs, and alkaline phosphatase or GFPuv chimeric protein fusions into the FliO protein, we demonstrated that FliO is bitopic with its N-terminus in the periplasm and C-terminus in the cytoplasm. Truncation analysis of FliO demonstrated that overexpression of FliO43–125 or FliO1–95 was able to rescue motility of the ΔfliO mutant. Further, residue leucine 91 in the cytoplasmic domain was identified to be important for function. Based on secondary structure prediction, the cytoplasmic domain, FliO43–125, should contain beta-structure and alpha-helices. FliO43–125-Ala was purified and studied using circular dichroism spectroscopy; however, this domain was disordered, and its structure was a mixture of beta-sheet and random coil. Coexpression of full-length FliO with FliP increased expression levels of FliP, but coexpression with the cytoplasmic domain of FliO did not enhance FliP expression levels. Overexpression of the cytoplasmic domain of FliO further rescued motility of strains deleted for the fliO gene expressing bypass mutations in FliP. These results suggest FliO maintains FliP stability through transmembrane domain interaction. The results also demonstrate that the cytoplasmic domain of FliO has functionality, and it presumably becomes structured while interacting with its binding partners. PMID:20941389

FliO regulation of FliP in the formation of the Salmonella enterica flagellum.

Directory of Open Access Journals (Sweden)

Clive S Barker

2010-09-01

Full Text Available The type III secretion system of the Salmonella flagellum consists of 6 integral membrane proteins: FlhA, FlhB, FliO, FliP, FliQ, and FliR. However, in some other type III secretion systems, a homologue of FliO is apparently absent, suggesting it has a specialized role. Deleting the fliO gene from the chromosome of a motile strain of Salmonella resulted in a drastic decrease of motility. Incubation of the ΔfliO mutant strain in motility agar, gave rise to pseudorevertants containing extragenic bypass mutations in FliP at positions R143H or F190L. Using membrane topology prediction programs, and alkaline phosphatase or GFPuv chimeric protein fusions into the FliO protein, we demonstrated that FliO is bitopic with its N-terminus in the periplasm and C-terminus in the cytoplasm. Truncation analysis of FliO demonstrated that overexpression of FliO₄₃-₁₂₅ or FliO₁-₉₅ was able to rescue motility of the ΔfliO mutant. Further, residue leucine 91 in the cytoplasmic domain was identified to be important for function. Based on secondary structure prediction, the cytoplasmic domain, FliO₄₃-₁₂₅, should contain beta-structure and alpha-helices. FliO₄₃-₁₂₅-Ala was purified and studied using circular dichroism spectroscopy; however, this domain was disordered, and its structure was a mixture of beta-sheet and random coil. Coexpression of full-length FliO with FliP increased expression levels of FliP, but coexpression with the cytoplasmic domain of FliO did not enhance FliP expression levels. Overexpression of the cytoplasmic domain of FliO further rescued motility of strains deleted for the fliO gene expressing bypass mutations in FliP. These results suggest FliO maintains FliP stability through transmembrane domain interaction. The results also demonstrate that the cytoplasmic domain of FliO has functionality, and it presumably becomes structured while interacting with its binding partners.

A Method to Identify Flight Obstacles on Digital Surface Model

Institute of Scientific and Technical Information of China (English)

ZHAO Min; LIN Xinggang; SUN Shouyu; WANG Youzhi

2005-01-01

In modern low-altitude terrain-following guidance, a constructing method of the digital surface model (DSM) is presented in the paper to reduce the threat to flying vehicles of tall surface features for safe flight. The relationship between an isolated obstacle size and the intervals of vertical- and cross-section in the DSM model is established. The definition and classification of isolated obstacles are proposed, and a method for determining such isolated obstacles in the DSM model is given. The simulation of a typical urban district shows that when the vertical- and cross-section DSM intervals are between 3 m and 25 m, the threat to terrain-following flight at low-altitude is reduced greatly, and the amount of data required by the DSM model for monitoring in real time a flying vehicle is also smaller. Experiments show that the optimal results are for an interval of 12.5 m in the vertical- and cross-sections in the DSM model, with a 1:10 000 DSM scale grade.

The Waypoint Planning Tool: Real Time Flight Planning for Airborne Science

Science.gov (United States)

He, M.; Goodman, H. M.; Blakeslee, R.; Hall, J. M.

2010-12-01

NASA Earth science research utilizes both spaceborne and airborne real time observations in the planning and operations of its field campaigns. The coordination of air and space components is critical to achieve the goals and objectives and ensure the success of an experiment. Spaceborne imagery provides regular and continual coverage of the Earth and it is a significant component in all NASA field experiments. Real time visible and infrared geostationary images from GOES satellites and multi-spectral data from the many elements of the NASA suite of instruments aboard the TRMM, Terra, Aqua, Aura, and other NASA satellites have become norm. Similarly, the NASA Airborne Science Program draws upon a rich pool of instrumented aircraft. The NASA McDonnell Douglas DC-8, Lockheed P3 Orion, DeHavilland Twin Otter, King Air B200, Gulfstream-III are all staples of a NASA’s well-stocked, versatile hangar. A key component in many field campaigns is coordinating the aircraft with satellite overpasses, other airplanes and the constantly evolving, dynamic weather conditions. Given the variables involved, developing a good flight plan that meets the objectives of the field experiment can be a challenging and time consuming task. Planning a research aircraft mission within the context of meeting the science objectives is complex task because it is much more than flying from point A to B. Flight plans typically consist of flying a series of transects or involve dynamic path changes when “chasing” a hurricane or forest fire. These aircraft flight plans are typically designed by the mission scientists then verified and implemented by the navigator or pilot. Flight planning can be an arduous task requiring frequent sanity checks by the flight crew. This requires real time situational awareness of the weather conditions that affect the aircraft track. Scientists at the University of Alabama-Huntsville and the NASA Marshall Space Flight Center developed the Waypoint Planning Tool

Integrated modeling and robust control for full-envelope flight of robotic helicopters

Science.gov (United States)

La Civita, Marco

Robotic helicopters have attracted a great deal of interest from the university, the industry, and the military world. They are versatile machines and there is a large number of important missions that they could accomplish. Nonetheless, there are only a handful of documented examples of robotic-helicopter applications in real-world scenarios. This situation is mainly due to the poor flight performance that can be achieved and---more important---guaranteed under automatic control. Given the maturity of control theory, and given the large body of knowledge in helicopter dynamics, it seems that the lack of success in flying high-performance controllers for robotic helicopters, especially by academic groups and by small industries, has nothing to do with helicopters or control theory as such. The problem lies instead in the large amount of time and resources needed to synthesize, test, and implement new control systems with the approach normally followed in the aeronautical industry. This thesis attempts to provide a solution by presenting a modeling and control framework that minimizes the time, cost, and both human and physical resources necessary to design high-performance flight controllers. The work is divided in two main parts. The first consists of the development of a modeling technique that allows the designer to obtain a high-fidelity model adequate for both real-time simulation and controller design, with few flight, ground, and wind-tunnel tests and a modest level of complexity in the dynamic equations. The second consists of the exploitation of the predictive capabilities of the model and of the robust stability and performance guarantees of the Hinfinity loop-shaping control theory to reduce the number of iterations of the design/simulated-evaluation/flight-test-evaluation procedure. The effectiveness of this strategy is demonstrated by designing and flight testing a wide-envelope high-performance controller for the Carnegie Mellon University robotic

High Strength Lightweight Concrete Made with Ternary Mixtures of Cement-Fly Ash-Silica Fume and Scoria as Aggregate

OpenAIRE

YAŞAR, Ergül; ATIŞ, Cengiz Duran; KILIÇ, Alaettin

2014-01-01

This paper presents part of the results of an ongoing laboratory study carried out to design a structural lightweight high strength concrete (SLWHSC) made with and without ternary mixtures of cement-fly ash-silica fume. In the mixtures, lightweight basaltic-pumice (scoria) aggregate was used. A concrete mixture made with lightweight scoria, and another lightweight scoria concrete mixture incorporating 20% fly ash and 10% silica fume as a cement replacement, were prepared. Two normal...

The FLP microsatellite platform flight operations manual

CERN Document Server

2016-01-01

This book represents the Flight Operations Manual for a reusable microsatellite platform – the “Future Low-cost Platform” (FLP), developed at the University of Stuttgart, Germany. It provides a basic insight on the onboard software functions, the core data handling system and on the power, communications, attitude control and thermal subsystem of the platform. Onboard failure detection, isolation and recovery functions are treated in detail. The platform is suited for satellites in the 50-150 kg class and is baseline of the microsatellite “Flying Laptop” from the University. The book covers the essential information for ground operators to controls an FLP-based satellite applying international command and control standards (CCSDS and ECSS PUS). Furthermore it provides an overview on the Flight Control Center in Stuttgart and on the link to the German Space Agency DLR Ground Station which is used for early mission phases. Flight procedure and mission planning chapters complement the book. .

Generation of the pitch moment during the controlled flight after takeoff of fruitflies.

Directory of Open Access Journals (Sweden)

Mao Wei Chen

Full Text Available In the present paper, the controlled flight of fruitflies after voluntary takeoff is studied. Wing and body kinematics of the insects after takeoff are measured using high-speed video techniques, and the aerodynamic force and moment are calculated by the computational fluid dynamics method based on the measured data. How the control moments are generated is analyzed by correlating the computed moments with the wing kinematics. A fruit-fly has a large pitch-up angular velocity owing to the takeoff jump and the fly controls its body attitude by producing pitching moments. It is found that the pitching moment is produced by changes in both the aerodynamic force and the moment arm. The change in the aerodynamic force is mainly due to the change in angle of attack. The change in the moment arm is mainly due to the change in the mean stroke angle and deviation angle, and the deviation angle plays a more important role than the mean stroke angle in changing the moment arm (note that change in deviation angle implies variation in the position of the aerodynamic stroke plane with respect to the anatomical stroke plane. This is unlike the case of fruitflies correcting pitch perturbations in steady free flight, where they produce pitching moment mainly by changes in mean stroke angle.

Generation of the pitch moment during the controlled flight after takeoff of fruitflies.

Science.gov (United States)

Chen, Mao Wei; Wu, Jiang Hao; Sun, Mao

2017-01-01

In the present paper, the controlled flight of fruitflies after voluntary takeoff is studied. Wing and body kinematics of the insects after takeoff are measured using high-speed video techniques, and the aerodynamic force and moment are calculated by the computational fluid dynamics method based on the measured data. How the control moments are generated is analyzed by correlating the computed moments with the wing kinematics. A fruit-fly has a large pitch-up angular velocity owing to the takeoff jump and the fly controls its body attitude by producing pitching moments. It is found that the pitching moment is produced by changes in both the aerodynamic force and the moment arm. The change in the aerodynamic force is mainly due to the change in angle of attack. The change in the moment arm is mainly due to the change in the mean stroke angle and deviation angle, and the deviation angle plays a more important role than the mean stroke angle in changing the moment arm (note that change in deviation angle implies variation in the position of the aerodynamic stroke plane with respect to the anatomical stroke plane). This is unlike the case of fruitflies correcting pitch perturbations in steady free flight, where they produce pitching moment mainly by changes in mean stroke angle.

An overview of quarantine for fruit flies

International Nuclear Information System (INIS)

Frampton, E.R.

2000-01-01

What is meant by 'quarantine for fruit flies'? The Collins dictionary describes 'quarantine' as a period of isolation or detention, especially of persons or animals arriving from abroad, to prevent the spread of disease. In providing an overview of quarantine for fruit flies, a broader definition needs to be applied, that is, the combination of activities required to maintain the fruit fly status of a particular geographical area - perhaps better referred to as a 'quarantine system'. Familiarity with New Zealand's quarantine system for fruit flies (Diptera: Tephritidae) provides a useful basis for subsequent comparison with other countries' systems where some fruit fly species may be present. But, why have 'quarantine for fruit flies'? The multivoltine life history of many species. combined with a relatively long-lived adult stage and highly fecund females, results in a high potential for rapid population increase (Bateman 1979, Fletcher 1987). These factors and the close association of fruit flies with harvested fruit or vegetables explain the high quarantine profile of these insects. However, there is no international requirement for a country to have a quarantine system and unless there are natural quarantine barriers (e.g., mountain range, oceans, deserts) that can be utilised, effective quarantine by an individual country may be an impossible task. The implementation of a successful quarantine system is very expensive and therefore, it would be expected that any benefits attained outweigh the costs (Ivess 1998). Ivess (1998) listed the following benefits from the implementation of an effective quarantine system: minimising production costs (including post harvest treatments), maintaining competitive advantages for market access due to the ongoing freedom from particular pests of quarantine significance, an environment free from many pests harmful to plant health, the maintenance of ecosystems

Development and Implementation of a Model-Driven Envelope Protection System for In-Flight Ice Contamination

Science.gov (United States)

Gingras, David R.; Barnhart, Billy P.; Martos, Borja; Ratvasky, Thomas P.; Morelli, Eugene

2011-01-01

Fatal loss-of-control (LOC) accidents have been directly related to in-flight airframe icing. The prototype system presented in this paper directly addresses the need for real-time onboard envelope protection in icing conditions. The combinations of a-priori information and realtime aerodynamic estimations are shown to provide sufficient input for determining safe limits of the flight envelope during in-flight icing encounters. The Icing Contamination Envelope Protection (ICEPro) system has been designed and implemented to identify degradations in airplane performance and flying qualities resulting from ice contamination and provide safe flight-envelope cues to the pilot. Components of ICEPro are described and results from preliminary tests are presented.

Differences in the Aerobic Capacity of Flight Muscles between Butterfly Populations and Species with Dissimilar Flight Abilities

Science.gov (United States)

Rauhamäki, Virve; Wolfram, Joy; Jokitalo, Eija; Hanski, Ilkka; Dahlhoff, Elizabeth P.

2014-01-01

Habitat loss and climate change are rapidly converting natural habitats and thereby increasing the significance of dispersal capacity for vulnerable species. Flight is necessary for dispersal in many insects, and differences in dispersal capacity may reflect dissimilarities in flight muscle aerobic capacity. In a large metapopulation of the Glanville fritillary butterfly in the Åland Islands in Finland, adults disperse frequently between small local populations. Individuals found in newly established populations have higher flight metabolic rates and field-measured dispersal distances than butterflies in old populations. To assess possible differences in flight muscle aerobic capacity among Glanville fritillary populations, enzyme activities and tissue concentrations of the mitochondrial protein Cytochrome-c Oxidase (CytOx) were measured and compared with four other species of Nymphalid butterflies. Flight muscle structure and mitochondrial density were also examined in the Glanville fritillary and a long-distance migrant, the red admiral. Glanville fritillaries from new populations had significantly higher aerobic capacities than individuals from old populations. Comparing the different species, strong-flying butterfly species had higher flight muscle CytOx content and enzymatic activity than short-distance fliers, and mitochondria were larger and more numerous in the flight muscle of the red admiral than the Glanville fritillary. These results suggest that superior dispersal capacity of butterflies in new populations of the Glanville fritillary is due in part to greater aerobic capacity, though this species has a low aerobic capacity in general when compared with known strong fliers. Low aerobic capacity may limit dispersal ability of the Glanville fritillary. PMID:24416122

Comparing aerodynamic efficiency in birds and bats suggests better flight performance in birds.

Directory of Open Access Journals (Sweden)

Florian T Muijres

Full Text Available Flight is one of the energetically most costly activities in the animal kingdom, suggesting that natural selection should work to optimize flight performance. The similar size and flight speed of birds and bats may therefore suggest convergent aerodynamic performance; alternatively, flight performance could be restricted by phylogenetic constraints. We test which of these scenarios fit to two measures of aerodynamic flight efficiency in two passerine bird species and two New World leaf-nosed bat species. Using time-resolved particle image velocimetry measurements of the wake of the animals flying in a wind tunnel, we derived the span efficiency, a metric for the efficiency of generating lift, and the lift-to-drag ratio, a metric for mechanical energetic flight efficiency. We show that the birds significantly outperform the bats in both metrics, which we ascribe to variation in aerodynamic function of body and wing upstroke: Bird bodies generated relatively more lift than bat bodies, resulting in a more uniform spanwise lift distribution and higher span efficiency. A likely explanation would be that the bat ears and nose leaf, associated with echolocation, disturb the flow over the body. During the upstroke, the birds retract their wings to make them aerodynamically inactive, while the membranous bat wings generate thrust and negative lift. Despite the differences in performance, the wake morphology of both birds and bats resemble the optimal wake for their respective lift-to-drag ratio regimes. This suggests that evolution has optimized performance relative to the respective conditions of birds and bats, but that maximum performance is possibly limited by phylogenetic constraints. Although ecological differences between birds and bats are subjected to many conspiring variables, the different aerodynamic flight efficiency for the bird and bat species studied here may help explain why birds typically fly faster, migrate more frequently and migrate

Comparing aerodynamic efficiency in birds and bats suggests better flight performance in birds.

Science.gov (United States)

Muijres, Florian T; Johansson, L Christoffer; Bowlin, Melissa S; Winter, York; Hedenström, Anders

2012-01-01

Flight is one of the energetically most costly activities in the animal kingdom, suggesting that natural selection should work to optimize flight performance. The similar size and flight speed of birds and bats may therefore suggest convergent aerodynamic performance; alternatively, flight performance could be restricted by phylogenetic constraints. We test which of these scenarios fit to two measures of aerodynamic flight efficiency in two passerine bird species and two New World leaf-nosed bat species. Using time-resolved particle image velocimetry measurements of the wake of the animals flying in a wind tunnel, we derived the span efficiency, a metric for the efficiency of generating lift, and the lift-to-drag ratio, a metric for mechanical energetic flight efficiency. We show that the birds significantly outperform the bats in both metrics, which we ascribe to variation in aerodynamic function of body and wing upstroke: Bird bodies generated relatively more lift than bat bodies, resulting in a more uniform spanwise lift distribution and higher span efficiency. A likely explanation would be that the bat ears and nose leaf, associated with echolocation, disturb the flow over the body. During the upstroke, the birds retract their wings to make them aerodynamically inactive, while the membranous bat wings generate thrust and negative lift. Despite the differences in performance, the wake morphology of both birds and bats resemble the optimal wake for their respective lift-to-drag ratio regimes. This suggests that evolution has optimized performance relative to the respective conditions of birds and bats, but that maximum performance is possibly limited by phylogenetic constraints. Although ecological differences between birds and bats are subjected to many conspiring variables, the different aerodynamic flight efficiency for the bird and bat species studied here may help explain why birds typically fly faster, migrate more frequently and migrate longer distances

Ternary blends containing demercurated lighting phosphor and MSWI fly ash as high-performance binders for stabilizing and recycling electroplating sludge.

Science.gov (United States)

Huang, Wu-Jang; Wu, Chia-Teng; Wu, Chang-En; Hsieh, Lin-Huey; Li, Chang-Chien; Lain, Chi-Yuan; Chu, Wei

2008-08-15

This paper describes the solidification and stabilization of electroplating sludge treated with a high-performance binder made from portland type-I cement, municipal solid waste incineration fly ash, and lighting phosphor powder (called as cement-fly ash-phosphor binder, CFP). The highest 28-day unconfined compressive strength of the CFP-treated paste was 816 kg/cm(2) at a ratio of cement to fly ash to lighting phosphor powder of 90:5:5; the strength of this composition also fulfilled the requirement of a high-strength concrete (>460 kg/cm(2) at 28 days). The CFP-stabilized sludge paste samples passed the Taiwanese EPA toxicity characteristic leaching procedure test and, therefore, could be used either as a building material or as a controlled low-strength material, depending on the sludge-to-CFP binder ratio.

Evaluating the geometric shape of a flying paraglider

Directory of Open Access Journals (Sweden)

K. Hanke

2014-06-01

Full Text Available This paper describes the photogrammetric approach to find the geometric shape of a paraglider. As its geometry is only available during the flight this had to be done under special conditions. The layout of the camera positions was limited by the strict safety of the pilot as well as a wind and flying situation that guarantees a stable geometry of the object for several minutes. The data acquisition was finally carried out in the area of Lake Garda and the pilot had the challenging task to handle the calibrated camera using a telescope arm in predefined positions during his flight. The evaluation of the 3D position of selected discrete points representing the paraglider's shape was done by employing a bundle adjustment software and led to very satisfying results which were also proof of the stability of the paraglider during data acquisition as well as of the symmetry of the resulting shape.

Producing zeolites from fly ash

International Nuclear Information System (INIS)

Rayalu, S.; Labhestwar, N.K.; Biniwale, R.B.; Udhoji, J.S.; Meshram, S.U.; Khanna, P.

1998-01-01

Fly ash has virtually become a menace of thermal power generation, leading to its devastating effects on the environment. Development of alternate methods of its disposal - especially those with recourse to recovery of valuable materials-has thus become imperative. This paper deals with the utilisation of fly ash for the production of high value-added products, viz., commercial grade zeolites. The physico-chemical and morphological characteristics of fly ash based Zeolite-A (FAZ-A) compares well with commercial Zeolite-A. High calcium binding capacity, appropriate particle/pore size and other detergency characteristics of FAZ-A brings forth its potential as a substitute for phosphatic detergent builder. The technology is extremely versatile, and other products like Zeolite-X, Zeolite-Y, sodalite and mordenite are also amenable for cost effective production with modifications in certain reaction parameters. Low temperature operations, ready availability of major raw materials, simplicity of process and recycling of unused reactants and process water are special features of the process. (author)

Dispersal aspects of 32 P-labelled Mediterranean fruit fly Ceratitis capitata (Wied., 1824) (Diptera: Tephritidae) in citrus orchard

International Nuclear Information System (INIS)

Silva, E.B. da.

1990-02-01

The dispersion of artificially-reared and gamma-sterilized males of the fruit fly Ceratitis capitata was studied in a citrus orchard. About 10,000 adults were tagged through a 32 P artificial medium and released into two different place of the orchard, one place had ripe fruits and the other place without ripe fruits. Flies trapped were collected daily during the first 8 days and then three more surveys once a week. Radioactive flies were detected by liquid scintillator through Cerenkov effect. The data suggested that the number of male trapped was affected by the presence of ripe fruit and by period between release and trapping. The climate factors during the period of the experiment, did not affect the flight distance neither the trapping data. (author)

Operational Overview for UAS Integration in the NAS Project Flight Test Series 3

Science.gov (United States)

Valkov, Steffi B.; Sternberg, Daniel; Marston, Michael

2018-01-01

The National Aeronautics and Space Administration Unmanned Aircraft Systems Integration in the National Airspace System Project has conducted a series of flight tests intended to support the reduction of barriers that prevent unmanned aircraft from flying without the required waivers from the Federal Aviation Administration. The 2015 Flight Test Series 3, supported two separate test configurations. The first configuration investigated the timing of Detect and Avoid alerting thresholds using a radar equipped unmanned vehicle and multiple live intruders flown at varying encounter geometries.

Cementing Efficiency of Low Calcium Fly Ash in Fly Ash Concretes

OpenAIRE

T. D. Gunneswara Rao; Mudimby Andal

2014-01-01

Research on the utilization of fly ash will no longer refer the fly ash as a waste material of thermal power plants. Use of fly ash in concrete making, makes the concrete economical as well as durable. The fly ash is being added to the concrete in three ways namely, as partial replacement to cement, as partial replacement to fine aggregates and as admixture. Addition of fly ash to the concrete in any one of the form mentioned above, makes the concrete more workable and durable than the conven...

Analysis of Seasonal Risk for Importation of the Mediterranean Fruit Fly, Ceratitis capitata (Diptera: Tephritidae), via Air Passenger Traffic Arriving in Florida and California.

Science.gov (United States)

Szyniszewska, A M; Leppla, N C; Huang, Z; Tatem, A J

2016-12-01

The Mediterranean fruit fly, Ceratitis capitata (Wiedemann), is one of the most economically damaging pests in the world and has repeatedly invaded two major agricultural states in the United States, Florida and California, each time requiring costly eradication. The Mediterranean fruit fly gains entry primarily in infested fruit carried by airline passengers and, since Florida and California each receive about 13 million international passengers annually, the risk of Mediterranean fruit fly entering the United States is potentially very high. The risk of passengers bringing the pest into Florida or California from Mediterranean fruit fly-infested countries was determined with two novel models, one estimated seasonal variation in airline passenger number and the other defined the seasonal and spatial variability in Mediterranean fruit fly abundance. These models elucidated relationships among the risk factors for Mediterranean fruit fly introduction, such as amount of passenger traffic, routes traveled, season of travel, abundance of Mediterranean fruit fly in countries where flights departed, and risk of the pest arriving at destination airports. The risk of Mediterranean fruit fly being introduced into Florida was greatest from Colombia, Brazil, Panama, Venezuela, Argentina, and Ecuador during January-August, whereas primarily the risk to California was from Brazil, Panama, Colombia, and Italy in May-August. About three times more Mediterranean fruit flies were intercepted in passenger baggage at airports in Florida than California, although the data were compromised by a lack of systematic sampling and other limitations. Nevertheless, this study achieved the goal of analyzing available data on seasonal passenger flow and Mediterranean fruit fly population levels to determine when surveillance should be intensified at key airports in Florida and California. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America

The memory template in Drosophila pattern vision at the flight simulator.

Science.gov (United States)

Ernst, R; Heisenberg, M

1999-11-01

Pattern recognition is studied in flight orientation of fixed flying Drosophila melanogaster controlling the horizontal rotations of an arena. Earlier experiments had suggested a simple mechanism of pattern recognition in which a memory template and the actual image are retinotopically matched. In contrast, we now show that Drosophila extracts at least two and probably four pattern parameters: size, vertical position of the center of gravity and, presumably horizontal/vertical extent as well as vertical separatedness of pattern elements. Moreover, the fly treats isolated pattern elements as a compound figure. Retinal transfer is possible between training and test if the centers of gravity of the compound figures are retained.

Ballooning for Biologists: Mission Essentials for Flying Experiments on Large NASA Balloons

Science.gov (United States)

Smith, David J.; Sowa, Marianne

2017-01-01

Despite centuries of scientific balloon flights, only a handful of experiments have produced biologically-relevant results. Yet unlike orbital spaceflight, it is much faster and cheaper to conduct biology research with balloons, sending specimens to the near space environment of Earths stratosphere. Samples can be loaded the morning of a launch and sometimes returned to the laboratory within one day after flying. The National Aeronautics and Space Administration (NASA) flies large, unmanned scientific balloons from all over the globe, with missions ranging from hours to weeks in duration. A payload in the middle portion of the stratosphere (approx. 35 km above sea level) will be exposed to an environment similar to the surface of Mars: temperatures generally around -36 C, atmospheric pressure at a thin 1 kPa, relative humidity levels <1%, and a harsh illumination of ultraviolet (UV) and cosmic radiation levels (about 100 W/sq m and 0.1 mGy/d, respectively) that can be obtained nowhere else on the surface of the Earth, including environmental chambers and particle accelerator facilities attempting to simulate space radiation effects. Considering the operational advantages of ballooning and the fidelity of space-like stressors in the stratosphere, researchers in aerobiology, astrobiology, and space biology can benefit from balloon flight experiments as an intermediary step on the extraterrestrial continuum (ground, low Earth orbit, and deep space studies). Our presentation targets biologists with no background or experience in scientific ballooning. We will provide an overview of large balloon operations, biology topics that can be uniquely addressed in the stratosphere, and a roadmap for developing payloads to fly with NASA.

Applying GIS and high performance agent-based simulation for managing an Old World Screwworm fly invasion of Australia.

Science.gov (United States)

Welch, M C; Kwan, P W; Sajeev, A S M

2014-10-01

Agent-based modelling has proven to be a promising approach for developing rich simulations for complex phenomena that provide decision support functions across a broad range of areas including biological, social and agricultural sciences. This paper demonstrates how high performance computing technologies, namely General-Purpose Computing on Graphics Processing Units (GPGPU), and commercial Geographic Information Systems (GIS) can be applied to develop a national scale, agent-based simulation of an incursion of Old World Screwworm fly (OWS fly) into the Australian mainland. The development of this simulation model leverages the combination of massively data-parallel processing capabilities supported by NVidia's Compute Unified Device Architecture (CUDA) and the advanced spatial visualisation capabilities of GIS. These technologies have enabled the implementation of an individual-based, stochastic lifecycle and dispersal algorithm for the OWS fly invasion. The simulation model draws upon a wide range of biological data as input to stochastically determine the reproduction and survival of the OWS fly through the different stages of its lifecycle and dispersal of gravid females. Through this model, a highly efficient computational platform has been developed for studying the effectiveness of control and mitigation strategies and their associated economic impact on livestock industries can be materialised. Copyright © 2014 International Atomic Energy Agency 2014. Published by Elsevier B.V. All rights reserved.

Bernoulli's Principle: The Effects of Instruction on Young Children's Understanding of Flight.

Science.gov (United States)

Fleege, Pamela O.; And Others

This study examined the effects of hands-on instruction on young children's understanding of an aspect of flight, specifically Bernoulli's principle. First, 137 public school children, ages 5 through 8 years, were interviewed about their understanding of how an airplane flies. Two weeks later, the subjects participated in two hands-on…

Are flying-foxes coming to town? Urbanisation of the spectacled flying-fox (Pteropus conspicillatus in Australia.

Directory of Open Access Journals (Sweden)

Jessica Tait

Full Text Available Urbanisation of wildlife populations is a process with significant conservation and management implications. While urban areas can provide habitat for wildlife, some urbanised species eventually come into conflict with humans. Understanding the process and drivers of wildlife urbanisation is fundamental to developing effective management responses to this phenomenon. In Australia, flying-foxes (Pteropodidae are a common feature of urban environments, sometimes roosting in groups of tens of thousands of individuals. Flying-foxes appear to be becoming increasingly urbanised and are coming into increased contact and conflict with humans. Flying-fox management is now a highly contentious issue. In this study we used monitoring data collected over a 15 year period (1998-2012 to examine the spatial and temporal patterns of association of spectacled flying-fox (Pteropus conspicillatus roost sites (camps with urban areas. We asked whether spectacled flying-foxes are becoming more urbanised and test the hypothesis that such changes are associated with anthropogenic changes to landscape structure. Our results indicate that spectacled flying-foxes were more likely to roost near humans than might be expected by chance, that over the period of the study the proportion of the flying-foxes in urban-associated camps increased, as did the number of urban camps. Increased urbanisation of spectacled flying-foxes was not related to changes in landscape structure or to the encroachment of urban areas on camps. Overall, camps tended to be found in areas that were more fragmented, closer to human habitation and with more urban land cover than the surrounding landscape. This suggests that urbanisation is a behavioural response rather than driven by habitat loss.

Identification of Algerian Field-Caught Phlebotomine Sand Fly Vectors by MALDI-TOF MS.

Directory of Open Access Journals (Sweden)

Ismail Lafri

2016-01-01

Full Text Available Phlebotomine sand flies are known to transmit Leishmania parasites, bacteria and viruses that affect humans and animals in many countries worldwide. Precise sand fly identification is essential to prevent phlebotomine-borne diseases. Over the past two decades, progress in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS has emerged as an accurate tool for arthropod identification. The objective of the present study was to investigate the usefulness of MALDI-TOF MS as a tool for identifying field-caught phlebotomine.Sand flies were captured in four sites in north Algeria. A subset was morphologically and genetically identified. Six species were found in these areas and a total of 28 stored frozen specimens were used for the creation of the reference spectrum database. The relevance of this original method for sand fly identification was validated by two successive blind tests including the morphological identification of 80 new specimens which were stored at -80°C, and 292 unknown specimens, including engorged specimens, which were preserved under different conditions. Intra-species reproducibility and inter-species specificity of the protein profiles were obtained, allowing us to distinguish specimens at the gender level. Querying of the sand fly database using the MS spectra from the blind test groups revealed concordant results between morphological and MALDI-TOF MS identification. However, MS identification results were less efficient for specimens which were engorged or stored in alcohol. Identification of 362 phlebotomine sand flies, captured at four Algerian sites, by MALDI-TOF MS, revealed that the subgenus Larroussius was predominant at all the study sites, except for in M'sila where P. (Phlebotomus papatasi was the only sand fly species detected.The present study highlights the application of MALDI-TOF MS for monitoring sand fly fauna captured in the field. The low cost, reliability and

Identification of Algerian Field-Caught Phlebotomine Sand Fly Vectors by MALDI-TOF MS.

Science.gov (United States)

Lafri, Ismail; Almeras, Lionel; Bitam, Idir; Caputo, Aurelia; Yssouf, Amina; Forestier, Claire-Lise; Izri, Arezki; Raoult, Didier; Parola, Philippe

2016-01-01

Phlebotomine sand flies are known to transmit Leishmania parasites, bacteria and viruses that affect humans and animals in many countries worldwide. Precise sand fly identification is essential to prevent phlebotomine-borne diseases. Over the past two decades, progress in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has emerged as an accurate tool for arthropod identification. The objective of the present study was to investigate the usefulness of MALDI-TOF MS as a tool for identifying field-caught phlebotomine. Sand flies were captured in four sites in north Algeria. A subset was morphologically and genetically identified. Six species were found in these areas and a total of 28 stored frozen specimens were used for the creation of the reference spectrum database. The relevance of this original method for sand fly identification was validated by two successive blind tests including the morphological identification of 80 new specimens which were stored at -80°C, and 292 unknown specimens, including engorged specimens, which were preserved under different conditions. Intra-species reproducibility and inter-species specificity of the protein profiles were obtained, allowing us to distinguish specimens at the gender level. Querying of the sand fly database using the MS spectra from the blind test groups revealed concordant results between morphological and MALDI-TOF MS identification. However, MS identification results were less efficient for specimens which were engorged or stored in alcohol. Identification of 362 phlebotomine sand flies, captured at four Algerian sites, by MALDI-TOF MS, revealed that the subgenus Larroussius was predominant at all the study sites, except for in M'sila where P. (Phlebotomus) papatasi was the only sand fly species detected. The present study highlights the application of MALDI-TOF MS for monitoring sand fly fauna captured in the field. The low cost, reliability and rapidity of MALDI