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Sample records for swashplateless ultralight helicopter

  1. Performance of Swashplateless Ultralight Helicopter Rotor with Trailing-edge Flaps for Primary Flight Control

    Science.gov (United States)

    Shen, Jin-Wei; Chopra, Inderjit

    2003-01-01

    The objective of present study is to evaluate the rotor performance, trailing-edge deflections and actuation requirement of a helicopter rotor with trailing-edge flap system for primary flight control. The swashplateless design is implemented by modifying a two-bladed teetering rotor of an production ultralight helicopter through the use of plain flaps on the blades, and by replacing the pitch link to fixed system control system assembly with a root spring. A comprehensive rotorcraft analysis based on UMARC is carried out to obtain the results for both the swashplateless and a conventional baseline rotor configuration. The predictions show swashplateless configuration achieve superior performance than the conventional rotor attributed from reduction of parasite drag by eliminating swashplate mechanic system. It is indicated that optimal selection of blade pitch index angle, flap location, length, and chord ratio reduces flap deflections and actuation requirements, however, has virtually no effect on rotor performance.

  2. Development of swashplateless helicopter blade pitch control system using the limited angle direct-drive motor (LADDM

    Directory of Open Access Journals (Sweden)

    Wang Jian

    2015-10-01

    Full Text Available It can be greatly beneficial to remove the swashplate of conventional helicopter, because the swashplate is usually complicated, aerodynamically resistive, and obstacle of more complex pitch control for improving performance. The present technologies for helicopter vibration reduction are usually narrow in effective range or requiring additional actuators and signal transfer links, and more effective technology is desired. Helicopter blade pitch control system, which is removed of swashplate and integrated high-frequency pitch control function for active vibration reduction, is likely the suitable solution at current technical level. Several potential implementation schemes are discussed, such as blades being directly or indirectly driven by actuators mounted in rotating frame and application of different types of actuators, especially implementation schemes of electro-mechanical actuator with or without gear reducer. It is found that swashplateless blade pitch control system based on specially designed limited angle direct-drive motor (LADDM is a more practical implementation scheme. An experimental prototype of the finally selected implementation scheme has been designed, fabricated and tested on rotor tower. The test results show considerable feasibility of the swashplateless helicopter blade pitch control system using the LADDM.

  3. Swashplateless Helicopter Experimental Investigation: Primary Control with Trailing Edge Flaps Actuated with Piezobenders

    Science.gov (United States)

    Copp, Peter

    Helicopter rotor primary control is conventionally carried out using a swashplate with pitch links. Eliminating the swashplate promises to reduce the helicopter's parasitic power in high speed forward flight, as well as may lead to a hydraulic-less vehicle. A Mach-scale swashplateless rotor is designed with integrated piezobender-actuated trailing edge flaps and systematically tested on the benchtop, in the vacuum chamber and on the hoverstand. The blade is nominally based on the UH-60 rotor with a hover tip Mach number of 0.64. The blade diameter is 66 inches requiring 2400 RPM for Mach scale simulation. The rotor hub is modified to reduce the blade fundamental torsional frequency to less than 2.0/rev by replacing the rigid pitch links with linear springs, which results in an increase of the blade pitching response to the trailing edge flaps. Piezoelectric multilayer benders provide the necessary bandwidth, stroke and stiffness to drive the flaps for primary control while fitting inside the blade profile and withstanding the high centrifugal forces. This work focuses on several key issues. A piezobender designed from a soft piezoelectric material, PZT-5K4, is constructed. The new material is used to construct multi-layer benders with increased stroke for the same stiffness relative to hard materials such as PZT-5H2. Each layer has a thickness of 10 mils. The soft material with gold electrodes requires a different bonding method than hard material with nickel electrodes. With this new bonding method, the measured stiffness matches precisely the predicted stiffness for a 12 layer bender with 1.26 inch length and 1.0 inch width with a stiffness of 1.04 lb/mil. The final in-blade bender has a length of 1.38 inches and 1.0 inch width with a stiffness of 0.325 lb/mil and stroke of 20.2 mils for an energy output of 66.3 lb-mil. The behavior of piezobenders under very high electric fields is investigated. High field means +18.9 kV/cm (limited by arcing in air) and -3.54k

  4. Development of swashplateless helicopter blade pitch control system using the limited angle direct-drive motor (LADDM)

    OpenAIRE

    Wang, Jian(PRISMA Cluster of Excellence & Mainz Institute for Theoretical Physics, Johannes Gutenberg University, D-55099, Mainz, Germany); Wang, Haowen; Wu, Chao

    2015-01-01

    It can be greatly beneficial to remove the swashplate of conventional helicopter, because the swashplate is usually complicated, aerodynamically resistive, and obstacle of more complex pitch control for improving performance. The present technologies for helicopter vibration reduction are usually narrow in effective range or requiring additional actuators and signal transfer links, and more effective technology is desired. Helicopter blade pitch control system, which is removed of swashplate ...

  5. Comprehensive aeroelastic analysis of helicopter rotor with trailing-edge flap for primary control and vibration control

    Science.gov (United States)

    Shen, Jinwei

    A comprehensive aeroelastic analytical model of helicopter rotors with trailing-edge flaps for primary and vibration controls has been developed. The derivation of system equations is based on Hamilton principles, and implemented with finite element method in space and time. The blade element consists of fifteen degrees of freedom representing blade flap, lag, torsional, and axial deformations. Three aerodynamic models of flapped airfoils were implemented in the present analysis, the unsteady Hariharan-Leishman model for trailing-edge flaps without aerodynamic balance, a quasi-steady Theodorsen theory for an aerodynamic balanced trailing-edge flap, and table lookup based on wind tunnel test data. The trailing-edge flap deflections may be modeled as a degree of freedom so that the actuator dynamics can be captured properly. The coupled trim procedures for swashplateless rotor are solved in either wind tunnel trim or free flight condition. A multicyclic controller is also implemented to calculate the flap control inputs for minimization of vibratory rotor hub loads. The coupled blade equations of motion are linearized by using small perturbations about a steady trimmed solution. The aeroelastic stability characteristics of trailing-edge flap rotors is then determined from an eigenanalysis of the homogeneous equations using Floquet method. The correlation studies of a typical bearingless rotor and an ultralight teetering rotor are respectively based on wind tunnel test data and simulations of another comprehensive analysis (CAMRAD II). Overall, good correlations are obtained. Parametric study identifies that the effect of actuator dynamics cannot be neglected, especially for a torsionally soft smart actuator system. Aeroelastic stability characteristics of a trailing-edge flap rotor system are shown to be sensitive to flap aerodynamic and mass balances. Key parameters of trailing-edge flap system for primary rotor control are identified as blade pitch index angle

  6. Prospect of ultralight airplanes development

    OpenAIRE

    Adam KONICZEK; Robert KONIECZKA

    2015-01-01

    The article presents characteristic of ultralight airplanes, rules and current interest of them. The purpose is to determine prospect of ultralight airplanes development on the basis of Civil Aviation Authority statistics analysis and trend of aviation market.

  7. Prospect of ultralight airplanes development

    Directory of Open Access Journals (Sweden)

    Adam KONICZEK

    2015-09-01

    Full Text Available The article presents characteristic of ultralight airplanes, rules and current interest of them. The purpose is to determine prospect of ultralight airplanes development on the basis of Civil Aviation Authority statistics analysis and trend of aviation market.

  8. Investigation into the aerodynamics of swashplateless rotors using CFD-CSD analysis

    Science.gov (United States)

    Jose, Arun Isaac

    This study obtains a better understanding of the aerodynamics of integrated trailing edge flap (TEF) based swashplateless rotors. Both two dimensional (2D) and three dimensional (3D) analysis/simulations are performed to understand the behavior of TEF airfoils and integrated TEF based swashplateless rotors. The 2D aerodynamics of TEF airfoils is explored in detail. A semi-empirical approach is developed for modeling drag for TEF airfoils in steady flows based on baseline airfoil drag data alone. Extensive 2D CFD simulations are performed for a wide range of flow conditions in order to better understand various aspects of the aerodynamics of TEF airfoils. The trends in the airloads (lift, drag, pitching moment, hinge moment) for TEF airfoils are obtained. Nonlinear phenomena such as flow separation, shocks and unsteady vortex shedding are investigated, and the flow conditions and trends associated with them are studied. The effect of airfoil properties such as thickness and overhang are studied. Various approaches are used to model the effect of gaps at the leading edge of the flap. An approximate "gap averaging" technique is developed, which provides good predictions of steady airloads at almost the same computational cost as a simulation where the gap is not modeled. Direct modeling of the gap is done by using a patched mesh in the gap region. To solve problems (such as poor grid quality/control and poor convergence) that are associated with the patched mesh simulations, an alternate approach using overlapping meshes is used. It is seen that for TEF airfoils, the presence of gaps adversely affects the effectiveness of the flap. The change in airloads is not negligible, especially at the relatively higher flap deflections associated with swashplateless TEF rotors. Finally, uncoupled and coupled computational fluid/structural dynamics (CFD-CSD) simulations of conventional (baseline) and swashplateless TEF rotors is performed in hovering flight. The CFD-CSD code is

  9. Ultralight Magnesium-Lithium Alloys

    OpenAIRE

    A. Białobrzeski; K. Saja; Hubner, K.

    2007-01-01

    The article gives basic information on the chief constituents of Mg-Li alloys and on their expected properties. A schematic representation and technical performance of a pilot stand for melting and pouring of reactive ultralight magnesium-based alloys have been presented. The preliminary data regarding the manufactured magnesium alloys with about 2-3 % Li and about 10 % Li have been given in the form of microstructures and chemical compositions.

  10. Primary control of a Mach scale swashplateless rotor using brushless DC motor actuated trailing edge flaps

    Science.gov (United States)

    Saxena, Anand

    The focus of this research was to demonstrate a four blade rotor trim in forward flight using integrated trailing edge flaps instead of using a swashplate controls. A compact brushless DC motor was evaluated as an on-blade actuator, with the possibility of achieving large trailing edge flap amplitudes. A control strategy to actuate the trailing edge flap at desired frequency and amplitude was developed and large trailing edge flap amplitudes from the motor (instead of rotational motion) were obtained. Once the actuator was tested on the bench-top, a lightweight mechanism was designed to incorporate the motor in the blade and actuate the trailing edge flaps. A six feet diameter, four bladed composite rotor with motor-flap system integrated into the NACA 0012 airfoil section was fabricated. Systematic testing was carried out for a range of load conditions, first in the vacuum chamber followed by hover tests. Large trailing edge flap deflections were observed during the hover testing, and a peak to peak trailing edge flap amplitude of 18 degree was achieved at 2000 rotor RPM with hover tip Mach number of 0.628. A closed loop controller was designed to demonstrate trailing edge flap mean position and the peak to peak amplitude control. Further, a soft pitch link was designed and fabricated, to replace the stiff pitch link and thereby reduce the torsional stiffness of the blade to 2/rev. This soft pitch link allowed for blade root pitch motion in response to the trailing edge flap inputs. Blade pitch response due to both steady as well as sinusoidal flap deflections were demonstrated. Finally, tests were performed in Glenn L. Martin wind tunnel using a model rotor rig to assess the performance of motor-flap system in forward flight. A swashplateless trim using brushless DC motor actuated trailing edge flaps was achieved for a rotor operating at 1200 RPM and an advance ratio of 0.28. Also, preliminary exploration was carried out to test the scalability of the motor

  11. Helicopter controllability

    OpenAIRE

    Carico, Dean

    1989-01-01

    Approved for public release; distribution is unlimited The concept of helicopter controllability is explained. A background study reviews helicopter development in the U.S. General helicopter configurations, linearized equations of motion, stability, and piloting requirements are discussed. Helicopter flight controls, handling qualities, and associated specification are reviewed. Analytical, simulation and flight test methods for evaluating helicopter automatic flight control systems ar...

  12. Ultra-Light Asymmetric Photovoltaic Sandwich Structures

    OpenAIRE

    Rion, J.; Leterrier, Y.; Månson, J.-A. E.; Blairon, Jean-Marie

    2009-01-01

    This work evaluated the possibility of using silicon solar cells as load-carrying elements in composite sandwich structures. Such an ultra-light multifunctional structure is a new concept enabling weight, and thus energy, to be saved in high-tech applications such as solar cars, solar planes or satellites. Composite sandwich structures with a weight of not, vert, similar800 g/m2 were developed, based on one 140 μm thick skin made of 0/90° carbon fiber-reinforced plastic (CFRP), one skin made ...

  13. 14 CFR 61.69 - Glider and unpowered ultralight vehicle towing: Experience and training requirements.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Glider and unpowered ultralight vehicle... GROUND INSTRUCTORS Aircraft Ratings and Pilot Authorizations § 61.69 Glider and unpowered ultralight... a glider or unpowered ultralight vehicle unless that person— (1) Holds a private, commercial or...

  14. Perturbations of ultralight vector field dark matter

    CERN Document Server

    Cembranos, J A R; Jareño, S J Núñez

    2016-01-01

    We study the dynamics of cosmological perturbations in models of dark matter based on ultralight coherent vector fields. Very much as for scalar field dark matter, we find two different regimes in the evolution: for modes with $k^2\\ll {\\cal H}ma$, we have a particle-like behaviour indistinguishable from cold dark matter, whereas for modes with $k^2\\gg {\\cal H}ma$, we get a wave-like behaviour in which the sound speed is non-vanishing and of order $c_s^2\\simeq k^2/m^2a^2$. This implies that, also in these models, structure formation could be suppressed on small scales. However, unlike the scalar case, the fact that the background evolution contains a non-vanishing homogeneous vector field implies that, in general, the evolution of the three kinds of perturbations (scalar, vector and tensor) can no longer be decoupled at the linear level. More specifically, in the particle regime, the three types of perturbations are actually decoupled, whereas in the wave regime, the three vector field perturbations generate o...

  15. Brief History of Ultra-light Scalar Dark Matter Models

    Directory of Open Access Journals (Sweden)

    Lee Jae-Weon

    2018-01-01

    dark matter, BEC dark matter, wave dark matter, or ultra-light axion. In this model ultra-light scalar dark matter particles with mass m = O(10-22eV condense in a single Bose-Einstein condensate state and behave collectively like a classical wave. Galactic dark matter halos can be described as a self-gravitating coherent scalar field configuration called boson stars. At the scale larger than galaxies the dark matter acts like cold dark matter, while below the scale quantum pressure from the uncertainty principle suppresses the smaller structure formation so that it can resolve the small scale crisis of the conventional cold dark matter model.

  16. Brief History of Ultra-light Scalar Dark Matter Models

    OpenAIRE

    Lee Jae-Weon

    2018-01-01

    This is a review on the brief history of the scalar field dark matter model also known as fuzzy dark matter, BEC dark matter, wave dark matter, or ultra-light axion. In this model ultra-light scalar dark matter particles with mass m = O(10-22)eV condense in a single Bose-Einstein condensate state and behave collectively like a classical wave. Galactic dark matter halos can be described as a self-gravitating coherent scalar field configuration called boson stars. At the scale larger than ga...

  17. Brief History of Ultra-light Scalar Dark Matter Models

    OpenAIRE

    Lee Jae-Weon

    2018-01-01

    This is a review on the brief history of the scalar field dark matter model also known as fuzzy dark matter, BEC dark matter, wave dark matter, or ultra-light axion. In this model ultra-light scalar dark matter particles with mass $m = O(10^{-22})eV$ condense in a single Bose-Einstein condensate state and behave collectively like a classical wave. Galactic dark matter halos can be described as a self-gravitating coherent scalar field configuration called boson stars. At the scale larger than ...

  18. Brief History of Ultra-light Scalar Dark Matter Models

    OpenAIRE

    Lee, Jae-Weon

    2017-01-01

    This is an ongoing review on the brief history of the scalar field dark matter model also known as fuzzy dark matter, BEC dark matter, wave dark matter, or ultra-light axion. In this model ultra-light scalar dark matter particles with mass $m = O(10^{-22})eV$ condense in a single Bose-Einstein condensate state and behave collectively like a classical wave. Galactic dark matter halos can be described as a self-gravitating coherent scalar field configuration called boson stars. At the scale lar...

  19. HELICOPTER ROTOR DESIGN

    Directory of Open Access Journals (Sweden)

    IONESCU Cristian Andrei

    2011-06-01

    Full Text Available The objective of this paper is to analyze the role of helicopter rotor, to classify them by type, and to imagine new types of helicopter rotors that can equip future helicopters. Finally, the author shows a coaxial rotor 3D model such a best alternative to equip the new helicopters.

  20. Helicopter Aeromechanics

    Science.gov (United States)

    1985-04-01

    34, NASA TN D-1548, October 1982. 1975. 96. SHEEHY T.W., "A General Review of Helicopter 113. GALLOT J., "Am6lioration du bilan propulsif Rotor Hub Drag...bearingless rotor (CBR). The rotor used a flat flexbeam of carbon -epoxy, and a torque rod behind the flexbeam. A cantilever torque rod configuration...and low stress) with a midchord torque rod. A damper, consisting of an elastomeric layer bonded to the flex- beam and covered by a stiff carbon fiber

  1. Light propagation in an ultra-light dark matter medium

    CERN Document Server

    Frias Perez, Miguel

    2017-01-01

    In this notes four different ultra-light dark matter backgrounds are studied using classical fields theories. Light propagation is considered in all four, and anomalous propagation is found in all of them. In this context, we can constrain the nature of one of the models, millicharged particles.

  2. Development of an Ultra-Light Multipurpose Drill and Tooling for the Transportable Array in Alaska

    Science.gov (United States)

    Coyle, B. J.; Lundgren, M.; Busby, R. W.

    2014-12-01

    Over the next four years the EarthScope Transportable Array (TA) will install approximately 250 to 275 broadband seismic stations in Alaska and Western Canada. The station plans build on recent developments in posthole broadband seismometer design and call for sensors to be installed in boreholes 7 inches diameter, from 1 to 5 meters deep. These boreholes will be lined with PVC or steel casing, grouted in place. The proposed station locations are in a grid-like pattern with a nominal spacing of 85 km. Since most of these locations will only be accessible by helicopter, it was necessary to develop an ultra-light drilling system that could be transported to site in one sling load by a high performance light helicopter (i.e. AS350B2 or Bell 407) and still be able to drill the variety of ground conditions we expect to encounter. In the past year we have developed a working prototype, gasoline-hydraulic drill rig that can be configured to run auger, diamond core or DTH tools, and weighs <1,300 lbs, including tooling. We have successfully drilled over 30 boreholes with this drill, including 12 for TA installations in Alaska and 13 at the Piñon Flat Observatory for testing sensor performance and placement techniques. Our drilling solution comprises: - Hydraulic system using a variable flow pump with on-demand load sensing valves to reduce the engine size needed and to cut down on heat build-up; - Rotation head mounting system on the travelling block to enable quick change of drilling tools; - Low speed, high torque rotation head for the auger, and an anchoring system that enables us to apply up to 5,000 lbs downforce for augering in permafrost; - Custom DTH that can run on low air pressure and air flow, yet is still robust enough to drill a 7 inch hole 2.5 meters through solid rock; - One-trip casing advance drilling with the DTH, steel casing is loaded at the start of drilling and follows the drill bit down; - Grout-through bottom caps for sealing the borehole casing

  3. Brief History of Ultra-light Scalar Dark Matter Models

    Science.gov (United States)

    Lee, Jae-Weon

    2018-01-01

    This is a review on the brief history of the scalar field dark matter model also known as fuzzy dark matter, BEC dark matter, wave dark matter, or ultra-light axion. In this model ultra-light scalar dark matter particles with mass m = O(10-22)eV condense in a single Bose-Einstein condensate state and behave collectively like a classical wave. Galactic dark matter halos can be described as a self-gravitating coherent scalar field configuration called boson stars. At the scale larger than galaxies the dark matter acts like cold dark matter, while below the scale quantum pressure from the uncertainty principle suppresses the smaller structure formation so that it can resolve the small scale crisis of the conventional cold dark matter model.

  4. Ultralight Radar for Small and Micro-Uav Navigation

    Science.gov (United States)

    Scannapieco, A. F.; Renga, A.; Fasano, G.; Moccia, A.

    2017-08-01

    This paper presents a radar approach to navigation of small and micro Unmanned Aerial Vehicles (UAV) in environments challenging for common sensors. A technique based on radar odometry is briefly explained and schemes for complete integration with other sensors are proposed. The focus of the paper is set on ultralight radars and interpretation of outputs of such sensor when dealing with autonomous navigation in complex scenario. The experimental setup used to analyse the proposed approach comprises one multi-rotor UAV and one ultralight commercial radar. Results from flight tests in which both forward-only motion and mixed motion are presented and analysed, providing a reference for understanding outputs of radar in complex scenarios. The radar odometry solution is compared with ground truth provided by GPS sensor.

  5. ULTRALIGHT RADAR FOR SMALL AND MICRO-UAV NAVIGATION

    Directory of Open Access Journals (Sweden)

    A. F. Scannapieco

    2017-08-01

    Full Text Available This paper presents a radar approach to navigation of small and micro Unmanned Aerial Vehicles (UAV in environments challenging for common sensors. A technique based on radar odometry is briefly explained and schemes for complete integration with other sensors are proposed. The focus of the paper is set on ultralight radars and interpretation of outputs of such sensor when dealing with autonomous navigation in complex scenario. The experimental setup used to analyse the proposed approach comprises one multi-rotor UAV and one ultralight commercial radar. Results from flight tests in which both forward-only motion and mixed motion are presented and analysed, providing a reference for understanding outputs of radar in complex scenarios. The radar odometry solution is compared with ground truth provided by GPS sensor.

  6. DESIGN AND ANALYSIS OF WING OF AN ULTRALIGHT AIRCRAFT

    OpenAIRE

    Sarath Raj N. S*, Chithirai Pon Selvan M, Michael G. Bseliss

    2017-01-01

    This paper deals with the structural design and analysis of high wing of an ultralight aircraft. The wing design involves its initial considerations like planform selection, location to the aircraft and the structural design involves the design calculations for the selection of airfoil, area of the wing, wing loading characteristics and weight of the wing. The design is done corresponding to the calculated values with the help of designing software ANSYS FLUENT.

  7. ULTRALIGHT RADAR FOR SMALL AND MICRO-UAV NAVIGATION

    OpenAIRE

    A. F. Scannapieco; A. Renga; Fasano, G.; A. Moccia

    2017-01-01

    This paper presents a radar approach to navigation of small and micro Unmanned Aerial Vehicles (UAV) in environments challenging for common sensors. A technique based on radar odometry is briefly explained and schemes for complete integration with other sensors are proposed. The focus of the paper is set on ultralight radars and interpretation of outputs of such sensor when dealing with autonomous navigation in complex scenario. The experimental setup used to analyse the proposed app...

  8. Ultra-Light Overhead Conveyor Systems for Logistics Applications

    OpenAIRE

    Batin Latif Aylak; Bernd Noche

    2013-01-01

    Overhead conveyor systems satisfy by their simple construction, wide application range and their full compatibility with other manufacturing systems, which are designed according to international standards. Ultra-light overhead conveyor systems are rope-based conveying systems with individually driven vehicles. The vehicles can move automatically on the rope and this can be realized by energy and signals. Crossings are realized by switches. Overhead conveyor systems are p...

  9. Direct Detection of Ultralight Dark Matter via Astronomical Ephemeris

    OpenAIRE

    Fukuda, Hajime; Matsumoto, Shigeki; Yanagida, Tsutomu T.

    2018-01-01

    A novel idea of the direct detection to search for a ultralight dark matter based on the interaction between the dark matter and a nucleon is proposed. Solar system bodies feel the dark matter wind and it acts as a resistant force opposing their motions. The astronomical ephemeris of solar system bodies is so precise that it has a strong capability to detect a dark matter whose mass is much lighter than O(1) eV. We have estimated the resistant force based on the calculation of the elastic sca...

  10. Forecasting LSST Sensitivity to Ultra-Light Dark Matter Axions

    Science.gov (United States)

    Trott, Emery; Grin, Daniel

    2018-01-01

    Axions are proposed dark matter particles whose effects have yet to be measured by the current generation of telescopes. With the Large Synoptic Survey Telescope (LSST) planning to start its scientific mission in 2021 we focus on the sensitivity of LSST to the cosmological effects of axions via measurements of galaxy clustering. By using axionCAMB to compute the effects that axions have on the matter power spectrum at high wavenumbers and taking into account the specifications of LSST we forecast constraints on the axion energy density over a wide range of ultra-light axion masses.

  11. Small Business Innovations (Helicopters)

    Science.gov (United States)

    1992-01-01

    The amount of engine power required for a helicopter to hover is an important, but difficult, consideration in helicopter design. The EHPIC program model produces converged, freely distorted wake geometries that generate accurate analysis of wake-induced downwash, allowing good predictions of rotor thrust and power requirements. Continuum Dynamics, Inc., the Small Business Innovation Research (SBIR) company that developed EHPIC, also produces RotorCRAFT, a program for analysis of aerodynamic loading of helicopter blades in forward flight. Both helicopter codes have been licensed to commercial manufacturers.

  12. Ultralight axion in supersymmetry and strings and cosmology at small scales

    Science.gov (United States)

    Halverson, James; Long, Cody; Nath, Pran

    2017-09-01

    Dynamical mechanisms to generate an ultralight axion of mass ˜10-21- 10-22 eV in supergravity and strings are discussed. An ultralight particle of this mass provides a candidate for dark matter that may play a role for cosmology at scales of 10 kpc or less. An effective operator approach for the axion mass provides a general framework for models of ultralight axions, and in one case recovers the scale 10-21- 10-22 eV as the electroweak scale times the square of the hierarchy with an O (1 ) Wilson coefficient. We discuss several classes of models realizing this framework where an ultralight axion of the necessary size can be generated. In one class of supersymmetric models an ultralight axion is generated by instanton-like effects. In the second class higher-dimensional operators involving couplings of Higgs, standard model singlets, and axion fields naturally lead to an ultralight axion. Further, for the class of models considered the hierarchy between the ultralight scale and the weak scale is maintained. We also discuss the generation of an ultralight scale within string-based models. In the single-modulus Kachru-Kallosh-Linde-Trivedi moduli stabilization scheme an ultralight axion would require an ultralow weak scale. However, within the large volume scenario, the desired hierarchy between the axion scale and the weak scale is achieved. A general analysis of couplings of Higgs fields to instantons within the string framework is discussed and it is shown that the condition necessary for achieving such couplings is the existence of vector-like zero modes of the instanton. Some of the phenomenological aspects of these models are also discussed.

  13. Ultralight Weight Optical Systems Using Nano-Layered Synthesized Materials

    Science.gov (United States)

    Clark, Natalie; Breckinridge, James

    2014-01-01

    Optical imaging is important for many NASA science missions. Even though complex optical systems have advanced, the optics, based on conventional glass and mirrors, require components that are thick, heavy and expensive. As the need for higher performance expands, glass and mirrors are fast approaching the point where they will be too large, heavy and costly for spacecraft, especially small satellite systems. NASA Langley Research Center is developing a wide range of novel nano-layered synthesized materials that enable the development and fabrication of ultralight weight optical device systems that enable many NASA missions to collect science data imagery using small satellites. In addition to significantly reducing weight, the nano-layered synthesized materials offer advantages in performance, size, and cost.

  14. Requirements for a Hydrogen Powered All-Electric Manned Helicopter

    Science.gov (United States)

    Datta, Anubhav

    2012-01-01

    The objective of this paper is to set propulsion system targets for an all-electric manned helicopter of ultra-light utility class to achieve performance comparable to combustion engines. The approach is to begin with a current two-seat helicopter (Robinson R 22 Beta II-like), design an all-electric power plant as replacement for its existing piston engine, and study performance of the new all-electric aircraft. The new power plant consists of high-pressure Proton Exchange Membrane fuel cells, hydrogen stored in 700 bar type-4 tanks, lithium-ion batteries, and an AC synchronous permanent magnet motor. The aircraft and the transmission are assumed to remain the same. The paper surveys the state of the art in each of these areas, synthesizes a power plant using best available technologies in each, examines the performance achievable by such a power plant, identifies key barriers, and sets future technology targets to achieve performance at par with current internal combustion engines.

  15. 78 FR 65180 - Airworthiness Directives; MD Helicopters, Inc., Helicopters

    Science.gov (United States)

    2013-10-31

    ..., 369H, 369HE, 369HM, 369HS, 369F and 369FF helicopters with certain MDHI or Helicopter Technology... the paint. This new AD retains some of the requirements of AD 2003-08-51 and also requires paint... ; Web site http://www.mdhelicopters.com or contact Helicopter Technology Company, 12923 South Spring...

  16. CAS, interdiction, and attack helicopters

    OpenAIRE

    Groenke, Andrew S.

    2005-01-01

    Within days of a major failed strike by attack helicopters during Operation Iraqi Freedom (OIF) analysts were questioning the value of such platforms on the modern battlefield. As OIF moved from combat to stability operations, helicopter losses from enemy action actually increased seemingly strengthening the argument of those who see the helicopter as unsuitable to some combat operations. Attack helicopter operations have diverged into two distinct categories, interdiction and close air sup...

  17. Development of ultralight, super-elastic, hierarchical metallic meta-structures with i3DP technology

    Science.gov (United States)

    Zhang, Dongxing; Xiao, Junfeng; Moorlag, Carolyn; Guo, Qiuquan; Yang, Jun

    2017-11-01

    Lightweight and mechanically robust materials show promising applications in thermal insulation, energy absorption, and battery catalyst supports. This study demonstrates an effective method for creation of ultralight metallic structures based on initiator-integrated 3D printing technology (i3DP), which provides a possible platform to design the materials with the best geometric parameters and desired mechanical performance. In this study, ultralight Ni foams with 3D interconnected hollow tubes were fabricated, consisting of hierarchical features spanning three scale orders ranging from submicron to centimeter. The resultant materials can achieve an ultralight density of as low as 5.1 mg cm-3 and nearly recover after significant compression up to 50%. Due to a high compression ratio, the hierarchical structure exhibits superior properties in terms of energy absorption and mechanical efficiency. The relationship of structural parameters and mechanical response was established. The ability of achieving ultralight density indicates an advantage over the previous stochastic metal foams. Overall, this initiator-integrated 3D printing approach provides metallic structures with substantial benefits from the hierarchical design and fabrication flexibility to ultralight applications.

  18. Search for Ultralight Scalar Dark Matter with Atomic Spectroscopy.

    Science.gov (United States)

    Van Tilburg, Ken; Leefer, Nathan; Bougas, Lykourgos; Budker, Dmitry

    2015-07-03

    We report new limits on ultralight scalar dark matter (DM) with dilatonlike couplings to photons that can induce oscillations in the fine-structure constant α. Atomic dysprosium exhibits an electronic structure with two nearly degenerate levels whose energy splitting is sensitive to changes in α. Spectroscopy data for two isotopes of dysprosium over a two-year span are analyzed for coherent oscillations with angular frequencies below 1  rad s-1. No signal consistent with a DM coupling is identified, leading to new constraints on dilatonlike photon couplings over a wide mass range. Under the assumption that the scalar field comprises all of the DM, our limits on the coupling exceed those from equivalence-principle tests by up to 4 orders of magnitude for masses below 3×10(-18)  eV. Excess oscillatory power, inconsistent with fine-structure variation, is detected in a control channel, and is likely due to a systematic effect. Our atomic spectroscopy limits on DM are the first of their kind, and leave substantial room for improvement with state-of-the-art atomic clocks.

  19. Potential Environmental Benefits of Ultralight Particleboards with Biobased Foam Cores

    Directory of Open Access Journals (Sweden)

    Christelle Ganne-Chédeville

    2015-01-01

    Full Text Available A new generation of ultralight particleboards (ULPB with an expanded foam core layer produced in an in-line foaming step is under development. The environmental impacts of three types of ULPB containing foam based on 100% polylactic acid (PLA, 100% expanded polystyrene, and 50% PLA/50% polymethyl methacrylate, as well as a conventional particleboard (PB, have been compared in an LCA. Two approaches were chosen for the assessment: first, the “EPD-approach” in accordance with EN 15804 for EPD of building materials and second, a holistic-approach which allows an expansion of the system boundaries in order to forecast the consequences of a broader replacement of PB with ULPB. The results show that most of the environmental impacts are related to raw materials and end-of-life stages. Both approaches show that the exchange of PB with ULPB with a foam core based on PLA leads to a reduction of greenhouse gas emissions. On the other hand, the PLA is responsible for higher ecotoxicity results in comparison to non-bio-based polymers mainly due to agricultural processes. Both approaches allowed the drafting of complementary advisories for environmental impact reduction addressed to the developers.

  20. Ultralight Linerless Composite Tanks for In-Space Applications

    Science.gov (United States)

    Mallick, Kaushik; Cronin, John; Tupper, Michael L.; Grimes-Ledesma, Lorie; Lewis, Joseph C.; Paul, Chris; Welsh, Jeffrey S.

    2004-01-01

    NASA missions are becoming increasingly more demanding of propulsion capability, driving the mass of propulsion systems higher, even as the science mass of electronics is reduced. Typically, the propulsion tank is the single largest highest dry mass item of an in-space propulsion system. Ultralight linerless composite tanks (ULLCTs) promise to achieve the efficiencies that will make future propulsion systems viable and minimize propulsion system mass growth. ULLCTS may offer up to a 25 percent weight reduction compared to conventional metal lined composite overwrapped tanks, allowing increased reactant storage and/or reduced launch mass. For successful design of such a tank, the composite shell itself is required to provide an integral impermeable barrier, in addition to carrying the pressure and environmental loads for in-space propulsion. Significant materials technologies are required to achieve the microcrack resistance of the composites in order to contain small molecule gases such as helium (He). The goal is to develop a material that can limit the leakage rate of gaseous He to 10(exp -4) scc/sec at 1% biaxial strain level. The current paper details an integrated systematic approach to developing novel composite materials that can meet such performance requirements. It also explains how micromechanical models and material testing can be combined to define material performance indicators critical for designing an ULLCT, such as the material's resistance to microcracking and permeability.

  1. Ultra-light duct for an anechoic wind tunnel

    Science.gov (United States)

    Lambourion, J.; Lewy, S.; Papirnyk, O.; Rahier, G.; Remandet, J.-N.

    1989-01-01

    A tunnel ultra-light (or TUL) is a duct composed of acoustically transparent cloth designed to transform an open-jet wind tunnel into a closed-jet wind tunnel. This concept is of interest (a priori) for anechoic wind tunnels because it improves the aerodynamic quality without hindering the measurement of sound in the far field. A full scale device designed for the 3 m diameter test section of CEPRA 19 was described. The apparatus installation did not develop any significant problems, and the mechanical support turned out to be excellent. Aerodynamic and acoustic tests are discussed. Certain imperfections in the installation as tested - instabilities above 25 m/s and acceptable cloth transmission up to 4kHz were revealed. The system as tested could eventually be used in certain applications, for example, in ground based transport. However, the concept of TUL must be developed further to arrive at a reliable mechanism for use in a large number of applications.

  2. First star formation in ultralight particle dark matter cosmology

    Science.gov (United States)

    Hirano, Shingo; Sullivan, James M.; Bromm, Volker

    2018-01-01

    The formation of the first stars in the high-redshift Universe is a sensitive probe of the small-scale, particle physics nature of dark matter (DM). We carry out cosmological simulations of primordial star formation in ultralight, axion-like particle DM cosmology, with masses of 10-22 and 10-21 eV, with de Broglie wavelengths approaching galactic scales (∼ kpc). The onset of star formation is delayed, and shifted to more massive host structures. For the lightest DM particle mass explored here, first stars form at z ∼ 7 in structures with ∼109 M⊙, compared to the standard minihalo environment within the Λ cold dark matter (ΛCDM) cosmology, where z ∼ 20-30 and ∼105-106 M⊙. Despite this greatly altered DM host environment, the thermodynamic behaviour of the metal-free gas as it collapses into the DM potential well asymptotically approaches a very similar evolutionary track. Thus, the fragmentation properties are predicted to remain the same as in ΛCDM cosmology, implying a similar mass scale for the first stars. These results predict intense starbursts in the axion cosmologies, which may be amenable to observations with the James Webb Space Telescope.

  3. Ultralight anisotropic foams from layered aligned carbon nanotube sheets

    Science.gov (United States)

    Faraji, Shaghayegh; L. Stano, Kelly; Yildiz, Ozkan; Li, Ang; Zhu, Yuntian; Bradford, Philip D.

    2015-10-01

    In this work, we present large scale, ultralight aligned carbon nanotube (CNT) structures which have densities an order of magnitude lower than CNT arrays, have tunable properties and exhibit resiliency after compression. By stacking aligned sheets of carbon nanotubes and then infiltrating with a pyrolytic carbon (PyC), resilient foam-like materials were produced that exhibited complete recovery from 90% compressive strain. With density as low as 3.8 mg cm-3, the foam structure is over 500 times less dense than bulk graphite. Microscopy revealed that PyC coated the junctions among CNTs, and also increased CNT surface roughness. These changes in the morphology explain the transition from inelastic behavior to foam-like recovery of the layered CNT sheet structure. Mechanical and thermal properties of the foams were tuned for different applications through variation of PyC deposition duration while dynamic mechanical analysis showed no change in mechanical properties over a large temperature range. Observation of a large and linear electrical resistance change during compression of the aligned CNT/carbon (ACNT/C) foams makes strain/pressure sensors a relevant application. The foams have high oil absorption capacities, up to 275 times their own weight, which suggests they may be useful in water treatment and oil spill cleanup. Finally, the ACNT/C foam's high porosity, surface area and stability allow for demonstration of the foams as catalyst support structures.In this work, we present large scale, ultralight aligned carbon nanotube (CNT) structures which have densities an order of magnitude lower than CNT arrays, have tunable properties and exhibit resiliency after compression. By stacking aligned sheets of carbon nanotubes and then infiltrating with a pyrolytic carbon (PyC), resilient foam-like materials were produced that exhibited complete recovery from 90% compressive strain. With density as low as 3.8 mg cm-3, the foam structure is over 500 times less dense than

  4. Gravitational wave searches for ultralight bosons with LIGO and LISA

    Science.gov (United States)

    Brito, Richard; Ghosh, Shrobana; Barausse, Enrico; Berti, Emanuele; Cardoso, Vitor; Dvorkin, Irina; Klein, Antoine; Pani, Paolo

    2017-09-01

    Ultralight bosons can induce superradiant instabilities in spinning black holes, tapping their rotational energy to trigger the growth of a bosonic condensate. Possible observational imprints of these boson clouds include (i) direct detection of the nearly monochromatic (resolvable or stochastic) gravitational waves emitted by the condensate, and (ii) statistically significant evidence for the formation of "holes" at large spins in the spin versus mass plane (sometimes also referred to as "Regge plane") of astrophysical black holes. In this work, we focus on the prospects of LISA and LIGO detecting or constraining scalars with mass in the range ms∈[10-19,10-15] eV and ms∈[10-14,10-11] eV , respectively. Using astrophysical models of black-hole populations calibrated to observations and black-hole perturbation theory calculations of the gravitational emission, we find that, in optimistic scenarios, LIGO could observe a stochastic background of gravitational radiation in the range ms∈[2 ×10-13,10-12] eV , and up to 1 04 resolvable events in a 4-year search if ms˜3 ×10-13 eV . LISA could observe a stochastic background for boson masses in the range ms∈[5 ×10-19,5 ×10-16], and up to ˜103 resolvable events in a 4-year search if ms˜10-17 eV . LISA could further measure spins for black-hole binaries with component masses in the range [103,107]M⊙, which is not probed by traditional spin-measurement techniques. A statistical analysis of the spin distribution of these binaries could either rule out scalar fields in the mass range ˜[4 ×10-18,10-14] eV , or measure ms with ten percent accuracy if light scalars in the mass range ˜[10-17,10-13] eV exist.

  5. Unbiased constraints on ultralight axion mass from dwarf spheroidal galaxies

    Science.gov (United States)

    González-Morales, Alma X.; Marsh, David J. E.; Peñarrubia, Jorge; Ureña-López, Luis A.

    2017-12-01

    It has been suggested that the internal dynamics of dwarf spheroidal galaxies (dSphs) can be used to test whether or not ultralight axions with ma ˜ 10-22 eV are a preferred dark matter candidate. However, comparisons to theoretical predictions tend to be inconclusive for the simple reason that while most cosmological models consider only dark matter, one observes only baryons. Here, we use realistic kinematic mock data catalogues of Milky Way (MW) dSph's to show that the `mass-anisotropy degeneracy' in the Jeans equations leads to biased bounds on the axion mass in galaxies with unknown dark matter halo profiles. In galaxies with multiple chemodynamical components, this bias can be partly removed by modelling the mass enclosed within each subpopulation. However, analysis of the mock data reveals that the least-biased constraints on the axion mass result from fitting the luminosity-averaged velocity dispersion of the individual chemodynamical components directly. Applying our analysis to two dSph's with reported stellar subcomponents, Fornax and Sculptor, and assuming that the halo profile has not been acted on by baryons, yields core radii rc > 1.5 and 1.2 kpc, respectively, and ma < 0.4 × 10-22 eV at 97.5 per cent confidence. These bounds are in tension with the number of observed satellites derived from simple (but conservative) estimates of the subhalo mass function in MW-like galaxies. We discuss how baryonic feedback might affect our results, and the impact of such a small axion mass on the growth of structures in the Universe.

  6. Alien plant monitoring with ultralight airborne imaging spectroscopy.

    Directory of Open Access Journals (Sweden)

    María Calviño-Cancela

    Full Text Available Effective management of invasive plants requires a precise determination of their distribution. Remote sensing techniques constitute a promising alternative to field surveys and hyperspectral sensors (also known as imaging spectrometers, with a large number of spectral bands and high spectral resolution are especially suitable when very similar categories are to be distinguished (e.g. plant species. A main priority in the development of this technology is to lower its cost and simplify its use, so that its demonstrated aptitude for many environmental applications can be truly realized. With this aim, we have developed a system for hyperspectral imaging (200 spectral bands in the 380-1000 nm range and circa 3 nm spectral resolution operated on board ultralight aircraft (namely a gyrocopter, which allows a drastic reduction of the running costs and operational complexity of image acquisition, and also increases the spatial resolution of the images (circa 5-8 pixels/m(2 at circa 65 km/h and 300 m height. The detection system proved useful for the species tested (Acacia melanoxylon, Oxalis pes-caprae, and Carpobrotus aff. edulis and acinaciformis, with user's and producer's accuracy always exceeding 90%. The detection accuracy reported corresponds to patches down to 0.125 m(2 (50% of pixels 0.5 × 0.5 m in size, a very small size for many plant species, making it very effective for initial stages of invasive plant spread. In addition, its low operating costs, similar to those of a 4WD ground vehicle, facilitate frequent image acquisition. Acquired images constitute a permanent record of the status of the study area, with great amount of information that can be analyzed in the future for other purposes, thus greatly facilitating the monitoring of natural areas at detailed spatial and temporal scales for improved management.

  7. Ultralight, Flexible, and Semi-Transparent Metal Oxide Papers for Photoelectrochemical Water Splitting

    DEFF Research Database (Denmark)

    Zhang, Minwei; Hou, Chengyi; Halder, Arnab

    2017-01-01

    ) papers, serving as a sacrificial template, to design and synthesize two-dimensional (2D) layered and free-standing MO papers with ultrafine nanostructures. Physicochemical characterizations showed that these MO materials are nanostructured, porous, flexible, and ultralight. The as-synthesized materials...... that the synthesis method is generally valid for many earth-abundant transition metals including copper, nickel, iron, cobalt, and manganese....

  8. Improvement of hang glider performance by use of ultralight elastic wing

    Science.gov (United States)

    Wolf, J. S.

    1979-01-01

    The problem of the lateral controllability of the hang glider by the pilot's weight shift was considered. The influence of the span and the torsional elasticity of the wing was determined. It was stated that an ultralight elastic wing of a new kind was most suitable for good control. The wing also has other advantageous properties.

  9. Helicopter visual aid system

    Science.gov (United States)

    Baisley, R. L.

    1973-01-01

    The helicopter visual aid system has been built and flight tested in situations representative of actual flight missions. The mechanisms discussed contributed greatly to the successful performance of the system throughout the 160 hours of flight testing. It has demonstrated that the visual aid concept can provide improved daytime visual capability, greatly improved nighttime capability, surveillance from greater distances and/or altitudes, covert operation at night through the use of the IR searchlight, and a photographic recording at the scene being viewed.

  10. 76 FR 10489 - Special Conditions: Bell Helicopter Textron Canada Limited Model 407 Helicopter, Installation of...

    Science.gov (United States)

    2011-02-25

    ... control functions, since this model helicopter has been certificated to meet the applicable requirements... Federal Aviation Administration 14 CFR Part 27 Special Conditions: Bell Helicopter Textron Canada Limited Model 407 Helicopter, Installation of a Hoh Aeronautics, Inc. Autopilot/ Stabilization Augmentation...

  11. The Autonomous Helicopter System

    Science.gov (United States)

    Gilmore, John F.

    1984-06-01

    This paper describes an autonomous airborne vehicle being developed at the Georgia Tech Engineering Experiment Station. The Autonomous Helicopter System (AHS) is a multi-mission system consisting of three distinct sections: vision, planning and control. Vision provides the local and global scene analysis which is symbolically represented and passed to planning as the initial route planning constraints. Planning generates a task dependent path for the vehicle to traverse which assures maximum mission system success as well as safety. Control validates the path and either executes the given route or feeds back to previous sections in order to resolve conflicts.

  12. Ultralight three-dimensional boron nitride foam with ultralow permittivity and superelasticity.

    Science.gov (United States)

    Yin, Jun; Li, Xuemei; Zhou, Jianxin; Guo, Wanlin

    2013-07-10

    Dielectrics with ultralow permittivity within 2 times that of air, excellent mechanical performance, and high thermal stability are highly attractive to many applications. However, since the finding of silica aerogels in the 1930s, no alternative ultralight porous dielectric with density below 10 mg/cm(3) has been developed. Here we present three-dimensional hierarchical boron nitride foam with permittivity of 1.03 times that of air, density of 1.6 mg/cm(3), and thermal stability up to 1200 °C obtained by chemical vapor deposition on a nickel foam template. This BN foam exhibits complete recovery after cyclic compression exceeding 70% with permittivity within 1.12 times that of air. Gathering all these exceptional characters, the BN foam should create a breakthrough development of flexible ultralow-permittivity dielectrics and ultralight materials.

  13. Teaching migration routes to canada geese and trumpeter swans using ultralight aircraft, 1990-2001

    Science.gov (United States)

    Sladen, William J. L.; Lishman, W.A.; Ellis, D.H.; Shire, G.G.; Rininger, D.L.; Rees, Eileen C.; Earnst, Susan L.; Coulson, John C.

    2002-01-01

    This paper summarizes eleven years (1990-2001) of experiments to teach Canada Geese (Branta canadensis) and Trumpeter Swans (Cygnus buccinator) pre-selected migration routes using ultralight aircraft. When Canada Geese were trained to follow an ultralight aircraft for southward autumn migrations of 680 or 1,320 km, 81% (83/103) returned on their own in the next spring to near their place of training. In contrast, none returned of 21 similarly raised geese that were transported south in a closed truck over a route of 680 km. Trumpeter Swans have proven more difficult to train. However, in two experiments in which Trumpeter Swans followed an ultralight for the entire pre-selected route, one of three and two of four returned close to their training area. A stage-by-stage method, in which swans were transported in trucks between stops, flown in the vicinity and penned with a view of the night sky, has shown some promise. So far an established migration route (north and south twice) has been confirmed in only two geese

  14. Modeling, Control and Coordination of Helicopter Systems

    CERN Document Server

    Ren, Beibei; Chen, Chang; Fua, Cheng-Heng; Lee, Tong Heng

    2012-01-01

    Modeling, Control and Coordination of Helicopter Systems provides a comprehensive treatment of helicopter systems, ranging from related nonlinear flight dynamic modeling and stability analysis to advanced control design for single helicopter systems, and also covers issues related to the coordination and formation control of multiple helicopter systems to achieve high performance tasks. Ensuring stability in helicopter flight is a challenging problem for nonlinear control design and development. This book is a valuable reference on modeling, control and coordination of helicopter systems,providing readers with practical solutions for the problems that still plague helicopter system design and implementation. Readers will gain a complete picture of helicopters at the systems level, as well as a better understanding of the technical intricacies involved. This book also: Presents a complete picture of modeling, control and coordination for helicopter systems Provides a modeling platform for a general class of ro...

  15. Vertebral pain in helicopter pilots

    Science.gov (United States)

    Auffret, R.; Delahaye, R. P.; Metges, P. J.; VICENS

    1980-01-01

    Pathological forms of spinal pain engendered by piloting helicopters were clinically studied. Lumbalgia and pathology of the dorsal and cervical spine are discussed along with their clinical and radiological signs and origins.

  16. 41 CFR 302-7.20 - If my HHG shipment includes an item (e.g., boat, trailer, ultralight vehicle) for which a weight...

    Science.gov (United States)

    2010-07-01

    ... includes an item (e.g., boat, trailer, ultralight vehicle) for which a weight additive is assessed by the...) General Rules § 302-7.20 If my HHG shipment includes an item (e.g., boat, trailer, ultralight vehicle) for... shipment includes an item (e.g., boat or trailer of reasonable size) for which a weight additive is...

  17. Investigating Flight with a Toy Helicopter

    Science.gov (United States)

    Liebl, Michael

    2010-01-01

    Flight fascinates people of all ages. Recent advances in battery technology have extended the capabilities of model airplanes and toy helicopters. For those who have never outgrown a childhood enthusiasm for the wonders of flight, it is possible to buy inexpensive, remotely controlled planes and helicopters. A toy helicopter offers an opportunity…

  18. Assessing Conventional Army Demands and Requirements for Ultra-Light Tactical Mobility

    Science.gov (United States)

    2015-01-01

    hitch with a receiver mount pintle hook and a two inch ball combination SAE J1924 (ROPS) SAE J1924 (ROPS)Roll Over Protection (KPP) 300 feet below sea...Vietnam,” Tropic Lightning News, undated. 45 U.S. Army, Motorbike Evaluation Interim Report MASSTER Test No. 1034, 1972. 46 U.S. Army, 1972. 47 Ben...Press, 2002. 160 Assessing Conventional Army Demands and Requirements for Ultra-Light Tactical Mobility Ramsey, Kirk, “Tropic Lightning News, 25th

  19. Aerodynamic Bio-Mimetics of Gliding Dragonflies for Ultra-Light Flying Robot

    Directory of Open Access Journals (Sweden)

    Akira Obata

    2014-05-01

    Full Text Available A detailed investigation including a low-speed flow study is presented on the development of ultra-light dragonfly mimetic flying robots with a focus on the dragonfly’s remarkable gliding capability. It is revealed that the dragonfly’s corrugated wing structure and cruciform configuration provide superior flying characteristics for fixed wing robots in low Reynolds number flight. It was also found that the dragonfly configuration has additional merit in its compatibility with propellers or high lift devices. This combination with such classic aero-engineering makes possible robots with broader flight envelope than conventional fixed-wing flying robots.

  20. 77 FR 12991 - Airworthiness Directives; Robinson Helicopter Company Helicopters

    Science.gov (United States)

    2012-03-05

    ... Airplane Directorate, FAA, 3960 Paramount Blvd., Lakewood, CA 90712; telephone (562) 627-5348; email [email protected] (regarding Model R22 helicopters); or Fred Guerin, Aerospace Engineer, Los Angeles Aircraft Certification Office, Transport Airplane Directorate, FAA, 3960 Paramount Blvd., Lakewood, CA...

  1. 78 FR 27867 - Airworthiness Directives; MD Helicopters Inc. Helicopters

    Science.gov (United States)

    2013-05-13

    ... Helicopter Technology Company (HTC) tail rotor blades installed. The existing AD currently requires reducing... been detected under the paint. This proposed AD would retain some of the requirements in the existing AD but would require paint removal for all pitch horn inspections, inspecting for pitting and the...

  2. 78 FR 45845 - Airworthiness Directives; Bell Helicopter Textron Helicopters

    Science.gov (United States)

    2013-07-30

    ..., corrosion (may be indicated by blistering, peeling, flaking, bubbling, or cracked paint), a nick, scratch... helicopter. (iv) If any blistering, peeling, flaking, bubbling, or cracked paint is detected anywhere on the blade, remove the paint from the affected area by sanding in a spanwise direction with abrasive cloth or...

  3. Ultralight Graphene Foam/Conductive Polymer Composites for Exceptional Electromagnetic Interference Shielding.

    Science.gov (United States)

    Wu, Ying; Wang, Zhenyu; Liu, Xu; Shen, Xi; Zheng, Qingbin; Xue, Quan; Kim, Jang-Kyo

    2017-03-15

    Ultralight, high-performance electromagnetic interference (EMI) shielding graphene foam (GF)/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) composites are developed by drop coating of PEDOT:PSS on cellular-structured, freestanding GFs. To enhance the wettability and the interfacial bonds with PEDOT:PSS, GFs are functionalized with 4-dodecylbenzenesulfonic acid. The GF/PEDOT:PSS composites possess an ultralow density of 18.2 × 10 -3 g/cm 3 and a high porosity of 98.8%, as well as an enhanced electrical conductivity by almost 4 folds from 11.8 to 43.2 S/cm after the incorporation of the conductive PEDOT:PSS. Benefiting from the excellent electrical conductivity, ultralight porous structure, and effective charge delocalization, the composites deliver remarkable EMI shielding performance with a shielding effectiveness (SE) of 91.9 dB and a specific SE (SSE) of 3124 dB·cm 3 /g, both of which are the highest among those reported in the literature for carbon-based polymer composites. The excellent electrical conductivities of composites arising from both the GFs with three-dimensionally interconnected conductive networks and the conductive polymer coating, as well as the left-handed composites with absolute permittivity and/or permeability larger than one give rise to significant microwave attenuation by absorption.

  4. Experimental Study of Ultralight (<300 kg/m3 Foamed Concrete

    Directory of Open Access Journals (Sweden)

    Xianjun Tan

    2014-01-01

    Full Text Available A type of ultralight (<300 kg/m3 foamed concrete (FC, which can be used as a new energy-conservation and environmental-protection building material and is particularly suitable for the thermal-insulation engineering of building external walls, was produced. The influences of different mixing amounts of fly ash, fly ash activator, WC (WC ratio, and foaming agent (FA on the compressive strength of FC were reported. The experimental study indicated that (1 the addition of fly ash reduced the strength of the FC and that the appropriate mixing amount of fly ash in this ultralight FC system should not exceed 45%; (2 with the increasing of fly ash activator, the strength of the FC sample is notably enhanced and the appropriate mixing amount of fly ash activator is 2.5%; (3 the optimized proportion of WC ratio is 0.45, and the FC that was produced according to this proportion has relatively high compressive strength; (4 by increasing the mixing amount of FA, the compressive strength of the FC notably decreases, and the optimal mixing amount of FA in this experiment is 3.5%.

  5. Smart actuation for helicopter rotorblades

    NARCIS (Netherlands)

    Paternoster, Alexandre; Loendersloot, Richard; de Boer, Andries; Akkerman, Remko; Berselli, G.; Vertechy, R.; Vassura, G.

    2012-01-01

    Successful rotorcrafts were only achieved when the differences between hovering flight conditions and a stable forward flight were understood. During hovering, the air speed on all helicopter blades is linearly distributed along each blade and is the same for each. However, during forward flight,

  6. Helicopter Toy and Lift Estimation

    Science.gov (United States)

    Shakerin, Said

    2013-01-01

    A $1 plastic helicopter toy (called a Wacky Whirler) can be used to demonstrate lift. Students can make basic measurements of the toy, use reasonable assumptions and, with the lift formula, estimate the lift, and verify that it is sufficient to overcome the toy's weight. (Contains 1 figure.)

  7. Helicopter-Ship Qualification Testing

    NARCIS (Netherlands)

    Hoencamp, A.

    2015-01-01

    The goal of this research project is to develop a novel test methodology which can be used for optimizing cost and time efficiency of helicopter-ship qualification testing without reducing safety. For this purpose, the so-called “SHOL-X” test methodology has been established, which includes the

  8. Helicopter detection and classification demonstrator

    NARCIS (Netherlands)

    Koersel, A.C. van

    2000-01-01

    A technology demonstrator that detects and classifies different helicopter types automatically, was developed at TNO-FEL. The demonstrator is based on a PC, which receives its acoustic input from an all-weather microphone. The demonstrator uses commercial off-the-shelf hardware to digitize the

  9. Anticipatory routing of police helicopters

    NARCIS (Netherlands)

    van Urk, Rick; van Urk, Rick; Mes, Martijn R.K.; Hans, Elias W.

    2013-01-01

    We have developed a decision support application for the Dutch Aviation Police and Air Support unit for routing their helicopters in anticipation of unknown future incidents. These incidents are not known in advance, yet do require a swift response. A response might include the dispatch of a police

  10. 76 FR 2607 - Airworthiness Directives; MD Helicopters, Inc. (MDHI) Model MD900 Helicopters

    Science.gov (United States)

    2011-01-14

    ... MDHI Model MD900 helicopters. That AD currently requires turning on both Vertical Stabilizer Control... Stability Augmentation System (YSAS) for the Model 500N and 600N helicopters and to the VSCS for the Model... also requires turning ON both VSCS switches to reduce pilot workload and to help control the helicopter...

  11. Use of ultralight aircraft for material location and road surveys in remote rural areas

    CSIR Research Space (South Africa)

    Jones, DJ

    2006-10-01

    Full Text Available photographs and maps are often not available. The best method available to conduct the various types of survey is thus by helicopter or fixed wing aircraft, although the higher speeds of fixed wing aircraft typically render this option unsuitable... for certain functions. However, the costs of operating helicopters and fixed wing aircraft are very expensive and thus they are usually only used in the initial stages of projects for the basic surveys and thereafter all work is done from the ground...

  12. Predicting Constraints on Ultra-Light Axion Parameters due to LSST Observations

    Science.gov (United States)

    Given, Gabriel; Grin, Daniel

    2018-01-01

    Ultra-light axions (ULAs) are a type of dark matter or dark energy candidate (depending on the mass) that are predicted to have a mass between $10^{‑33}$ and $10^{‑18}$ eV. The Large Synoptic Survey Telescope (LSST) is expected to provide a large number of weak lensing observations, which will lower the statistical uncertainty on the convergence power spectrum. I began work with Daniel Grin to predict how accurately the data from the LSST will be able to constrain ULA properties. I wrote Python code that takes a matter power spectrum calculated by axionCAMB and converts it to a convergence power spectrum. My code then takes derivatives of the convergence power spectrum with respect to several cosmological parameters; these derivatives will be used in Fisher Matrix analysis to determine the sensitivity of LSST observations to axion parameters.

  13. THE ACCURACY OF AUTOMATIC PHOTOGRAMMETRIC TECHNIQUES ON ULTRA-LIGHT UAV IMAGERY

    Directory of Open Access Journals (Sweden)

    O. Küng

    2012-09-01

    Full Text Available This paper presents an affordable, fully automated and accurate mapping solutions based on ultra-light UAV imagery. Several datasets are analysed and their accuracy is estimated. We show that the accuracy highly depends on the ground resolution (flying height of the input imagery. When chosen appropriately this mapping solution can compete with traditional mapping solutions that capture fewer high-resolution images from airplanes and that rely on highly accurate orientation and positioning sensors on board. Due to the careful integration with recent computer vision techniques, the post processing is robust and fully automatic and can deal with inaccurate position and orientation information which are typically problematic with traditional techniques.

  14. Development of Ultra-Light 2-Axes Sun Sensor for Small Satellite

    Directory of Open Access Journals (Sweden)

    Su-jeoung Kim

    2005-03-01

    Full Text Available This paper addresses development of the ultra-light analog sun sensors for small satellite applications. The sun sensor is suitable for attitude determination for small satellite because of its small, light, low-cost, and low power consumption characteristics. The sun sensor is designed, manufactured and characteristic-tested with the target requirements of ±60° FOV (Field of View and pointing accuracy of ±2°. Since the sun sensor has nonlinear characteristics between output measurement voltage and incident angle of sunlight, a higher order calibration equation is required for error correction. The error was calculated by using a polynomial calibration equation that was computed by the least square method obtained from the measured voltages vs. angles characteristics. Finally, the accuracies of 1-axis and 2-axes sun sensors, which consist of 2 detectors, are compared.

  15. Development of Ultra-Light Composite Material to Build the Platform of a Shaking Table

    Directory of Open Access Journals (Sweden)

    Botero-Jaramillo Eduardo

    2013-10-01

    Full Text Available Based on the developments of the last decades in the area of ultra-light materials, their application in the construction of the platform of the new one direction hydrau- lic shaking table was proposed, with capacity of one ton and frequency range from 0.4 Hz to 4.0 Hz for the Geotechnical Laboratory of the Institute of Engineering, UNAM. The aim was to replace the heavy conventional steel platforms, used in shaking tables, by a composite material based on wood and Kevlar, hence reducing its weight and optimizing the hydraulic equipment capacity available in the labora- tory. Accordingly, an experimental investigation was conducted to characterize the stress-strain behavior of composite materials under monotonically increasing load. This research involved the determination of the adequate proportions of the different constituent materials and manufacturing techniques that best suit the needs and available resources.

  16. Flow bench testing of prototype intake manifolds for ultralight aircraft engine

    Directory of Open Access Journals (Sweden)

    Swiatek Piotr

    2017-01-01

    Full Text Available The article describes the research on the intake manifold for ultralight aircraft engine Vaxell 100i. It presents the actual and new redesigned manifold construction and points out the design requirements. The results of previously made numerical simulation of air flow inside the manifold are discussed. Computer analysis confirmed the appropriateness of internal guide vanes usage to improve the uniform air distribution between cylinders. For verification, a flow bench test stand was made for multicylinder intake manifold testing. A prototype manifold was built with the possibility of guide vane adjustment. The best variant had almost 5 times better uniformity of air distribution comparing to variant without the guide vane. Flow bench results confirmed the conclusions from numerical simulations.

  17. Helicopter location and tracking using seismometer recordings

    Science.gov (United States)

    Eibl, Eva P. S.; Lokmer, Ivan; Bean, Christopher J.; Akerlie, Eggert

    2017-05-01

    We use frequency domain methods usually applied to volcanic tremor to analyse ground based seismic recordings of a helicopter. We preclude misinterpretations of tremor sources and show alternative applications of our seismological methods. On a volcano, the seismic source can consist of repeating, closely spaced, small earthquakes. Interestingly, similar signals are generated by helicopters due to repeating pressure pulses from the rotor blades. In both cases the seismic signals are continuous and referred to as tremor. As frequency gliding is in this case merely caused by the Doppler effect, not a change in the source, we can use its shape to deduce properties of the helicopter and its flight path. We show in this analysis that the number of rotor blades, rotor revolutions per minute, helicopter speed, flight direction, altitude and location can be deduced from seismometer recordings. Access to GPS determined flight path data from the helicopter offers us a robust way to test our location method.

  18. Ultralight electrospun cellulose sponge with super-high capacity on absorption of organic compounds.

    Science.gov (United States)

    Xu, Tao; Wang, Zhao; Ding, Yichun; Xu, Wenhui; Wu, Weidong; Zhu, Zhengtao; Fong, Hao

    2018-01-01

    Three-dimensional, cost-effective, and renewable/recyclable absorbent materials with high capacities on absorption of organic compounds are urgently in demand. Herein, a facile while innovative approach is reported to develop ultralight electrospun cellulose sponge (UECS). The prepared UECS exhibits super-high absorption capacity (up to 232 times of its own weight) towards absorption of organic compounds due to high porosity (99.57%), low density (6.45mg/cm3), and hydrophobic surface feature (with water contact angle of 141.2°). Furthermore, the UECS is mechanically robust thus can be readily cut into different shapes; and it also possesses excellent stability against various organic compounds. Intriguingly, upon absorption of an organic compound, the shape-stable UECS organic gel can be formed. Hence, the developed UECS would be promising as environmental friendly absorbent on high-performance separation of organic compounds from aqueous systems; while the UECS organic gel could be utilized for the applications such as drug delivery and sensor. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Ultralight and Flexible Polyurethane/Silver Nanowire Nanocomposites with Unidirectional Pores for Highly Effective Electromagnetic Shielding.

    Science.gov (United States)

    Zeng, Zhihui; Chen, Mingji; Pei, Yongmao; Seyed Shahabadi, Seyed Ismail; Che, Boyang; Wang, Peiyu; Lu, Xuehong

    2017-09-20

    Flexible waterborne polyurethane (WPU)/silver nanowire (AgNW) nanocomposites with unidirectionally aligned micrometer-sized pores are fabricated using a facile freeze-drying process, and their dimensions, densities, and AgNW contents are easily controllable. The high-aspect-ratio AgNWs are well-dispersed in the nanocomposite cell walls, giving the nanocomposites good compression strength and excellent electrical conductivity even at very low densities. The large conductivity mismatch between the AgNWs and WPU also induces substantial interfacial polarization that benefits the absorption of electromagnetic (EM) waves, whereas the aligned cell walls promote multireflections of the waves in the porous architectures, further facilitating the absorption. The synergistic actions of the AgNWs, WPU, and unidirectionally aligned pores lead to ultrahigh EM shielding performance. The X-band shielding effectiveness (SE) of the nanocomposites is 64 and 20 dB at the densities of merely 45 and 8 mg/cm(3), respectively, and ultrahigh surface specific SE of ∼1087 dB cm(3)/(g mm) is achieved with only 0.027 vol % AgNWs, demonstrating that they are promising ultralight, flexible, mechanically robust, high-performance EM shielding materials.

  20. Mechanical response of ultralight nickel kagomé structure to compression

    Science.gov (United States)

    Rajak, Pankaj; Kalia, Rajiv; Nakano, Aiichiro; Vashishta, Priya

    Deformation behavior of an ultralight architecture consisting of hollow Ni nanotubes and solid nanorods arranged as a 3-D kagomé structure is studied using Molecular dynamics simulations. As a precursor, we have also investigated mechanical response of a single hollow Ni nanotube and nanorod under uniaxial compression. We observe that 1/6(112) Shockley partial dislocations and twin formation at 3.5% compression collapse the nanotube and nanorod. Kagomé structure made from solid nanorods shows deformation both near the node of kagomé lattice and the eight beams connected to it for compression above 5%. In the case of hollow nanotube architecture, most of the deformation is observed near the node of the kagomé structure for strains higher than 6%. At 8% and 12.5% compression, we observe plastic buckling of solid and hollow architecture, respectively. Hence hollow nanotube architecture can withstand much larger compression with very little deformation of the system than the solid nanorod architecture. The deformation in all these systems is caused by 1/6(112) Shockley partial and 1/2(110) dislocations. This research supported by the Department of Energy Grant: DE-FG02-04ER 46130.

  1. STUDY ON SAFETY TECHNOLOGY SCHEME OF THE UNMANNED HELICOPTER

    Directory of Open Access Journals (Sweden)

    Z. Lin

    2013-08-01

    Full Text Available Nowadays the unmanned helicopter is widely used for its' unique strongpoint, however, the high failure rate of unmanned helicopter seriously limits its further application and development. For solving the above problems, in this paper, the reasons for the high failure rate of unmanned helicopter is analyzed and the corresponding solution schemes are proposed. The main problem of the failure cause of the unmanned helicopter is the aircraft engine fault, and the failure cause of the unmanned helicopter is analyzed particularly. In order to improving the safety performance of unmanned helicopter system, the scheme of adding the safety parachute system to the unmanned helicopter system is proposed and introduced. These schemes provide the safety redundancy of the unmanned helicopter system and lay on basis for the unmanned helicopter applying into residential areas.

  2. Helicopter Urban Navigation Training Using Virtual Environments

    National Research Council Canada - National Science Library

    Wright, George

    2000-01-01

    .... Navigation is a means to an end. Helicopter operations, being inherently expensive and unforgiving of mistakes, are prime candidates for such innovative training techniques as virtual (3-D) fly-throughs...

  3. Helicopter Flight Procedures for Community Noise Reduction

    Science.gov (United States)

    Greenwood, Eric

    2017-01-01

    A computationally efficient, semiempirical noise model suitable for maneuvering flight noise prediction is used to evaluate the community noise impact of practical variations on several helicopter flight procedures typical of normal operations. Turns, "quick-stops," approaches, climbs, and combinations of these maneuvers are assessed. Relatively small variations in flight procedures are shown to cause significant changes to Sound Exposure Levels over a wide area. Guidelines are developed for helicopter pilots intended to provide effective strategies for reducing the negative effects of helicopter noise on the community. Finally, direct optimization of flight trajectories is conducted to identify low noise optimal flight procedures and quantify the magnitude of community noise reductions that can be obtained through tailored helicopter flight procedures. Physically realizable optimal turns and approaches are identified that achieve global noise reductions of as much as 10 dBA Sound Exposure Level.

  4. Small crack test program for helicopter materials

    Science.gov (United States)

    Annigeri, Bal; Schneider, George

    1994-01-01

    Crack propagation tests were conducted to determine crack growth behavior in five helicopter materials for surface cracks between 0.005 to 0.020 inches in depth. Constant amplitude tests were conducted at stress ratios R equals 0.1 and 0.5, and emphasis was placed on near threshold data (i.e., 10-8 to 10-6 inches/cycle). Spectrum tests were conducted using a helicopter spectrum. The test specimen was an unnotched tension specimen, and cracks were initiated from a small EDM notch. An optical/video system was used to monitor crack growth. The material for the test specimens was obtained from helicopter part forgings. Testing was conducted at stresses below yield to reflect actual stresses in helicopter parts.

  5. Tail Rotor Airfoils Stabilize Helicopters, Reduce Noise

    Science.gov (United States)

    2010-01-01

    Founded by former Ames Research Center engineer Jim Van Horn, Van Horn Aviation of Tempe, Arizona, built upon a Langley Research Center airfoil design to create a high performance aftermarket tail rotor for the popular Bell 206 helicopter. The highly durable rotor has a lifetime twice that of the original equipment manufacturer blade, reduces noise by 40 percent, and displays enhanced performance at high altitudes. These improvements benefit helicopter performance for law enforcement, military training, wildfire and pipeline patrols, and emergency medical services.

  6. Development of helicopter engine seals

    Science.gov (United States)

    Lynwander, P.

    1973-01-01

    An experimental evaluation of main shaft seals for helicopter gas turbine engines was conducted with shaft speeds to 213 m/s(700 ft/sec), air pressures to 148 N/sq cm (215 psia), and air temperatures to 645 K (675 F). Gas leakage test results indicate that conventional seals will not be satisfactory for high-pressure sealing because of excessive leakage. The self-acting face seal, however, had significantly lower leakage and operated with insignificant wear during a 150-hour endurance test at sliding speeds to 145 m/s (475 ft/sec), air pressures to 124 N/sq cm (180 psia), and air temperatures to 408 K (275 F). Wear measurements indicate that noncontact operation was achieved at shaft speeds of 43,000 rpm. Evaluation of the self-acting circumferential seal was inconclusive because of seal dimensional variations.

  7. Progress in helicopter infrared signature suppression

    Directory of Open Access Journals (Sweden)

    Zhang Jingzhou

    2014-04-01

    Full Text Available Due to their low-attitude and relatively low-speed fight profiles, helicopters are subjected to serious threats from radio, infrared (IR, visual, and aural detection and tracking. Among these threats, infrared detection and tracking are regarded as more crucial for the survivability of helicopters. In order to meet the requirements of infrared stealth, several different types of infrared suppressor (IRS for helicopters have been developed. This paper reviews contemporary developments in this discipline, with particular emphasis on infrared signature suppression, advances in mixer-ejectors and prediction for helicopters. In addition, several remaining challenges, such as advanced IRS, emissivity optimization technique, helicopter infrared characterization, etc., are proposed, as an initial guide and stimulation for future research. In the future, the comprehensive infrared suppression in the 3–5 μm and 8–14 μm bands will doubtfully become the emphasis of helicopter stealth. Multidisciplinary optimization of a complete infrared suppression system deserves further investigation.

  8. Ultra-light weight undamped tuned dynamic absorber for cryogenically cooled infrared electro-optic payload

    Science.gov (United States)

    Veprik, Alexander; Babitsky, Vladimir

    2017-04-01

    Attenuation of tonal cryocooler induced vibration in infrared electro-optical payloads may be achieved by using of Tuned Dynamic Absorber (TDA) which is, generally speaking, a passive, weakly damped mass-spring system the resonant frequency of which is precisely matched with the driving frequency. Added TDA results in a favorable modification of the frequency response functions of combined structure. In particular, a favorable antiresonant notch appears at the frequency of tonal excitation along with the adjacent secondary resonance, the width and depth of which along with its closeness to the secondary resonance are strongly dependent on the mass and damping ratios. Using heavier TDA favorably results in wider and deeper antiresonant notch along with increased gap between antiresonant and resonant frequencies. Lowering damping in TDA favorably results in deepening the antiresonant notch. The weight of TDA is usually subjected to tight design constrains. Use of lightweight TDA not only diminishes the attainable performance but also complicates the procedure of frequency matching. Along these lines, even minor frequency deviations may negate the TDA performance and even result in TDA failure in case of resonant build up. The authors are presenting theoretical and practical aspects of designing and constructing ultra-light weight TDA in application to vibration attenuation of electro-optical infrared payload relying on Split Stirling linear cryocooler, the driving frequency of which is fixed and may be accurately tuned and maintained using a digital controller over the entire range of working conditions and lifetime; the lack of mass ratio is compensated by minimizing the damping ratio. In one particular case, in excess of 100-fold vibration attenuation has been achieved by adding as little as 5% to the payload weight.

  9. Helicopter Rotor Blade Monitoring using Autonomous Wireless Sensor Network

    NARCIS (Netherlands)

    Sanchez Ramirez, Andrea; Loendersloot, Richard; Tinga, Tiedo; Basu, B.

    2013-01-01

    The advancement on Wireless Sensor Networks for vibration monitoring presents important possibilities for helicopter rotor health and usage monitoring. While main rotor blades account for the main source of lift for helicopters, rotor induced vibration establishes an important source for

  10. Examining the stability derivatives of a compound helicopter

    OpenAIRE

    Ferguson, Kevin; Thomson, Douglas

    2017-01-01

    Some helicopter manufacturers are exploring the compound helicopter design as it could potentially satisfy the new emerging requirements placed on the next generation of rotorcraft. It is well understood that the main benefit of the compound helicopter is its ability to reach speeds that significantly surpass the conventional helicopter. However, it is possible that the introduction of compounding may lead to a vehicle with significantly different flight characteristics when compared to a con...

  11. Does Helicopter Emergency Care Service Improve Blunt Trauma Mortality

    Science.gov (United States)

    1991-01-01

    NUMBERS Does Helicopter Emergency Care Service Improve Blunt Trauma Mortality 6. AUTHOR(S) Kenneth Duane Oefinger, Major 7. PERFORMING ORGANIZATION NAME...8217 = ’:" ’ _’ -. " 9 DOES HELICOPTER EMERGENCY CARE SE,’RV-E . IMPROVE BLUNT TRAUMA MORTALITY BY Major Kenneth Duane Oefina, USAF NC 4991 38 ,-ages Masters of...helicopter should be dispatched. This would allow for the monitoring of effective utilization of the hospital service. DOES HELICOPTER EMERGENCY CARE SERVICE

  12. 77 FR 18965 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2012-03-29

    ... Directives; Eurocopter France Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice... Eurocopter France Model SA341G helicopters. This proposed AD is prompted by an analysis and tests performed... 26, 2004, to correct an unsafe condition for Eurocopter France Model SA 341/342 helicopters. The DGAC...

  13. 78 FR 18230 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-03-26

    ... new airworthiness directive (AD) for Eurocopter France (Eurocopter) Model EC130 B4 helicopters with a... proposed to amend 14 CFR part 39 to include an AD that would apply to Eurocopter Model EC130 B4 helicopters...), to correct an unsafe condition for the Eurocopter Model EC130 B4 helicopter. EASA advises of a...

  14. 77 FR 43738 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2012-07-26

    ... EC130 B4 helicopters with a cabin vibration damper installed. This proposed AD is prompted by a crack... condition for Eurocopter Model EC130 B4 helicopters. EASA advises of a cracked cabin vibration damper blade...) Applicability This AD applies to Model EC130 B4 helicopters with a cabin vibration damper installed, except...

  15. Evolution of civil aeromedical helicopter aviation.

    Science.gov (United States)

    Meier, D R; Samper, E R

    1989-07-01

    The rapid increase in the use of helicopters for hospital transport during the 1980s is the culmination of several hundred years of military medical innovation. Mass battefield casualties spurred both technologic and medical changes necessary for today's sophisticated helicopter systems in use worldwide, particularly in the United States. The Napoleonic Era and the American Civil War provided the framework for the evolution of today's state-of-the-art emergency medical techniques. The use of airplanes to evacuate the wounded eventually led to using helicopters for rescue missions in World War II. The combat experiences of the United States in Korea, the British in Malaya, and the French in Indochina proved that rotary-wing aircraft were invaluable in reducing battlefield death rates. Any skepticism about the efficacy of helicopter medical evacuation was erased during the Vietnam conflict. As an integral part of the modern battlefield, these specialized aircraft became a necessity. The observations and experience of American servicemen and medical personnel in Vietnam established the foundation for the acceptance of helicopter transport in modern hospital systems.

  16. Helicopter industry - early beginnings to now; an outlook on the helicopter market and its major players in the rotorcraft industry

    NARCIS (Netherlands)

    Spranger, L.

    2013-01-01

    The helicopter is probably the most flexible aircraft that we know today. Although its history dates back to around 1500, the first practical helicopter wasn’t manufactured until the 1940s, roughly three decades after the Wright brothers’ first powered human flight. Today, helicopters fulfil a wide

  17. Simulation of Flow around Isolated Helicopter Fuselage

    Directory of Open Access Journals (Sweden)

    Garipov A.O.

    2013-04-01

    Full Text Available Low fuselage drag has always been a key target of helicopter manufacturers. Therefore, this paper focuses on CFD predictions of the drag of several components of a typical helicopter fuselage. In the first section of the paper, validation of the obtained CFD predictions is carried out using wind tunnel measurements. The measurements were carried out at the Kazan National Research Technical University n.a. A. Tupolev. The second section of the paper is devoted to the analysis of drag contributions of several components of the ANSAT helicopter prototype fuselage using the RANS approach. For this purpose, several configurations of fuselages are considered with different levels of complexity including exhausts and skids. Depending on the complexity of the considered configuration and CFD mesh both the multi-block structured HMB solver and the unstructured commercial tool Fluent are used. Finally, the effect of an actuator disk on the predicted drag is addressed.

  18. MITEE: A Compact Ultralight Nuclear Thermal Propulsion Engine for Planetary Science Missions

    Science.gov (United States)

    Powell, J.; Maise, G.; Paniagua, J.

    2001-01-01

    A new approach for a near-term compact, ultralight nuclear thermal propulsion engine, termed MITEE (Miniature Reactor Engine) is described. MITEE enables a wide range of new and unique planetary science missions that are not possible with chemical rockets. With U-235 nuclear fuel and hydrogen propellant the baseline MITEE engine achieves a specific impulse of approximately 1000 seconds, a thrust of 28,000 newtons, and a total mass of only 140 kilograms, including reactor, controls, and turbo-pump. Using higher performance nuclear fuels like U-233, engine mass can be reduced to as little as 80 kg. Using MITEE, V additions of 20 km/s for missions to outer planets are possible compared to only 10 km/s for H2/O2 engines. The much greater V with MITEE enables much faster trips to the outer planets, e.g., two years to Jupiter, three years to Saturn, and five years to Pluto, without needing multiple planetary gravity assists. Moreover, MITEE can utilize in-situ resources to further extend mission V. One example of a very attractive, unique mission enabled by MITEE is the exploration of a possible subsurface ocean on Europa and the return of samples to Earth. Using MITEE, a spacecraft would land on Europa after a two-year trip from Earth orbit and deploy a small nuclear heated probe that would melt down through its ice sheet. The probe would then convert to a submersible and travel through the ocean collecting samples. After a few months, the probe would melt its way back up to the MITEE lander, which would have replenished its hydrogen propellant by melting and electrolyzing Europa surface ice. The spacecraft would then return to Earth. Total mission time is only five years, starting from departure from Earth orbit. Other unique missions include Neptune and Pluto orbiter, and even a Pluto sample return. MITEE uses the cermet Tungsten-UO2 fuel developed in the 1960's for the 710 reactor program. The W-UO2 fuel has demonstrated capability to operate in 3000 K hydrogen for

  19. Efficient fault diagnosis of helicopter gearboxes

    Science.gov (United States)

    Chin, H.; Danai, K.; Lewicki, D. G.

    1993-01-01

    Application of a diagnostic system to a helicopter gearbox is presented. The diagnostic system is a nonparametric pattern classifier that uses a multi-valued influence matrix (MVIM) as its diagnostic model and benefits from a fast learning algorithm that enables it to estimate its diagnostic model from a small number of measurement-fault data. To test this diagnostic system, vibration measurements were collected from a helicopter gearbox test stand during accelerated fatigue tests and at various fault instances. The diagnostic results indicate that the MVIM system can accurately detect and diagnose various gearbox faults so long as they are included in training.

  20. 75 FR 62639 - Air Ambulance and Commercial Helicopter Operations, Part 91 Helicopter Operations, and Part 135...

    Science.gov (United States)

    2010-10-12

    .... Helicopter air medical transportation was first used prominently during the Korean War to move injured... Drug and Alcohol Testing Program, and would therefore not be required to undergo drug testing...

  1. Equipment for pre-hospital airway management on Helicopter Emergency Medical System helicopters in central Europe.

    Science.gov (United States)

    Schmid, M; Schüttler, J; Ey, K; Reichenbach, M; Trimmel, H; Mang, H

    2011-05-01

    For advanced out-of-hospital airway management, skilled personnel and adequate equipment are key prerequisites. There are little data on the current availability of airway management equipment and standards of medical staff on Helicopter Emergency Medical System (HEMS) helicopters in central Europe. An internet search identified all HEMS helicopters in Austria, Switzerland and Luxembourg. We identified 15 HEMS helicopter bases in Switzerland, 28 in Austria and three in Luxembourg. A questionnaire was sent to all bases, asking both for the details of the clinical background and experience of participating staff, and details of airway management equipment carried routinely on board. Replies were received from 14 helicopter bases in Switzerland (93%), 25 bases in Austria (89%) and all three bases in Luxembourg. Anaesthesiologists were by far the most frequent attending physicians (68-85%). All except one bases reported to have at least one alternative supraglottic airway device. All bases had capnometry and succinylcholine. All bases in the study except two in Austria had commercial pre-packed sets for a surgical airway. All helicopters were equipped with automatic ventilators, although not all were suitable for non-invasive ventilation (NIV; Switzerland: 43%, Austria: 12%, Luxembourg: 100%). Masks for NIV were rarely available in Switzerland (two bases; 14%) and in Austria (three bases; 12%), whereas all three bases in Luxembourg carried those masks. Most HEMS helicopters carry appropriate equipment to meet the demands of modern advanced airway management in the pre-hospital setting. Further work is needed to ensure that appropriate airway equipment is carried on all HEMS helicopters.

  2. Does Modern Helicopter Construction Reduce Noise Exposure in Helicopter Rescue Operations?

    OpenAIRE

    Küpper, Thomas; Jansing, Paul; Schöffl, Volker; van Der Giet, Simone

    2017-01-01

    Background: During helicopter rescue operations the medical personnel are at high risk for hearing damage by noise exposure. There are two important factors to be taken into account: first, the extreme variability, with some days involving no exposure but other days with extreme exposure; second, the extreme noise levels during work outside the helicopter, e.g. during winch operations. The benefit of modern, less noisier constructions and the consequences for noise protection are still unknow...

  3. Helicopter Maritime Environment Trainer: Software Test Document

    Science.gov (United States)

    2011-06-01

    flying pilot ( NFP ) takes control while the flying pilot (FP) continues to watch the instruments. This case does not apply because a single helicopter... NFP Non-Flying Pilot OOW Officer of The Watch OSD Operational Sequence Diagrams PC Personal Computer PDV Post Delivery Validation PROM

  4. HH-60D night hawk helicopter

    Science.gov (United States)

    Richardson, C. S.

    1984-01-01

    Fundamental development issues, system requirements and improvements are reported for the HH-60D night hawk helicopter. The HH-60D mission requirements are for combat search and rescue (aerospace rescue and recovery service user based at Scott AFB) and special operations (special operations forces based at Hurlburt AFB). Cockpit design, computer architecture and software are described in detail.

  5. Control of a hybrid helicopter with wings

    NARCIS (Netherlands)

    de Wagter, C.; Smeur, E.J.J.

    2017-01-01

    This work investigates the design parameters and their consequences in the control of a helicopter rotor combined with a pair of fixed wings. This hybrid vehicle has a light and aerodynamically efficient rotor with a large range of pitch angles to enable both hover and forward flight. Because of the

  6. Silica fume reinforced polystyrene-based composite particles used as ultra-light weight proppants in hydraulic fracturing

    Science.gov (United States)

    Liang, Tian; Yan, Chunjie; Zhou, Sen; Zhang, Yonghan

    2017-11-01

    A new kind composite particle which could be utilized as ultra-light weight proppant was prepared via suspension polymerization in this work. The composite particles were composed of polystyrene and modified silica fume. This study indicated the composite particles had a bulk density (around 0.65 g cm‑3) that is even lower than most of the commercial proppants. The pure polystyrene particles had a glass transition temperature of 130.3 °C and a crushing rate of 5.0% under the pressure of 52 MPa for 3 min. While the heat-treated composite particles had a higher glass transition temperature of 146.1 °C and a lower crushing rate of 1.0% under the same testing condition. In addition, the processes of synthesizing composite particles, procedures of heat treatment, effects of different incorporation amount and dispersion of modified silica fume in polymer matrix were systematically investigated.

  7. Multicenter observational prehospital resuscitation on helicopter study.

    Science.gov (United States)

    Holcomb, John B; Swartz, Michael D; DeSantis, Stacia M; Greene, Thomas J; Fox, Erin E; Stein, Deborah M; Bulger, Eileen M; Kerby, Jeffrey D; Goodman, Michael; Schreiber, Martin A; Zielinski, Martin D; O'Keeffe, Terence; Inaba, Kenji; Tomasek, Jeffrey S; Podbielski, Jeanette M; Appana, Savitri N; Yi, Misung; Wade, Charles E

    2017-07-01

    Earlier use of in-hospital plasma, platelets, and red blood cells (RBCs) has improved survival in trauma patients with severe hemorrhage. Retrospective studies have associated improved early survival with prehospital blood product transfusion (PHT). We hypothesized that PHT of plasma and/or RBCs would result in improved survival after injury in patients transported by helicopter. Adult trauma patients transported by helicopter from the scene to nine Level 1 trauma centers were prospectively observed from January to November 2015. Five helicopter systems had plasma and/or RBCs, whereas the other four helicopter systems used only crystalloid resuscitation. All patients meeting predetermined high-risk criteria were analyzed. Patients receiving PHT were compared with patients not receiving PHT. Our primary analysis compared mortality at 3 hours, 24 hours, and 30 days, using logistic regression to adjust for confounders and site heterogeneity to model patients who were matched on propensity scores. Twenty-five thousand one hundred eighteen trauma patients were admitted, 2,341 (9%) were transported by helicopter, of which 1,058 (45%) met the highest-risk criteria. Five hundred eighty-five of 1,058 patients were flown on helicopters carrying blood products. In the systems with blood available, prehospital median systolic blood pressure (125 vs 128) and Glasgow Coma Scale (7 vs 14) was significantly lower, whereas median Injury Severity Score was significantly higher (21 vs 14). Unadjusted mortality was significantly higher in the systems with blood products available, at 3 hours (8.4% vs 3.6%), 24 hours (12.6% vs 8.9%), and 30 days (19.3% vs 13.3%). Twenty-four percent of eligible patients received a PHT. A median of 1 unit of RBCs and plasma were transfused prehospital. Of patients receiving PHT, 24% received only plasma, 7% received only RBCs, and 69% received both. In the propensity score matching analysis (n = 109), PHT was not significantly associated with mortality

  8. IMPACT OF AN UNDERSLUNG LOAD ON A HELICOPTER CONTROLLABILITY

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available This article is aimed at finding the causes of controllability variations of a helicopter while transporting sling load.The maximum angular acceleration taken by the helicopter at similar controller displacement at different flight speeds was taken as a quantity characteristic of controllability efficiency to study the load impact on the helicopter cont- rollability.This article offers research results obtained with the use of the НеliСargо software. This software has proven to be a great tool for integrated research of the impact of an underslung load on the parameters of a helicopter controllability, and allows carrying out an analysis of the impact of an underslung load on the parameters of controllability under its dyna- mic behavior.The performed computational experiments have shown that the helicopter maximum angular acceleration with an underslung load significantly rises, as compared to a helicopter without cargo or a helicopter carrying the same load inside the cargo compartment. The data obtained during computational experiments corresponds to the results of analytical computations, and is in line with the literature based on the experience of helicopter flight operations.The cause of the variation in the helicopter controllability parameters during transportation of an underslung load has been found, that is - the underslung load considerably increases the main rotor thrust, due to sling load, as compared to a helicopter without cargo. When compared to a helicopter carrying a load inside the cargo compartment, this increased efficiency is mainly attributed to the fact that a helicopter with an underslung load has lower rotational inertia, since the load is not inside the cargo compartment, but outside.The obtained results can be used to improve flight manuals and flight personnel training publications, which could play a significant part in ensuring flight safety and security, and increasing the operational efficiency of

  9. Research on the Propagation of AE Signals in Helicopter Structural Components

    Directory of Open Access Journals (Sweden)

    Urbahs Aleksandrs

    2016-12-01

    Full Text Available The paper contains results of experimental research carried out helicopter bench. In order to create an attenuation chart for AE signal amplitude in helicopter fuselage, a number of experiments were performed on the frame and stringers, inside the fuselage. Later helicopter test bench was used to develop defect localization methodology of helicopter structure fatigue damage technical diagnostics. Analysing helicopter structural defects for different helicopters types it is concluded that the joint elements of helicopter tail boom are still exposed to fatigue crack formation. AE method shows highly effective results predicting fracture of helicopter joint elements.

  10. LQR Based PID Controller Design for 3-DOF Helicopter System

    OpenAIRE

    Santosh Kr. Choudhary

    2014-01-01

    In this article, LQR based PID controller design for 3DOF helicopter system is investigated. The 3-DOF helicopter system is a benchmark laboratory model having strongly nonlinear characteristics and unstable dynamics which make the control of such system a challenging task. This article first presents the mathematical model of the 3DOF helicopter system and then illustrates the basic idea and technical formulation for controller design. The paper explains the simple appro...

  11. 78 FR 52407 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-08-23

    ... issued AD 2011-0185 to correct an unsafe condition for Eurocopter Model EC120 and EC130 helicopters. EASA... 0, dated July 11, 2011 (ASB EC120-25A026), for Model EC120B helicopters and ASB No. EC130-25A042, Revision 0, dated July 11, 2011 (ASB EC130-25A042), for Model EC130B4 helicopters. Both ASBs specify...

  12. 78 FR 22213 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-04-15

    ... correct an unsafe condition for the Eurocopter Model EC120 and EC130 helicopters. EASA advises that during..., 2011 (ASB EC120-25A026), for Model EC120B helicopters and ASB No. EC130-25A042, Revision 0, dated July 11, 2011 (ASB EC130-25A042), for Model EC130B4 helicopters. Both ASBs specify modifying certain part...

  13. Planning German Army helicopter maitenance and mission assignment

    OpenAIRE

    Sgaslik, Achim

    1994-01-01

    Approved for public release; distribution unlimited. German Army light helicopter transportation regiments operate 45 Bell UH-1D helicopters to support demanding missions throughout Europe. Maintenance period scheduling, major exercise and regular mission assignment decisions directly influence the readiness of the helicopter fleet. Currently, all planning is done manually, which is unstructured and time consuming. This thesis describes a decision support system designed to assist with mai...

  14. H II control for model helicopter in hover

    Science.gov (United States)

    Kim, Moo Seok; Kim, Joon Ki; Han, Jeong Yup; Park, Hong Bae; Kang, Soon Ju

    2005-12-01

    This paper presents mathematical model of six degree-of-freedom (6-DOF) helicopter (ERGO50) in hover, and H II feedback controller which is a powerful technique for the MIMO system as a helicopter. Mathematical model of the helicopter is multi-input multi-output (MIMO) and linearized system which accommodates aerodynamics. H II controller based on optimal control theory is used in a myriad application and plays an important role as a valuable precursor to other advanced methods for future work, when we need to improve stability of the helicopter. We design linear-quadratic-gaussian controller as H II controller. Simulation results show good performance.

  15. Helicopter mission optimization study. [portable computer technology for flight optimization

    Science.gov (United States)

    Olson, J. R.

    1978-01-01

    The feasibility of using low-cost, portable computer technology to help a helicopter pilot optimize flight parameters to minimize fuel consumption and takeoff and landing noise was demonstrated. Eight separate computer programs were developed for use in the helicopter cockpit using a hand-held computer. The programs provide the helicopter pilot with the ability to calculate power required, minimum fuel consumption for both range and endurance, maximum speed and a minimum noise profile for both takeoff and landing. Each program is defined by a maximum of two magnetic cards. The helicopter pilot is required to key in the proper input parameter such as gross weight, outside air temperature or pressure altitude.

  16. Automatic guidance and control laws for helicopter obstacle avoidance

    Science.gov (United States)

    Cheng, Victor H. L.; Lam, T.

    1992-01-01

    The authors describe the implementation of a full-function guidance and control system for automatic obstacle avoidance in helicopter nap-of-the-earth (NOE) flight. The guidance function assumes that the helicopter is sufficiently responsive so that the flight path can be readily adjusted at NOE speeds. The controller, basically an autopilot for following the derived flight path, was implemented with parameter values to control a generic helicopter model used in the simulation. Evaluation of the guidance and control system with a 3-dimensional graphical helicopter simulation suggests that the guidance has the potential for providing good and meaningful flight trajectories.

  17. 78 FR 40956 - Airworthiness Directives; Eurocopter Deutschland (Eurocopter) Helicopters

    Science.gov (United States)

    2013-07-09

    ... Deutschland (Eurocopter) Helicopters AGENCY: Federal Aviation Administration (FAA), Department of... Eurocopter Deutschland (Eurocopter): Amendment 39-17484; Docket No. FAA-2013-0520; Directorate Identifier...

  18. Structural Dynamics, Stability, and Control of Helicopters

    Science.gov (United States)

    Meirovitch, L.; Hale, A. L.

    1978-01-01

    The dynamic synthesis of gyroscopic structures consisting of point-connected substructures is investigated. The objective is to develop a mathematical model capable of an adequate simulation of the modal characteristics of a helicopter using a minimum number of degrees of freedom. The basic approach is to regard the helicopter structure as an assemblage of flexible substructures. The variational equations for the perturbed motion about certain equilibrium solutions are derived. The discretized variational equations can be conveniently exhibited in matrix form, and a great deal of information about the system modal characteristics can be extracted from the coefficient matrices. The derivation of the variational equations requires a monumental amount of algebraic operations. To automate this task a symbolic manipulation program on a digital computer is developed.

  19. Cost Modelling of Composite Componentsfor Helicopter Applications

    OpenAIRE

    Idstam, Patrik

    2015-01-01

    Composite materials are becoming more popular than ever. The increasing envi-ronmental concerns results in new challenges, where one of the biggest is to reduce the emission of greenhouse gases. Both the aerospace industry and the automotive industry work hard to become more environmental friendly. To reduce the emissions of vehicles such as cars, planes and helicopters reduction of weight is important as lower weight reduces fuel consumptions. To save weight more of the structural and load-b...

  20. Aeromechanics Analysis of a Compound Helicopter

    Science.gov (United States)

    Yeo, Hyeonsoo; Johnson, Wayne

    2006-01-01

    A design and aeromechanics investigation was conducted for a 100,000-lb compound helicopter with a single main rotor, which is to cruise at 250 knots at 4000 ft/95 deg F condition. Performance, stability, and control analyses were conducted with the comprehensive rotorcraft analysis CAMRAD II. Wind tunnel test measurements of the performance of the H-34 and UH-1D rotors at high advance ratio were compared with calculations to assess the accuracy of the analysis for the design of a high speed helicopter. In general, good correlation was obtained with the increase of drag coefficients in the reverse flow region. An assessment of various design parameters (disk loading, blade loading, wing loading) on the performance of the compound helicopter was made. Performance optimization was conducted to find the optimum twist, collective, tip speed, and taper using the comprehensive analysis. Blade twist was an important parameter on the aircraft performance and most of the benefit of slowing the rotor occurred at the initial 20 to 30% reduction of rotor tip speed. No stability issues were observed with the current design and the control derivatives did not change much with speed, but did exhibit significant coupling.

  1. Optimum Design of a Compound Helicopter

    Science.gov (United States)

    Yeo, Hyeonsoo; Johnson, Wayne

    2006-01-01

    A design and aeromechanics investigation was conducted for a 100,000-lb compound helicopter with a single main rotor, which is to cruise at 250 knots at 4000 ft/95 deg F condition. Performance, stability, and control analyses were conducted with the comprehensive rotorcraft analysis CAMRAD II. Wind tunnel test measurements of the performance of the H-34 and UH-1D rotors at high advance ratio were compared with calculations to assess the accuracy of the analysis for the design of a high speed helicopter. In general, good correlation was obtained when an increase of drag coefficients in the reverse flow region was implemented. An assessment of various design parameters (disk loading, blade loading, wing loading) on the performance of the compound helicopter was conducted. Lower wing loading (larger wing area) and higher blade loading (smaller blade chord) increased aircraft lift-to-drag ratio. However, disk loading has a small influence on aircraft lift-to-drag ratio. A rotor parametric study showed that most of the benefit of slowing the rotor occurred at the initial 20 to 30% reduction of the advancing blade tip Mach number. No stability issues were observed with the current design. Control derivatives did not change significantly with speed, but the did exhibit significant coupling.

  2. On the capability of helicopter gravimetry.

    Science.gov (United States)

    Bielenberg, Olaf; Meyer, Uwe; Götze, Hans-Jürgen; Choi, Sungchan

    2010-05-01

    Affordable, high performance inertial navigation systems, their integration with GPS, and modern high performance airborne vertical sensors make helicopter gravimetry an attractive alternative to other methods for obtaining gravity data. As part of the Dead Sea Integrated Research Project (DESIRE) in late spring 2007 a helicopter borne gravimetry survey was conducted over the Dead Sea Basin along and across the rift between Aquaba and the Dead Sea. A German Sikorsky S-76B helicopter system was used to carry a GT-1A gravity meter system supplied by Canadian Micro Gravity. The GT-1A is an airborne, single vertical sensor, GPS-INS scalar gravity meter with a Schuler-tuned three-axis gyro-stabilized inertial platform, that uses intelligent platform control to maintain platform verticality during turbulent motion. Low speed and terrain following helicopter gravity flights were performed to acquire the best possible data quality and high resolution, considering extreme elevation differences associated with the Dead Sea Basin. The Dead Sea Valley lies more than 400 m below sea level, while the shoulders are more than 1500 m high. The resulting initial airborne gravity data were merged with existent ground based data for enhanced mapping and modelling providing a seamless gravity map of the area. During terrain following flights the vertical accelerations effecting the helicopter and also the vertical sensor of the gravity meter are logically much higher compared to straight level flights. To investigate the effects of this two different flight performances on the gravity measurements, a test flight over flat terrain at a constant altitude with very small vertical accelerations was performed. The acceleration data occurred during this simulated airborne survey flight were recorded using an inertial measurement unit iVRU-FC constructed by iMAR-Navigation, which was also part of the equipment used during the gravimetry survey flights of DESIRE. This means that the

  3. Sleep and Alertness in North Sea Helicopter Operations

    NARCIS (Netherlands)

    Simons, M.; Wilschut, E.S.; Valk, P.J.L.

    2011-01-01

    Introduction : Dutch North Sea helicopter operations are characterized by multiple sector flights to offshore platforms under difficult environmental conditions. In the context of a Ministry of Transport program to improve safety levels of helicopter operations, we assessed effects of pre-duty

  4. Basic Helicopter Handbook, Revised. AC 61-13A.

    Science.gov (United States)

    Federal Aviation Administration (DOT), Washington, DC. Flight Standards Service.

    This technical manual was designed to assist applicants preparing for the private, commercial, and flight instructor pilot certificates with a helicopter rating. The chapters outline general aerodynamics, aerodynamics of flight, loads and load factors, function of controls, other helicopter components and their functions, introduction to the…

  5. 29 CFR 1926.958 - External load helicopters.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false External load helicopters. 1926.958 Section 1926.958 Labor... External load helicopters. In all operations performed using a rotorcraft for moving or placing external loads, the provisions of § 1926.551 of subpart N of this part shall be complied with. ...

  6. 78 FR 21233 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-04-10

    ...-010-AD; Amendment 39-17409; AD 2013-07-05] RIN 2120-AA64 Airworthiness Directives; Eurocopter France... new airworthiness directive (AD) for Eurocopter France EC130B4 helicopters. This AD requires visually... 39 to include an AD that would apply to Eurocopter France EC130B4 helicopters with a center...

  7. 77 FR 56755 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2012-09-14

    ...-51-AD; Amendment 39-17172; AD 2012-17-09] RIN 2120-AA64 Airworthiness Directives; Eurocopter France... new airworthiness directive (AD) for Eurocopter France Model SA341G helicopters. This AD requires... apply to Eurocopter France Model SA341G helicopters, with rotating star, part number (P/N) 341A31.4116...

  8. 78 FR 36129 - Airworthiness Directives; Eurocopter France (Eurocopter) Model Helicopters

    Science.gov (United States)

    2013-06-17

    ... Directives; Eurocopter France (Eurocopter) Model Helicopters AGENCY: Federal Aviation Administration, DOT... directive (AD) for Eurocopter Model AS350B, BA, B1, B2, C, D, and D1 helicopters and Model AS355E, F, F1, F2... identified in this proposed AD, contact American Eurocopter Corporation, 2701 N. Forum Drive, Grand Prairie...

  9. 77 FR 36213 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2012-06-18

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Eurocopter France...). SUMMARY: We propose to adopt a new airworthiness directive (AD) for Eurocopter France EC130B4 helicopters... unsafe condition for the Eurocopter France EC130B4 helicopters. EASA states that it received reports that...

  10. 78 FR 857 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-01-07

    ...-17302; AD 2012-26-07] RIN 2120-AA64 Airworthiness Directives; Eurocopter France Helicopters AGENCY... airworthiness directive (AD) for Eurocopter France (Eurocopter) Model AS350BA helicopters with certain AERAZUR... amends Sec. 39.13 by adding the following new airworthiness directive (AD): 2012-26-07 Eurocopter France...

  11. 78 FR 57047 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-09-17

    ...-034-AD; Amendment 39-17541; AD 2013-16-03] RIN 2120-AA64 Airworthiness Directives; Eurocopter France... new airworthiness directive (AD) for Eurocopter France (Eurocopter) Model AS350 and AS355 helicopters...): 2013-16-03 EUROCOPTER FRANCE HELICOPTERS (EUROCOPTER): Amendment 39- 17541; Docket No. FAA-2013-0119...

  12. 77 FR 54796 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2012-09-06

    ...-007-AD; Amendment 39-17166; AD 2012-17-03] RIN 2120-AA64 Airworthiness Directives; Eurocopter France... new airworthiness directive (AD) for certain Eurocopter France Model AS350 helicopters. This AD...): 2012-17-03 Eurocopter France Helicopters: Amendment 39-17166; Docket No. FAA-2012-0222; Directorate...

  13. 77 FR 5991 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2012-02-07

    ... the Eurocopter France (ECF) Model AS332L2 helicopter and superseding an AD for the Model EC225LP... 2010-SW-091-AD; Amendment 39-16914; AD 2012-01-03] RIN 2120-AA64 Airworthiness Directives; Eurocopter France Helicopters AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT...

  14. Hover flight control of helicopter using optimal control theory

    Directory of Open Access Journals (Sweden)

    Ahmed ABOULFTOUH

    2015-09-01

    Full Text Available This paper represents the optimal control theory and its application to the full scale helicopters. Generally the control of a helicopter is a hard task, because its system is very nonlinear, coupled and sensitive to the control inputs and external disturbances which might destabilize the system. As a result of these instabilities, it is essential to use a control process that helps to improve the systems performance, confirming stability and robustness. The main objective of this part is to develop a control system design technique using Linear Quadratic Regulator (LQR to stabilize the helicopter near hover flight. In order to achieve this objective, firstly, the nonlinear model of the helicopter is linearized using small disturbance theory. The linear optimal control theory is applied to the linearized state space model of the helicopter to design the LQR controller. To clarify robustness of the controller, the effects of external wind gusts and mass change are taken into concern. Wind gusts are taken as disturbances in all directions which are simulated as a sine wave. Many simulations were made to validate and verify the response of the linear controller of the helicopter. The results show that the use of an optimal control process as LQR is a good solution for MIMO helicopter system, achieving a good stabilization and refining the final behavior of the helicopter and handling the external wind gusts disturbances as shown in the different simulations.

  15. 78 FR 12648 - Airworthiness Directives; Robinson Helicopter Company

    Science.gov (United States)

    2013-02-25

    ... Company AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). SUMMARY: We propose to supersede an existing airworthiness directive (AD) for Robinson Helicopter Company... identified in this proposed AD, contact Robinson Helicopter Company, 2901 Airport Drive, Torrance, CA 90505...

  16. Input Shaping for Helicopter Slung Load Swing Reduction

    DEFF Research Database (Denmark)

    Bisgaard, Morten; la Cour-Harbo, Anders; Bendtsen, Jan Dimon

    2008-01-01

    This chapter presents a feedforward swing reducing control system for augmenting already existing helicopter controllers and enables slung load flight with autonomous helicopters general cargo transport. The feedforward controller is designed to avoid excitation of the lightly damped modes of the...

  17. The Helicopter Parent (Part 2): International Arrivals and Departures

    Science.gov (United States)

    Somers, Patricia; Settle, Jim

    2010-01-01

    The phenomenon of helicopter parenting has been widely reported, yet the research literature is anemic on the topic. Based on interviews and focus groups involving 190 academic and student services professionals, this article continues by discussing the social, psychological, economic, and cultural factors that influence helicoptering; exploring…

  18. The Helicopter Parent: Research toward a Typology (Part I)

    Science.gov (United States)

    Somers, Patricia; Settle, Jim

    2010-01-01

    With 117,000 hits on a recent Google[TM] search, the phenomenon of helicopter parenting has been widely reported in the popular press. Yet the scholarly literature is anemic on the topic. This article, part one of a two-part series, presents the small body of research on helicopter parenting and describes a qualitative study of 190 participants…

  19. 78 FR 17593 - Airworthiness Directives; Bell Helicopter Textron, Inc.

    Science.gov (United States)

    2013-03-22

    ... helicopters. This AD requires establishing a lower life limit on certain swashplate outer ring assemblies... helicopters, with a swashplate outer ring assembly (outer ring), part number (P/N) 412- 010-407-105... Component (JASC) Code: 6230, Main Rotor Mast/Swashplate. Issued in Fort Worth, Texas, on March 6, 2013...

  20. Heat stress reduction of helicopter crew wearing a ventilated vest

    NARCIS (Netherlands)

    Reffeltrath, P.A.

    2006-01-01

    Background: Helicopter pilots are often exposed to periods of high heat strain, especially when wearing survival suits. Therefore, a prototype of a ventilated vest was evaluated on its capability to reduce the heat strain of helicopter pilots during a 2-h simulated flight. Hypothesis: It was

  1. Small-Scale Helicopter Automatic Autorotation : Modeling, Guidance, and Control

    NARCIS (Netherlands)

    Taamallah, S.

    2015-01-01

    Our research objective consists in developing a, model-based, automatic safety recovery system, for a small-scale helicopter Unmanned Aerial Vehicle (UAV) in autorotation, i.e. an engine OFF flight condition, that safely flies and lands the helicopter to a pre-specified ground location. In pursuit

  2. 77 FR 30230 - Airworthiness Directives; Eurocopter Deutschland Helicopters

    Science.gov (United States)

    2012-05-22

    ... Deutschland Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed... Deutschland GmbH Model MBB-BK117 C-2 helicopters with certain Generator Control Units (GCU) installed. This... September 30, 2011 (AD ] 2011-0149R1), to correct an unsafe condition for the Eurocopter Deutschland GmbH...

  3. 77 FR 7005 - Airworthiness Directives; Eurocopter Deutschland GMBH Helicopters

    Science.gov (United States)

    2012-02-10

    ... Directives; Eurocopter Deutschland GMBH Helicopters AGENCY: Federal Aviation Administration (FAA), DOT... (AD) for Eurocopter Deutschland GMBH (ECD) Model MBB-BK 117 C-1 and C-2 helicopters. This proposed AD... Directive (AD): Eurocopter Deutschland GMBH: Docket No. FAA-2012-0101; Directorate Identifier 2010-SW-042-AD...

  4. Power harvesting using piezoelectric materials: applications in helicopter rotors

    NARCIS (Netherlands)

    de Jong, Pieter

    2013-01-01

    The blades of helicopters are heavily loaded and are critical components. Failure of any one blade will lead to loss of the aircraft. Currently, the technical lifespan of helicopter blades is calculated using a worst-case operation scenario. The consequence is that a blade that may be suitable for,

  5. Autonomous Navigation, Guidance and Control of Small Electric Helicopter

    Directory of Open Access Journals (Sweden)

    Satoshi Suzuki

    2013-01-01

    Full Text Available In this study, we design an autonomous navigation, guidance and control system for a small electric helicopter. Only small, light-weight, and inaccurate sensors can be used for the control of small helicopters because of the payload limitation. To overcome the problem of inaccurate sensors, a composite navigation system is designed. The designed navigation system enables us to precisely obtain the position and velocity of the helicopter. A guidance and control system is designed for stabilizing the helicopter at an arbitrary point in three-dimensional space. In particular, a novel and simple guidance system is designed using the combination of optimal control theory and quaternion kinematics. The designs of the study are validated experimentally, and the experimental results verify the efficiency of our navigation, guidance and control system for a small electric helicopter.

  6. A Simplified Mobile Ad Hoc Network Structure for Helicopter Communication

    Directory of Open Access Journals (Sweden)

    Abdeldime Mohamed Salih Abdelgader

    2016-01-01

    Full Text Available There are a number of volunteer and statutory organizations who are capable of conducting an emergency response using helicopters. Rescue operations require a rapidly deployable high bandwidth network to coordinate necessary relief efforts between rescue teams on the ground and helicopters. Due to massive destruction and loss of services, ordinary communication infrastructures may collapse in these situations. Consequently, information exchange becomes one of the major challenges in these circumstances. Helicopters can be also employed for providing many services in rugged environments, military applications, and aerial photography. Ad hoc network can be used to provide alternative communication link between a set of helicopters, particularly in case of significant amount of data required to be shared. This paper addresses the ability of using ad hoc networks to support the communication between a set of helicopters. A simplified network structure model is presented and extensively discussed. Furthermore, a streamlined routing algorithm is proposed. Comprehensive simulations are conducted to evaluate the proposed routing algorithm.

  7. A NASA helicopter arrives at KSC for painting

    Science.gov (United States)

    2000-01-01

    A NASA helicopter lands on S.R. 3 for transfer to Patrick Air Force Base. It is one of four UH-1H helicopters that will have its blades painted, changing the black to a pattern of white and yellow stripes. The pattern provides better visibility in smoke and fire conditions. When the rotors are turning, the stripes create a yellow and white circle that is more easily seen by a second helicopter from above. The helicopters, primarily used for security and medical evacuation for NASA, will be used to deliver water via buckets during brush fires. The change was made to comply with U.S. Fish and Wildlife and Department of Forestry regulations for helicopter-assisted fire control.

  8. 78 FR 4759 - Airworthiness Directives; Bell Helicopter Textron, Inc. (Bell) Helicopters

    Science.gov (United States)

    2013-01-23

    ... Helicopter model Types of operation lifts and takeoffs hours TIS factor hours TIS x hours TIS factor) Yokes...-power or higher magnifying glass, visually inspect each pillow block bushing hole, spindle radius, and... glass, visually inspect each pillow block bushing hole, spindle radius, and center section web for any...

  9. 78 FR 24368 - Airworthiness Directives; Bell Helicopter Textron, Inc. (Bell) Model Helicopters

    Science.gov (United States)

    2013-04-25

    ... should include procedures to slowly operate the cockpit anti-torque control pedals during the inspection... the Model 204B helicopter, which specifies to visually inspect the chain using a 10-power magnifying...-hour TIS intervals using a 10-power or higher magnifying glass and a light; revising the inspection...

  10. 78 FR 34286 - Airworthiness Directives; Bell Helicopter Textron Canada Limited (Bell) Helicopters

    Science.gov (United States)

    2013-06-07

    ...) Install placard P/N 230-075-213-111, or equivalent, directly below the NR/NP dual tachometer. (f... certain Bell Model 407 helicopters. This proposed AD would require installing a placard beneath the NR/NP... to the ``Mail'' address between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays...

  11. Ultralight Cut-Paper-Based Self-Charging Power Unit for Self-Powered Portable Electronic and Medical Systems.

    Science.gov (United States)

    Guo, Hengyu; Yeh, Min-Hsin; Zi, Yunlong; Wen, Zhen; Chen, Jie; Liu, Guanlin; Hu, Chenguo; Wang, Zhong Lin

    2017-05-23

    The development of lightweight, superportable, and sustainable power sources has become an urgent need for most modern personal electronics. Here, we report a cut-paper-based self-charging power unit (PC-SCPU) that is capable of simultaneously harvesting and storing energy from body movement by combining a paper-based triboelectric nanogenerator (TENG) and a supercapacitor (SC), respectively. Utilizing the paper as the substrate with an assembled cut-paper architecture, an ultralight rhombic-shaped TENG is achieved with highly specific mass/volume charge output (82 nC g(-1)/75 nC cm(-3)) compared with the traditional acrylic-based TENG (5.7 nC g(-1)/5.8 nC cm(-3)), which can effectively charge the SC (∼1 mF) to ∼1 V in minutes. This wallet-contained PC-SCPU is then demonstrated as a sustainable power source for driving wearable and portable electronic devices such as a wireless remote control, electric watch, or temperature sensor. This study presents a potential paper-based portable SCPU for practical and medical applications.

  12. Ultra-light and flexible pencil-trace anode for high performance potassium-ion and lithium-ion batteries

    Directory of Open Access Journals (Sweden)

    Zhixin Tai

    2017-07-01

    Full Text Available Engineering design of battery configurations and new battery system development are alternative approaches to achieve high performance batteries. A novel flexible and ultra-light graphite anode is fabricated by simple friction drawing on filter paper with a commercial 8B pencil. Compared with the traditional anode using copper foil as current collector, this innovative current-collector-free design presents capacity improvement of over 200% by reducing the inert weight of the electrode. The as-prepared pencil-trace electrode exhibits excellent rate performance in potassium-ion batteries (KIBs, significantly better than in lithium-ion batteries (LIBs, with capacity retention of 66% for the KIB vs. 28% for the LIB from 0.1 to 0.5 A g−1. It also shows a high reversible capacity of ∼230 mAh g−1 at 0.2 A g−1, 75% capacity retention over 350 cycles at 0.4 A g−1and the highest rate performance (based on the total electrode weight among graphite electrodes for K+ storage reported so far. Keywords: Current-collector-free, Flexible pencil-trace electrode, Potassium-ion battery, Lithium-ion battery, Layer-by-layer interconnected architecture

  13. Does modern helicopter construction reduce noise exposure in helicopter rescue operations?

    Science.gov (United States)

    Küpper, Thomas; Jansing, Paul; Schöffl, Volker; van Der Giet, Simone

    2013-01-01

    During helicopter rescue operations the medical personnel are at high risk for hearing damage by noise exposure. There are two important factors to be taken into account: first, the extreme variability, with some days involving no exposure but other days with extreme exposure; second, the extreme noise levels during work outside the helicopter, e.g. during winch operations. The benefit of modern, less noisier constructions and the consequences for noise protection are still unknown. We estimated the noise exposure of the personnel for different helicopter types used during rescue operations in the Alps and in other regions of the world with special regard to the advanced types like Eurocopter EC 135 to compare the benefit of modern constructions for noise protection with earlier ones. The rescue operations over 1 year of four rescue bases in the Alps (Raron and Zermatt in Switzerland; Landeck and Innsbruck in Austria, n = 2731) were analyzed for duration of rescue operations (noise exposure). Noise levels were measured during rescue operations at defined points inside and outside the different aircraft. The setting is according to the European standard (Richtlinie 2003/10/EG Amtsblatt) and to Class 1 DIN/IEC 651. With both data sets the equivalent noise level L(eq8h) was calculated. For comparison it was assumed that all rescue operations were performed with a specific type of helicopter. Then model calculations for noise exposure by different helicopter types, such as Alouette IIIb, Alouette II 'Lama', Ecureuil AS350, Bell UH1D, Eurocopter EC135, and others were performed. Depending on modern technologies the situation for the personnel has been improved significantly. Nevertheless noise prevention, which includes noise intermissions in spare time, is essential. Medical checks of the crews by occupational medicine (e.g. 'G20' in Germany) are still mandatory.

  14. Modeling, State Estimation and Control of Unmanned Helicopters

    Science.gov (United States)

    Lau, Tak Kit

    Unmanned helicopters hold both tremendous potential and challenges. Without risking the lives of human pilots, these vehicles exhibit agile movement and the ability to hover and hence open up a wide range of applications in the hazardous situations. Sparing human lives, however, comes at a stiff price for technology. Some of the key difficulties that arise in these challenges are: (i) There are unexplained cross-coupled responses between the control axes on the hingeless helicopters that have puzzled researchers for years. (ii) Most, if not all, navigation on the unmanned helicopters relies on Global Navigation Satellite Systems (GNSSs), which are susceptible to jamming. (iii) It is often necessary to accommodate the re-configurations of the payload or the actuators on the helicopters by repeatedly tuning an autopilot, and that requires intensive human supervision and/or system identification. For the dynamics modeling and analysis, we present a comprehensive review on the helicopter actuation and dynamics, and contributes toward a more complete understanding on the on-axis and off-axis dynamical responses on the helicopter. We focus on a commonly used modeling technique, namely the phase-lag treatment, and employ a first-principles modeling method to justify that (i) why that phase-lag technique is inaccurate, (ii) how we can analyze the helicopter actuation and dynamics more accurately. Moreover, these dynamics modeling and analysis reveal the hard-to-measure but crucial parameters on a helicopter model that require the constant identifications, and hence convey the reasoning of seeking a model-implicit method to solve the state estimation and control problems on the unmanned helicopters. For the state estimation, we present a robust localization method for the unmanned helicopter against the GNSS outage. This method infers position from the acceleration measurement from an inertial measurement unit (IMU). In the core of our method are techniques of the sensor

  15. Analysis of potential helicopter vibration reduction concepts

    Science.gov (United States)

    Landgrebe, A. J.; Davis, M. W.

    1985-01-01

    Results of analytical investigations to develop, understand, and evaluate potential helicopter vibration reduction concepts are presented in the following areas: identification of the fundamental sources of vibratory loads, blade design for low vibration, application of design optimization techniques, active higher harmonic control, blade appended aeromechanical devices, and the prediction of vibratory airloads. Primary sources of vibration are identified for a selected four-bladed articulated rotor operating in high speed level flight. The application of analytical design procedures and optimization techniques are shown to have the potential for establishing reduced vibration blade designs through variations in blade mass and stiffness distributions, and chordwise center-of-gravity location.

  16. Performance and Vibration Analyses of Lift-Offset Helicopters

    Directory of Open Access Journals (Sweden)

    Jeong-In Go

    2017-01-01

    Full Text Available A validation study on the performance and vibration analyses of the XH-59A compound helicopter is conducted to establish techniques for the comprehensive analysis of lift-offset compound helicopters. This study considers the XH-59A lift-offset compound helicopter using a rigid coaxial rotor system as a verification model. CAMRAD II (Comprehensive Analytical Method of Rotorcraft Aerodynamics and Dynamics II, a comprehensive analysis code, is used as a tool for the performance, vibration, and loads analyses. A general free wake model, which is a more sophisticated wake model than other wake models, is used to obtain good results for the comprehensive analysis. Performance analyses of the XH-59A helicopter with and without auxiliary propulsion are conducted in various flight conditions. In addition, vibration analyses of the XH-59A compound helicopter configuration are conducted in the forward flight condition. The present comprehensive analysis results are in good agreement with the flight test and previous analyses. Therefore, techniques for the comprehensive analysis of lift-offset compound helicopters are appropriately established. Furthermore, the rotor lifts are calculated for the XH-59A lift-offset compound helicopter in the forward flight condition to investigate the airloads characteristics of the ABC™ (Advancing Blade Concept rotor.

  17. Helicopter attitude stabilization using individual-blade-control

    Science.gov (United States)

    Ham, N. D.

    1984-01-01

    A theoretical study is presented on the application of the Individual-Blade-Control concept to helicopter attitude stabilization. The design of a system controlling blade flapping dynamics, and related testing of the system on a model rotor in the wind tunnel, is described. The control inputs considered are blade pitch changes proportional to blade flapping acceleration, velocity, and displacement. The effect of such a system on helicopter rotor damping-in-pitch, and angle-of-attack stability is then evaluated. It is shown that helicopter attitude stabilization is achieved, with a corresponding improvement in flying qualities.

  18. CH-47F Improved Cargo Helicopter (CH-47F)

    Science.gov (United States)

    2015-12-01

    funding lines changed starting in FY 2010 to CH-47 Helicopter (A05101) - a parent (roll-up) of New Build and Service Life Extension Program (SLEP...Selected Acquisition Report (SAR) RCS: DD-A&T(Q&A)823-278 CH-47F Improved Cargo Helicopter (CH-47F) As of FY 2017 President’s Budget Defense...December 2015 SAR March 21, 2016 18:18:21 UNCLASSIFIED 4 LTC Richard Bratt Office of the Project Manager Cargo Helicopters Building 5678 Redstone Arsenal

  19. Optical Shaft-Angle Encoder For Helicopter Rotor

    Science.gov (United States)

    Golub, Robert A.; Fitzpatrick, Fred; Dennis, Dale V.; Taylor, Bryant D.

    1993-01-01

    Angular position of helicopter rotor blade determined precisely. Accomplished by use of optical shaft-angle encoder called "256 Ring" on rotor swashplate. Each 360 degree rotation of helicopter main rotor broken down into 256 reflective segments. As rotor rotates, beam of light reflected in turn from each segment into optoelectronic system. One of 256 segments reflects larger pulse than others do. Position of rotor determined by counting number of pulses after this reference pulse. While swashplate mounting requirements unique to each type of helicopter, concept applicable to all types of rotorcraft.

  20. Adaptive Control System for Autonomous Helicopter Slung Load Operations

    DEFF Research Database (Denmark)

    Bisgaard, Morten; la Cour-Harbo, Anders; Bendtsen, Jan Dimon

    2010-01-01

    system on the helicopter that measures the position of the slung load. The controller is a combined feedforward and feedback scheme for simultaneous avoidance of swing excitation and active swing damping. Simulations and laboratory flight tests show the effectiveness of the combined control system......This paper presents design and verification of an estimation and control system for a helicopter slung load system. The estimator provides position and velocity estimates of the slung load and is designed to augment existing navigation in autonomous helicopters. Sensor input is provided by a vision...

  1. Simulating effectiveness of helicopter evasive manoeuvres to RPG attack

    Science.gov (United States)

    Anderson, D.; Thomson, D. G.

    2010-04-01

    The survivability of helicopters under attack by ground troops using rocket propelled grenades has been amply illustrated over the past decade. Given that an RPG is unguided and it is infeasible to cover helicopters in thick armour, existing optical countermeasures are ineffective - the solution is to compute an evasive manoeuvre. In this paper, an RPG/helicopter engagement model is presented. Manoeuvre profiles are defined in the missile approach warning sensor camera image plane using a local maximum acceleration vector. Required control inputs are then computed using inverse simulation techniques. Assessments of platform survivability to several engagement scenarios are presented.

  2. Helicopter stability and control modeling improvements and verification on two helicopters

    Science.gov (United States)

    Schrage, D. P.; Peters, D. A.; Prasad, J. V. R.; Stumpf, W. F.; He, Chengjian

    1988-01-01

    A linearized model of helicopter flight dynamics is developed which includes the flapping, lead-lag, and dynamic inflow degrees of freedom (DOF). The model is a combination of analytical terms and numerically determined stability derivatives, and is used to investigate the importance of the rotor DOF to stability and control modeling. The results show that the rotor DOF can have a significant impact on some of the natural modes in a linear model. The flap and dynamic inflow DOF show the greatest influence. Flapping exhibits strong coupling to the body, dynamic inflow, and to lead-lag to a lesser extent. Dynamic inflow tends to damp the high-frequency flapping modes, and reduces the damping on coupled body-flap motion. Dynamic inflow also couples to the flapping motion to produce complex roots. With body-flap and lag regressing modes as exceptions, the results show essentially similar behavior for most modes of articulated and hingeless rotor helicopters.

  3. Helicopter type and accident severity in Helicopter Emergency Medical Services missions.

    Science.gov (United States)

    Hinkelbein, Jochen; Schwalbe, Mandy; Wetsch, Wolfgang A; Spelten, Oliver; Neuhaus, Christopher

    2011-12-01

    Whereas accident rates and fatal accident rates for Helicopter Emergency Medical Services (HEMS) were investigated sufficiently, resulting consequences for the occupants remain largely unknown. The present study aimed to classify HEMS accidents in Germany to prognosticate accident severity with regard to the helicopter model used. German HEMS accidents (1 Sept. 1970-31 Dec. 2009) were gathered as previously reported. Accidents were categorized in relation to the most severe injury, i.e., (1) no; (2) slight; (3) severe; and (4) fatal injuries. Only helicopter models with at least five accidents were analyzed to retrieve representative data. Prognostication was estimated by the relative percentage of each injury type compared to the total number of accidents. The model BO105 was most often involved in accidents (38 of 99), followed by BK117 and UH-1D. OfN = 99 accidents analyzed, N = 63 were without any injuries (63.6%), N = 8 resulted in minor injuries of the occupants (8.1%), and N = 9 in major injuries (9.1%). Additionally, N = 19 fatal accidents (19.2%) were registered. EC135 and BK1 17 had the highest incidence of uninjured occupants (100% vs. 88.2%) and the lowest percentage of fatal injuries (0% vs. 5.9%; all P > 0.05). Most fatal accidents occurred with the models UH-1D, Bell 212, and Bell 412. Use of the helicopter models EC135 and BK117 resulted in a high percentage of uninjured occupants. In contrast, the fatality rate was highest for the models Bell UH-I D, Bell 222, and Bell 412. Data from the present study allow for estimating accident risk in HEMS missions and prognosticating resulting fatalities, respectively.

  4. A Computational Tool for Helicopter Rotor Noise Prediction Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR project proposes to develop a computational tool for helicopter rotor noise prediction based on hybrid Cartesian grid/gridless approach. The uniqueness of...

  5. Commercial Pilot Practical Test Standards for Rotorcraft, Helicopter, Gyroplane

    Science.gov (United States)

    1996-04-01

    The Commercial Pilot Rotorcraft (Helicopter and Gyroplane) Practical Test : Standards (PTS) book has been published by the Federal Aviation : Administration (FAA) to establish the standards for commercial pilot certification : practical tests for the...

  6. Full State Estimation for Helicopter Slung Load System

    DEFF Research Database (Denmark)

    Bisgaard, Morten; la Cour-Harbo, Anders; Bendtsen, Jan Dimon

    2007-01-01

    coordinate formulation and can be used to model all body to body slung load suspension systems. Both estimators include bias estimation for the accelerometers and gyros and the model based estimator furthermore includes estimation of external wind disturbances. A vision system is used to measure the motion......This paper presents the design of a state estimator system for a generic helicopter based slung load system. The estimator is designed to deliver full rigid body state information for both helicopter and load and is based on the unscented Kalman filter. Two different approaches are investigated......: One based on a parameter free kinematic model and one based on a full aerodynamic helicopter and slung load model. The kinematic model approach uses acceleration and rate information from two Inertial Measurement Units, one on the helicopter and one on the load, to drive a simple kinematic model...

  7. Full State Estimation for Helicopter Slung Load System

    DEFF Research Database (Denmark)

    Bisgaard, Morten; la Cour-Harbo, Anders; Bendtsen, Jan Dimon

    coordinate formulation and can be used to model all body to body slung load suspension systems. Both estimators include bias estimation for the accelerometers and gyros and the model based estimator furthermore includes estimation of external wind disturbances. A vision system is used to measure the motion......This paper presents the design of a state estimator system for a generic helicopter based slung load system. The estimator is designed to deliver full rigid body state information for both helicopter and load and is based on the unscented Kalman filter. Two different approaches are investigated......: One based on a parameter free kinematic model and one based on a full aerodynamic helicopter and slung load model. The kinematic model approach uses acceleration and rate information from two Inertial Measurement Units, one on the helicopter and one on the load, to drive a simple kinematic model...

  8. The Use of Commercial Remote Sensing Predicting Helicopter Brownout Conditions

    Science.gov (United States)

    2007-09-01

    landing. 4 Figure 2. Soil caught in rotor downwash, start of brownout (from Brownout California soil resource lab) . A second issue ...Sensing in Predicting Helicopter Brownout Conditions. September 2006 (Top Secret). Tan, Kim H., First Edition, Enviromental Soil Science Marcel

  9. Modeling, Estimation, and Control of Helicopter Slung Load System

    DEFF Research Database (Denmark)

    Bisgaard, Morten

    This thesis treats the subject of autonomous helicopter slung load flight and presents the reader with a methodology describing the development path from modeling and system analysis over sensor fusion and state estimation to controller synthesis. The focus is directed along two different....... This first major contribution of this thesis is the development of a complete helicopter and slung load system model that is shared between the two branches. The generic slung load model can be used to model all body to body slung load suspension types and gives an intuitive and easy-to-use way of modeling...... and simulating different slung load suspension types. It further includes detection and response to wire slacking and tightening, it models the aerodynamic coupling between the helicopter and the load, and can be used for multilift systems with any combination of multiple helicopters and multiple loads...

  10. 78 FR 23686 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-04-22

    ... estimate that this proposed AD would affect six helicopters of U.S. registry. Based on an average estimated... January 2, 2008. (g) Subject Joint Aircraft Service Component (JASC) Code: 6520, Tail Rotor Gearbox...

  11. 78 FR 51048 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-08-20

    ... continued airworthiness of these helicopters. Costs of Compliance We estimate that this AD affects six....regulations.gov . (h) Subject Joint Aircraft Service Component (JASC) Code: 6520, Tail Rotor Gearbox. (i...

  12. Reporting Helicopter Emergency Medical Services in Major Incidents

    DEFF Research Database (Denmark)

    Fattah, Sabina; Johnsen, Anne Siri; Sollid, Stephen J M

    2016-01-01

    OBJECTIVE: Research on helicopter emergency medical services (HEMS) in major incidents is predominately based on case descriptions reported in a heterogeneous fashion. Uniform data reported with a consensus-based template could facilitate the collection, analysis, and exchange of experiences...

  13. Hover flight control of helicopter using optimal control theory

    OpenAIRE

    Ahmed ABOULFTOUH; Gamal EL-BAYOUMI; Mohamed MADBOULI

    2015-01-01

    This paper represents the optimal control theory and its application to the full scale helicopters. Generally the control of a helicopter is a hard task, because its system is very nonlinear, coupled and sensitive to the control inputs and external disturbances which might destabilize the system. As a result of these instabilities, it is essential to use a control process that helps to improve the systems performance, confirming stability and robustness. The main objective of this part is to ...

  14. The Evolution of the U.S. Helicopter Industry.

    Science.gov (United States)

    1984-12-01

    The failure of another ASW program, the Drone AntiSubmarine Helicopter (DASH) program, left Navy destroyers without an ASW capability. This pro...rapidly followed by the Frelon (a three turbine naval helicopter) in 1959, the Super Frelon (a thirty place three turbine upgrade of the Frelon ) in...leading to the Puma (twin engined 8000 lb. tactical transport), and the Super Frelon (three engined 15,000 lb. antisubmarine, passenger and cargo

  15. Evaluation of Dutch Helicopter Emergency Medical Services in transporting children.

    Science.gov (United States)

    Peters, Joost; Beekers, Christian; Eijk, Ruud; Edwards, Michael; Hoogerwerf, Nico

    2014-01-01

    In the Netherlands, helicopter emergency medical services (HEMS) function as an adjunct to paramedic ambulance service delivering hospital-level medical care to a prehospital location. The main goal of Dutch HEMS is to provide on-scene medical expertise and not primarily to serve as transport. The transportation of patients to specialized hospitals is sometimes mandatory, especially in cases of critically ill or wounded children. In the literature, no support can be found to support the safety of transportation by helicopter. We retrospectively evaluated the safety of this type of transportation and if any problems were encountered transporting children by helicopter. We reviewed our local HEMS database for all children (, 16 years) transported by helicopter to a level 1 trauma center between January 2007 and December 2012. A total number of 430 patients were transported by helicopter to a hospital (0-87 years, mean 5 31.6 years). Of these patients, 83 (19%) were younger than 16 years (0-15.7 years, mean 5 6.6 years). Causes for HEMS transport in children varied, but the main groups were road traffic accidents (40%), cardiopulmonary arrests (15%), falls from height (12%), and horse riding accidents (7%). In the children group, 1 accidental extubation of the orotracheal tube was noted while lifting the patient (10 years old) into the helicopter. This was immediately noticed, and the patient was reintubated without complications. No further adverse events were encountered during transportation time. The accidental extubation is not a specific complication of helicopter transportation but is inextricably linked with moving severely injured and intubated patients/children. We conclude that transporting children by helicopter is a safe method of transportation for critically ill children to adequately equipped medical centers. Copyright © 2014 Air Medical Journal Associates. Published by Elsevier Inc. All rights reserved.

  16. Inner-city and park-tour services using ultralight muscle solar-energy vehicles; Innerstaedtische und Park-Mobil-Dienste mit ultraleichten Muskel-Solar-Mobilen

    Energy Technology Data Exchange (ETDEWEB)

    Ruehlmann, K. [Technische Univ. Dresden (Germany). Fakultaet fuer Mathematik und Naturwissenschaften; Scharnowski, E. [Burg Giebichenstein Hochschule fuer Kunst und Design, Halle (Germany)

    1998-06-01

    IUPARD is a project, investigated at the University of Dresden. The word IUPARD is an acronym for, in German, city-sightseeing and park-tour services using ultralight muscle solar-energy mobiles. The aims of the project are, to develop UMS (ultralight muscle solar-energy vehicles) which use regenerative energies, thereby pointing at the global energy problems of our epoch, to contribute to a new ecologically safe and charming mobility of men in the city, in recreation or entertainment parks, in recreation areas or health resorts, and to create new jobs by the design and production of solar mobiles as well as by the running of solar mobile services and solar mobile rental services. In connection with these there need to be established technical standards for the registration of solar mobiles, legal regulations for the running of solar mobiles in the city-traffic, in pedestrian zones or in closed areas like recreation parks, exhibitions or zoological gardens, regulations concerning the insurance of solar mobiles, their drivers and their passengers, and calculations of the economic efficiency of solar mobile services and solar mobile rental services. (orig.)

  17. Idiopathic Syringomyelia in a Military Helicopter Pilot.

    Science.gov (United States)

    Schiemer, Anthony

    2017-10-01

    A syrinx is a fluid-filled cavity within the spinal cord. They can lead to a variety of symptoms, including limb weakness and back pain. Incidental finding of syringomyelia provides a challenge for clinicians due to the wide variety of possible symptoms. In military aviation, neurological findings in pilots can result in extensive investigation that can lead to potentially invasive management. Conversely, the potential for chronic progression of a spinal syrinx and subsequent neurological deterioration makes early identification critical. Ultimately, the discovery of a lesion may have implications for flying status and operational capability. A 25-yr-old man working as a navy Seahawk helicopter pilot presented with episodes of right arm paraesthesia and pain between the scapulae. On at least one occasion, these symptoms woke him at night. Upon magnetic resonance imaging, dilatation of the central canal in a syrinx-like pattern in the lower cervical region was noted. Neurology review suggested the finding was persistent and unlikely to be responsible for his symptoms. No surgical input was recommended. His symptoms were attributed to mild cervical spondylosis, which resolved with ongoing physiotherapy, and he was returned to flying status. This case highlights several issues involved with the incidental finding of a syringomyelia. Surgical intervention has been known to worsen symptoms. Conversely, studies have identified minimal radiological progression in cases of idiopathic syringomyelia, with fewer individuals displaying neurological deterioration. For aircrew, potentially unnecessary neurosurgical intervention poses risks to a flying career and overall operational capability.Schiemer A. Idiopathic syringomyelia in a military helicopter pilot. Aerosp Med Hum Perform. 2017; 88(10):962-965.

  18. THE COMPARATIVE ECONOMIC-MATHEMATICAL ANALYSIS OF EFFICIENCY OF APPLICATION ON THE ACW OF THE ULTRALIGHT X-32 "BEKAS" PLANE AND THE MOTOR HANG-GLIDER MD-50S

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available In this article the comparative economic-mathematical analysis of size of profit per a flight hour on use at the avia- tion-chemical works (ACW of two types of super light aircraft X-32 “Bekas” and a glider MD-50S which are widely used when cultivating farmland nowadays. The list of indicators which are used while carrying out the comparative technical and economic analysis of considered ultralights is given at the beginning of the article. Further their numerical values nec- essary for computations are given. The mathematical formula for calculation with use of the given data of profit on carrying out ACW with use of the considered models of the aircraft equipment is presented. Values of profit are calculated by means of the tabular Microsoft Excel editor for various values of cultivated farmland length and distance of approach from airfield to the cultivated plot. The applied values of cultivated farmland length lie in the range from 0.5 to 10 kilometers, and ap-proach distances vary from 0.5 to 2 kilometers respectively. Calculations are executed for each of two compared ultralights and results are given in a tabular form respectively. On the basis of the analysis of the obtained tabular data conclusions are drawn under what values of input and variables in the form of farmland length and distance of approach profit margin for each of two ultralights will be larger or smaller in comparison with each other. In the final part of article total conclusions about the most preferable ultralight of two compared for operation in fields of various configuration during ACW are drawn. At the end recommendations to the aviation enterprises about application of the most expedient option of ultralight for obtaining bigger profit margin on carrying out ACW.

  19. Helicopter rotor noise investigation during ice accretion

    Science.gov (United States)

    Cheng, Baofeng

    An investigation of helicopter rotor noise during ice accretion is conducted using experimental, theoretical, and numerical methods. This research is the acoustic part of a joint helicopter rotor icing physics, modeling, and detection project at The Pennsylvania State University Vertical Lift Research Center of Excellence (VLRCOE). The current research aims to provide acoustic insight and understanding of the rotor icing physics and investigate the feasibility of detecting rotor icing through noise measurements, especially at the early stage of ice accretion. All helicopter main rotor noise source mechanisms and their change during ice accretion are discussed. Changes of the thickness noise, steady loading noise, and especially the turbulent boundary layer - trailing edge (TBL-TE) noise due to ice accretion are identified and studied. The change of the discrete frequency noise (thickness noise and steady loading noise) due to ice accretion is calculated by using PSU-WOPWOP, an advanced rotorcraft acoustic prediction code. The change is noticeable, but too small to be used in icing detection. The small thickness noise change is due to the small volume of the accreted ice compared to that of the entire blade, although a large iced airfoil shape is used. For the loading noise calculation, two simplified methods are used to generate the loading on the rotor blades, which is the input for the loading noise calculation: 1) compact loading from blade element momentum theory, icing effects are considered by increasing the drag coefficient; and 2) pressure loading from the 2-D CFD simulation, icing effects are considered by using the iced airfoil shape. Comprehensive rotor broadband noise measurements are carried out on rotor blades with different roughness sizes and rotation speeds in two facilities: the Adverse Environment Rotor Test Stand (AERTS) facility at The Pennsylvania State University, and The University of Maryland Acoustic Chamber (UMAC). In both facilities the

  20. Procedural guide for modelling and analyzing the flight characteristics of a helicopter design using Flightlab

    OpenAIRE

    McVaney, Gary P.

    1993-01-01

    Approved for public release; distribution is unlimited. This thesis presents one method for modelling and analyzing a helicopter design using Flightlab. Flightlab is a computer program that provides for engineering design, analysis and simulation of aircraft using non-linear dynamic modeling techniques. The procedure to model a single main rotor helicopter is outlined using the sample helicopter design in the book 'Helicopter Performance, Stability, and Control' by Ray Prouty. The analysis...

  1. Optimal Aerodynamic Design of Conventional and Coaxial Helicopter Rotors in Hover and Forward Flight

    Science.gov (United States)

    2015-12-28

    SECURITY CLASSIFICATION OF: This dissertation investigates the optimal aerodynamic performance and design of conventional and coaxial helicopters...Approved for public release; distribution is unlimited. Optimal Aerodynamic Design of Conventional andCoaxial Helicopter Rotors in Hover and ForwardFlight...Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 rotor aerodynamics , optimal aerodynamics , hover, compund helicopters REPORT

  2. Helicopter Parenting: The Effect of an Overbearing Caregiving Style on Peer Attachment and Self-Efficacy

    Science.gov (United States)

    van Ingen, Daniel J.; Freiheit, Stacy R.; Steinfeldt, Jesse A.; Moore, Linda L.; Wimer, David J.; Knutt, Adelle D.; Scapinello, Samantha; Roberts, Amber

    2015-01-01

    Helicopter parenting, an observed phenomenon on college campuses, may adversely affect college students. The authors examined how helicopter parenting is related to self-efficacy and peer relationships among 190 undergraduate students ages 16 to 28 years. Helicopter parenting was associated with low self-efficacy, alienation from peers, and a lack…

  3. 78 FR 44050 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2013-07-23

    ... Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed... Deutschland GmbH (Eurocopter) Model EC135P2+ and EC135T2+ helicopters. This proposed AD would require... the following new airworthiness directive (AD): Eurocopter Deutschland GmbH Helicopters: Docket No...

  4. 77 FR 42958 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2012-07-23

    ... Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT... Eurocopter Deutschland GmbH (ECD) Model MBB-BK 117 (all versions) and BO-105LS A-3 helicopters. This AD... directive (AD): 2012-13-11 Eurocopter Deutschland GmbH Helicopters: Amendment 39- 17113; Docket No. FAA-2012...

  5. Terfenol-D driven flaps for helicopter vibration reduction

    Science.gov (United States)

    Fenn, Ralph C.; Downer, James R.; Bushko, Dariusz A.; Gondhalekar, Vijay; Ham, Norman D.

    1996-02-01

    The utility of helicopter aviation is limited by the high vibration levels caused by the interaction of each rotor blade with the wake of preceding blades. Existing full-blade actuation using a swashplate has various problems such as insufficient bandwidth, limitations in the number of harmonics controlled, high maintenance, and lack of spanwise lift variation. These problems are avoided by the proposed flap operated, individual blade control system, which uses magnetostrictive actuation technology. Terfenol-D actuation has many advantages over competing technologies such as hydraulic systems, electric motors, and piezoelectric elements. These benefits include all-electric operation, simplicity and reliability, low mass, low voltage, and insensitivity to centripetal acceleration. A blade mounted Terfenol-D actuator was developed for the high-weight-penalty helicopter application. The optimum coil to Terfenol-D volume ratio was derived that gives the highest mechanical power output for a small actuator envelope and mass. A fixed ability to dissipate coil resistive losses is assumed. The magnetostrictive actuation system will weigh less than 1% of gross vehicle weight, and use only 0.7% of cruise power. Other required subsystems of the vibration reduction system are available from commercial sources or are described in the literature. Helicopter vibration reduction greater than 90% is predicted because of superior actuator performance and individual blade control. This magnetostrictive actuator technology will also produce future helicopter systems having lower noise and higher performance. Such advances will significantly improve the utility and competitiveness of helicopters for civilian and military transportation.

  6. A VORTEX MODEL OF A HELICOPTER ROTOR

    Directory of Open Access Journals (Sweden)

    Valentin BUTOESCU

    2009-06-01

    Full Text Available A vortex model of a helicopter rotor is presented. Each blade of the rotor has three degrees of freedom: flapping, lagging and feathering. The motions after each degree of freedom are also known for all blades. The blade is modelled as a thin vortex surface. The wakes are free fluid surfaces. A system of five equations are obtained: the first one is the integral equation of the lifting surface (rotor, the next three describe the wakes motion, and the last one relates the vortex strength on the wakes and the variation of vorticity on the rotor. A numerical solution of this system is presented. To avoid the singularities that can occur due to the complexity of vortex system, a desingularized model of the vortex core was adopted. A Mathcad worksheet containing the method has been written.The original contribution of the work. The calculation method of the motion of the wakes free vortex system, the development of the vortex cores in time and a new method to approximate the aerodynamic influence of remoted wake regions.

  7. Flap motion of helicopter rotors with novel, dynamic stall model

    Directory of Open Access Journals (Sweden)

    Han Wei

    2016-01-01

    Full Text Available In this paper, a nonlinear flapping equation for large inflow angles and flap angles is established by analyzing the aerodynamics of helicopter blade elements. In order to obtain a generalized flap equation, the Snel stall model was first applied to determine the lift coefficient of the helicopter rotor. A simulation experiment for specific airfoils was then conducted to verify the effectiveness of the Snel stall model as it applies to helicopters. Results show that the model requires no extraneous parameters compared to the traditional stall model and is highly accurate and practically applicable. Based on the model, the relationship between the flapping angle and the angle of attack was analyzed, as well as the advance ratio under the dynamic stall state.

  8. Cognitive perspectives on map displays for helicopter flight

    Science.gov (United States)

    Harwood, Kelly

    1989-01-01

    Currently accessible technologies are providing entirely new display concepts for enhancing helicopter navigation. Yet the effectiveness of such displays depends on the extent to which they are configured according to principles from research on human performance. Computer generated map displays in the present study were configured according to previous research on maps, navigational problem solving, and spatial cognition in large scale environments. Interest centered on the representation of different spatial relationships that would best support helicopter navigational problem solving. One map display emphasized the global relationships between objects in the environment. The other map showed the pilot's relationship to objects as he traveled through the environment. Twenty skilled pilots used the maps to complete several navigational tasks that occurred within a realistic simulation program tailored for helicopter navigation. Findings indicate that the type of task and mode of flight (low level or Nap of the Earth (NOE)) are important determinants of map display effectiveness.

  9. Deterministic learning enhanced neutral network control of unmanned helicopter

    Directory of Open Access Journals (Sweden)

    Yiming Jiang

    2016-11-01

    Full Text Available In this article, a neural network–based tracking controller is developed for an unmanned helicopter system with guaranteed global stability in the presence of uncertain system dynamics. Due to the coupling and modeling uncertainties of the helicopter systems, neutral networks approximation techniques are employed to compensate the unknown dynamics of each subsystem. In order to extend the semiglobal stability achieved by conventional neural control to global stability, a switching mechanism is also integrated into the control design, such that the resulted neural controller is always valid without any concern on either initial conditions or range of state variables. In addition, deterministic learning is applied to the neutral network learning control, such that the adaptive neutral networks are able to store the learned knowledge that could be reused to construct neutral network controller with improved control performance. Simulation studies are carried out on a helicopter model to illustrate the effectiveness of the proposed control design.

  10. Robust Helicopter Stabilization in the Face of Wind Disturbance

    DEFF Research Database (Denmark)

    A. Danapalasingam, Kumeresan; Leth, John-Josef; la Cour-Harbo, Anders

    2010-01-01

    When a helicopter is required to hover with minimum deviations from a desired position without measurements of an affecting persistent wind disturbance, a robustly stabilizing control action is vital. In this paper, the stabilization of the position and translational velocity of a nonlinear...... controller is then designed based on nonlinear adaptive output regulations and robust stabilization of a chain of integrators by a saturated feedback. Simulation results show the effectiveness of the control design in the stabilization of helicopter motion and the built-in robustness of the controller...... helicopter model affected by a wind disturbance is addressed. The wind disturbance is assumed to be a sum of a fixed number of sinusoids with unknown amplitudes, frequencies and phases. An estimate of the disturbance is introduced to be adapted using state measurements for control purposes. A nonlinear...

  11. Development and evaluation of a generic active helicopter vibration controller

    Science.gov (United States)

    Davis, M. W.

    1984-01-01

    A computerized generic active controller is developed, which alleviates helicopter vibration by closed-loop implementation of higher harmonic control (HHC). In the system, the higher harmonic blade pitch is input through a standard helicopter swashplate; for a four-blade helicopter rotor the 4/rev vibration in the rotorcraft is minimized by inducing cyclic pitch motions at 3, 4, and 5/rev in the rotating system. The controller employs the deterministic, cautious, and dual control approaches and two linear system models (local and global), as well as several methods of limiting control. Based on model testing, performed at moderate to high values of forward velocity and rotor thrust, reductions in the rotor test apparatus vibration from 75 to 95 percent are predicted, with HHC pitch amplitudes of less than one degree. Good performance is also noted for short-duration maneuvers.

  12. Registration of Melting and Crystallization Process of Ultra-light Weight MgLi12,5 Alloy with Use of ATND Method

    Directory of Open Access Journals (Sweden)

    A. Białobrzeski

    2012-04-01

    Full Text Available To the main advantages of magnesium alloys belongs their low density, and just because of such property the alloys are used in aviation and rocket structures, and in all other applications, where mass of products have significant importance for conditions of their operation. To additional advantages of the magnesium alloys belongs good corrosion resistance, par with or even surpassing aluminum alloys. Magnesium is the lightest of all the engineering metals, having a density of 1.74 g/cm3. It is 35% lighter than aluminum (2.7 g/cm3 and over four times lighter than steel (7.86 g/cm3. The Mg-Li alloys belong to a light-weight metallic structural materials having mass density of 1.35-1.65 g/cm3, what means they are two times lighter than aluminum alloys. Such value of mass density means that density of these alloys is comparable with density of plastics used as structural materials, and therefore Mg–Li alloys belong to the lightest of all metal alloys. In the present paper are discussed melting and crystallization processes of ultra-light weight MgLi12,5 alloys recorded with use of ATND methods. Investigated magnesium alloy was produced in Krakow Foundry Research Institute on experimental stand to melting and casting of ultra-light weight alloys. Obtained test results in form of recorded curves from ATND methods have enabled determination of characteristic temperatures of phase transitions of the investigated alloy.

  13. Helicopter emergency medical service in Italy: reality and perspectives.

    Science.gov (United States)

    Marinangeli, Franco; Tomei, Marco; Ursini, Maria Laura; Ricotti, Valeria; Varrassi, Giustino

    2007-01-01

    The organization of a homogeneous medical emergency system was developed in Italy in 1999. Currently, 104 stations manage medical emergencies with ambulances and 47 helicopter-capable bases for more difficult missions. The current study describes the organization of the helicopter emergency system in Italy. Data were collected from questionnaires filled in by each base commander. Six hundred twenty-seven physicians are enrolled in helicopter-capable base emergency teams. Of those physicians, 89.5% are specialists in anesthesiology. Professional nurses are enrolled in 46 bases. Twenty-six bases specialize in search-and-rescue (SAR) missions (which take place in geographically unfriendly terrain), where a mountain rescue technician (CNSAS) is part of the team. Twenty-one bases are for missions in geographically friendly terrain (HEMS bases). Eight bases provide 24-hour service. Specialized training is given to physicians and nurses: it is considered of first level (high standard) in 21 bases, of second level (intermediary) in 17 bases, and of third level (low) in nine bases. In the mountain bases (Alps and Apennines), the more widely used helicopters are the AB412 and the BK117C1. During 2004, there were 20,660 primary interventions and 7,790 secondary interventions. From 1999 to 2004 there was a 33% increase of activity for primary and 35% for secondary interventions. The data show the activity of the helicopter-ambulance service, the role of anesthetists within the helicopter-based Advanced Cardiac Life Support (ACLS) team, and the diverse organization of training for medical staff in different regions of Italy.

  14. CH-53K Heavy Lift Replacement Helicopter (CH-53K)

    Science.gov (United States)

    2015-12-01

    Selected Acquisition Report (SAR) RCS: DD-A&T(Q&A)823-390 CH-53K Heavy Lift Replacement Helicopter (CH-53K) As of FY 2017 President’s Budget...December 2015 SAR March 4, 2016 10:04:18 UNCLASSIFIED 4 Col Henry Vanderborght PMA-261 Heavy Lift Helicopters Program Executive Office - Air, Anti...757-5780 Fax: 301-757-5109 DSN Phone: 757-5780 DSN Fax: 757-5109 Date Assigned: May 29, 2014 Program Information Program Name CH-53K Heavy Lift

  15. Helicopter air resonance modeling and suppression using active control

    Science.gov (United States)

    Takahashi, M. D.; Friedmann, P. P.

    1991-01-01

    A coupled rotor/fuselage helicopter analysis with the important effects of blade torsional flexibility, unsteady aerodynamics, and forward flight is presented. Using this mathematical model, a nominal configuration is selected with an air resonance instability throughout most of its flight envelope. A multivariable compensator is then designed using two swashplate inputs and a single-body roll rate measurement. The controller design is based on the linear quadratic Gaussian technique and the loop transfer recovery method. The controller is shown to suppress the air resonance instability throughout a wide range of helicopter loading conditions and forward flight speeds.

  16. Comparison of acoustic performance of five muffler configurations on a small helicopter. [acoustic properties of modified helicopter exhaust system

    Science.gov (United States)

    Pegg, R. J.; Hilton, D. A.

    1974-01-01

    A field noise measurement program has been conducted on a standard Bell 47 series helicopter and on one that had been modified with specially designed, airframe-mounted mufflers to reduce the engine exhaust noise. The purpose of the study was to evaluate the acoustic performance of five experimental exhaust muffler configurations for a helicopter reciprocating engine in an operational environment. All muffler configurations produced beneficial engine exhaust noise reductions but some configurations were markedly better than others. Flyover noise results indicated that maximum overall noise reductions of approximately 8 db were obtained with the various mufflers. The rotor noise was judged to be the dominant noise component for the muffler-equipped helicopters whereas the engine noise was the dominant component for the basic configuration.

  17. Acoustic Helicopter and FW Aircraft Detection and Classification

    NARCIS (Netherlands)

    Koersel, A.C. van

    2001-01-01

    The possibility to detect the passage of aircraft (either propeller or jet) with one or more mechanical wave sensors (acoustic or seismic) is investigated. An existing algorithm-sensor demonstator can detect and classify helicopter targets. In its current form it is developed to reject other

  18. Using Paper Helicopters to Teach Statistical Process Control

    Science.gov (United States)

    Johnson, Danny J.

    2011-01-01

    This hands-on project uses a paper helicopter to teach students how to distinguish between common and special causes of variability when developing and using statistical process control charts. It allows the student to experience a process that is out-of-control due to imprecise or incomplete product design specifications and to discover how the…

  19. 78 FR 9634 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-02-11

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Eurocopter France...). SUMMARY: We propose to adopt a new airworthiness directive (AD) for Eurocopter France (Eurocopter) Model... directive (AD): Eurocopter France Helicopters (Eurocopter): Docket No. FAA-2013- 0119; Directorate...

  20. 78 FR 51115 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-08-20

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Eurocopter France...). SUMMARY: We propose to adopt a new airworthiness directive (AD) for certain Eurocopter France (Eurocopter...): Eurocopter France (Eurocopter) Helicopters: Docket No. FAA-2013- 0737; Directorate Identifier 2012-SW-111-AD...

  1. 77 FR 64706 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2012-10-23

    ...-064-AD; Amendment 39-17225; AD 2012-21-09] RIN 2120-AA64 Airworthiness Directives; Eurocopter France... France (Eurocopter) Model EC225 helicopters with certain epicyclic modules installed. This AD requires...): 2012-21-09 Eurocopter France: Amendment 39-17225; Docket No. FAA- 2012-1128; Directorate Identifier...

  2. 78 FR 40072 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-07-03

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Eurocopter France... France (Eurocopter) Model AS332C1 and AS332L1 helicopters. This proposed AD would require replacing the.... 39.13 by adding the following new airworthiness directive (AD): Eurocopter France: Docket No. FAA...

  3. 78 FR 40045 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-07-03

    ... Directives; Eurocopter France Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice... (AD) for Eurocopter France (Eurocopter) Model AS350B, BA, B1, B2, B3, D, AS355E, F, F1, F2, and N..., October 14, 2010), and adding the following new AD: Eurocopter France: Docket No. FAA-2013-0354...

  4. 78 FR 23107 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-04-18

    ...-32-AD; Amendment 39-17424; AD 2013-08-07] RIN 2120-AA64 Airworthiness Directives; Eurocopter France... new airworthiness directive (AD) for Eurocopter France (ECF) Model AS332C, L, and L1 helicopters to...): 2013-08-07 Eurocopter France: Amendment 39-17424; Docket No. FAA- 2012-1087; Directorate Identifier...

  5. 78 FR 54380 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-09-04

    ...-060-AD; Amendment 39-17565; AD 2013-17-01] RIN 2120-AA64 Airworthiness Directives; Eurocopter France... new airworthiness directive (AD) for certain Eurocopter France (Eurocopter) Model AS350 and AS355...): 2013-17-01 Eurocopter France Helicopters: Amendment 39-17565; Docket No. FAA-2013-0240; Directorate...

  6. 78 FR 25365 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-05-01

    ...-52-AD; Amendment 39-17437; AD 2013-08-19] RIN 2120-AA64 Airworthiness Directives; Eurocopter France... new airworthiness directive (AD) for Eurocopter France (Eurocopter) Model AS350B, AS350BA, AS350B1...): ] 2013-08-19 Eurocopter France Helicopters: Amendment 39-17437; Docket No. FAA-2009-0951; Directorate...

  7. 78 FR 60188 - Airworthiness Directives; Eurocopter France (Eurocopter) Helicopters

    Science.gov (United States)

    2013-10-01

    ...-035-AD; Amendment 39-17601; AD 2013-19-19] RIN 2120-AA64 Airworthiness Directives; Eurocopter France (Eurocopter) Helicopters AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT... amends Sec. 39.13 by adding the following new airworthiness directive (AD): 2013-19-19 Eurocopter France...

  8. 78 FR 24041 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-04-24

    ... directive (EAD) for Eurocopter France (Eurocopter) Model AS350B3 helicopters with certain part-numbered...): 2012-25-04 Eurocopter France: Amendment 39-17285; Docket No. FAA- 2012-1297; Directorate Identifier 2012-SW-100-AD. (a) Applicability This AD applies to Eurocopter France (Eurocopter) Model AS350B3...

  9. 78 FR 33766 - Airworthiness Directives; Eurocopter France (Eurocopter) Helicopters

    Science.gov (United States)

    2013-06-05

    ... Directives; Eurocopter France (Eurocopter) Helicopters AGENCY: Federal Aviation Administration (FAA), DOT... adding the following new airworthiness directive (AD): Eurocopter France (Eurocopter): Docket No. FAA... (AD) for Eurocopter Model SA-365N, SA-365N1, AS-365N2, AS 365 N3, EC 155B, EC155B1, AS332C, AS332L...

  10. 77 FR 50582 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2012-08-22

    ... are adopting a new airworthiness directive (AD) for Eurocopter France Model EC155B and EC155B1... Eurocopter France Model EC155B and EC155B1 helicopters with a VIP 4-seat bench. That NPRM proposed to require... airworthiness directive (AD): 2012-16-02 Eurocopter France: Amendment 39-17149; Docket No. FAA- 2012-0177...

  11. 77 FR 58971 - Airworthiness Directives; Eurocopter France (Eurocopter) Helicopters

    Science.gov (United States)

    2012-09-25

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Eurocopter France (Eurocopter) Helicopters AGENCY: Federal Aviation Administration (FAA) DOT. ACTION: Notice of proposed.... The FAA amends Sec. 39.13 by adding the following new airworthiness directive (AD): Eurocopter France...

  12. 77 FR 14310 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2012-03-09

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Eurocopter France...). SUMMARY: We propose to adopt a new airworthiness directive (AD) for certain Eurocopter France Model AS350... Directive (AD): Eurocopter France Helicopters: Docket No. FAA-2012-0222; Directorate Identifier 2011-SW-007...

  13. 77 FR 44118 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2012-07-27

    ...-056-AD; Amendment 39-17133; AD 2012-15-04] RIN 2120-AA64 Airworthiness Directives; Eurocopter France... France (Eurocopter) Model EC155B1 helicopters with a certain automated flight control system installed...): ] 2012-15-04 EUROCOPTER FRANCE: Amendment 39-17133; Docket No. FAA- 2012-0766; Directorate Identifier...

  14. 78 FR 66668 - Airworthiness Directives; Eurocopter France (Eurocopter) Helicopters

    Science.gov (United States)

    2013-11-06

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Eurocopter France... airworthiness directive (AD): Eurocopter France Helicopters: Docket No. FAA-2013-0938; Directorate Identifier 2012-SW-057-AD. (a) Applicability This AD applies to Eurocopter France (Eurocopter) Model SA-365N, SA...

  15. 78 FR 44422 - Airworthiness Directives; Eurocopter France (Eurocopter) Helicopters

    Science.gov (United States)

    2013-07-24

    ...-026-AD; Amendment 39-17519; AD 2013-15-03] RIN 2120-AA64 Airworthiness Directives; Eurocopter France (Eurocopter) Helicopters AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT... amends Sec. 39.13 by adding the following new airworthiness directive (AD): 2013-15-03 Eurocopter France...

  16. 78 FR 60681 - Airworthiness Directives; Eurocopter France (Eurocopter) Helicopters

    Science.gov (United States)

    2013-10-02

    ...-090-AD; Amendment 39-17589; AD 2013-19-07] RIN 2120-AA64 Airworthiness Directives; Eurocopter France (Eurocopter) Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We...): 2013-19-07 Eurocopter France (Eurocopter): Amendment 39-17589; Docket No. FAA-2013-0480; Directorate...

  17. Swing Damping for Helicopter Slung Load Systems using Delayed Feedback

    DEFF Research Database (Denmark)

    Bisgaard, Morten; la Cour-Harbo, Anders; Bendtsen, Jan Dimon

    2009-01-01

    helicopters. The delayed feedback controller is added to actively reduce oscillations of the slung load by improving the damping of the slung load pendulum modes. Furthermore, it is intended for integration with a feedforward control scheme based on input shaping for concurrent avoidance and dampening...

  18. 78 FR 63853 - Airworthiness Directives; Eurocopter France (Eurocopter) Helicopters

    Science.gov (United States)

    2013-10-25

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION... pitch horn, loss of the anti-torque function, and subsequent loss of control of the helicopter. DATES.... FOR FURTHER INFORMATION CONTACT: Robert Grant, Aviation Safety Engineer, Safety Management Group, FAA...

  19. Nonlinear Feedforward Control for Wind Disturbance Rejection on Autonomous Helicopter

    DEFF Research Database (Denmark)

    Bisgaard, Morten; la Cour-Harbo, Anders; A. Danapalasingam, Kumeresan

    2010-01-01

    for the purpose. The model is inverted for the calculation of rotor collective and cyclic pitch angles given the wind disturbance. The control strategy is then applied on a small helicopter in a controlled wind environment and flight tests demonstrates the effectiveness and advantage of the feedforward controller....

  20. 77 FR 69556 - Airworthiness Directives; Eurocopter Deutschland Helicopters

    Science.gov (United States)

    2012-11-20

    ... . You may review the referenced service information at the FAA, Office of the Regional Counsel...: George Schwab, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Safety Management Group, 2601... continued safe flight and landing, and subsequent loss of control of the helicopter. The European Aviation...

  1. Application of Floquet Theory to Helicopter Blade Flapping Stability.

    Science.gov (United States)

    1984-12-01

    34Aeroelastic Stability of Trimmed Helicopter Blades in Forward Flight," Vertica, 1: 189-211 (1977). 11. Friedmann, P. and L.J. Silverthorn ...8217, . ... ’ .. _2 J .e> ..e’ , . . > e . "’. e ’ -, .; ... ,. 13. Friedmann, P. and L.J. Silverthorn . "Aeroelastic Stability of Periodic

  2. Helicopters in Irregular Warfare: Algeria, Vietnam, and Afghanistan

    Science.gov (United States)

    2013-06-13

    caused safety concerns by limiting visibility for gunship support and increasing accident frequency at remote LZs. Even with the detrimental effects of...without much regard for political goals. Helicopters proved they were able to ensure tactical military dominance, if applied correctly. Drunk on the

  3. Enhancing Public Helicopter Safety as a Component of Homeland Security

    Science.gov (United States)

    2016-12-01

    flight rules 2. Crew endurance (pilot rest) 3. Pre-flight risk assessments Each of these risk categories are codes used to analyze the three ...FLIGHT RULES RATING A factor in all three helicopter crashes studied in this thesis was inclement weather. To prevent future accidents due to poor...13 E. ACCIDENT REPORTS ................................................................. 16 1. Overview of the New Mexico

  4. 77 FR 39911 - The New York North Shore Helicopter Route

    Science.gov (United States)

    2012-07-06

    ..., shall prescribe * * * (ii) regulations to control and abate aircraft noise * * *'' I. Executive Summary... function of filters in the survey that are designed to focus on helicopters that are actively flown. \\2... terminal traffic away from the Oberlin College Conservatory of Music to avoid audible disturbances; 35 FR...

  5. 78 FR 38826 - Airworthiness Directives; Various Helicopter Models

    Science.gov (United States)

    2013-06-28

    ... inspection test, and recording the results on the hoist component history card or equivalent record. The... European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union. EASA issued AD 2013-0065-E to correct an unsafe condition for helicopters with certain part...

  6. At Issue: Helicopter Parents and Millennial Students, an Annotated Bibliography

    Science.gov (United States)

    Pricer, Wayne F.

    2008-01-01

    Technological advances have made it easy for parents and children--many of them students--to communicate instantaneously. Devices and technologies such as cell phones, laptops, texting, and e-mail all enable various forms of instant communication. "Helicopter parents" are regarded as very overprotective and overly involved in the affairs of their…

  7. From Self-Flying Helicopters to Classrooms of the Future

    Science.gov (United States)

    Young, Jeffrey R.

    2012-01-01

    On a summer day four years ago, a Stanford University computer-science professor named Andrew Ng held an unusual air show on a field near the campus. His fleet of small helicopter drones flew under computer control, piloted by artificial-intelligence software that could teach itself to fly after watching a human operator. By the end of the day,…

  8. 78 FR 23462 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-04-19

    ...-serivce (TIS) and before installing a MGB on any applicable helicopter. AD 2012-01-03, Amendment 39-16914... substantial direct effect on the States, on the relationship between the national Government and the States...) You may view this service information that is incorporated by reference at the National Archives and...

  9. 78 FR 59298 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-09-26

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Eurocopter France...). SUMMARY: We propose to revise airworthiness directive (AD) 2011-22-05 for Eurocopter France (Eurocopter... These helicopters have been approved by the aviation authority of France and are approved for operation...

  10. 78 FR 59306 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-09-26

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Eurocopter France...). SUMMARY: We propose to adopt a new airworthiness directive (AD) for Eurocopter France (Eurocopter) Model... helicopters have been approved by the aviation authority of France and ] are approved for operation in the...

  11. 78 FR 65871 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-11-04

    ... France Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for Eurocopter France (Eurocopter) Model AS332C... aviation authority of France and are approved for operation in the United States. Pursuant to our bilateral...

  12. 78 FR 69989 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-11-22

    ...-091-AD; Amendment 39-17664; AD 2013-23-09] RIN 2120-AA64 Airworthiness Directives; Eurocopter France... new airworthiness directive (AD) for Eurocopter France (Eurocopter) Model AS350B, AS350BA, AS350B1... These helicopters have been approved by the aviation authority of France and are approved for operation...

  13. Model predictive control of a 3-DOF helicopter system using ...

    African Journals Online (AJOL)

    ... by simulation, and its performance is compared with that achieved by linear model predictive control (LMPC). Keywords: nonlinear systems, helicopter dynamics, MIMO systems, model predictive control, successive linearization. International Journal of Engineering, Science and Technology, Vol. 2, No. 10, 2010, pp. 9-19 ...

  14. 77 FR 58794 - Airworthiness Directives; Bell Helicopter Textron, Inc.

    Science.gov (United States)

    2012-09-24

    ... swashplate outer ring assemblies (outer ring). This AD would establish a lower life limit on certain outer... Bell Model 412 and 412EP helicopters, with a swashplate outer ring assembly (outer ring), part number... Component (JASC) Code: 6230, Main Rotor Mast/Swashplate. Issued in Fort Worth, Texas, on September 14, 2012...

  15. 78 FR 44043 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-07-23

    ... failure of the swashplate and subsequent loss of helicopter control. DATES: We must receive comments on... corrosion on the rotating and stationary swashplates under the retaining flanges of the swashplate sub... a rotating swashplate, part number (P/N) 332A31-3074-00 or 332A31-3076-00, and stationary swashplate...

  16. Routing helicopters for crew exchanges on off-shore locations

    NARCIS (Netherlands)

    Sierksma, G.; Tijssen, G.A.

    This paper deals with a vehicle routing problem with split demands, namely the problem of determining a flight schedule for helicopters to off-shore platform locations for exchanging crew people employed on these platforms. The problem is formulated as an LP model and solved by means of a

  17. Neuroevolutionary reinforcement learning for generalized control of simulated helicopters

    NARCIS (Netherlands)

    Koppejan, R.; Whiteson, S.

    2011-01-01

    This article presents an extended case study in the application of neuroevolution to generalized simulated helicopter hovering, an important challenge problem for reinforcement learning. While neuroevolution is well suited to coping with the domain’s complex transition dynamics and high-dimensional

  18. Neck Pain in Military Helicopter Pilots: Prevalence and Associated Factors

    NARCIS (Netherlands)

    van den Oord, Marieke H. A. H.; de Loose, Veerle; Meeuwsen, Ted; Sluiter, Judith K.; Frings-Dresen, Monique H. W.

    2010-01-01

    Our aim is to estimate the self-reported one-year prevalence of neck pain in military helicopter pilots and to compare work-related, individual, and health-related factors in the pilots with (neck pain group) and without (reference group) regular or continuous neck pain. A questionnaire was

  19. 78 FR 40954 - Airworthiness Directives; Various Restricted Category Helicopters

    Science.gov (United States)

    2013-07-09

    ...-1E, UH-1F, UH-1H, UH-1L, and UH-1P helicopters are: Arrow Falcon Exporters Inc.; AST, Inc.; Bell... Identifier 2011-SW-041- AD. (a) Applicability This AD applies to Arrow Falcon Exporters Inc.; AST, Inc.; Bell... of the P/N on the fitting's component history card or equivalent record. (f) Alternative Methods of...

  20. 78 FR 51127 - Airworthiness Directives; Various Restricted Category Helicopters

    Science.gov (United States)

    2013-08-20

    ... holders include but are not limited to Arrow Falcon Exporters Inc.; AST, Inc.; Bell Helicopter Textron...-1L, and UH- 1P; current type certificate holders include but are not limited to Arrow Falcon... cable assembly is terminating action for the inspections required by paragraph (e)(2) of this AD. (f...

  1. Physics Based Modeling of Helicopter Brownout for Piloted Simulation Applications

    Science.gov (United States)

    2008-12-01

    for over 40 years in many applications including erosion modeling, sand dune formation and nuclear blast waves (l-Iartenbaum, 1971; Mirels , 1984...Environment." American ’Helicopter Society 6I~\\ Annual Forum, Grapevine, TX, June 2005. Mirels , H. (1984). "Blowing Model for Turbolent BoundarywLayer Dust

  2. The need for a dedicated public service helicopter design

    Science.gov (United States)

    Morrison, R.

    1984-01-01

    The need to provide the necessary funding to research, design and contract the building of an advanced technology rotorcraft that will meet the mission demands of public service (fire, police, paramedics and rescue) operators is discussed. Noise and cost factors, the greatest objections on the part of many police and public adminstrators are addressed. The growth of helicopter utilization in public service is documented.

  3. 77 FR 58925 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2012-09-25

    ... tail rotor hub (TRH) for a crack and removing the TRH if a crack exists. This AD is prompted by reports of cracks on two TRHs. These actions are intended to prevent the tail rotor from jamming, which could...-365N1, AS-365N2 and AS 365 N3 helicopters. Eurocopter reported that a technician found cracks on the TRH...

  4. Helicopter blades running elevation measurement using omnidirectional vision

    Directory of Open Access Journals (Sweden)

    Chengtao CAI

    2017-12-01

    Full Text Available Omnidirectional dynamic space parameters of high-speed rotating helicopter blades are precise 3D vector description of the blades. In particular, the elevation difference is directly related to the aerodynamic performance and maneuverability of the helicopter. The state of the art detection techniques based on optics and common vision have several drawbacks, such as high demands on devices but poor extensibility, limited measurement range and fixed measurement position. In this paper, a novel approach of helicopter blades running elevation measurement is proposed based on omnidirectional vision. With the advantages of panoramic visual imaging integration, 360° field of view and rotation in-variance, high-resolution images of all rotating blades positions are obtained at one time. By studying the non-linear calibration and calculation model of omnidirectional vision system, aiming at solving the problem of inaccurate visual space mapping model, the omnidirectional and full-scale measurement of the elevation difference are finalized. Experiments are carried out on our multifunctional simulation blades test system and the practical blades test tower, respectively. The experimental results demonstrate the effectiveness of the proposed method and show that the proposed method can considerably reduce the complexity of measurement. Keywords: Full-scale measurement, Helicopter blades elevation, Non-linear calibration, Omnidirectional vision, Unified sphere model

  5. Feasibility study of a superconducting motor for electrical helicopter propulsion

    NARCIS (Netherlands)

    Simons, C.A.B.A.E.; Sanabria-Walter, C.; Polinder, H.

    2014-01-01

    During the past decades, superconducting electrical machines have become more suitable to replace conventional iron based designs, because of their lower weight and higher torque density. These properties make them good candidates for use in More Electric Aircraft (MEA). Especially helicopter

  6. 77 FR 32884 - Airworthiness Directives; Eurocopter Deutschland GMBH Helicopters

    Science.gov (United States)

    2012-06-04

    ... Deutschland GMBH Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. ] SUMMARY: We are adopting a new airworthiness directive (AD) for Eurocopter Deutschland GMBH (ECD) Model MBB-BK... EUROCOPTER DEUTSCHLAND GMBH: Amendment 39-17046; Docket No. FAA-2012-0101; Directorate Identifier 2010-SW-042...

  7. 78 FR 20234 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-04-04

    ... reports of deviations between the displayed attitude on the attitude display screen and the independent... display error of a slow drift in the roll axis, disorientation of the pilot, and subsequent loss of... helicopters, with the GV76-1 vertical gyro unit installed on the left-hand (LH) or right- hand (RH) shelf in...

  8. Recent developments in rotor wake modeling for helicopter noise prediction

    Science.gov (United States)

    Poling, D.; Dadone, L.; Althoff, S.

    1991-01-01

    A preliminary test/theory correlation evaluation is conducted for wake measurement test results obtained by LDV for a B360 helicopter rotor, at conditions critical to the understanding of wake-rollup and blade-vortex interaction phenomena. The LDV data were complemented by acoustic, blade pressure, rotor performance, and blade/control load measurements.

  9. Analog neural network-based helicopter gearbox health monitoring system.

    Science.gov (United States)

    Monsen, P T; Dzwonczyk, M; Manolakos, E S

    1995-12-01

    The development of a reliable helicopter gearbox health monitoring system (HMS) has been the subject of considerable research over the past 15 years. The deployment of such a system could lead to a significant saving in lives and vehicles as well as dramatically reduce the cost of helicopter maintenance. Recent research results indicate that a neural network-based system could provide a viable solution to the problem. This paper presents two neural network-based realizations of an HMS system. A hybrid (digital/analog) neural system is proposed as an extremely accurate off-line monitoring tool used to reduce helicopter gearbox maintenance costs. In addition, an all analog neural network is proposed as a real-time helicopter gearbox fault monitor that can exploit the ability of an analog neural network to directly compute the discrete Fourier transform (DFT) as a sum of weighted samples. Hardware performance results are obtained using the Integrated Neural Computing Architecture (INCA/1) analog neural network platform that was designed and developed at The Charles Stark Draper Laboratory. The results indicate that it is possible to achieve a 100% fault detection rate with 0% false alarm rate by performing a DFT directly on the first layer of INCA/1 followed by a small-size two-layer feed-forward neural network and a simple post-processing majority voting stage.

  10. 77 FR 70360 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2012-11-26

    ..., which caused a pilot to experience a heavy jerk in the yaw control during in-flight autorotation... experienced a heavy jerk in the yaw control at the time of resynchronization. The free-wheel assembly of the... loss of control of the helicopter. DATES: This AD is effective December 31, 2012. The Director of the...

  11. 78 FR 37154 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-06-20

    ... ``double lock'' the lower ball-joint bolts. Eurocopter designates the maintenance procedure and design..., with nut, P/N 22542K060, and lock-washer, P/N 23351AC060LE, on the lower ball-joint bolt. FAA's... develop on other helicopters of the same type design. Related Service Information Eurocopter has issued...

  12. The development of the nation's oldest operating civilian hospital-sponsored aeromedical helicopter service.

    Science.gov (United States)

    Thomas, F

    1988-06-01

    The Vietnam War heightened civilian awareness as to the use of helicopters for medical evacuations. This led to the initiation of federally funded projects aimed at determining whether helicopters were practical for civilian aeromedical transports. In 1972, a Department of Transportation (DOT) summary concluded that helicopters for civilian medical transports were largely economically prohibitive and provided limited medical benefits in limited locales. Despite this report, in 1972 St. Anthony Hospital initiated a hospital-based emergency medical helicopter service (HEMS). This paper provides a historical review of the individuals and events responsible for the early success of the nation's longest operating civilian hospital-sponsored helicopter service. The author concludes that the early success of this program was due in part to the selection of an affordable, high altitude, helicopter; rapid response times to the scene of injury; the development of excellent EMS communications systems; the use of specialty trained flight crewmembers; and integration of HEMS into the existing EMS system.

  13. Contributions to the dynamics of helicopters with active rotor controls

    Science.gov (United States)

    Malpica, Carlos A.

    This dissertation presents an aeromechanical closed loop stability and response analysis of a hingeless rotor helicopter with a Higher Harmonic Control (HHC) system for vibration reduction. The analysis includes the rigid body dynamics of the helicopter and blade flexibility. The gain matrix is assumed to be fixed and computed off-line. The discrete elements of the HHC control loop are rigorously modeled, including the presence of two different time scales in the loop. By also formulating the coupled rotor-fuselage dynamics in discrete form, the entire coupled helicopter-HHC system could be rigorously modeled as a discrete system. The effect of the periodicity of the equations of motion is rigorously taken into account by converting the system into an equivalent system with constant coefficients and identical stability properties using a time lifting technique. The most important conclusion of the present study is that the discrete elements in the HHC loop must be modeled in any HHC analysis. Not doing so is unconservative. For the helicopter configuration and HHC structure used in this study, an approximate continuous modeling of the HHC system indicates that the closed loop, coupled helicopter-HHC system remains stable for optimal feedback control configurations which the more rigorous discrete analysis shows can result in closed loop instabilities. The HHC gains must be reduced to account for the loss of gain margin brought about by the discrete elements. Other conclusions of the study are: (i) the HHC is effective in quickly reducing vibrations, at least at its design condition, although the time constants associated with the closed loop transient response indicate closed loop bandwidth to be 1 rad/sec on average, thus overlapping with FCS or pilot bandwidths, and raising the issue of potential interactions; (ii) a linearized model of helicopter dynamics is adequate for HHC design, as long as the periodicity of the system is correctly taken into account, i

  14. Modeling helicopter blade dynamics using a modified Myklestad-Prohl transfer matrix method

    OpenAIRE

    Cuesta, Juan D.

    1994-01-01

    Approved for public release, distribution unlimited Rotor blade vibratory stresses are of utmost importance in helicopter design. A modified Myklestad-Prohl method for rotating beams has been coded to assist in preliminary helicopter rotor blade design. The rotor blade dynamics program is part of the Joint Army/Navy Rotorcraft Analysis and Design (JANRAD) program which was developed to aid in the preliminary design and analysis of helicopter rotor performance, stability and control, and ro...

  15. MODELING, CONTROL AND NAVIGATION OF AN AUTONOMOUS QUAD-ROTOR HELICOPTER

    Directory of Open Access Journals (Sweden)

    Damir Šoštarić

    2016-06-01

    Full Text Available Autonomous outdoor quad-rotor helicopters increasingly attract the attention of potential researchers. Several structures and configurations have been developed to allow 3D movements. The quadrotor helicopter is made of a rigid cross frame equipped with four rotors. The autonomous quad-rotor architecture has been chosen for this research for its low dimension, good manoeuvrability, simple mechanics and payload capability. This article presents the modelling, control and navigation of an autonomous outdoor quad-rotor helicopter.

  16. Quadrotor helicopter for surface hydrological measurements

    Science.gov (United States)

    Pagano, C.; Tauro, F.; Porfiri, M.; Grimaldi, S.

    2013-12-01

    Surface hydrological measurements are typically performed through user-assisted and intrusive field methodologies which can be inadequate to monitor remote and extended areas. In this poster, we present the design and development of a quadrotor helicopter equipped with digital acquisition system and image calibration units for surface flow measurements. This custom-built aerial vehicle is engineered to be lightweight, low-cost, highly customizable, and stable to guarantee optimal image quality. Quadricopter stability guarantees minimal vibrations during image acquisition and, therefore, improved accuracy in flow velocity estimation through large scale particle image velocimetry algorithms or particle tracking procedures. Stability during the vehicle pitching and rolling is achieved by adopting large arm span and high-wing configurations. Further, the vehicle framework is composed of lightweight aluminum and durable carbon fiber for optimal resilience. The open source Ardupilot microcontroller is used for remote control of the quadricopter. The microcontroller includes an inertial measurement unit (IMU) equipped with accelerometers and gyroscopes for stable flight through feedback control. The vehicle is powered by a 3 cell (11.1V) 3000 mAh Lithium-polymer battery. Electronic equipment and wiring are hosted into the hollow arms and on several carbon fiber platforms in the waterproof fuselage. Four 35A high-torque motors are supported at the far end of each arm with 10 × 4.7 inch propellers. Energy dissipation during landing is accomplished by four pivoting legs that, through the use of shock absorbers, prevent the impact energy from affecting the frame thus causing significant damage. The data capturing system consists of a GoPro Hero3 camera and in-house built camera gimbal and shock absorber damping device. The camera gimbal, hosted below the vehicle fuselage, is engineered to maintain the orthogonality of the camera axis with respect to the water surface by

  17. Optimal control of helicopters following power failure. Helicopter no engine koshoji no saiteki hiko seigyo

    Energy Technology Data Exchange (ETDEWEB)

    Okuno, Y.

    1993-01-01

    In order to study the optimal control of helicopters, the control procedures following power failure were theoretically investigated by applying nonlinear optimal control theory to the following four optimization problems. The first was minimization of the touchdown speed following power failure. Comparisons between the calculated optimal solutions and the empirical flight test results showed that pilots used nonoptimal controls, especially in the timing and amplitude of the collective flare before touchdowns. The second was prediction of the height-velocity (H-V) boundaries. The calculated H-V boundaries showed good correlation with the flight test results. The third was optimization of the takeoff procedures for category A STOL operation following power failure. The results showed that the required takeoff distance using the normal takeoff procedure can be significantly reduced. The fourth was evaluation of the takeoff performance for category A VTOL operation. The calculating method of the maximum takeoff weight was confirmed, and possibility of allowing the payload to be increased was shown. 38 refs., 53 figs.

  18. Fluid mechanics mechanisms in the stall process of helicopters

    Science.gov (United States)

    Young, W. H., Jr.

    1981-01-01

    Recent experimental results from airfoils in the Mach number, Reynolds number, or reduced frequency ranges typical of helicopter rotor blades have identified the most influential flow mechanisms in the dynamic stall process. The importance of secondary shed vortices, downstream wake action, and the flow in the separated region is generally acknowledged but poorly understood. By means of surface pressure cross-correlations and flow field measurements in static stall, several new hypotheses have been generated. It is proposed that vortex shedding may be caused by acoustic disturbances propagating forward in the lower (pressure) surface boundary layer, that wake closure is a misnomer, and that the shed vortex leaves a trail of vorticity that forms a turbulent free shear layer. The known dynamic stall flow mechanisms are reviewed and the potential importance of recently proposed and hypothetical flow phenomena with respect to helicopter blade aeroelastic response are assessed.

  19. Lift capability prediction for helicopter rotor blade-numerical evaluation

    Science.gov (United States)

    Rotaru, Constantin; Cîrciu, Ionicǎ; Luculescu, Doru

    2016-06-01

    The main objective of this paper is to describe the key physical features for modelling the unsteady aerodynamic effects found on helicopter rotor blade operating under nominally attached flow conditions away from stall. The unsteady effects were considered as phase differences between the forcing function and the aerodynamic response, being functions of the reduced frequency, the Mach number and the mode forcing. For a helicopter rotor, the reduced frequency at any blade element can't be exactly calculated but a first order approximation for the reduced frequency gives useful information about the degree of unsteadiness. The sources of unsteady effects were decomposed into perturbations to the local angle of attack and velocity field. The numerical calculus and graphics were made in FLUENT and MAPLE soft environments. This mathematical model is applicable for aerodynamic design of wind turbine rotor blades, hybrid energy systems optimization and aeroelastic analysis.

  20. Direct Self-Repairing Control for Quadrotor Helicopter Attitude Systems

    Directory of Open Access Journals (Sweden)

    Huiliao Yang

    2014-01-01

    Full Text Available A quadrotor helicopter with uncertain actuator faults, such as loss of effectiveness and lock-in-place, is studied in this paper. An adaptive fuzzy sliding mode controller based on direct self-repairing control is designed for such nonlinear system to track the desired output signal, when any actuator of this quadrotor helicopter is loss of effectiveness or stuck at some place. Moreover, using the Lyapunov stability theory, the stability of the whole system and the convergence of the tracking error can be guaranteed. Finally, the availability of the proposed method is verified by simulation on 3-DOF hover to ensure that the system performance under faulty conditions can be quickly recovered to its normal level. And this proposed method is also proved to be better than that of LQR through simulation.

  1. Sliding mode tracking control for miniature unmanned helicopters

    Directory of Open Access Journals (Sweden)

    Bin Xian

    2015-02-01

    Full Text Available A sliding mode control design for a miniature unmanned helicopter is presented. The control objective is to let the helicopter track some predefined velocity and yaw trajectories. A new sliding mode control design method is developed based on a linearized dynamic model. In order to facilitate the control design, the helicopter’s dynamic model is divided into two subsystems, such as the longitudinal-lateral and the heading-heave subsystem. The proposed controller employs sliding mode control technique to compensate for the immeasurable flapping angles’ dynamic effects and external disturbances. The global asymptotic stability (GAS of the closed-loop system is proved by the Lyapunov based stability analysis. Numerical simulations demonstrate that the proposed controller can achieve superior tracking performance compared with the proportional-integral-derivative (PID and linear-quadratic regulator (LQR cascaded controller in the presence of wind gust disturbances.

  2. Helicopter Acoustic Flight Test with Altitude Variation and Maneuvers

    Science.gov (United States)

    Watts, Michael E.; Greenwood, Eric; Sim, Ben; Stephenson, James; Smith, Charles D.

    2016-01-01

    A cooperative flight test campaign between NASA and the U.S. Army was performed from September 2014 to February 2015. The purposes of the testing were to: investigate the effects of altitude variation on noise generation, investigate the effects of gross weight variation on noise generation, establish the statistical variability in acoustic flight testing of helicopters, and characterize the effects of transient maneuvers on radiated noise for a medium-lift utility helicopter. This test was performed at three test sites (0, 4000, and 7000 feet above mean sea level) with two aircraft (AS350 SD1 and EH-60L) tested at each site. This report provides an overview of the test, documents the data acquired and describes the formats of the stored data.

  3. Magnetostrictively actuated control flaps for vibration reduction in helicopter rotors

    Energy Technology Data Exchange (ETDEWEB)

    Millott, T.; Friedmann, P.P. [Univ. of California, Los Angeles, CA (United States). Mechanical, Aerospace and Nuclear Engineering Dept.

    1994-12-31

    High vibration levels can impose constraints on helicopter operations and hinder passenger acceptance. Vibration reduction using blade root pitch control introduces a significant power penalty and may adversely affect the airworthiness of the flight control system. Comparable levels of vibration reduction can be achieved using considerably less power through an actively controlled trailing edge flap mounted on the blade. Such a device would have no effect on helicopter airworthiness since it is controlled by a loop separate from the primary flight control system which utilizes the swashplate. Control flap actuation using the magnetostrictive material Terfenol-D is studied in this paper by designing a minimum weight actuator, subject to a set of actuation and stress constraints. The resulting device is capable of producing vibration reduction in excess of 90% at cruise conditions.

  4. Helicopters In Irregular Warfare: Capabilities, Challenges, And Missed Opportunities

    Science.gov (United States)

    2012-04-01

    Africans used combined helicopter borne and armored vehicle QRFs. In each case the intent was the same – a ground unit would radio for the QRF...58; McCall, Adapting Airpower in Counterinsurgency, 10. 4 McCall, Adapting Airpower in Counterinsurgency, 12-13, 16-17; Beckett , Modern Insurgencies... Beckett , Modern Insurgencies and Counterinsurgencies, 147; The Russian General Staff, The Soviet Afghan War, 313; Oliker, Russia’s Chechen Wars, 25

  5. MH-60R Multi-Mission Helicopter (MH-60R)

    Science.gov (United States)

    2016-03-23

    Operations that replaces the aging SH-60B and SH-60F helicopters. The avionics upgrades over the existing SH-60B/F include: a glass cockpit common...1087 Contract Number: N00019-11-C-0077 Contract Type: Firm Fixed Price (FFP) Award Date: September 27, 2011 Definitization Date: September 27...2011 Contract Price Initial Contract Price ($M) Current Contract Price ($M) Estimated Price At Completion ($M) Target Ceiling Qty Target Ceiling Qty

  6. 77 FR 54353 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2012-09-05

    ...; AD 2012-17-02] RIN 2120-AA64 Airworthiness Directives; Eurocopter France Helicopters AGENCY: Federal... directive (AD) for all Eurocopter France (EC) Model SA-365N, SA-365N1, SA-366G1, AS-365N2, AS 365 N3, EC... to amend 14 CFR part 39 to include an AD that would apply to all Eurocopter France (EC) Model SA-365N...

  7. Stability and control modelling. [helicopters in near hovering flight

    Science.gov (United States)

    Curtiss, H. C., Jr.

    1986-01-01

    This paper discusses the influence of rotor dynamics and dynamic inflow on the stability and control characteristics of single rotor helicopters in near hovering flight. Body attitude and rate feedback gain limitations which arise due to rotor dynamics and dynamic inflow are discussed. It is shown that attitude feedback gain is limited primarily by body-flap coupling and rate gain is limited by the lag degrees of freedom. Dynamic inflow is shown to produce significant changes in the modes of motion.

  8. Using of particle swarm for control of helicopter

    Directory of Open Access Journals (Sweden)

    Rezaee Alireza

    2010-01-01

    Full Text Available The CE150 Helicopter is one of the ranges offered by HUMUSOFT for teaching systems dynamics and control engineering principles. It has two degrees of freedom and is a MIMO system. We consider only Azimuth system for identification and control. There are many approaches to system identification. We choose NN structure and train it by Back-propagation and then use GA and PSO for optimizing the NN's training. At last we design PSO controller of Azimuth system.

  9. Helicopter Nighttime Parking Test Results - UH-1H

    Science.gov (United States)

    1992-05-01

    done with a large, heavy UH-lH helicopter, the results do not represent the most demanding case. The results of FAA/CT-TN88/30 also indicated that...I MY .. mX.IOW ANFO ,. 0 J 00o0 oWIND TYPE & TOTAL: UJOI -HEAD- 7 CL -TAIL- 8 0 O -CROSS- 7 I-) <o_ r; 01 LLu,- 0-~- H C 0 H C - < 0 >0-5 >5-10 >10-15

  10. Engineering Design Handbook. Helicopter Engineering. Part Two. Detail Design

    Science.gov (United States)

    1976-01-01

    TO FULLY CHARGED ELECTROL YTE I AS’ RECHARGI EORSINEATG RQUESCL!MTHD PEAR CHNAGE FREQUENCY OETERMINED PT AC- BATTERY RfCIURNS WHEN BATTERY DVC ORAhINU...NTROD CTIONlong1 with related climatic and drnvironmental fac-15- baRO UC IcON tors. Helicopter and subsystem installations should lion, ad rquiemets...Easential avionics times working under adverse climatic and ceiviran- 8. Hydraulic subsystem mental conditions, are employed to provide ’he *Aram

  11. The Effects of Modafinil on Aviator Performance During 40 Hours of Continuous Wakefulness: A UH-60 Helicopter Simulator Study

    National Research Council Canada - National Science Library

    Caidwell, John

    1999-01-01

    ...) activation in helicopter pilots who had been deprived of sleep. Six Army helicopter pilots were each exposed to two 40-hour periods of continuous wakefulness separated by one night of recovery sleep...

  12. Targeting and Fire Control System Analysis of the New Turkish Attack Helicopter "The AH-1Z King Cobra"

    National Research Council Canada - National Science Library

    Reyhan, Gokhan

    2001-01-01

    .... Turkey has chosen Bell Helicopter's KingCobra as its attack helicopter. The major difference between the USMC version of AH-1Z and the Turkish version KingCobra is the Targeting and Fire Control System...

  13. 76 FR 68301 - Airworthiness Directives; Bell Helicopter Textron, Inc. (Bell), Model 205A-1, 205B, 210, and 212...

    Science.gov (United States)

    2011-11-04

    ... helicopters for signs of an edge void, corrosion, or a crack, including a hair-line crack in the blade paint... helicopter. Wipe dry with a clean cloth. (4) Immediately after accomplishing paragraph (a)(3) of this AD...

  14. Simulation Analysis of Helicopter Ground Resonance Nonlinear Dynamics

    Science.gov (United States)

    Zhu, Yan; Lu, Yu-hui; Ling, Ai-min

    2017-07-01

    In order to accurately predict the dynamic instability of helicopter ground resonance, a modeling and simulation method of helicopter ground resonance considering nonlinear dynamic characteristics of components (rotor lead-lag damper, landing gear wheel and absorber) is presented. The numerical integral method is used to calculate the transient responses of the body and rotor, simulating some disturbance. To obtain quantitative instabilities, Fast Fourier Transform (FFT) is conducted to estimate the modal frequencies, and the mobile rectangular window method is employed in the predictions of the modal damping in terms of the response time history. Simulation results show that ground resonance simulation test can exactly lead up the blade lead-lag regressing mode frequency, and the modal damping obtained according to attenuation curves are close to the test results. The simulation test results are in accordance with the actual accident situation, and prove the correctness of the simulation method. This analysis method used for ground resonance simulation test can give out the results according with real helicopter engineering tests.

  15. Management of Mass Casualties Using Doctor Helicopters and Doctor Cars.

    Science.gov (United States)

    Ohsaka, Hiromichi; Ishikawa, Kouhei; Omori, Kazuhiko; Jitsuiki, Kei; Yoshizawa, Toshihiko; Yanagawa, Youichi

    At approximately 10 o'clock in September 2015, a minibus carrying 18 people accidentally slid backwards because of a malfunctioning brake system while climbing a steep incline on Togasayama Mountain, colliding with a van (Toyota HiAce wagon) carrying 11 people that was situated behind the minibus. Togasayama Mountain is located 1 hour by car and 10 minutes by helicopter from our hospital. The minibus slid off a roadside cliff at a height of 0.5 m and rolled over after colliding with the van. There were 7 victims with yellow tags and 22 with green tags. Two Doctor Helicopters and 1 Doctor Car cooperated with the fire departments by providing medical treatments, selection of medical facilities, and dispersion transportation. In this mass casualty event, there were no mortalities, and all of the victims recovered without sequelae. The coordinated and combined use of Doctor Helicopters and Doctor Cars in addition to the activities of the fire department in response to a mass casualty event resulted in appropriate triage, medical treatments, selection of medical facilities, and dispersion transportation. Copyright © 2017 Air Medical Journal Associates. Published by Elsevier Inc. All rights reserved.

  16. Principal Components Analysis of Triaxial Vibration Data From Helicopter Transmissions

    Science.gov (United States)

    Tumer, Irem Y.; Huff, Edward M.

    2001-01-01

    Research on the nature of the vibration data collected from helicopter transmissions during flight experiments has led to several crucial observations believed to be responsible for the high rates of false alarms and missed detections in aircraft vibration monitoring systems. This work focuses on one such finding, namely, the need to consider additional sources of information about system vibrations. In this light, helicopter transmission vibration data, collected using triaxial accelerometers, were explored in three different directions, analyzed for content, and then combined using Principal Components Analysis (PCA) to analyze changes in directionality. In this paper, the PCA transformation is applied to 176 test conditions/data sets collected from an OH58C helicopter to derive the overall experiment-wide covariance matrix and its principal eigenvectors. The experiment-wide eigenvectors. are then projected onto the individual test conditions to evaluate changes and similarities in their directionality based on the various experimental factors. The paper will present the foundations of the proposed approach, addressing the question of whether experiment-wide eigenvectors accurately model the vibration modes in individual test conditions. The results will further determine the value of using directionality and triaxial accelerometers for vibration monitoring and anomaly detection.

  17. Selected Problems Of Transmission Wear Of The Mi-24 Helicopter

    Directory of Open Access Journals (Sweden)

    Gębura Andrzej

    2015-12-01

    Full Text Available The hypothesis of mutual, destructive impact of the worn upper bearing of the WR-24 transmission on the Mi-24 helicopter's gearbox was stated. The Mi-24 is the only helicopter operated in Poland, in which the gearbox is mounted outside the main transmission – in the centre of the transmission shaft, between the main gearbox and the tail rotor. Damage to the gears in the gearbox of power generators is equivalent to termination of the tail rotor's drive. Such a termination immediately causes rotation of the body in the direction opposite to the direction of rotation of the main rotor. It is associated with the loss of lift and steering. It may lead to a disaster. Such an incident occurred in January 2011 in Afghanistan – both authors participated in its investigation. The authors, taking into account very good, almost legendary combat properties of the Mi-24, and their research of the specifics of wear and tear of the transmission elements, they think that, first, funds for development and implementation of the drive unit monitoring system should be made available specially for this helicopter. For this purpose, the authors propose to use the FAM-C method. It is characterised with significant ergonomics. Thank to this, multiple kinematic pairs can be observed simultaneously, and, therefore, the relationships between them as well.

  18. Automatic shearography inspection system for helicopter rotor blades

    Science.gov (United States)

    Walz, Thomas; Ettemeyer, Andreas

    1998-03-01

    Helicopter rotor blades are highly sophisticated products composed of a variety of materials and components and therefore, 100 percent quality control has to be assured. Therefore, the French helicopter producer, Eurocopter S.A., Paris, has installed a system for automatic and 100 percent inspection of rotor blades on structural defects. In this system, laser shearography is used as an inspection technique. The rotor blades are mounted in a vacuum chamber and loaded with a relative pressure difference. At this load, bonding and structural defects show up as tiny deformations of the surface and are recorded with two shearography cameras, positioned on both sides of the rotor blade. After each measurement, they are automatically moved to the next inspection position. In this way, the entire rotor blade is automatically inspected in several measuring steps. As this helicopter blade inspection system is the first automatic production control system based on laser shearography in Europe, this application is an important step in bringing shearography techniques into production control. In this paper, the complete inspection system is presented.

  19. Development of helicopter attitude axes controlled hover flight without pilot assistance and vehicle crashes

    Science.gov (United States)

    Simon, Miguel

    In this work, we show how to computerize a helicopter to fly attitude axes controlled hover flight without the assistance of a pilot and without ever crashing. We start by developing a helicopter research test bed system including all hardware, software, and means for testing and training the helicopter to fly by computer. We select a Remote Controlled helicopter with a 5 ft. diameter rotor and 2.2 hp engine. We equip the helicopter with a payload of sensors, computers, navigation and telemetry equipment, and batteries. We develop a differential GPS system with cm accuracy and a ground computerized navigation system for six degrees of freedom (6-DoF) free flight while tracking navigation commands. We design feedback control loops with yet-to-be-determined gains for the five control "knobs" available to a flying radio-controlled (RC) miniature helicopter: engine throttle, main rotor collective pitch, longitudinal cyclic pitch, lateral cyclic pitch, and tail rotor collective pitch. We develop helicopter flight equations using fundamental dynamics, helicopter momentum theory and blade element theory. The helicopter flight equations include helicopter rotor equations of motions, helicopter rotor forces and moments, helicopter trim equations, helicopter stability derivatives, and a coupled fuselage-rotor helicopter 6-DoF model. The helicopter simulation also includes helicopter engine control equations, a helicopter aerodynamic model, and finally helicopter stability and control equations. The derivation of a set of non-linear equations of motion for the main rotor is a contribution of this thesis work. We design and build two special test stands for training and testing the helicopter to fly attitude axes controlled hover flight, starting with one axis at a time and progressing to multiple axes. The first test stand is built for teaching and testing controlled flight of elevation and yaw (i.e., directional control). The second test stand is built for teaching and

  20. Modelling and control of small-scale helicopter on a test platform

    Science.gov (United States)

    Lai, Gilbert M. Y.

    The helicopter is a Multiple-Input Multiple-Output (MIMO) system with highly coupled characteristics, which increases the complexity of the system dynamics. In addition, the system dynamics of the helicopter are unstable [1], referring to its tendency to deviate from an equilibrium when disturbed. Despite the complexity in its modelling and control, the benefit of using a helicopter for unmanned, autonomous applications can be tremendous. One particular application that motivates this research is the use of an unmanned small-scale helicopter in an autonomous survey mission over an area struck by disaster, such as an earthquake. The work presented in this thesis provides a framework for utilizing a platform system for research and development of small-scale helicopter systems. A platform system enables testing and analysis to be performed indoor in a controlled environment. This can provide a more convenient mean for helicopter research since the system is not affected by environmental elements, such as wind, rain or snow condition. However, the presence of the platform linkages poses challenges for analysis and controller design as it alters the helicopter system flight dynamics. Through a six degree-of-freedom (6 DOF) platform model derived in this research, the criteria for matching the trim conditions between the platform system and a stand alone helicopter have been identified. With the matched trim conditions, linearization is applied to perform analysis on the effects that the platform has on the system dynamics. The results of the analysis provide insights into both the limitations and benefits of utilizing the platform system for helicopter research. Finally, a Virtual Joint Control scheme is proposed as an unified control strategy for both the platform and the stand alone helicopter systems. Having a consistent control scheme between the two systems allows for comparisons between simulation and experimental results for the two systems to be made more

  1. Implementation of a Helicopter Flight Simulator with Individual Blade Control

    Science.gov (United States)

    Zinchiak, Andrew G.

    2011-12-01

    Nearly all modern helicopters are designed with a swashplate-based system for control of the main rotor blades. However, the swashplate-based approach does not provide the level of redundancy necessary to cope with abnormal actuator conditions. For example, if an actuator fails (becomes locked) on the main rotor, the cyclic inputs are consequently fixed and the helicopter may become stuck in a flight maneuver. This can obviously be seen as a catastrophic failure, and would likely lead to a crash. These types of failures can be overcome with the application of individual blade control (IBC). IBC is achieved using the blade pitch control method, which provides complete authority of the aerodynamic characteristics of each rotor blade at any given time by replacing the normally rigid pitch links between the swashplate and the pitch horn of the blade with hydraulic or electronic actuators. Thus, IBC can provide the redundancy necessary for subsystem failure accommodation. In this research effort, a simulation environment is developed to investigate the potential of the IBC main rotor configuration for fault-tolerant control. To examine the applications of IBC to failure scenarios and fault-tolerant controls, a conventional, swashplate-based linear model is first developed for hover and forward flight scenarios based on the UH-60 Black Hawk helicopter. The linear modeling techniques for the swashplate-based helicopter are then adapted and expanded to include IBC. Using these modified techniques, an IBC based mathematical model of the UH-60 helicopter is developed for the purposes of simulation and analysis. The methodology can be used to model and implement a different aircraft if geometric, gravimetric, and general aerodynamic data are available. Without the kinetic restrictions of the swashplate, the IBC model effectively decouples the cyclic control inputs between different blades. Simulations of the IBC model prove that the primary control functions can be manually

  2. A helicopter that flaps its wings : The Ornicopter flaps its wings like a bird to get into the air

    NARCIS (Netherlands)

    Van Holten, T.; Mols, B.

    2003-01-01

    No other type of aircraft is as manoeuvrable as a helicopter. Reverse in full flight, rotate in the air, hover at a standstill, the helicopter can do it all. The police, fire services, medical services, military and civil aviation all use the helicopter for the freedom of flight it offers. However,

  3. 75 FR 63052 - Airworthiness Directives; Eurocopter France (ECF) Model AS350B3 and EC130 B4 Helicopters

    Science.gov (United States)

    2010-10-14

    ... (ECF) Model AS350B3 and EC130 B4 Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... Model AS350B3 and EC130 B4 helicopters. This amendment is prompted by a mandatory continuing... amend 14 CFR part 39 to include an AD that would apply to ECF Model AS350B3 and EC130 B4 helicopters on...

  4. 77 FR 55684 - Airworthiness Directives; Agusta S.p.A. Helicopters

    Science.gov (United States)

    2012-09-11

    ....A. (Agusta) Model AB412 and AB412 EP helicopters with certain hoist hook assemblies (hook) installed. This AD requires inspecting the hook for correct assembly of the nut and body. This AD is prompted by a... Agusta Model AB412 and AB412EP helicopters. EASA advises of a report where a hoist hook separated from an...

  5. FlyTact : A tactile display improves a helicopter pilot's landing performance in degraded visual environments

    NARCIS (Netherlands)

    Jansen, C.; Wennemers, A.S.; Vos, W.K.; Groen, E.L.

    2008-01-01

    Helicopter landings are more challenging in 'brownout' conditions, in which sand and dust is stirred up by the rotary wing aircraft, obscuring visibility. Safe brownout landings require new sensor and display technologies to provide the pilot with information on helicopter motion. In this respect

  6. 76 FR 27952 - Airworthiness Directives; Eurocopter France Model EC 120B Helicopters

    Science.gov (United States)

    2011-05-13

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Eurocopter France... Eurocopter France Model EC 120B helicopters. This proposed AD would require modifying the pilot cyclic... correct an unsafe condition for the Eurocopter France Model EC 120B helicopters. Related Service...

  7. 75 FR 47201 - Airworthiness Directives; Eurocopter France Model EC 130 B4 Helicopters

    Science.gov (United States)

    2010-08-05

    ...-63-AD; Amendment 39-16369; AD 2010-15-03] RIN 2120-AA64 Airworthiness Directives; Eurocopter France... Eurocopter France helicopters. This action requires inspecting certain electrical harnesses for damage and if... Eurocopter France Model EC 130 B4 helicopters that have been modified in accordance with MOD 073774, and have...

  8. 75 FR 79950 - Airworthiness Directives; Kaman Aerospace Corporation (Kaman) Model K-1200 Helicopters

    Science.gov (United States)

    2010-12-21

    ... Corporation (Kaman) Model K-1200 Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final... Model K-1200 helicopters. This AD requires revising the Limitations section of the Instructions for... AD, contact Kaman Aerospace Corporation, K-max Product Support Center, Building 33, P.O. Box 2, 1332...

  9. Improvement of helicopter attitude stability by active control of the conventional swash plate

    Science.gov (United States)

    Ham, Norman D.

    1993-01-01

    The Final Report on improvement of helicopter attitude stability by active control of the conventional swash plate covering the period from Nov. 1986 to Dec. 1993 is presented. A paper on the history, principles, and applications of helicopter individual-blade-control is included.

  10. 14 CFR Appendix B to Part 29 - Airworthiness Criteria for Helicopter Instrument Flight

    Science.gov (United States)

    2010-01-01

    .... Static longitudinal stability. (a) General. The helicopter must possess positive static longitudinal control force stability at critical combinations of weight and center of gravity at the conditions... and landing; (iii) For Category A helicopters, the dynamic stability requirements of Subpart B must...

  11. 14 CFR Appendix B to Part 27 - Airworthiness Criteria for Helicopter Instrument Flight

    Science.gov (United States)

    2010-01-01

    ... longitudinal stability. (a) General. The helicopter must possess positive static longitudinal control force.... Stability must be shown throughout the speed range 20 knots either side of trim with— (i) The helicopter... speed, there must be no negative dihedral stability perceptible to the pilot through lateral control...

  12. Factors of Non-Persistence in Civilian Helicopter Flight Training: A Narrative Inquiry of Pilot Attrition

    Science.gov (United States)

    Wentworth, Rebecca

    2012-01-01

    Previous literature on retention of student helicopter pilots shows a gap in research of civilian schools and qualitative studies. To address this gap in the literature and to help helicopter flight schools better understand the incidents of attrition from flight training, this qualitative study investigated student and school-based factors…

  13. 76 FR 12643 - Proposed Establishment of Helicopter Area Navigation (RNAV) Routes; Northeast United States

    Science.gov (United States)

    2011-03-08

    ... suitably equipped helicopters having IFR- approved Global Positioning System (GPS)/Global Navigation... informal docket may also be examined during normal business hours at the office of the Eastern Service... opportunities for helicopter operators to take advantage of developments in Performance Based Navigation...

  14. Neck Strength, Position Sense, and Motion in Military Helicopter Crew With and Without Neck Pain

    NARCIS (Netherlands)

    van den Oord, Marieke H. A. H.; de Loose, Veerle; Sluiter, Judith K.; Frings-Dresen, Monique H. W.

    2010-01-01

    Introduction: Neck pain in military helicopter pilots and rear aircrew is an occupational health problem that may interfere with flying performance. The aim of the present study was to investigate possible differences in the physical abilities of the cervical spines of helicopter pilots and rear

  15. 76 FR 76068 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2011-12-06

    ... Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). SUMMARY: We propose to adopt a new airworthiness directive (AD) for Eurocopter Deutschland... Deutschland Model BO-105A, BO-105C, BO-105D, BO-105LS A-1, BO-105LS A-3, and BO- 105S helicopters, all...

  16. 76 FR 27956 - Airworthiness Directives; Eurocopter Deutschland Model EC135 Helicopters

    Science.gov (United States)

    2011-05-13

    ... Deutschland Model EC135 Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of... Deutschland (ECD) Model EC135 helicopters. This proposed AD results from a mandatory continuing airworthiness.... 39.13 by adding the following new AD: Eurocopter Deutschland: Docket No. FAA-2011-0453; Directorate...

  17. 78 FR 78710 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2013-12-27

    ... Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for Eurocopter Deutschland GmbH (Eurocopter) Model...): 2013-21-06 Eurocopter Deutschland GmbH Helicopters: Amendment 39- 17630; Docket No. FAA-2013-0340...

  18. 78 FR 7312 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2013-02-01

    ... Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration, DOT. ACTION: Notice of proposed... Deutschland GmbH (Eurocopter) Model MBB-BK 117 C-2 helicopters. This proposed AD would require changing the... Directive (AD): Eurocopter Deutschland GmbH: Docket No. FAA-2013-0021; Directorate Identifier 2010-SW-040-AD...

  19. 78 FR 31394 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2013-05-24

    ...-10-05] RIN 2120-AA64 Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters AGENCY... comments. SUMMARY: We are adopting a new airworthiness directive (AD) for Eurocopter Deutschland GmbH (ECD... new airworthiness directive (AD): 2013-10-05 Eurocopter Deutschland GmbH Helicopters: Amendment 39...

  20. 77 FR 72913 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2012-12-07

    ... Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for all Eurocopter Deutschland GmbH (ECD) Model... apply to all Eurocopter Deutschland GmbH (ECD) model EC135 helicopters, except the EC 135 P2+ and T2...

  1. 78 FR 42409 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2013-07-16

    ... Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ] ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for Eurocopter Deutschland GmbH (Eurocopter) Model... airworthiness directive (AD): 2013-12-05 Eurocopter Deutschland GmbH Helicopters: Amendment 39- 17483; Docket No...

  2. 77 FR 8722 - Airworthiness Directives; Eurocopter Deutschland Model EC135 Helicopters

    Science.gov (United States)

    2012-02-15

    ... Deutschland Model EC135 Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for Eurocopter Deutschland (ECD) Model EC135... include an AD that would apply to the Eurocopter Deutschland (ECD) Model EC135 helicopters. That NPRM was...

  3. 78 FR 30793 - Airworthiness Directives; Eurocopter Deutschland GmbH Model Helicopters

    Science.gov (United States)

    2013-05-23

    ... Deutschland GmbH Model Helicopters AGENCY: Federal Aviation Administration (FAA) DOT. ACTION: Notice of... Deutschland GmbH (Eurocopter) Model EC135 P1, P2, P2+, T1, T2, and T2+ helicopters to require inspecting each.... 39.13 by adding the following new Airworthiness Directive (AD): Eurocopter Deutschland GmbH: Docket...

  4. 77 FR 27659 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2012-05-11

    ... Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed... Deutschland GmbH (ECD) Model BO-105A, BO-105C, and BO-105S helicopters. This proposed AD is prompted by... Directive (AD): Eurocopter Deutschland GMBH: Docket No. FAA-2012-0503; Directorate Identifier 2011-SW-032-AD...

  5. 78 FR 25361 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2013-05-01

    ...; AD 2013-03-18] RIN 2120-AA64 Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters AGENCY... airworthiness directive (AD) for Eurocopter Deutschland GmbH (Eurocopter) Model MBB-BK 117 C-2 helicopters. This... airworthiness directive (AD): 2013-03-18 Eurocopter Deutschland GmbH (Eurocopter): Amendment 39- 17352; Docket...

  6. 77 FR 43736 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2012-07-26

    ... Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration, DOT. ACTION: Notice of proposed... Deutschland GmbH (Eurocopter) Model MBB-BK 117 C-2 helicopters. This proposed AD is prompted by the discovery... Deutschland GmbH: Docket No. FAA-2012-0773; Directorate Identifier 2009-SW-71-AD. (a) Applicability This AD...

  7. 78 FR 44039 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2013-07-23

    ... Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). SUMMARY: We propose to adopt a new airworthiness directive (AD) for Eurocopter Deutschland... directive (AD): Eurocopter Deutschland GmbH Helicopters (Eurocopter): Docket No. FAA-2013-0642; Directorate...

  8. 78 FR 16196 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2013-03-14

    ... Directives; Eurocopter Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA), DOT... (AD) for all Eurocopter Deutschland GmbH (ECD) EC 135 P1, P2, P2+, T1, T2, and T2+ helicopters... Deutschland GmbH: Docket No. FAA-2013-0239; Directorate Identifier 2010-SW-087-AD. (a) Applicability This AD...

  9. Specific exercise training for reducing neck and shoulder pain among military helicopter pilots and crew members

    DEFF Research Database (Denmark)

    Murray, Mike; Lange, Britt; Nørnberg, Bo Riebeling

    2015-01-01

    was to investigate whether a specifically tailored exercise intervention would reduce the prevalence and incidence rate of neck/shoulder pain among helicopter pilots and crew members. METHOD: This study used a prospective, parallel group, single blinded, randomized controlled design. Participants were military......BACKGROUND: Flight-related neck/shoulder pain is frequent among military helicopter pilots and crew members. With a lifetime prevalence of 81 % for pilots and 84 % for crew members, the prevalence of neck pain is considered high compared to the general population. The aim of this study...... helicopter pilots and crew members recruited from the Royal Danish Air Force. Inclusion criteria were: 1) employed within the Royal Danish Air Force as a helicopter pilot or onboard crew member (technician, systems-operator, tactical helicopter observer and/or navigator), 2) maintaining operational flight...

  10. Quad-Rotor Helicopter Autonomous Navigation Based on Vanishing Point Algorithm

    Directory of Open Access Journals (Sweden)

    Jialiang Wang

    2014-01-01

    Full Text Available Quad-rotor helicopter is becoming popular increasingly as they can well implement many flight missions in more challenging environments, with lower risk of damaging itself and its surroundings. They are employed in many applications, from military operations to civilian tasks. Quad-rotor helicopter autonomous navigation based on the vanishing point fast estimation (VPFE algorithm using clustering principle is implemented in this paper. For images collected by the camera of quad-rotor helicopter, the system executes the process of preprocessing of image, deleting noise interference, edge extracting using Canny operator, and extracting straight lines by randomized hough transformation (RHT method. Then system obtains the position of vanishing point and regards it as destination point and finally controls the autonomous navigation of the quad-rotor helicopter by continuous modification according to the calculated navigation error. The experimental results show that the quad-rotor helicopter can implement the destination navigation well in the indoor environment.

  11. Calculated hovering helicopter flight dynamics with a circulation-controlled rotor

    Science.gov (United States)

    Johnson, W.; Chopra, I.

    1979-01-01

    The flight dynamics of a hovering helicopter with a circulation-controlled rotor are analyzed. The influence of the rotor blowing coefficient on the calculated eigenvalues of the helicopter motion is examined for a range of values of the rotor lift and the blade flap frequency. The control characteristics of a helicopter with a circulation-controlled rotor are discussed. The principal effect of the blowing is a reduction in the rotor speed stability derivative. Above a critical level of blowing coefficient, which depends on the flap frequency and rotor lift, negative speed stability is produced and the dynamic characteristics of the helicopter are radically altered. The handling qualities of a helicopter with negative speed stability are probably unacceptable without a stability augmentation system.

  12. THE USE OF CORRELATION ANALYSIS OF TWO-DIMENSION STOCHASTIC PROCESS FOR HELICOPTER MAINTENANCE WORKABILITY ESTIMATION

    Directory of Open Access Journals (Sweden)

    Yuriy Michaylovich Chinyuchin

    2017-01-01

    Full Text Available The new calculated program complex which main task is to find the optimal algorithm of stochastic helicopter de- sign and assembling in terms of maintenance efficiency is described. It is shown that the use of the developed calculated program complex allows to efficiently solve the problems of helicopter construction with high-rating maintenance worka- bility factors.It is shown that for efficient problem solving connected with Maintenance and Repair costs reduction while heli- copter engineering and assembling in design office it is appropriate to use correlated analysis for maintenance workability estimation with the use of CAD system. The calculated program complex is based on mathematical apparatus of linear cor-related dependence of two-dimension (stochastic process. The linear correlated dependence is considered as linear or anyconnection close to it between two variables for which the correlated analysis theorem is true.The algorithm of calculated program complex for helicopter maintenance workability estimation consists of five steps: choice of equipment that needs to be installed on the helicopter; correlation coefficient calculation for helicopters having this equipment and revealing of optimal variants of location; zone partition of the developed helicopter and analysis of possi- ble disposal of clusters in optimal order; disposal of clusters on the designed helicopter; correlation coefficient calculation, direct regression construction for the designed helicopter and comparison of these readings with helicopters-analogues. The calculation data of correlated analysis characteristics which indicate a possibility of increase of helicopter maintenance worka- bility level with a modicum of effort and time when working out the particular functional system is given.

  13. A search for gamma-ray imprints of annihilating dark matter in the galaxy, and the astrophysical implications of ultra-light fundamental vector bosons

    Energy Technology Data Exchange (ETDEWEB)

    Zechlin, Hannes-Sebastian

    2013-12-15

    Standard Model extensions imply new elementary particles that can lead to specific astrophysical signatures. In particular, weakly interacting massive particles (WIMPs) can constitute the unknown non-luminous cold dark matter, which contributes approximately 84% to the matter content of the Universe. Annihilation or decay of WIMPs may lead to high-energy gamma-rays. In this thesis, new methods of searching for gamma-ray signals from annihilating dark matter are developed and applied. Moreover, astrophysical imprints of new ultra-light hidden U(1) gauge bosons in radio data are investigated. Hierarchical structure formation predicts a variety of smaller bound dark matter sub-halos in Milky-Way-like galactic hosts. It is shown that the Fermi-LAT is sufficiently sensitive for detecting up to a few nearby dark matter subhalos in terms of faint gamma-ray sources with a moderate angular extent. Searches in the first and second Fermi-LAT source catalogs reveal about ten candidate sources each. To discriminate the source candidates from conventional astrophysical objects, an analysis for spectral, spatial, positional, and temporal gamma-ray properties using 3.5 years of Fermi-LAT data is carried out. In addition, a multi-wavelength analysis of archival data or follow-up observations in the radio, infrared, optical, UV, X-ray, high-energy, and very-high energy gamma-ray bands is carried out. The broad-band spectra of all promising candidates are compatible with AGN, in particular high-energy peaked BL-Lac type objects (HBLs). Dark matter annihilation can contribute to the small-scale angular anisotropy spectrum of the diffuse gamma-ray background (DGB). The detection capabilities of currently operating imaging atmospheric Cherenkov telescopes and the planned Cherenkov Telescope Array (CTA) are studied. With CTA, a relative gamma-ray contribution from annihilating dark matter of 10% to the extragalactic DGB can be resolved via angular anisotropies. In terms of the dark

  14. Efficient Helicopter Aerodynamic and Aeroacoustic Predictions on Parallel Computers

    Science.gov (United States)

    Wissink, Andrew M.; Lyrintzis, Anastasios S.; Strawn, Roger C.; Oliker, Leonid; Biswas, Rupak

    1996-01-01

    This paper presents parallel implementations of two codes used in a combined CFD/Kirchhoff methodology to predict the aerodynamics and aeroacoustics properties of helicopters. The rotorcraft Navier-Stokes code, TURNS, computes the aerodynamic flowfield near the helicopter blades and the Kirchhoff acoustics code computes the noise in the far field, using the TURNS solution as input. The overall parallel strategy adds MPI message passing calls to the existing serial codes to allow for communication between processors. As a result, the total code modifications required for parallel execution are relatively small. The biggest bottleneck in running the TURNS code in parallel comes from the LU-SGS algorithm that solves the implicit system of equations. We use a new hybrid domain decomposition implementation of LU-SGS to obtain good parallel performance on the SP-2. TURNS demonstrates excellent parallel speedups for quasi-steady and unsteady three-dimensional calculations of a helicopter blade in forward flight. The execution rate attained by the code on 114 processors is six times faster than the same cases run on one processor of the Cray C-90. The parallel Kirchhoff code also shows excellent parallel speedups and fast execution rates. As a performance demonstration, unsteady acoustic pressures are computed at 1886 far-field observer locations for a sample acoustics problem. The calculation requires over two hundred hours of CPU time on one C-90 processor but takes only a few hours on 80 processors of the SP2. The resultant far-field acoustic field is analyzed with state of-the-art audio and video rendering of the propagating acoustic signals.

  15. Nonlinear State Estimation and Modeling of a Helicopter UAV

    Science.gov (United States)

    Barczyk, Martin

    Experimentally-validated nonlinear flight control of a helicopter UAV has two necessary conditions: an estimate of the vehicle’s states from noisy multirate output measurements, and a nonlinear dynamics model with minimum complexity, physically controllable inputs and experimentally identified parameter values. This thesis addresses both these objectives for the Applied Nonlinear Controls Lab (ANCL)'s helicopter UAV project. A magnetometer-plus-GPS aided Inertial Navigation System (INS) for outdoor flight as well as an Attitude and Heading Reference System (AHRS) for indoor testing are designed, implemented and experimentally validated employing an Extended Kalman Filter (EKF), using a novel calibration technique for the magnetometer aiding sensor added to remove the limitations of an earlier GPS-only aiding design. Next the recently-developed nonlinear observer design methodology of invariant observers is adapted to the aided INS and AHRS examples, employing a rotation matrix representation for the state manifold to obtain designs amenable to global stability analysis, obtaining a direct nonlinear design for gains of the AHRS observer, modifying the previously-proposed Invariant EKF systematic method for computing gains, and culminating in simulation and experimental validation of the observers. Lastly a nonlinear control-oriented model of the helicopter UAV is derived from first principles, using a rigid-body dynamics formulation augmented with models of the on-board subsystems: main rotor forces and blade flapping dynamics, the Bell-Hiller system and flybar flapping dynamics, tail rotor forces, tail gyro unit, engine and rotor speed, servo operation, fuselage drag, and tail stabilizer forces. The parameter values in the resulting models are identified experimentally. Using these the model is further simplified to be tractable for model-based control design.

  16. Exercise therapy for improved neck muscle function in helicopter aircrew.

    Science.gov (United States)

    Salmon, Danielle M; Harrison, Michael F; Sharpe, Donald; Candow, Darren; Albert, Wayne J; Neary, J Patrick

    2013-10-01

    To address the high prevalence of neck dysfunction in helicopter aircrew, a 12-wk training program was designed to examine the effects on neck muscular strength and endurance. Subjects were recruited from Canadian Forces (CF) helicopter aircrew and randomized into either a neck coordination training program (CTP; N = 10), an endurance training program (ETP; N = 11), or a nontreatment control (CON; N = 8). Baseline assessments determined maximal voluntary contraction (MVC) strength and endurance capacity using a submaximal contraction to fatigue at 70% of their MVC for extension, flexion, and left (Ltflx) and right (Rtflx) lateral flexion. The ETP subjects performed dynamic contractions at 30% of their MVC in the four testing directions using a head harness and Thera-band tubing. The CTP consisted of exercises that focused on strengthening the deep cervical musculature using the mass of the head as resistance and progressing to exercises that incorporated the superficial cervical muscles. Post-intervention, the ETP achieved the only statistically significant increase in maximal force when compared to the CON (14.4%). Improved times to fatigue were achieved by the CTP for flexion (26.34 +/- 20.72 s), Ltflx (23.54 +/- 13.94 s), and Rtflx (28.72 +/- 4.88 s). The provision of an ETP and CTP resulted in a positive trend toward improved maximal force and muscular endurance. The greatest improvements in endurance and strength were found for those subjects assigned to the CTP treatment. Our research demonstrates the importance of including a designed and supervised training program into the daily routine of helicopter aviators.

  17. System and Method for Finite Element Simulation of Helicopter Turbulence

    Science.gov (United States)

    McFarland, R. E. (Inventor); Dulsenberg, Ken (Inventor)

    1999-01-01

    The present invention provides a turbulence model that has been developed for blade-element helicopter simulation. This model uses an innovative temporal and geometrical distribution algorithm that preserves the statistical characteristics of the turbulence spectra over the rotor disc, while providing velocity components in real time to each of five blade-element stations along each of four blades. for a total of twenty blade-element stations. The simulator system includes a software implementation of flight dynamics that adheres to the guidelines for turbulence set forth in military specifications. One of the features of the present simulator system is that it applies simulated turbulence to the rotor blades of the helicopter, rather than to its center of gravity. The simulator system accurately models the rotor penetration into a gust field. It includes time correlation between the front and rear of the main rotor, as well as between the side forces felt at the center of gravity and at the tail rotor. It also includes features for added realism, such as patchy turbulence and vertical gusts in to which the rotor disc penetrates. These features are realized by a unique real time implementation of the turbulence filters. The new simulator system uses two arrays one on either side of the main rotor to record the turbulence field and to produce time-correlation from the front to the rear of the rotor disc. The use of Gaussian Interpolation between the two arrays maintains the statistical properties of the turbulence across the rotor disc. The present simulator system and method may be used in future and existing real-time helicopter simulations with minimal increase in computational workload.

  18. Terfenol-D-driven flaps for helicopter vibration reduction

    Science.gov (United States)

    Fenn, Ralph C.; Downer, James R.; Bushko, Dariusz A.; Gondhalekar, Vijay; Ham, Norman D.

    1993-09-01

    The utility of helicopter aviation is limited by the high vibration levels caused by interaction of each rotor blade with the wake of preceding blades. Existing full blade actuation using a swashplate has various problems such as insufficient bandwidth, limitations in the number of harmonics controlled, high maintenance, and lack of spanwise lift variation. These problems are avoided by the proposed flap operated, individual blade control system, which uses magnetostrictive actuation technology. Terfenol-D actuation has many advantages over competing technologies such as hydraulic systems, electric motors, and piezoelectric elements. These benefits include all-electric operation, simplicity and reliability, low mass, low voltage, and insensitivity to centripetal acceleration.

  19. Helicopter Emergency Medical Service in the Republic of Croatia

    Directory of Open Access Journals (Sweden)

    Andrija Vidović

    2007-11-01

    Full Text Available Current situation of emergency medical assistance indicatesthe need to organize faster and more efficient system oflinking all the parts of the Republic of Croatia. The solutioncan be found in the implementation of aviation as the fastestand therefore the best method of transporting the injured, diseasedand other persons who need urgent transpmt. The use ofmilitary helicopters for the purposes of emergency aviation doesnot satisfy the needs of the Republic of Croatia from the organizationaland legal aspect. There were 597 fatalities on the Croatianroads in 2005 and with the establishment of emergencyhelicopter medical service, the number of fatalities may be reducedby one third.

  20. Model Predictive Control for a Small Scale Unmanned Helicopter

    Directory of Open Access Journals (Sweden)

    Jianfu Du

    2008-11-01

    Full Text Available Kinematical and dynamical equations of a small scale unmanned helicoper are presented in the paper. Based on these equations a model predictive control (MPC method is proposed for controlling the helicopter. This novel method allows the direct accounting for the existing time delays which are used to model the dynamics of actuators and aerodynamics of the main rotor. Also the limits of the actuators are taken into the considerations during the controller design. The proposed control algorithm was verified in real flight experiments where good perfomance was shown in postion control mode.

  1. Comparison of calculated and measured helicopter rotor lateral flapping angles

    Science.gov (United States)

    Johnson, W.

    1980-01-01

    Calculated and measured values of helicopter rotor flapping angles in forward flight are compared for a model rotor in a wind tunnel and an autogiro in gliding flight. The lateral flapping angles can be accurately predicted when a calculation of the nonuniform wake-induced velocity is used. At low advance ratios, it is also necessary to use a free wake geometry calculation. For the cases considered, the tip vortices in the rotor wake remain very close to the tip-path plane, so the calculated values of the flapping motion are sensitive to the fine details of the wake structure, specifically the viscous core radius of the tip vortices.

  2. Full-Scale Crash Test of an MD-500 Helicopter

    Science.gov (United States)

    Littell, Justin

    2011-01-01

    A full-scale crash test was successfully conducted in March 2010 of an MD-500 helicopter at NASA Langley Research Center s Landing and Impact Research Facility. The reasons for conducting this test were threefold: 1 To generate data to be used with finite element computer modeling efforts, 2 To study the crashworthiness features typically associated with a small representative helicopter, and 3 To compare aircraft response to data collected from a previously conducted MD-500 crash test, which included an externally deployable energy absorbing (DEA) concept. Instrumentation on the airframe included accelerometers on various structural components of the airframe; and strain gages on keel beams, skid gear and portions of the skin. Three Anthropomorphic Test Devices and a specialized Human Surrogate Torso Model were also onboard to collect occupant loads for evaluation with common injury risk criteria. This paper presents background and results from this crash test conducted without the DEA concept. These results showed accelerations of approximately 30 to 50 g on the airframe at various locations, little energy attenuation through the airframe, and moderate to high probability of occupant injury for a variety of injury criteria.

  3. Helicopter noise in hover: Computational modelling and experimental validation

    Science.gov (United States)

    Kopiev, V. F.; Zaytsev, M. Yu.; Vorontsov, V. I.; Karabasov, S. A.; Anikin, V. A.

    2017-11-01

    The aeroacoustic characteristics of a helicopter rotor are calculated by a new method, to assess its applicability in assessing rotor performance in hovering. Direct solution of the Euler equations in a noninertial coordinate system is used to calculate the near-field flow around the spinning rotor. The far-field noise field is calculated by the Ffowcs Williams-Hawkings (FW-H) method using permeable control surfaces that include the blade. For a multiblade rotor, the signal obtained is duplicated and shifted in phase for each successive blade. By that means, the spectral characteristics of the far-field noise may be obtained. To determine the integral aerodynamic characteristics of the rotor, software is written to calculate the thrust and torque characteristics from the near-field flow solution. The results of numerical simulation are compared with experimental acoustic and aerodynamic data for a large-scale model of a helicopter main rotor in an open test facility. Two- and four-blade configurations of the rotor are considered, in different hover conditions. The proposed method satisfactorily predicts the aerodynamic characteristics of the blades in such conditions and gives good estimates for the first harmonics of the noise. That permits the practical use of the proposed method, not only for hovering but also for forward flight.

  4. System life and reliability modeling for helicopter transmissions

    Science.gov (United States)

    Savage, M.; Brikmanis, C. K.

    1986-01-01

    A computer program which simulates life and reliability of helicopter transmissions is presented. The helicopter transmissions may be composed of spiral bevel gear units and planetary gear units - alone, in series or in parallel. The spiral bevel gear units may have either single or dual input pinions, which are identical. The planetary gear units may be stepped or unstepped and the number of planet gears carried by the planet arm may be varied. The reliability analysis used in the program is based on the Weibull distribution lives of the transmission components. The computer calculates the system lives and dynamic capacities of the transmission components and the transmission. The system life is defined as the life of the component or transmission at an output torque at which the probability of survival is 90 percent. The dynamic capacity of a component or transmission is defined as the output torque which can be applied for one million output shaft cycles for a probability of survival of 90 percent. A complete summary of the life and dynamic capacity results is produced by the program.

  5. Quad-Rotor Unmanned Aerial Vehicle Helicopter Modelling & Control

    Directory of Open Access Journals (Sweden)

    Yogianandh Naidoo

    2011-09-01

    Full Text Available This paper presents the investigation of the modelling and control of a quad-rotor helicopter and forms part of research involving the development of an unmanned aerial vehicle (UAV to be used in search and rescue applications. Quad-rotor helicopters consist of two pairs of counter rotating rotors situated at the ends of a cross, symmetric about the centre of gravity, which coincides with the origin of the reference system used. These rotors provide the predominant aerodynamic forces which act on the rotorcraft, and are modelled using momentum theory as well as blade element theory. From this, one can determine the expected payload capacity and lift performance of the rotorcraft. The Euler-Lagrange method has been used to derive the defining equations of motion of the six degree-of-freedom system. The Lagrangian was obtained by modelling the kinetic and potential energy of the system and the external forces obtained from the aerodynamic analysis. Based on this model, a control strategy was developed using linear PD controllers. A numerical simulation was then conducted using MATLAB® Simulink®. First, the derived model was simulated to investigate the behaviour of the rotorcraft, and then a second investigation was conducted to determine the effectiveness of the implemented control system. The results and findings of these investigations are then presented and discussed.

  6. Some thoughts on the implementation of pilot night vision devices for helicopters

    Science.gov (United States)

    Tucker, G. E.

    1984-01-01

    Night vision enhancement devices greatly expand the range and quality of services by extending night operational capabilities. Evolving military tactical concepts for helicopters survivability and battlefield effectiveness necessitate nap-of-the-earth (NOE) flying under both day and night conditions. From a pilot workload standpoint, flying a helicopter NOE in day VFR conditions with minimum clearance between rotors and obstacles is quite demanding. Doing the same job at night is several times more difficult. There are two general categories of night vision devices in operation in helicopter aviation: the Night Vision Goggles (NVG) and forward looking infrared (FLIR) system. The capabilities and limitations of those two devices are discussed.

  7. A helicopter emergency medical service may allow faster access to highly specialised care

    DEFF Research Database (Denmark)

    Afzali, Monika; Hesselfeldt, Rasmus; Steinmetz, Jacob

    2013-01-01

    Centralization of the hospital system entails longer transport for some patients. A physician-staffed helicopter may provide effective triage, advanced management and fast transport to highly specialized treatment for time-critical patients. The aim of this study was to describe activity and poss......Centralization of the hospital system entails longer transport for some patients. A physician-staffed helicopter may provide effective triage, advanced management and fast transport to highly specialized treatment for time-critical patients. The aim of this study was to describe activity...... and possible beneficial effect of a physician-staffed helicopter in a one-year trial period in eastern Denmark....

  8. Psychoacoustic considerations for helicopter noise quantification: Metrics, human response and criteria

    Science.gov (United States)

    Powell, C. A.

    1982-01-01

    The purpose of this paper is to examine several aspects of helicopter noise quantification from the standpoint of psychoacoustics. Noise metrics in common use to describe far-field aircraft noise and the noise characteristics which they consider are discussed. Some findings of recent psychoacoustic research related specifically to helicopter noise quantification are presented. Criteria for the accuracy of noise metrics to quantify helicopter noise are discussed. Finally, the prospects for improved metrics and research needed to develop and validate improved metrics or existing metrics are discussed.

  9. Exploring a Chromakeyed Augmented Virtual Environment for Viability as an Embedded Training System for Military Helicopters

    National Research Council Canada - National Science Library

    Lennerton, Mark

    2004-01-01

    Once the military helicopter pilot deploys aboard a naval vessel he leaves behind all training platforms, short of the actual aircraft, that present enough fidelity for him to maintain the highest levels of readiness...

  10. Adaptive Fuzzy Sliding Mode Control for a Model-Scaled Unmanned Helicopter

    Directory of Open Access Journals (Sweden)

    Amir Razzaghian

    2016-11-01

    Full Text Available This paper presents a novel Adaptive Fuzzy Sliding Mode Controller (AFSMC for a model-scaled unmanned helicopter as real nonlinear plant. First, in order to efficient control law design, the nonlinear model of the helicopter is reformulated as an affine nonlinear system. To do this aim, a Dynamic Inverter (DI is introduced as a bijective function. The proposed DI is used to interconnect the helicopter actuators' main inputs to the helicopter dynamic inputs. Then, AFSMC is designed to control it, and the asymptotic stability of the closed loop system is proved using Lyapunov stability theorem. To verify the merits of the proposed controller, it is compared with traditional sliding mode control system. Simulation results confirmed that the controller as a robust and stable control method has desired controlling performance and well cope with the undesirable chattering phenomenon.

  11. A Hybrid Flight Control for a Simulated Raptor-30 V2 Helicopter

    Directory of Open Access Journals (Sweden)

    Arbab Nighat Khizer

    2015-04-01

    Full Text Available This paper presents a hybrid flight control system for a single rotor simulated Raptor-30 V2 helicopter. Hybrid intelligent control system, combination of the conventional and intelligent control methodologies, is applied to small model helicopter. The proposed hybrid control used PID as a traditional control and fuzzy as an intelligent control so as to take the maximum advantage of advanced control theory. The helicopter?s model used; comes from X-Plane flight simulator and their hybrid flight control system was simulated using MATLAB/SIMULINK in a simulation platform. X-Plane is also used to visualize the performance of this proposed autopilot design. Through a series of numerous experiments, the operation of hybrid control system was investigated. Results verified that the proposed hybrid control has an excellent performance at hovering flight mode.

  12. A community survey of helicopter noise annoyance conducted under controlled noise exposure conditions

    Science.gov (United States)

    Fields, J. M.; Powell, C. A.

    1985-01-01

    Reactions to low numbers of helicopter noise events (less than 50 per day) were studied in a community setting. Community residents were repeatedly interviewed about daily noise annoyance reactions on days when helicopter noise exposures were, without the residents' knowledge, controlled. The effects of maximum noise level and number of noise events on helicopter noise annoyance are consistent with the principles contained in LEQ-based noise indices. The effect of the duration of noise events is also consistent with LEQ-based indices. After removing the effect of differences in noise levels (LEQ) there is not an important difference between reactions to impulsive and nonimpulsive types of helicopters. EPNL, where corrected for number of overflights, and LEQ are approximately equally successful in representing the characteristics of noise which are related to human response. The new type of design provided estimates of the parameters in a noise reaction model which would not obtained with a similar degree of precision from conventional study designs.

  13. Safety in alpine helicopter rescue operations--minimal requirements of alpine skills for rescue personnel

    National Research Council Canada - National Science Library

    Küpper, Thomas; Hillebrandt, David; Steffgen, Juergen; Schöffl, Volker

    2013-01-01

    There is a lack of data to establish minimal requirements for technical alpine climbing skills needed by rescue teams involved in alpine helicopter rescue operations to perform such operations safely...

  14. Prehospital interventions before and after implementation of a physician-staffed helicopter

    DEFF Research Database (Denmark)

    Sonne, Asger; Wulffeld, Sandra; Steinmetz, Jacob

    2017-01-01

    INTRODUCTION: Implementation of a physician-staffed helicopter emergency medical service (HEMS) in eastern Denmark was associated with increased survival for severely injured patients. This study aimed to assess the potential impact of advanced prehospital interventions by comparing the proportion...

  15. Application of an X-ray Fluorescence Instrument to Helicopter Wear Debris Analysis

    National Research Council Canada - National Science Library

    Becker, Andrew

    2008-01-01

    This report describes the application of an X-ray Fluorescence (XRF) instrument to determine the composition of wear debris collected from helicopter magnetic chip detectors and oil filters. The Twin-X XRF...

  16. Study on Helicopter Antitorque Device Based on Cross-Flow Fan Technology

    Directory of Open Access Journals (Sweden)

    Du Siliang

    2016-01-01

    Full Text Available In order to improve low-altitude flight security of single-rotor helicopter, an experimental model of a helicopter antitorque device is developed for wind tunnel test. The model is based on the flow control technology of the cross-flow fan (CFF. Wind tunnel tests show that the model can produce side force. It is concluded that the influence of the CFF rotating speed, the rotor collective pitch, and the forward flight speed on the side force of the model is great. At the same time, the numerical simulation calculation method of the model has been established. Good agreement between experimental and numerical side force and power shows that results of numerical solution are reliable. Therefore, the results in actual helicopter obtained from Computational Fluid Dynamics (CFD solution are acceptable. This proves that this antitorque device can be used for a helicopter.

  17. 77 FR 49705 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2012-08-17

    ... Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule; request... published in the Federal Register. That AD applies to Eurocopter Deutschland GmbH Model MBB-BK 117 C-2...

  18. 78 FR 23696 - Airworthiness Directives; Eurocopter Deutschland GmbH (ECD) Helicopters

    Science.gov (United States)

    2013-04-22

    ... Deutschland GmbH (ECD) Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of... directive (AD): EUROCOPTER DEUTSCHLAND GmbH (ECD): Docket No. FAA-2013-0020; Directorate Identifier 2010-SW...

  19. 78 FR 37150 - Airworthiness Directives; Eurocopter Deutschland GmbH (ECD) Helicopters

    Science.gov (United States)

    2013-06-20

    ... Deutschland GmbH (ECD) Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of... Deutschland GmbH (ECD): Docket No. FAA-2013-0519; Directorate Identifier 2010-SW-068-AD. (a) Applicability...

  20. 78 FR 52412 - Airworthiness Directives; Eurocopter Deutschland GmbH (ECD) Helicopters

    Science.gov (United States)

    2013-08-23

    ... Deutschland GmbH (ECD) Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule...): 2013-16-20 Eurocopter Deutschland GmbH (ECD): Amendment 39-17558; Docket No. FAA-2013-0020; Directorate...

  1. Final assessment of vibro-acoustic source strength descriptors of helicopter gearboxes

    DEFF Research Database (Denmark)

    Ohlrich, Mogens; Rasmussen, Ulrik Møller

    1996-01-01

    Two novel measurement techniques have been developed for quantifying the vibro-aqcoustic source strength of lightweight helicopter gearboxes. The accuracy, robustness and implementation of these methods have been examined by a comprehensive investigation, including theoretical studies of simple...... multi-modal beam systems and extensive experiments with more realistic small scale models and with large, detailed 3/4-scale test structures of a medium-size helicopter. In addition, partial verification tests have been conducted with the Eurocopter BK 117 helicopter and its main rotor gearbox....... The results of this work are essential as input for any prediction code of the internal noise in a helicopter cabin, because the prediction requires knowledge of the major sources, that is, the rotors, engines and gearboxes....

  2. Development of Helicopter Capabilities in the U.S. Army During the Korean and Vietnam Wars

    Science.gov (United States)

    2016-06-10

    DEVELOPMENT OF HELICOPTER CAPABILITIES IN THE U.S. ARMY DURING THE KOREAN AND VIETNAM WARS A thesis presented to the Faculty...Korean and Vietnam Wars 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Major Denys Soboliev 5d. PROJECT...Distribution is Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT The Vietnam War was the first conflict with a large helicopter involvement from the

  3. The Effects of Ambient Conditions on Helicopter Rotor Source Noise Modeling

    Science.gov (United States)

    Schmitz, Frederic H.; Greenwood, Eric

    2011-01-01

    A new physics-based method called Fundamental Rotorcraft Acoustic Modeling from Experiments (FRAME) is used to demonstrate the change in rotor harmonic noise of a helicopter operating at different ambient conditions. FRAME is based upon a non-dimensional representation of the governing acoustic and performance equations of a single rotor helicopter. Measured external noise is used together with parameter identification techniques to develop a model of helicopter external noise that is a hybrid between theory and experiment. The FRAME method is used to evaluate the main rotor harmonic noise of a Bell 206B3 helicopter operating at different altitudes. The variation with altitude of Blade-Vortex Interaction (BVI) noise, known to be a strong function of the helicopter s advance ratio, is dependent upon which definition of airspeed is flown by the pilot. If normal flight procedures are followed and indicated airspeed (IAS) is held constant, the true airspeed (TAS) of the helicopter increases with altitude. This causes an increase in advance ratio and a decrease in the speed of sound which results in large changes to BVI noise levels. Results also show that thickness noise on this helicopter becomes more intense at high altitudes where advancing tip Mach number increases because the speed of sound is decreasing and advance ratio increasing for the same indicated airspeed. These results suggest that existing measurement-based empirically derived helicopter rotor noise source models may give incorrect noise estimates when they are used at conditions where data were not measured and may need to be corrected for mission land-use planning purposes.

  4. The Human Factors Relating to Escape and Survival from Helicopters Ditching in Water

    Science.gov (United States)

    1989-08-01

    helicopter floated for on); a very short time, then capsized rapidl*. The Norwegian Aircraft Accident Commission identified one additional sea water...the sea could not be established. Additional European statistics were submitted by the Swedish Board of Accident Investigation (Table 6). They have had...difficulty making their es-pe. And fifth, manifacturers have incorporated little current crashworthy technology into helicopters. 9 CHAPTER 2: SURVIVAL

  5. Stability Analysis of a Helicopter with an External Slung Load System

    OpenAIRE

    Thanapalan, Kary

    2016-01-01

    This paper describes the stability analysis of a helicopter with an underslung external load system. The Lyapunov second method is considered for the stability analysis. The system is considered as a cascade connection of uncertain nonlinear system. The stability analysis is conducted to ensure the stabilisation of the helicopter system and the positioning of the underslung load at hover condition. Stability analysis and numerical results proved that if desired condition for the stability is ...

  6. Helicopter Parenting and Related Issues: Psychological Well Being, Basic Psychological Needs and Depression on University Students

    OpenAIRE

    Okray, Zihniye

    2016-01-01

    Helicopter parenting is not a new dimension of parenting but it is a parenting that involves hovering parents who are potentially over-involved in the lives of their child. (Padilla-Walker, Nelson, 2012) Helicopter parenting is a unique phenomenon (Odenweller et al, 2014) and unique form of parental control (Willoughby et al., 2013) which can be described as highly involved, intensive, a hands-on method. (Schiffrin et al, 2014) In this study, university students examined about their parental ...

  7. Noise measurements on the helicopter BK 117 design. Weighted noise levels and influence of airspeed

    Science.gov (United States)

    Splettstoesser, Wolf R.; Anders, Klaus P.; Spiegel, Karl-Heinz

    1986-11-01

    Noise measurements on the prototype helicopter BK 117 were performed in strict compliance with the proposed international Civil Aviation Organization regulations for noise certification of helicopters. Measurement procedure, noise data acquisition, analysis and reduction as well as applied correction procedures are described. Effective perceived noise levels (EPNL) and other noise descriptors were evaluated and related to the proposed noise limits. Additional level flyover tests with variable airspeed were conducted to investigate the resulting effect on the EPNL and other noise measures.

  8. Using Discrete Event Simulation To Analyze Personnel Requirements For The Malaysian Armys New Utility Helicopter Fleet

    Science.gov (United States)

    2016-06-01

    HELICOPTER FLEET Hasnan bin Mohamad Rais Major, Malaysian Army B.S., University Technology of Malaysia , 2000 Submitted in partial...Sitinoor Taqua, and my four children , Aideed, Azwa, Hazeeq and Anas, deserve as much credit for my success as I do. Their sacrifices and endless love...matter expert. 7. Documentation All flying hours recorded by the helicopter are documented in a special log-book used as the reference for calculating

  9. Abbreviated Assessment of Three Moving Map Displays for the UH-60 Helicopter

    Science.gov (United States)

    2000-12-01

    ARMY RESEARCH LABORATORY Abbreviated Assessment of Three Moving Map Displays for the UH-60 Helicopter David B. Durbin Richard N. Armstrong ARL...the UH-60 Helicopter David B. Durbin Richard N. Armstrong Human Research & Engineering Directorate Approved for public release; distribution is...DR HARVEY A TAUB RSCH SECTION PSYCH SECTION VETERANS ADMIN HOSPITAL IRVING AVE & UNIVERSITY PLACE SYRACUSE NY 13210 DR ROBERT C SUGARMAN 132

  10. 77 FR 20321 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2012-04-04

    ... Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed... Deutschland GmbH (ECD) MBB-BK 117 A-3, MBB-BK 117 A-4, MBB- BK B-1, MBB-BK 117 B-2, and MBB-BK C-1 helicopters... Eurocopter Deutschland GmbH (ECD) Model MBB-BK 117 A-4 model. The EASA AD makes no mention of this model. The...

  11. Detection of Naturally Occurring Gear and Bearing Faults in a Helicopter Drivetrain

    Science.gov (United States)

    2014-01-01

    Detection of Naturally Occurring Gear and Bearing Faults in a Helicopter Drivetrain by Kelsen E. LaBerge, Eric C. Ames, and Brian D. Dykas...5066 ARL-TR-6795 January 2014 Detection of Naturally Occurring Gear and Bearing Faults in a Helicopter Drivetrain Kelsen E. LaBerge...ELEMENT NUMBER 6. AUTHOR(S) Kelsen E. LaBerge, Eric C. Ames, and Brian D. Dykas 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER

  12. Applications of numerical optimization methods to helicopter design problems: A survey

    Science.gov (United States)

    Miura, H.

    1984-01-01

    A survey of applications of mathematical programming methods is used to improve the design of helicopters and their components. Applications of multivariable search techniques in the finite dimensional space are considered. Five categories of helicopter design problems are considered: (1) conceptual and preliminary design, (2) rotor-system design, (3) airframe structures design, (4) control system design, and (5) flight trajectory planning. Key technical progress in numerical optimization methods relevant to rotorcraft applications are summarized.

  13. Applications of numerical optimization methods to helicopter design problems - A survey

    Science.gov (United States)

    Miura, H.

    1985-01-01

    A survey of applications of mathematical programming methods is used to improve the design of helicopters and their components. Applications of multivariable search techniques in the finite dimensional space are considered. Five categories of helicopter design problems are considered: (1) conceptual and preliminary design, (2) rotor-system design, (3) airframe structures design, (4) control system design, and (5) flight trajectory planning. Key technical progress in numerical optimization methods relevant to rotorcraft applications are summarized.

  14. Performance of a real-time sensor and processing system on a helicopter

    OpenAIRE

    F. Kurz; Rosenbaum, D.; O. Meynberg; Mattyus, G.; P. Reinartz

    2014-01-01

    A new optical real-time sensor system (4k system) on a helicopter is now ready to use for applications during disasters, mass events and traffic monitoring scenarios. The sensor was developed light-weighted, small with relatively cheap components in a pylon mounted sideward on a helicopter. The sensor architecture is finally a compromise between the required functionality, the development costs, the weight and the sensor size. Aboard processors are integrated in the 4k sensor system ...

  15. Data acquisition and processing - helicopter radiometric survey, Krageroe, 1998

    CERN Document Server

    Beard, L P

    2000-01-01

    On 07 October 1998 a helicopter radiometric survey was flown in the vicinity of Krageroe municipality. The purpose of the survey was to provide radiometric information to help assess radon hazard from radioactive rocks in the area. A total of 60 line-kilometres of radiometric data were acquired in a single flight, covering an area of approximately 3 square km with a 50-m line spacing. The data were collected by Geological Survey of Norway (NGU) personnel and processed at NGU. Radiometric data were reduced using the three-channel procedure recommended by the International Atomic Energy Association. All data were gridded using square cells with 30-m sides and geophysical maps were produced at a scale of 1:5000. This report covers aspects of data acquisition and processing (Author)

  16. Helicopter individual-blade-control and its applications

    Science.gov (United States)

    Ham, N. D.

    1984-01-01

    A new, advanced type of active control for helicopters and its applications are described. The system, based on previously developed M.I.T. Individual-Blade-Control hardware, employs blade-mounted accelerometers to sense blade motion and feeds back information to control blade pitch in such a manner as to reduce the response of selected blade modes. A linear model of the blade and control system dynamics is used to give guidance in the design process as well as to aid in analysis of experimental results. System performance in wind tunnel tests is described, and evidence is given of the system's ability to provide substantial reduction in blade modal responses, including blade bending vibration.

  17. Stability Analysis of the Slowed-Rotor Compound Helicopter Configuration

    Science.gov (United States)

    Floros, Matthew W.; Johnson, Wayne

    2007-01-01

    The stability and control of rotors at high advance ratio are considered. Teetering, articulated, gimbaled, and rigid hub types are considered for a compound helicopter (rotor and fixed wing). Stability predictions obtained using an analytical rigid flapping blade analysis, a rigid blade CAMRAD II model, and an elastic blade CAMRAD II model are compared. For the flapping blade analysis, the teetering rotor is the most stable, showing no instabilities up to an advance ratio of 3 and a Lock number of 18. A notional elastic blade model of a teetering rotor is unstable at an advance ratio of 1.5, independent of pitch frequency. Analysis of the trim controls and blade flapping shows that for small positive collective pitch, trim can be maintained without excessive control input or flapping angles.

  18. Magnetorheological Fluid and Elastomeric Lag Damper for Helicopter Stability Augmentation

    Science.gov (United States)

    Hu, Wei; Wereley, Norman M.

    The feasibility of utilizing a composite magnetorheological fluid plus elastomeric (MRFE) damper is assessed. To emulate the loading conditions for a helicopter lag damper, the MRFE damper emulation was subjected to single frequency (lag/rev) and dual frequency (lag/rev and 1/rev) sinusoidal loading, and equivalent viscous damping was used to compare the MRFE damping characteristics with a conventional elastomeric damper. The preliminary MRFE damper showed nonlinear behavior: damping was reduced as displacement amplitude increased. Upon application of a magnetic field, the damping level was controlled according to a specific damping objective as a function of the excitation amplitude. Under dual frequency conditions, damping degradation at lag frequency due to 1/rev motion was also mitigated by magnetic field input to the MR damper.

  19. Aeroelastic effects on stability and control of hingeless rotor helicopters

    Science.gov (United States)

    Celi, Roberto

    1988-01-01

    The combined effect of torsional flexibility and offset of the aerodynamic center relative to the elastic axis on the stability and control of a hingeless rotor helicopter in forward flight is studied in this paper. The aeroelastic model of the blade is based on fully coupled flap-lag-torsion equations of motion, which include kinematic nonlinearities due to moderate deflections. The equations are discretized using a finite element Galerkin method in space, and a classical Galerkin method in time. The vehicle trim calculations are coupled to the blade aeroelastic response calculations. Quasilinearization is used to compute aeroelastic stability. Reducing torsional stiffness and moving the elastic axis ahead of the aerodynamic center strongly stabilizes the phugoid mode without reducing control sensitivity. Aeroelastic stability calculations must accompany flight dynamics calculations to prevent aeroelastic instabilities that might easily go undetected.

  20. Damping augmentation of helicopter rotors using magnetorheological dampers

    Science.gov (United States)

    Zhao, Yongsheng

    This dissertation describes an investigation exploring the use of magnetorheological (MR) dampers to augment the stability of helicopter rotors. Helicopters with advanced soft in-plane rotors are susceptible to ground resonance instabilities due to the coupling of the lightly damped rotor lag modes and fuselage modes. Traditional passive lag dampers, such as hydraulic or elastomeric dampers, can be used to alleviate these instabilities. However, these passive dampers suffer from the disadvantages that they produce large damper loads in forward flight conditions. These damper forces increase fatigue loads and reduce component life. Thus, it is desirable to have lag dampers controllable or adaptable, so that the damper can apply loads only when needed. MR fluid based dampers have recently been considered for helicopter lag damping augmentation because the forces generated by these dampers can be controlled by an applied magnetic field. In this dissertation, control schemes to integrate MR dampers with helicopters are developed and the influences of the MR dampers on rotorcraft ground resonance are studied. Specifically, the MR dampers are incorporated into the ground resonance model in two ways: using a linear equivalent viscous damping and using a nonlinear damper model. The feasibility of using MR dampers to stabilize ground resonance is studied. The open loop on-off control is utilized where MR dampers are turned on over RPM where ground resonance occurs, and turned off otherwise. To further explore the damping control ability of MR dampers, the nonlinear semi-active closed loop feedback control strategies are developed: feedback linearization control and sliding mode control. The performance of the two control strategies is evaluated using two examples: to stabilize an unstable rotor and to augment the stability of a marginally stable rotor. In addition, the robustness of the closed loop control strategies is studied using two cases: damper degradation and

  1. Smart helicopter rotors optimization and piezoelectric vibration control

    CERN Document Server

    Ganguli, Ranjan; Viswamurthy, Sathyamangalam Ramanarayanan

    2016-01-01

    Exploiting the properties of piezoelectric materials to minimize vibration in rotor-blade actuators, this book demonstrates the potential of smart helicopter rotors to achieve the smoothness of ride associated with jet-engined, fixed-wing aircraft. Vibration control is effected using the concepts of trailing-edge flaps and active-twist. The authors’ optimization-based approach shows the advantage of multiple trailing-edge flaps and algorithms for full-authority control of dual trailing-edge-flap actuators are presented. Hysteresis nonlinearity in piezoelectric stack actuators is highlighted and compensated by use of another algorithm. The idea of response surfaces provides for optimal placement of trailing-edge flaps. The concept of active twist involves the employment of piezoelectrically induced shear actuation in rotating beams. Shear is then demonstrated for a thin-walled aerofoil-section rotor blade under feedback-control vibration minimization. Active twist is shown to be significant in reducing vibra...

  2. Pipes's distribution by helicopter in Amazonian forest

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Gilberto R.; Machado, Otto L.M.; Gomes, Antonio E. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2009-12-19

    The innumerable logistical problems encountered during the implementation of the gas pipeline Urucu - Coari - Manaus, located in the Amazon forest, connecting the Base Operations Geologist Pedro de Moura in Urucu to the refinery Isaac Sabba - Reman, in the city of Manaus, contributed considerably for PETROBRAS to seek non conventional solutions in the construction and assembly of pipelines in our country. Among these solutions, there is the technique of distributing pipes through cargo helicopters. The need for the usage of this technique, innovative in Brazil, comes from the lack and/or insufficiency of land access from Solimoes River to the gas pipeline main route, and the large quantities of flooded areas and/or flood plain, and also the type of soil, that together with the high index of rainfall in the region, makes the soil fully inappropriate to the traffic of heavy equipment. (author)

  3. Gulf of Mexico Helicopter Offshore System Technologies Recommended Development Path

    Science.gov (United States)

    Koenke, Edmund J.; Williams, Larry; Calafa, Caesar

    1999-01-01

    The National Aeronautics and Space Administration (NASA) Advanced Air Transportation Technologies (AATT) project in cooperation with the Department of Transportation (DOT) Volpe National Transportation Systems Center (VNTSC) contracted with the System Resources Corporation (SRC) for the evaluation of the existing environment and the identification of user and service provider needs in the Gulf of Mexico low-altitude Offshore Sector. The results of this contractor activity are reported in the Gulf of Mexico Helicopter Offshore System Technologies Engineering Needs Assessment. A recommended system design and transition strategy was then developed to satisfy the identified needs within the constraints of the environment. This work, also performed under contract to NASA, is the subject of this report.

  4. Advances in transitional flow modeling applications to helicopter rotors

    CERN Document Server

    Sheng, Chunhua

    2017-01-01

    This book provides a comprehensive description of numerical methods and validation processes for predicting transitional flows based on the Langtry–Menter local correlation-based transition model, integrated with both one-equation Spalart–Allmaras (S–A) and two-equation Shear Stress Transport (SST) turbulence models. A comparative study is presented to combine the respective merits of the two coupling methods in the context of predicting the boundary-layer transition phenomenon from fundamental benchmark flows to realistic helicopter rotors. The book will of interest to industrial practitioners working in aerodynamic design and the analysis of fixed-wing or rotary wing aircraft, while also offering advanced reading material for graduate students in the research areas of Computational Fluid Dynamics (CFD), turbulence modeling and related fields.

  5. Nonlinear Characteristics of Helicopter Rotor Blade Airfoils: An Analytical Evaluation

    Directory of Open Access Journals (Sweden)

    Constantin Rotaru

    2013-01-01

    Full Text Available Some results are presented about the study of airloads of the helicopter rotor blades, the aerodynamic characteristics of airfoil sections, the physical features, and the techniques for modeling the unsteady effects found on airfoil operating under nominally attached flow conditions away from stall. The unsteady problem was approached on the basis of Theodorsen's theory, where the aerodynamic response (lift and pitching moment is considered as a sum of noncirculatory and circulatory parts. The noncirculatory or apparent mass accounts for the pressure forces required to accelerate the fluid in the vicinity of the airfoil. The apparent mass contributions to the forces and pitching moments, which are proportional to the instantaneous motion, are included as part of the quasi-steady result.

  6. Simulation Based Training Improves Airway Management for Helicopter EMS Teams

    Science.gov (United States)

    Dhindsa, Harinder S.; Reid, Renee; Murray, David; Lovelady, James; Powell, Katie; Sayles, Jeff; Stevenson, Christopher; Baker, Kathy; Solada, Brian; Carroll, Scott; hide

    2011-01-01

    The use of paralytic medications in the performance of RSI intubation is a high risk intervention used by many HEMS crews. There is no margin for error in RSI intubation as the results can be fatal. Operating room access for airway management training has become more difficult, and is not representative of the environment in which HEMS crews typically function. LifeEvac of Virginia designed and implemented an SST airway management program to provide a realistic, consistent training platform. The dynamic program incorporates standardized scenarios, and real life challenging cases that this and other programs have encountered. SST is done in a variety of settings including the helicopter, back of ambulances, staged car crashes and simulation centers. The result has been the indoctrination of a well defined, consistent approach to every airway management intervention. The SST program facillitates enhancement of technical skills. as well as team dynamics and communication.

  7. Data acquisition and processing - helicopter radiometric survey, Krageroe, 1998

    Energy Technology Data Exchange (ETDEWEB)

    Beard, Les P.; Mogaard, John Olav

    2000-07-01

    On 07 October 1998 a helicopter radiometric survey was flown in the vicinity of Krageroe municipality. The purpose of the survey was to provide radiometric information to help assess radon hazard from radioactive rocks in the area. A total of 60 line-kilometres of radiometric data were acquired in a single flight, covering an area of approximately 3 square km with a 50-m line spacing. The data were collected by Geological Survey of Norway (NGU) personnel and processed at NGU. Radiometric data were reduced using the three-channel procedure recommended by the International Atomic Energy Association. All data were gridded using square cells with 30-m sides and geophysical maps were produced at a scale of 1:5000. This report covers aspects of data acquisition and processing (Author)

  8. Distribution of Acoustic Power Spectra for an Isolated Helicopter Fuselage

    Directory of Open Access Journals (Sweden)

    Kusyumov A.N.

    2016-01-01

    Full Text Available The broadband aerodynamic noise can be studied, assuming isotropic flow, turbulence and decay. Proudman’s approach allows practical calculations of noise based on CFD solutions of RANS or URANS equations at the stage of post processing and analysis of the solution. Another aspect is the broadband acoustic spectrum and the distribution of acoustic power over a range of frequencies. The acoustic energy spectrum distribution in isotropic turbulence is non monotonic and has a maximum at a certain value of Strouhal number. In the present work the value of acoustic power peak frequency is determined using a prescribed form of acoustic energy spectrum distribution presented in papers by S. Sarkar and M. Y. Hussaini and by G. M. Lilley. CFD modelling of the flow around isolated helicopter fuselage model was considered using the HMB CFD code and the RANS equations.

  9. Dynamics Modeling and Control of a Quad-rotor Helicopter

    Science.gov (United States)

    Hossain, Mohammed Raju

    Unmanned Aerial Vehicles (UAVs) have become a promising field of research due to the enormous potential for both military and civilian applications. This thesis focuses on increasing the autonomy of one type of rotary wing UAV; namely a Quad-rotor Helicopter. In this work a detailed mathematical model was introduced for simulation of the dynamics and control of this system. The dynamic model evolved from a simple set of equations, valid only for hovering, to a complex mathematical model with more realistic aerodynamic factors like thrust factor and drag factor. A simple yet precise tool was developed to measure these aerodynamic factors. An intelligent vision based control technique has been proposed for the critical, near-hovering flight of the vehicle. Finally, a platform was developed and a PD controller was implemented with inertial sensors in order to prepare the platform for implementing the vision-based control in the future.

  10. Model-based sensor location selection for helicopter gearbox monitoring

    Science.gov (United States)

    Jammu, Vinay B.; Wang, Keming; Danai, Kourosh; Lewicki, David G.

    1996-01-01

    A new methodology is introduced to quantify the significance of accelerometer locations for fault diagnosis of helicopter gearboxes. The basis for this methodology is an influence model which represents the effect of various component faults on accelerometer readings. Based on this model, a set of selection indices are defined to characterize the diagnosability of each component, the coverage of each accelerometer, and the relative redundancy between the accelerometers. The effectiveness of these indices is evaluated experimentally by measurement-fault data obtained from an OH-58A main rotor gearbox. These data are used to obtain a ranking of individual accelerometers according to their significance in diagnosis. Comparison between the experimentally obtained rankings and those obtained from the selection indices indicates that the proposed methodology offers a systematic means for accelerometer location selection.

  11. Stable Hovering Flight for a Small Unmanned Helicopter Using Fuzzy Control

    Directory of Open Access Journals (Sweden)

    Arbab Nighat Khizer

    2014-01-01

    Full Text Available Stable hover flight control for small unmanned helicopter under light air turbulent environment is presented. Intelligent fuzzy logic is chosen because it is a nonlinear control technique based on expert knowledge and is capable of handling sensor created noise and contradictory inputs commonly encountered in flight control. The fuzzy nonlinear control utilizes these distinct qualities for attitude, height, and position control. These multiple controls are developed using two-loop control structure by first designing an inner-loop controller for attitude angles and height and then by establishing outer-loop controller for helicopter position. The nonlinear small unmanned helicopter model used comes from X-Plane simulator. A simulation platform consisting of MATLAB/Simulink and X-Plane© flight simulator was introduced to implement the proposed controls. The main objective of this research is to design computationally intelligent control laws for hovering and to test and analyze this autopilot for small unmanned helicopter model on X-Plane under ideal and mild turbulent condition. Proposed fuzzy flight controls are validated using an X-Plane helicopter model before being embedded on actual helicopter. To show the effectiveness of the proposed fuzzy control method and its ability to cope with the external uncertainties, results are compared with a classical PD controller. Simulated results show that two-loop fuzzy controllers have a good ability to establish stable hovering for a class of unmanned rotorcraft in the presence of light turbulent environment.

  12. 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

  13. Helicopter flights with night-vision goggles: Human factors aspects

    Science.gov (United States)

    Brickner, Michael S.

    1989-01-01

    Night-vision goggles (NVGs) and, in particular, the advanced, helmet-mounted Aviators Night-Vision-Imaging System (ANVIS) allows helicopter pilots to perform low-level flight at night. It consists of light intensifier tubes which amplify low-intensity ambient illumination (star and moon light) and an optical system which together produce a bright image of the scene. However, these NVGs do not turn night into day, and, while they may often provide significant advantages over unaided night flight, they may also result in visual fatigue, high workload, and safety hazards. These problems reflect both system limitations and human-factors issues. A brief description of the technical characteristics of NVGs and of human night-vision capabilities is followed by a description and analysis of specific perceptual problems which occur with the use of NVGs in flight. Some of the issues addressed include: limitations imposed by a restricted field of view; problems related to binocular rivalry; the consequences of inappropriate focusing of the eye; the effects of ambient illumination levels and of various types of terrain on image quality; difficulties in distance and slope estimation; effects of dazzling; and visual fatigue and superimposed symbology. These issues are described and analyzed in terms of their possible consequences on helicopter pilot performance. The additional influence of individual differences among pilots is emphasized. Thermal imaging systems (forward looking infrared (FLIR)) are described briefly and compared to light intensifier systems (NVGs). Many of the phenomena which are described are not readily understood. More research is required to better understand the human-factors problems created by the use of NVGs and other night-vision aids, to enhance system design, and to improve training methods and simulation techniques.

  14. Dual frequency MM-wave radar for antitank helicopter

    Science.gov (United States)

    Jehle, F. X.; Meinel, H.

    1986-07-01

    Helicopters are gaining increasing significance for air close support, airborne landing, tank unit interdiction and both helicopter and tank engagement missions. To support these mission phases, sensors are required for obstacle warning, navigation, and moving and fixed target indication for weapon designation. The majority of the present systems use optical and infrared sensors; some of them apply laser systems. These sensor systems are subject to considerable limitations with respect to their capability of penetrating bad weather zones, fog, and battlefield environment (dust, smoke, man-made fog etc.). The design concept of a dual-frequency radar operating in millimeter wave range which avoids these drawbacks and complements existing sensors is presented. It consists of a 60 GHz radar subsystem for obstacle warning including the detection of wires up to a range of approximately 500 m; due to the selection of a frequency in the absorption line of oxygen resulting in a high atmospheric attenuation (16 dB/km), the susceptibility to interception and thus also to interference electronic countermeasures can be maintained at a very low level. A 50 GHz radar subsystem (attenuation as low as 0.3 dB/km) with its range of approximately 5 km against targets of interest is used for navigation, fixed and moving target indication as well as weapon designation. Due to the combination of the two subsystems (50/60 GHz), high-value components (antenna, scanner, receiver assemblies, control and indicator units) can be used jointly for both subsystems, so that the special features of each subsystem become available at reasonable expenses.

  15. Development of Fuzzy Logic Controller for Quanser Bench-Top Helicopter

    Science.gov (United States)

    Jafri, M. H.; Mansor, H.; Gunawan, T. S.

    2017-11-01

    Bench–top helicopter is a laboratory scale helicopter that usually used as a testing bench of the real helicopter behavior. This helicopter is a 3 Degree of Freedom (DOF) helicopter which works by three different axes wshich are elevation, pitch and travel. Thus, fuzzy logic controller has been proposed to be implemented into Quanser bench-top helicopter because of its ability to work with non-linear system. The objective for this project is to design and apply fuzzy logic controller for Quanser bench-top helicopter. Other than that, fuzzy logic controller performance system has been simulated to analyze and verify its behavior over existing PID controller by using Matlab & Simulink software. In this research, fuzzy logic controller has been designed to control the elevation angle. After simulation has been performed, it can be seen that simulation result shows that fuzzy logic elevation control is working for 4°, 5° and 6°. These three angles produce zero steady state error and has a fast response. Other than that, performance comparisons have been performed between fuzzy logic controller and PID controller. Fuzzy logic elevation control has a better performance compared to PID controller where lower percentage overshoot and faster settling time have been achieved in 4°, 5° and 6° step response test. Both controller are have zero steady state error but fuzzy logic controller is managed to produce a better performance in term of settling time and percentage overshoot which make the proposed controller is reliable compared to the existing PID controller.

  16. Identification, control and visually-guided behavior for a model helicopter

    Science.gov (United States)

    Saripalli, Srikanth

    Research on unmanned aerial vehicles is motivated by applications where human intervention is impossible, risky or expensive e.g. hazardous material recovery, traffic monitoring, disaster relief support, military operations etc. Due to its vertical take-off, landing and hover capabilities, a helicopter is an attractive platform for such applications. There are significant challenges to building an autonomous robotic helicopter - these span the areas of system identification, low-level control, state estimation, and planning. Towards the goal of fully-autonomous helicopters this thesis makes the following contributions. A continuous-discrete extended Kalman filter has been developed that combines inertial data with GPS and compass data to provide estimates of the 6DOF state of the helicopter. Using this filter a model for the helicopter has been identified based on frequency response techniques. The model has been validated in flight tests on a small helicopter testbed (1.6 m rotor diameter) at speeds upto 5 m/s. Based on evidence from this model a decoupled low-level controller has been developed which is embedded in a control architecture suitable for visually-guided navigation. As a novel application, we show how such a controller can be used to perform trajectory following on the helicopter where the desired trajectories are typical spacecraft landing trajectories, and the only controls available are thrusters. This in effect, produces a low-cost testbed for testing spacecraft landing and hazard avoidance on a planetary surface. Finally, we develop and extensively experimentally characterize algorithms for vision-based autonomous landing, object tracking, and sensor deployment.

  17. 76 FR 28637 - Airworthiness Directives; Eurocopter France Model AS350B, B1, B2, B3, BA, and EC130 B4 Helicopters

    Science.gov (United States)

    2011-05-18

    ... Model AS350B, B1, B2, B3, BA, and EC130 B4 Helicopters AGENCY: Federal Aviation Administration (FAA..., 2009, for the Model EC130 B4 helicopters. The Model AS350 BB helicopter is not type certificated in the...) None. Applicability (c) This AD applies to Model AS350B, B1, B2, B3, BA, and EC130 B4 helicopters with...

  18. Decay of Ultralight Axion Condensates

    Energy Technology Data Exchange (ETDEWEB)

    Eby, Joshua; Ma, Michael; Suranyi, Peter; Wijewardhana, L. C.R.

    2017-05-15

    Axion particles can form macroscopic condensates, whose size can be galactic in scale for models with very small axion masses $m\\sim10^{-22}$ eV, and which are sometimes referred to under the name of Fuzzy Dark Matter. Many analyses of these condensates are done in the non-interacting limit, due to the weakness of the self-interaction coupling of axions. We investigate here how certain results change upon inclusion of these interactions, finding a decreased maximum mass and a modified mass-radius relationship. Further, these condensates are, in general, unstable to decay through number-changing interactions. We analyze the stability of galaxy-sized condensates of axion-like particles, and sketch the parameter space of stable configurations as a function of a binding energy parameter. We find a strong lower bound on the size of Fuzzy Dark Matter condensates which are stable to decay, with lifetimes longer than the age of the universe.

  19. Modeling and simulation of coaxial helicopter rotor aerodynamics

    Science.gov (United States)

    Gecgel, Murat

    A framework is developed for the computational fluid dynamics (CFD) analyses of a series of helicopter rotor flowfields in hover and in forward flight. The methodology is based on the unsteady solutions of the three-dimensional, compressible Navier-Stokes equations recast in a rotating frame of reference. The simulations are carried out by solving the developed mathematical model on hybrid meshes that aim to optimally exploit the benefits of both the structured and the unstructured grids around complex configurations. The computer code is prepared for parallel processing with distributed memory utilization in order to significantly reduce the computational time and the memory requirements. The developed model and the simulation methodology are validated for single-rotor-in-hover flowfields by comparing the present results with the published experimental data. The predictive merit of different turbulence models for complex helicopter aerodynamics are tested extensively. All but the kappa-o and LES results demonstrate acceptable agreement with the experimental data. It was deemed best to use the one-equation Spalart-Allmaras turbulence model for the subsequent rotor flowfield computations. First, the flowfield around a single rotor in forward flight is simulated. These time---accurate computations help to analyze an adverse effect of increasing the forward flight speed. A dissymmetry of the lift on the advancing and the retreating blades is observed for six different advance ratios. Since the coaxial rotor is proposed to mitigate the dissymmetry, it is selected as the next logical step of the present investigation. The time---accurate simulations are successfully obtained for the flowfields generated by first a hovering then a forward-flying coaxial rotor. The results for the coaxial rotor in forward flight verify the aerodynamic balance proposed by the previously published advancing blade concept. The final set of analyses aims to investigate if the gap between the

  20. Designing an autonomous helicopter testbed: From conception through implementation

    Science.gov (United States)

    Garcia, Richard D.

    Miniature Unmanned Aerial Vehicles (UAVs) are currently being researched for a wide range of tasks, including search and rescue, surveillance, reconnaissance, traffic monitoring, fire detection, pipe and electrical line inspection, and border patrol to name only a few of the application domains. Although small/miniature UAVs, including both Vertical Takeoff and Landing (VTOL) vehicles and small helicopters, have shown great potential in both civilian and military domains, including research and development, integration, prototyping, and field testing, these unmanned systems/vehicles are limited to only a handful of university labs. For VTOL type aircraft the number is less than fifteen worldwide! This lack of development is due to both the extensive time and cost required to design, integrate and test a fully operational prototype as well as the shortcomings of published materials to fully describe how to design and build a "complete" and "operational" prototype system. This dissertation overcomes existing barriers and limitations by describing and presenting in great detail every technical aspect of designing and integrating a small UAV helicopter including the on-board navigation controller, capable of fully autonomous takeoff, waypoint navigation, and landing. The presented research goes beyond previous works by designing the system as a testbed vehicle. This design aims to provide a general framework that will not only allow researchers the ability to supplement the system with new technologies but will also allow researchers to add innovation to the vehicle itself. Examples include modification or replacement of controllers, updated filtering and fusion techniques, addition or replacement of sensors, vision algorithms, Operating Systems (OS) changes or replacements, and platform modification or replacement. This is supported by the testbed's design to not only adhere to the technology it currently utilizes but to be general enough to adhere to a multitude of

  1. Dynamics Control Approaches to Improve Vibratory Environment of the Helicopter Aircrew

    Science.gov (United States)

    Wickramasinghe, Viresh Kanchana

    Although helicopter has become a versatile mode of aerial transportation, high vibration levels leads to poor ride quality for its passengers and aircrew. Undesired vibration transmitted through the helicopter seats have been known to cause fatigue and discomfort to the aircrew in the short-term as well as neck strain and back pain injuries due to long-term exposure. This research study investigated the use of novel active as well as passive methodologies integrated in helicopter seats to mitigate the aircrew exposure to high vibration levels. Due to significantly less certification effort required to modify the helicopter seat structure, application of novel technologies to the seat is more practical compared to flight critical components such as the main rotor to reduce aircrew vibration. In particular, this research effort developed a novel adaptive seat mount approach based on active vibration control technology. This novel design that incorporated two stacked piezoelectric actuators as active struts increases the bending stiffness to avoid the low frequency resonance while generating forces to counteract higher harmonic vibration peaks. A real-time controller implemented using a feed-forward algorithm based on adaptive notches counteracted the forced vibration peaks while a robust feedback control algorithm suppressed the resonance modes. The effectiveness of the adaptive seat mount system was demonstrated through extensive closed-loop control tests on a full-scale helicopter seat using representative helicopter floor vibration profiles. Test results concluded that the proposed adaptive seat mount approach based on active control technology is a viable solution for the helicopter seat vibration control application. In addition, a unique flight test using a Bell-412 helicopter demonstrated that the aircrew is exposed to high levels of vibration during flight and that the whole body vibration spectrum varied substantially depending on operating conditions as

  2. The Effects of Ambient Conditions on Helicopter Harmonic Noise Radiation: Theory and Experiment

    Science.gov (United States)

    Greenwood, Eric; Sim, Ben W.; Boyd, D. Douglas, Jr.

    2016-01-01

    The effects of ambient atmospheric conditions, air temperature and density, on rotor harmonic noise radiation are characterized using theoretical models and experimental measurements of helicopter noise collected at three different test sites at elevations ranging from sea level to 7000 ft above sea level. Significant changes in the thickness, loading, and blade-vortex interaction noise levels and radiation directions are observed across the different test sites for an AS350 helicopter flying at the same indicated airspeed and gross weight. However, the radiated noise is shown to scale with ambient pressure when the flight condition of the helicopter is defined in nondimensional terms. Although the effective tip Mach number is identified as the primary governing parameter for thickness noise, the nondimensional weight coefficient also impacts lower harmonic loading noise levels, which contribute strongly to low frequency harmonic noise radiation both in and out of the plane of the horizon. Strategies for maintaining the same nondimensional rotor operating condition under different ambient conditions are developed using an analytical model of single main rotor helicopter trim and confirmed using a CAMRAD II model of the AS350 helicopter. The ability of the Fundamental Rotorcraft Acoustics Modeling from Experiments (FRAME) technique to generalize noise measurements made under one set of ambient conditions to make accurate noise predictions under other ambient conditions is also validated.

  3. System Identification and Control Design of an Unmanned Helicopter Using a PI-MPC Controller

    Science.gov (United States)

    Le Tri, Quang; Lai, Ying-Chih

    2017-03-01

    This paper presents the study of the system identification and controller design for an unmanned helicopter using the integration of Proportional Integral (PI) and Model Predictive Control (MPC). Since the dynamic model of a helicopter is highly nonlinear and contains many uncertainties, the system identification and control are challenging and complicated. To accelerate the development, the autonomous flight and trajectory tracking of an unmanned helicopter, this study first setup a software simulation environment of the helicopter using the X-Plane flight simulator. The prediction-error minimization (PEM) and subspace methods were applied in this study to identify the dynamic model of the interested flight trim conditions. The lateral, longitudinal, heave, and yaw dynamic models were predicted by using the System Identification Toolbox of MATLAB. To enhance the stability and eliminate the uncertainty of the control system, the Integration of Proportional Integral (PI) and MPC were introduced. The developed control system was then applied to perform the trajectory tracking of a helicopter. The simulation results show that the performance of the proposed approach can track the desired trajectory.

  4. Full-scale crash test of a CH-47C helicopter

    Science.gov (United States)

    Castle, C. B.

    1976-01-01

    A full-scale crash test of a large troop/cargo carrying CH-47C helicopter was conducted at the Langley impact dynamics research facility. The crash test of this large helicopter was performed as part of a joint U.S. Army-NASA helicopter test program to provide dynamic structural and seat response data. The test, the procedures employed, the instrumentation, a general assessment of the resulting damage, and typical levels of accelerations experienced during the crash are reported. Various energy-absorbing seating systems for crew and troops were installed and instrumented to provide data for use in the development of design criteria for future aircraft. The crash conditions were selected to simulate known crash conditions and are representative of the 95th percentile accident environment for an autorotating helicopter. Visual examination of the crashed test specimen indicated irreparable damage to many of the structural components. The highest accelerations were recorded by the accelerometers located on the cabin floor in the aft section of the helicopter, directly above the primary impact location and on the floor of the cockpit above the secondary impact location(s).

  5. The study of aerosol and ozone measurements in lower boundary layer with UAV helicopter platform

    Science.gov (United States)

    Lin, Po-hsiung; Chen, Wen-nai

    2013-04-01

    This study describes the aerosol and ozone measurement in the lower atmospheric boundary layer of highly polluted region at Kao-hsiung, Taiwan with a small unmanned aerial vehicle (UAV) helicopter platform. This UAV helicopter, modified from Gaui-X7 electronic-power model helicopter with autopilot AHRS (Altitude-Head-Reference System) kit, has fast climb speed up to 700 m height and keeps stable status for atmospheric measurements in five-minute fly leg. Several quick-replaced battery packages are ready on ground for field intensive observation. The payload rack under this UAV helicopter carries a micro-Aethalometer (black carbon concentration), ozone meter, temperature-humidity sensor, barometer and a time-lapse digital camera. The field measurement site closes to Linyuan Petrochemical Industrial Park, where is one of the heavy polluted regions in Taiwan. Balloon-borne Vaisala RS-92 radiosonde and CL31 Lidar Ceilometer are used to provide the background of the atmosphere at the same time. More data analysis measured by UAV helicopter and its potential application will be discussed.

  6. Correlate Life Predictions and Condition Indicators in Helicopter Tail Gearbox Bearings

    Science.gov (United States)

    Dempsey, Paula J.; Bolander, Nathan; Haynes, Chris; Branning, Jeremy; Wade, Daniel R.

    2010-01-01

    Research to correlate bearing remaining useful life (RUL) predictions with Helicopter Health Usage Monitoring Systems (HUMS) condition indicators (CI) to indicate the damage state of a transmission component has been developed. Condition indicators were monitored and recorded on UH-60M (Black Hawk) tail gearbox output shaft thrust bearings, which had been removed from helicopters and installed in a bearing spall propagation test rig. Condition indicators monitoring the tail gearbox output shaft thrust bearings in UH-60M helicopters were also recorded from an on-board HUMS. The spal-lpropagation data collected in the test rig was used to generate condition indicators for bearing fault detection. A damage progression model was also developed from this data. Determining the RUL of this component in a helicopter requires the CI response to be mapped to the damage state. The data from helicopters and a test rig were analyzed to determine if bearing remaining useful life predictions could be correlated with HUMS condition indicators (CI). Results indicate data fusion analysis techniques can be used to map the CI response to the damage levels.

  7. Multi-Scale Modeling of an Integrated 3D Braided Composite with Applications to Helicopter Arm

    Science.gov (United States)

    Zhang, Diantang; Chen, Li; Sun, Ying; Zhang, Yifan; Qian, Kun

    2017-10-01

    A study is conducted with the aim of developing multi-scale analytical method for designing the composite helicopter arm with three-dimensional (3D) five-directional braided structure. Based on the analysis of 3D braided microstructure, the multi-scale finite element modeling is developed. Finite element analysis on the load capacity of 3D five-directional braided composites helicopter arm is carried out using the software ABAQUS/Standard. The influences of the braiding angle and loading condition on the stress and strain distribution of the helicopter arm are simulated. The results show that the proposed multi-scale method is capable of accurately predicting the mechanical properties of 3D braided composites, validated by the comparison the stress-strain curves of meso-scale RVCs. Furthermore, it is found that the braiding angle is an important factor affecting the mechanical properties of 3D five-directional braided composite helicopter arm. Based on the optimized structure parameters, the nearly net-shaped composite helicopter arm is fabricated using a novel resin transfer mould (RTM) process.

  8. 75 FR 33159 - Airworthiness Directives; Bell Helicopter Textron Canada Model 222, 222B, 222U, 230, and 430...

    Science.gov (United States)

    2010-06-11

    ... based on hours TIS. Additionally, this AD does not require operators to send their blades to Rotor... does not have an excepted S/N or code, certificated in any category. Helicopter model Helicopter S/N... area. Let the area dry for 30 minutes to 1 hour. Then, apply one sealer coat of polyurethane, MILC85285...

  9. 14 CFR Appendix G to Part 141 - Flight Instructor Instrument (For an Airplane, Helicopter, or Powered-Lift Instrument Instructor...

    Science.gov (United States)

    2010-01-01

    ... Airplane, Helicopter, or Powered-Lift Instrument Instructor Rating, as Appropriate) Certification Course G...—Flight Instructor Instrument (For an Airplane, Helicopter, or Powered-Lift Instrument Instructor Rating.... (c) Flight Instructor Instrument—Powered-lift aircraft. 2. Eligibility for enrollment. A person must...

  10. Black Hawk Down?: Establishing Helicopter Parenting as a Distinct Construct from Other Forms of Parental Control during Emerging Adulthood

    Science.gov (United States)

    Padilla-Walker, Laura M.; Nelson, Larry J.

    2012-01-01

    The purpose of the current study was to establish a measure of helicopter parenting that was distinct from other forms of parental control, and to examine parental and behavioral correlates of helicopter parenting. Participants included 438 undergraduate students from four universities in the United States (M[subscript age] = 19.65, SD = 2.00,…

  11. Development of an analysis for the determination of coupled helicopter rotor/control system dynamic response. Part 2: Program listing

    Science.gov (United States)

    Sutton, L. R.

    1975-01-01

    A theoretical analysis is developed for a coupled helicopter rotor system to allow determination of the loads and dynamic response behavior of helicopter rotor systems in both steady-state forward flight and maneuvers. The effects of an anisotropically supported swashplate or gyroscope control system and a deformed free wake on the rotor system dynamic response behavior are included.

  12. 75 FR 52914 - Airworthiness Directives; Bell Helicopter Textron Canada Limited Models 206A, 206B, 206L, 206L-1...

    Science.gov (United States)

    2010-08-30

    ... Part Number (P/N) 101584-1 or -2, sold through Bell Helicopter Spares beginning March 2009, as an... maintenance records to determine if a disc assembly, part number (P/N) 101584-1 or -2, is installed. Do this... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Bell Helicopter...

  13. 76 FR 13063 - Airworthiness Directives; EUROCOPTER FRANCE Model SA330F, SA330G, and SA330J Helicopters

    Science.gov (United States)

    2011-03-10

    ... of the pedal unit on a SA 330 helicopter, the copilot set the position beyond the end limit (``tall... products. The MCAI states: While adjusting the position of the pedal unit on a SA 330 helicopter, the.... Any such differences are highlighted in a NOTE within the AD. Costs of Compliance We estimate that...

  14. 33 CFR 149.417 - What firefighting equipment must a helicopter landing deck on a manned deepwater port have?

    Science.gov (United States)

    2010-07-01

    ... a helicopter landing deck on a manned deepwater port have? 149.417 Section 149.417 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DEEPWATER PORTS DEEPWATER PORTS... § 149.417 What firefighting equipment must a helicopter landing deck on a manned deepwater port have...

  15. 75 FR 66657 - Airworthiness Directives; Eurocopter Deutschland GmbH Model MBB-BK 117 C-2 Helicopters

    Science.gov (United States)

    2010-10-29

    ... Deutschland GmbH Model MBB- BK 117 C-2 Helicopters AGENCY: Federal Aviation Administration, DOT. ACTION: Final... Deutschland GmbH (ECD) Model MBB BK 117 C-2 helicopters. This amendment results from a mandatory continuing... Eurocopter Deutschland GmbH: Amendment 39-16486; Docket No. FAA-2010-0780; Directorate Identifier 2009-SW-68...

  16. 75 FR 48615 - Airworthiness Directives; Eurocopter France (ECF) Model AS350B3 and EC130 B4 Helicopters

    Science.gov (United States)

    2010-08-11

    ... Directives; Eurocopter France (ECF) Model AS350B3 and EC130 B4 Helicopters AGENCY: Federal Aviation... 073254 and modification of the Model EC130 B4 by MOD 073773. Failure of a contactor can prevent switching... No. 05A009, for the Model EC130 B4 helicopters. Both ASB's are dated November 16, 2009. Both ASBs...

  17. Intelligent Control of Quadrotor Unmanned Helicopter in Hovering Mode

    Directory of Open Access Journals (Sweden)

    Neda Shamshiri

    2015-08-01

    Full Text Available A Quadrotor helicopter is an unmanned aerial vehicle (UAV. This vehicle has attracted lots of researchers’ attention because of its unique abilities such as being an under-actuated system, vertical take-off and landing, spot movement, more degree of freedom (DOF and military and non- military functions. Because of nonlinear and complex dynamic, modeling and controlling this vehicle is one of the most challenging areas in control engineering. In this paper modeling of a Quadrotor will be described using Newton-Euler equations. Stabilizing and controlling of altitude and its attitude are done by three controller including classic PID, Fuzzy- PID and Neural- Fuzzy based on PID. Performances of these controllers are analyzed in the presence of disturbances and mass uncertainties. The main aim of this paper is designing an intelligent PID algorithm which is made by combining fuzzy logic and neural system and it will introduce a Neural- Fuzzy controller which is based on PID. Simulation results are presented by MATLAB software.

  18. Helicopter Drop”: Perspectives on Modern Central Banking Challenges

    Directory of Open Access Journals (Sweden)

    Munteanu Bogdan

    2017-03-01

    Full Text Available This paper aims to discuss the idea of Milton Friedman’s “helicopter drop” of money, analyzing the concept. It is an unconventional measure of monetary policy seen as a permanent uplift in the nominal monetary mass with a zero nominal interest rate, to finance budget deficit of fiscal authority from money issued by Central Bank. It could be a fiscal stimulus or purchases by the Central Bank of non-monetary sovereign debt, in both cases without affecting the current public spending from state budget. The paper takes into account the opportunity costs of such measure being deployed by ECB, looking at end-users (consumers and psychology of decisions over money. In the end, the article reviews the opinions of leading economists and the conclusions reflect that it is not the time or necessity for ECB to resort to such measure now, as the previous measures of quantitative easing and negative interest rate are starting to pay-off producing the targeted result of 2% inflation rate.

  19. Apollo 11 Astronaut Neil Armstrong Approaches Practice Helicopter

    Science.gov (United States)

    1969-01-01

    In preparation of the nation's first lunar landing mission, Apollo 11, crew members underwent training to practice activities they would be performing during the mission. In this photograph Neil Armstrong approaches the helicopter he flew to practice landing the Lunar Module (LM) on the Moon. The Apollo 11 mission launched from the Kennedy Space Center (KSC) in Florida via the Marshall Space Flight Center (MSFC) developed Saturn V launch vehicle on July 16, 1969 and safely returned to Earth on July 24, 1969. Aboard the space craft were astronauts Neil A. Armstrong, commander; Michael Collins, Command Module (CM) pilot; and Edwin E. (Buzz) Aldrin Jr., Lunar Module (LM) pilot. The CM, 'Columbia', piloted by Collins, remained in a parking orbit around the Moon while the LM, 'Eagle'', carrying astronauts Armstrong and Aldrin, landed on the Moon. On July 20, 1969, Armstrong was the first human to ever stand on the lunar surface, followed by Aldrin. During 2½ hours of surface exploration, the crew collected 47 pounds of lunar surface material for analysis back on Earth. With the success of Apollo 11, the national objective to land men on the Moon and return them safely to Earth had been accomplished

  20. A study of helicopter gust response alleviation by automatic control

    Science.gov (United States)

    Saito, S.

    1983-01-01

    Two control schemes designed to alleviate gust-induced vibration are analytically investigated for a helicopter with four articulated blades. One is an individual blade pitch control scheme. The other is an adaptive blade pitch control algorithm based on linear optimal control theory. In both controllers, control inputs to alleviate gust response are superimposed on the conventional control inputs required to maintain the trim condition. A sinusoidal vertical gust model and a step gust model are used. The individual blade pitch control, in this research, is composed of sensors and a pitch control actuator for each blade. Each sensor can detect flapwise (or lead-lag or torsionwise) deflection of the respective blade. The acturator controls the blade pitch angle for gust alleviation. Theoretical calculations to predict the performance of this feedback system have been conducted by means of the harmonic method. The adaptive blade pitch control system is composed of a set of measurements (oscillatory hub forces and moments), an identification system using a Kalman filter, and a control system based on the minimization of the quadratic performance function.

  1. Flow Structures within a Helicopter Rotor Hub Wake

    Science.gov (United States)

    Elbing, Brian; Reich, David; Schmitz, Sven

    2015-11-01

    A scaled model of a notional helicopter rotor hub was tested in the 48'' Garfield Thomas Water Tunnel at the Applied Research Laboratory Penn State. The measurement suite included total hub drag and wake velocity measurements (LDV, PIV, stereo-PIV) at three downstream locations. The main objective was to understand the spatiotemporal evolution of the unsteady wake between the rotor hub and the nominal location of the empennage (tail). Initial analysis of the data revealed prominent two- and four-per-revolution fluid structures linked to geometric hub features persisting into the wake far-field. In addition, a six-per-revolution fluid structure was observed in the far-field, which is unexpected due to the lack of any hub feature with the corresponding symmetry. This suggests a nonlinear interaction is occurring within the wake to generate these structures. This presentation will provide an overview of the experimental data and analysis with particular emphasis on these six-per-revolution structures.

  2. Support of Helicopter 'Free Flight' Operations in the 1996 Olympics

    Science.gov (United States)

    Branstetter, James R.; Cooper, Eric G.

    1996-01-01

    The microcosm of activity surrounding the 1996 Olympic Games provided researchers an opportunity for demonstrating state-of-the art technology in the first large-scale deployment of a prototype digital communication/navigation/surveillance system in a confined environment. At the same time it provided an ideal opportunity for transportation officials to showcase the merits of an integrated transportation system in meeting the operational needs to transport time sensitive goods and provide public safety services under real-world conditions. Five aeronautical CNS functions using a digital datalink system were chosen for operational flight testing onboard 91 aircraft, most of them helicopters, participating in the Atlanta Short-Haul Transportation System. These included: GPS-based Automatic Dependent Surveillance, Cockpit Display of Traffic Information, Controller-Pilot Communications, Graphical Weather Information (uplink), and Automated Electronic Pilot Reporting (downlink). Atlanta provided the first opportunity to demonstrate, in an actual operating environment, key datalink functions which would enhance flight safety and situational awareness for the pilot and supplement conventional air traffic control. The knowledge gained from such a large-scale deployment will help system designers in development of a national infrastructure where aircraft would have the ability to navigate autonomously.

  3. Bispectral index monitoring in helicopter emergency medical services patients.

    Science.gov (United States)

    Heegaard, William; Fringer, Ryan Charles; Frascone, R J; Pippert, Greg; Miner, James

    2009-01-01

    Background. Many critically ill patients are given sedatives and paralytics to facilitate aeromedical transport. Bispectral index (BIS) monitoring is a computer-derived electroencephalography (EEG) analog currently used to monitor the level of awareness of sedated patients. It gives a score of 1-100, with 1 representing no brain function and 100 representing a completely alert patient. Objective. To evaluate whether critically ill patients are adequately sedated during aeromedical transport. Methods. This was a prospective, observational study of a convenience sample of critically ill patients transported by helicopter. All intubated patients who received sedatives and/or paralytics to facilitate transport were eligible for enrollment by the attending clinician. Prior to liftoff, a BIS sensor was applied to the patient's forehead. Minimum, maximum, and mean BIS index scores were recorded every minute during transport. Results. Forty-seven patients (57% male) were enrolled, with a median age of 60 years (interquartile range [IQR] 18-81, range 14 to 86 years). The median duration of monitoring was 15.0- minutes (IQR 6.0-26.0, range 2 to 33). The median BIS score was 54.6 (IQR 38.6-67.3, range 28 to 89.5). Only two patients (4.3%, 95% confidence interval [CI] 0.5% to 14.8%) had at least one BIS score greater than 85, the accepted threshold for recall. Conclusion. These results suggest that patients are adequately sedated during air medical transport.

  4. Neural network-based optimal adaptive output feedback control of a helicopter UAV.

    Science.gov (United States)

    Nodland, David; Zargarzadeh, Hassan; Jagannathan, Sarangapani

    2013-07-01

    Helicopter unmanned aerial vehicles (UAVs) are widely used for both military and civilian operations. Because the helicopter UAVs are underactuated nonlinear mechanical systems, high-performance controller design for them presents a challenge. This paper introduces an optimal controller design via an output feedback for trajectory tracking of a helicopter UAV, using a neural network (NN). The output-feedback control system utilizes the backstepping methodology, employing kinematic and dynamic controllers and an NN observer. The online approximator-based dynamic controller learns the infinite-horizon Hamilton-Jacobi-Bellman equation in continuous time and calculates the corresponding optimal control input by minimizing a cost function, forward-in-time, without using the value and policy iterations. Optimal tracking is accomplished by using a single NN utilized for the cost function approximation. The overall closed-loop system stability is demonstrated using Lyapunov analysis. Finally, simulation results are provided to demonstrate the effectiveness of the proposed control design for trajectory tracking.

  5. An investigation of the effects of pitch-roll (de)-coupling on helicopter handling qualities

    Science.gov (United States)

    Ockier, C. J.; Pausder, H. J.; Blanken, C. L.

    1995-01-01

    An investigation of the effects of pitch-roll coupling on helicopter handling qualities was performed by the US Army and DLR, using a NASA ground-based and a DLR inflight simulator. Over 90 different coupling configurations were evaluated using a roll-axis tracking task. The results show that although the current ADS-33C coupling criterion discriminates against those types of coupling typical of conventionally controlled helicopters, it not always suited for the prediction of handling qualities of helicopters with modern control systems. Based on the observation that high frequency inputs during tracking are used to alleviate coupling, a frequency domain pitch-roll coupling criterion that uses the average coupling ratio between the bandwidth and neutral stability frequency is formulated. This criterion provides a more comprehensive coverage with respect to the different types of coupling and shows excellent consistency.

  6. System Identification and 6-DOF Hovering Controller Design of Unmanned Model Helicopter

    Science.gov (United States)

    Kim, Byeongil; Chang, Yushin; Lee, Man Hyung

    For a maneuvering unmanned autonomous helicopter, it is necessary to design a proper controller for each flight mode. In this paper, the overall helicopter dynamics is derived and a hovering model is linearized and transformed into a state-space form. However, since it is difficult to obtain parameters for stability derivatives in the state-space directly, a linear control model is derived by a time-domain parametric system identification method with real flight data of a model helicopter. Then, two different controllers (a linear feedback controller with the proportional gain and a robust controller) are designed and their performances are compared. The simulation results show outstanding performance. The validated controllers can be utilized to enable autonomous flight of a RUAV (Rotorcraft-based Unmanned Aerial Vehicle).

  7. Robust output tracking control of a laboratory helicopter for automatic landing

    Science.gov (United States)

    Liu, Hao; Lu, Geng; Zhong, Yisheng

    2014-11-01

    In this paper, robust output tracking control problem of a laboratory helicopter for automatic landing in high seas is investigated. The motion of the helicopter is required to synchronise with that of an oscillating platform, e.g. the deck of a vessel subject to wave-induced motions. A robust linear time-invariant output feedback controller consisting of a nominal controller and a robust compensator is designed. The robust compensator is introduced to restrain the influences of parametric uncertainties, nonlinearities and external disturbances. It is shown that robust stability and robust tracking property can be achieved simultaneously. Experimental results on the laboratory helicopter for automatic landing demonstrate the effectiveness of the designed control approach.

  8. Backstepping Controller with Intelligent Parameters Selection for Stabilization of Quadrotor Helicopter

    Directory of Open Access Journals (Sweden)

    Mohd Ariffanan Mohd Basri

    2016-07-01

    Full Text Available In this paper, the dynamic model of quadrotor helicopter has been mathematically formulated. Then, an intelligent backstepping controller (IBC is designed for the quadrotor altitude and attitude stabilization in the existence of external disturbances and measurement noise. The designed controller consists of a backstepping controller which can automatically select its parameters on-line by a fuzzy supervisory mechanism. The stability criterion for the stabilization of the quadrotor is proven by the Lyapunov theorem. Several numerical simulations using the dynamic model of a four degree of freedom (DOF quadrotor helicopter show the effectiveness of the approach. Besides, the simulation results indicate that the proposed design techniques can stabilize the quadrotor helicopter with better performance than established linear design techniques.

  9. Initial Flight Evaluation of the Army/NASA RASCAL Variable Stability Helicopter

    Science.gov (United States)

    Moralez, Ernesto, III; Hindson, William S.; Arterburn, David R.

    2000-01-01

    NASA Ames Research Center and the U.S. Army Aeroflightdynamics Directorate (AFDD) [will] have performed initial flight evaluations of the Research Flight Control System (RFCS) that has been integrated into the Army/NASA Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL) variable stability helicopter. The RASCAL, a highly modified JUH-60A Black Hawk helicopter, is a variable-stability, in-flight simulator that is designed to support flight research programs that leverage on the flight control and handling qualities design tools developed by the Army and NASA. These tools are used in the flight control design life cycle from initial concept definition, through simulation, and ultimately into flight on-board the RASCAL helicopter. The RASCAL will be used to validate methodologies for reducing design cycle costs for new or modified aircraft, and it will serve as a base for the investigation of new rotorcraft technology.

  10. AUTONOMOUS UNMANNED HELICOPTER SYSTEM FOR REMOTE SENSING MISSIONS IN UNKNOWN ENVIRONMENTS

    Directory of Open Access Journals (Sweden)

    T. Merz

    2012-09-01

    Full Text Available This paper presents the design of an autonomous unmanned helicopter system for low-altitude remote sensing. The proposed concepts and methods are generic and not limited to a specific helicopter. The development was driven by the need for a dependable, modular, and affordable system with sufficient payload capacity suitable for both research and real-world deployment. The helicopter can be safely operated without a backup pilot in a contained area beyond visual range. This enables data collection in inaccessible or dangerous areas. Thanks to its terrain following and obstacle avoidance capability, the system does not require a priori information about terrain elevation and obstacles. Missions are specified in state diagrams and flight plans. We present performance characteristics of our system and show results of its deployment in real-world scenarios. We have successfully completed several dozen infrastructure inspection missions and crop monitoring missions facilitating plant phenomics studies.

  11. 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

  12. Interfacility transfer of pediatric trauma patients by helicopter does not predict the need for urgent intervention.

    Science.gov (United States)

    Engbrecht, Brett W; Hollenbeak, Christopher S; Lubin, Jeffrey S; Cilley, Robert E

    2013-06-01

    Helicopter transport can allow trauma patients to reach definitive treatment rapidly, but its appropriate utilization for interfacility transfer to a pediatric trauma center (PTC) has not been well evaluated. This study evaluated differences in variables associated with transport type and intervention at a PTC between helicopter and ground transport for interfacility trauma transfers. This retrospective study evaluated pediatric (patients transferred to a rural PTC over a 5-year period. Records (n = 423) were evaluated for transport type, injuries, mechanism, interventions (eg, operations, transfusions, intubation), and treatment time points. Multiple logistic regression and Cox regression survival analyses were performed to evaluate associations with type of transport and interventions. Thirty-five percent of patients received intervention at the PTC, with no significant difference between transport types. Helicopter transport was associated with transport distance, respiratory rate greater than 30 breaths/min, pedestrian struck by auto, subdural hematoma, epidural hematoma, pneumothorax, solid organ injury, and vascular compromise/open fracture. Intervention was associated with epidural hematoma, extremity and pelvic fractures, vascular compromise/open fracture, penetrating neck/trunk injury, and complex laceration. Cox regression at less than 6, less than 4, and less than 2 hours after arrival at the PTC demonstrated similar intervention associations. Helicopter transport also correlated with intervention at these time points. Most pediatric trauma patients transferred by helicopter did not require interventions. Epidural hematoma, vascular compromise/open fracture, and penetrating neck/trunk injuries predicted prompt interventions (<2 hours) and may have benefited from helicopter transport. There was a disparity between the perceived need for rapid transport and the need for urgent interventions.

  13. Attitude angle anti-windup control of small size unmanned helicopter

    Science.gov (United States)

    Shao, Taizhou; Long, Haihui; Zhao, Jiankang; Xia, Xuan; Yang, Guang

    2017-01-01

    This paper researches the small-size unmanned helicopter attitude control problem with actuator saturation limit. Traditional approach for this problem is often based on an accurate dynamic model which is complicated and difficult to achieve in engineering. In this paper, we propose an anti-windup PID approach which does not rely on sophicated helicopter dynamic model. The anti-windup PID controller is established by adding a phase-lead compensator to the conventional PID controller. The performance and merits of this proposed controller are exemplified by the simulations between the conventional PID controller and the anti-windup PID controller.

  14. Stability Analysis of a Helicopter with an External Slung Load System

    Directory of Open Access Journals (Sweden)

    Kary Thanapalan

    2016-01-01

    Full Text Available This paper describes the stability analysis of a helicopter with an underslung external load system. The Lyapunov second method is considered for the stability analysis. The system is considered as a cascade connection of uncertain nonlinear system. The stability analysis is conducted to ensure the stabilisation of the helicopter system and the positioning of the underslung load at hover condition. Stability analysis and numerical results proved that if desired condition for the stability is met, then it is possible to locate the load at the specified position or its neighbourhood.

  15. Consolidation Needed for Procurements of DoD H-60 Helicopter Spare Parts (REDACTED)

    Science.gov (United States)

    2016-10-12

    Information Act. Report No. DODIG-2017-002 O C T O B E R 1 2 , 2 0 1 6 Consolidation Needed for Procurements of DoD H-60 Helicopter Spare Parts I N T E G R...Brief Consolidation Needed for Procurements of DoD H-60 Helicopter Spare Parts October 12, 2016 Visit us at www.dodig.mil Objective We determined... consolidate its purchase of 2.9 million H-60 spare parts to maximize its market leverage, such as receiving quantity discounts. The lack of

  16. Impact of a physician-staffed helicopter on a regional trauma system

    DEFF Research Database (Denmark)

    Hesselfeldt, R; Steinmetz, J; Jans, H

    2013-01-01

    This study aims to compare the trauma system before and after implementing a physician-staffed helicopter emergency medical service (PS-HEMS). Our hypothesis was that PS-HEMS would reduce time from injury to definitive care for severely injured patients.......This study aims to compare the trauma system before and after implementing a physician-staffed helicopter emergency medical service (PS-HEMS). Our hypothesis was that PS-HEMS would reduce time from injury to definitive care for severely injured patients....

  17. Maneuver Acoustic Flight Test of the Bell 430 Helicopter Data Report

    Science.gov (United States)

    Watts, Michael E.; Greenwood, Eric; Smith, Charles D.; Snider, Royce; Conner, David A.

    2014-01-01

    A cooperative ight test by NASA, Bell Helicopter and the U.S. Army to characterize the steady state acoustics and measure the maneuver noise of a Bell Helicopter 430 aircraft was accomplished. The test occurred during June/July 2011 at Eglin Air Force Base, Florida. This test gathered a total of 410 test points over 10 test days and compiled an extensive database of dynamic maneuver measurements. Three microphone arrays with up to 31 microphon. es in each were used to acquire acoustic data. Aircraft data included Differential Global Positioning System, aircraft state and rotor state information. This paper provides an overview of the test and documents the data acquired.

  18. Design of a simple active controller to suppress helicopter air resonance

    Science.gov (United States)

    Takahashi, M. D.; Friedmann, P. P.

    1988-01-01

    A coupled rotor/fuselage helicopter analysis with the important effects of blade torsional flexibility, unsteady aerodynamics, and forward flight is presented. Using this mathematical model, a nominal configuration is selected that experiences an air resonance instability throughout most of its flight envelope. A simple multivariable compensator using conventional swashplate inputs and a single body roll rate measurement is then designed. The controller design is based on a linear estimator in conjunction with optimal feedback gains, and the design is done in the frequency domain using the Loop Transfer Recovery method. The controller is shown to suppress the air resonance instability throughout wide range helicopter loading conditions and forward flight speeds.

  19. Helicopter downwash measured by continuous-wave Doppler lidars with agile beam steering

    DEFF Research Database (Denmark)

    Sjöholm, Mikael; Angelou, Nikolas; Hansen, Per

    2012-01-01

    Scanners, all three components of the wind can be retrieved. Here, the first mean 2D turbulent wind fields measured in a horizontal and a vertical plane below a hovering search and rescue helicopter are presented. The line-of-sights of two synchronized WindScanners were scanned within the plane of interest......, minimizing the risk to aircraft and personnel when operating in a search and rescue role. The results from the application of the short-range WindScanner technology to the complex and turbulent helicopter downwash demonstrates the possibilities also within less demanding flows encountered within complex...

  20. Hybrid magnetorheological fluid elastomeric lag dampers for helicopter stability augmentation

    Science.gov (United States)

    Hu, Wei; Wereley, Norman M.

    2008-08-01

    A laboratory demonstration of a hybrid magnetorheological fluid-elastomeric (MRFE) damper is investigated for adjustable or programmable lag mode damping in helicopters, so that damping requirements can be varied as a function of different flight conditions. The laboratory demonstration of this hybrid MRFE lag damper consists of a double lap shear elastomeric damper in parallel with two magnetorheological (MR) flow mode dampers. This is compared to a damper where only elastomeric materials are implemented, i.e., a double lap shear specimen. The relationship between the output force and the quasi-steady harmonic displacement input to a flow mode MR damper is exploited, where the output force can be adjusted as a function of applied magnetic field. Equivalent viscous damping is used to compare the damping characteristics of the hybrid damper to a conventional elastomeric damper under steady-state sinusoidal displacement excitation. To demonstrate feasibility, a hybrid MRFE damper test setup is designed, and single frequency (lag frequency or rotor in-plane bending frequency) and dual frequency (lag frequency and rotor frequency) tests are conducted under different magnetic fields. The hybrid MRFE damper exhibits amplitude-dependent damping behavior. However, with application of a magnetic field, the damping level is controlled to a specific damping level objective as a function of displacement amplitude. Similarly, under dual frequency conditions, damping degradation at the lag frequency, because of lag motion at the rotor frequency, can also be recovered by increasing magnetic field. A time-domain analysis is developed to study the nonlinear dynamic behavior of the hybrid MRFE damper. Using rate-dependent elasto-slides, the amplitude-dependent behavior of the hybrid MRFE damper is accurately reconstructed using both constant and current-dependent (i.e. controllable) parameters. The analysis is physically motivated and can be applied to the elastomer and MR fluid

  1. Proposed Wind Turbine Aeroelasticity Studies Using Helicopter Systems Analysis

    Science.gov (United States)

    Ladkany, Samaan G.

    1998-01-01

    Advanced systems for the analysis of rotary wing aeroelastic structures (helicopters) are being developed at NASA Ames by the Rotorcraft Aeromechanics Branch, ARA. The research has recently been extended to the study of wind turbines, used for electric power generation Wind turbines play an important role in Europe, Japan & many other countries because they are non polluting & use a renewable source of energy. European countries such as Holland, Norway & France have been the world leaders in the design & manufacture of wind turbines due to their historical experience of several centuries, in building complex wind mill structures, which were used in water pumping, grain grinding & for lumbering. Fossil fuel cost in Japan & in Europe is two to three times higher than in the USA due to very high import taxes. High fuel cost combined with substantial governmental subsidies, allow wind generated power to be competitive with the more traditional sources of power generation. In the USA, the use of wind energy has been limited mainly because power production from wind is twice as expensive as from other traditional sources. Studies conducted at the National Renewable Energy Laboratories (NREL) indicate that the main cost in the production of wind turbines is due to the materials & the labor intensive processes used in the construction of turbine structures. Thus, for the US to assume world leadership in wind power generation, new lightweight & consequently very flexible wind turbines, that could be economically mass produced, would have to be developed [4,5]. This effort, if successful, would result in great benefit to the US & the developing nations that suffer from overpopulation & a very high cost of energy.

  2. Wireless Sensor Network for Helicopter Rotor Blade Vibration Monitoring: Requirements Definition and Technological Aspects

    NARCIS (Netherlands)

    Sanchez Ramirez, Andrea; Das, Kallol; Loendersloot, Richard; Tinga, Tiedo; Havinga, Paul J.M.; Basu, Biswajit

    The main rotor accounts for the largest vibration source for a helicopter fuselage and its components. However, accurate blade monitoring has been limited due to the practical restrictions on instrumenting rotating blades. The use of Wireless Sensor Networks (WSNs) for real time vibration monitoring

  3. 76 FR 28169 - Airworthiness Directives; Agusta S.p.A. Model AB412 Helicopters

    Science.gov (United States)

    2011-05-16

    ... related to the rescue hoist hook installed on this model helicopter. The aviation authority of Italy, with... the hoist hook and any load. The absence of the lock pin constitutes an unsafe condition, and this AD... that the hook assembly has the lock pin installed to prevent the loss of a rescue hoist hook and its...

  4. Army Preliminary Evaluation YAH-1R Improved Cobra Agility and Maneuverability Helicopter.

    Science.gov (United States)

    1975-05-01

    o ^ -I 0N IVNIMilMOl Midi WOdi ’J30~ Midi MOUd ’NI~ saamuiv sNomsud nubiNoo NW» \\^^M^MäMm U.O u o s: UJ to...Communications Center (SUR) Department of Transportation Library US Army Bell Plant Activity (SAVBE-F) Bell Helicopter Company AVCO Lycoming

  5. 77 FR 39444 - Airworthiness Directives; Agusta S.p.A. Helicopters

    Science.gov (United States)

    2012-07-03

    ... engine rotary variable differential transformer (RVDT) control box assemblies to determine if the control... exist or develop on other helicopters of the same type design. Related Service Information We reviewed... between the national Government and the States, or on the distribution of power and responsibilities among...

  6. Velocity-Aided Attitude Estimation for Helicopter Aircraft Using Microelectromechanical System Inertial-Measurement Units

    Directory of Open Access Journals (Sweden)

    Sang Cheol Lee

    2016-12-01

    Full Text Available This paper presents an algorithm for velocity-aided attitude estimation for helicopter aircraft using a microelectromechanical system inertial-measurement unit. In general, high- performance gyroscopes are used for estimating the attitude of a helicopter, but this type of sensor is very expensive. When designing a cost-effective attitude system, attitude can be estimated by fusing a low cost accelerometer and a gyro, but the disadvantage of this method is its relatively low accuracy. The accelerometer output includes a component that occurs primarily as the aircraft turns, as well as the gravitational acceleration. When estimating attitude, the accelerometer measurement terms other than gravitational ones can be considered as disturbances. Therefore, errors increase in accordance with the flight dynamics. The proposed algorithm is designed for using velocity as an aid for high accuracy at low cost. It effectively eliminates the disturbances of accelerometer measurements using the airspeed. The algorithm was verified using helicopter experimental data. The algorithm performance was confirmed through a comparison with an attitude estimate obtained from an attitude heading reference system based on a high accuracy optic gyro, which was employed as core attitude equipment in the helicopter.

  7. Optimal helmet use and adjustments with respect to neck load: The experience of military helicopter aircrew

    NARCIS (Netherlands)

    van den Oord, Marieke H. A. H.; Frings-Dresen, Monique H. W.; Sluiter, Judith K.

    2012-01-01

    Introduction: One solution to prevent flight-related neck pain in military helicopter pilots is to initiate ergonomic improvements in the equipment used by the pilots and loadmasters. The aim of the present study was to identify factors that may be important for optimizing helmet use and adjustments

  8. 75 FR 53857 - Airworthiness Directives; Eurocopter France Model SA330J Helicopters

    Science.gov (United States)

    2010-09-02

    ...-072-AD; Amendment 39-16410; AD 2010-16-51] RIN 2120-AA64 Airworthiness Directives; Eurocopter France... France (Eurocopter) Model SA330J helicopters by individual letters. This AD requires, within 10 hours... amended by adding a new airworthiness directive to read as follows: 2010-16-51 EUROCOPTER FRANCE...

  9. 76 FR 75772 - Airworthiness Directives; Eurocopter France Model EC 120B Helicopters

    Science.gov (United States)

    2011-12-05

    ...-51-AD; Amendment 39-16841; AD 2011-21-18] RIN 2120-AA64 Airworthiness Directives; Eurocopter France.... SUMMARY: This amendment adopts a new airworthiness directive (AD) for the Eurocopter France Model EC 120B... the Eurocopter France Model EC 120B helicopters. Related Service Information Eurocopter has issued...

  10. 76 FR 66618 - Airworthiness Directives; Eurocopter France (Eurocopter) Model EC225LP Helicopters

    Science.gov (United States)

    2011-10-27

    ...-43-AD; Amendment 39-16815; AD 2011-20-05] RIN 2120-AA64 Airworthiness Directives; Eurocopter France (Eurocopter) Model EC225LP Helicopters AGENCY: Federal Aviation Administration, DOT. ACTION: Final rule... directive to read as follows: 2011-20-05 Eurocopter France (Eurocopter): Amendment 39-16815; Docket No. FAA...

  11. 75 FR 69858 - Airworthiness Directives; Eurocopter France (Eurocopter) Model AS332L2 Helicopters

    Science.gov (United States)

    2010-11-16

    ... 2008-SW-40-AD; Amendment 39-16512; AD 2010-23-22] RIN 2120-AA64 Airworthiness Directives; Eurocopter France (Eurocopter) Model AS332L2 Helicopters AGENCY: Federal Aviation Administration (FAA), Department... the following new AD: 2010-23-22 Eurocopter France: Amendment 39-16512. Docket No. FAA- 2010-1125...

  12. 76 FR 66613 - Airworthiness Directives; Eurocopter France (Eurocopter) Model EC225LP Helicopters

    Science.gov (United States)

    2011-10-27

    ...-028-AD; Amendment 39-16834; AD 2011-21-11] RIN 2120-AA64 Airworthiness Directives; Eurocopter France (Eurocopter) Model EC225LP Helicopters AGENCY: Federal Aviation Administration, DOT. ACTION: Final rule... amended by adding a new airworthiness directive (AD) to read as follows: 2011-21-11 Eurocopter France...

  13. Validity of helicopter emergency medical services dispatch criteria for traumatic injuries: A systematic review

    NARCIS (Netherlands)

    A.N. Ringburg (Akkie); G. de Ronde (Gijs); S. Thomas (Siep); E.M.M. van Lieshout (Esther); P. Patka (Peter); I.B. Schipper (Inger)

    2009-01-01

    textabstractObjective. This review provides an overview of the validity of Helicopter Emergency Medical Services (HEMS) dispatch criteria for severely injured patients. Methods. A systematic literature search was performed. English written and peer-reviewed publications on HEMS dispatch criteria

  14. Wind tunnel testing of a full scale helicopter blade section with an upstream active Gurney flap

    NARCIS (Netherlands)

    Loendersloot, Richard; Freire Gomez, J.; Booker, J.D.

    2014-01-01

    Wind tunnel tests were performed on an aerofoil section comparable to that of a full scale helicopter blade section with an upstream active Gurney flap in the framework of the European project CleanSky ITD Green RotorCraft. A modified NACA0012 profile was used, with 23 Kulite pressure transducers

  15. Adaptive fuzzy tracking control for non-affine nonlinear yaw channel of unmanned aerial vehicle helicopter

    Directory of Open Access Journals (Sweden)

    Wenxu Yan

    2016-12-01

    Full Text Available The article deals with the problem of the yaw control of the unmanned aerial vehicle helicopter which is non-affine nonlinear by use of a novel projection-based adaptive fuzzy control approach. First, principle model and control design model of the yaw channel of the unmanned aerial vehicle helicopter are described. Then, a dynamic approximation technique is introduced to approach the non-affine model of the unmanned aerial vehicle helicopter into an affine model with variable parameters, which is applied to facilitate the design of nonlinear control scheme. Next, in the proposed controller, fuzzy controller is designed to deal with the unknown uncertainties and disturbances. Meanwhile, the projection-based adaptive law applied in fuzzy controller bounds the parameter estimation function and can also guarantee the robustness of the designed control scheme against uncertain disturbances. Moreover, the convergence and stability of the designed controller are proved by Lyapunov stability theory. Finally, the simulation results of the yaw channel of an unmanned aerial vehicle helicopter are performed to illustrate that the designed controller has good tracking performance, stability, and robustness under the condition of the time-vary uncertain disturbances.

  16. Full-Scale Crash Test and Finite Element Simulation of a Composite Prototype Helicopter

    Science.gov (United States)

    Jackson, Karen E.; Fasanella, Edwin L.; Boitnott, Richard L.; Lyle, Karen H.

    2003-01-01

    A full-scale crash test of a prototype composite helicopter was performed at the Impact Dynamics Research Facility at NASA Langley Research Center in 1999 to obtain data for validation of a finite element crash simulation. The helicopter was the flight test article built by Sikorsky Aircraft during the Advanced Composite Airframe Program (ACAP). The composite helicopter was designed to meet the stringent Military Standard (MIL-STD-1290A) crashworthiness criteria and was outfitted with two crew and two troop seats and four anthropomorphic dummies. The test was performed at 38-ft/s vertical and 32.5-ft/s horizontal velocity onto a rigid surface. An existing modal-vibration model of the Sikorsky ACAP helicopter was converted into a model suitable for crash simulation. A two-stage modeling approach was implemented and an external user-defined subroutine was developed to represent the complex landing gear response. The crash simulation was executed with a nonlinear, explicit transient dynamic finite element code. Predictions of structural deformation and failure, the sequence of events, and the dynamic response of the airframe structure were generated and the numerical results were correlated with the experimental data to validate the simulation. The test results, the model development, and the test-analysis correlation are described.

  17. Full-Scale Crash Test of a MD-500 Helicopter with Deployable Energy Absorbers

    Science.gov (United States)

    Kellas, Sotiris; Jackson, Karen E.; Littell, Justin D.

    2010-01-01

    A new externally deployable energy absorbing system was demonstrated during a full-scale crash test of an MD-500 helicopter. The deployable system is a honeycomb structure and utilizes composite materials in its construction. A set of two Deployable Energy Absorbers (DEAs) were fitted on the MD-500 helicopter for the full-scale crash demonstration. Four anthropomorphic dummy occupants were also used to assess human survivability. A demonstration test was performed at NASA Langley's Landing and Impact Research Facility (LandIR). The test involved impacting the helicopter on a concrete surface with combined forward and vertical velocity components of 40-ft/s and 26-ft/s, respectively. The objectives of the test were to evaluate the performance of the DEA concept under realistic crash conditions and to generate test data for validation of dynamic finite element simulations. Descriptions of this test as well as other component and full-scale tests leading to the helicopter test are discussed. Acceleration data from the anthropomorphic dummies showed that dynamic loads were successfully attenuated to within non-injurious levels. Moreover, the airframe itself survived the relatively severe impact and was retested to provide baseline data for comparison for cases with and without DEAs.

  18. Power harvesting in a helicopter rotor using a piezo stack in the lag damper

    NARCIS (Netherlands)

    de Jong, Pieter; de Boer, Andries; Loendersloot, Richard; van der Hoogt, Peter

    2012-01-01

    A piezoelectrically augmented helicopter lag damper has been simulated for the purpose of harvesting electrical energy within the rotor of the aircraft. This energy can then be consumed locally for sensing, processing and transmission of data to the cockpit. An 8.15m radius rotor is considered and

  19. Role Identification of Yaw and Sway Motion in Helicopter Yaw Control Tasks

    NARCIS (Netherlands)

    Ellerbroek, J.; Stroosma, O.; Van Paassen, M.M.; Mulder, M.

    2008-01-01

    A set of experiments has been conducted to investigate the relative effect of translational and rotational motion cues on pilot performance. Two helicopter yaw control tasks were performed on the SIMONA: a yaw capture task and a target-tracking task with simulated turbulence. The yaw capture task

  20. The Upside of Helicopter Parenting: Engaging Parents to Reduce First-Year Student Drinking

    Science.gov (United States)

    Earle, Andrew M.; LaBrie, Joseph W.

    2016-01-01

    University personnel tend to view "helicopter" parents as problematic. This article presents an alternative view in which these highly engaged parents can instead be utilized productively. The authors describe and assess the fidelity of a novel program in which involved parents were effectively leveraged to mitigate student…

  1. Lives Saved by Helicopter Emergency Medical Services: An Overview of Literature

    NARCIS (Netherlands)

    A.N. Ringburg (Akkie); S. Thomas (Siep); E.W. Steyerberg (Ewout); E.M.M. van Lieshout (Esther); P. Patka (Peter); I.B. Schipper (Inger)

    2009-01-01

    textabstractIntroduction: The objective of this review is to give an overview of literature on the survival benefits of Helicopter Emergency Medical Services (HEMS). The included studies were assessed by study design and statistical methodology. Methods: A literature search was performed in the

  2. Parental Involvement in U.S. Study Abroad: Helicopters or Helpers

    Science.gov (United States)

    Dostal Dauer, Kevin Lorenz

    2017-01-01

    Parental involvement in higher education has received much attention since the 1990s, though mostly through mainstream media sources. The term "helicopter parents" is now used to describe over-involved parents who "hover" over their children, intent on ensuring that their children's needs are addressed. The perception within…

  3. Golden eagle indifference to heli-skiing and military helicopters in northern Utah

    Science.gov (United States)

    Teryl G. Grubb; David K. Delaney; William W. Bowerman; Michael R. Wierda

    2010-01-01

    In 2006-2007, during Wasatch Powderbird Guides (WPG) permit renewal for heli-skiing in the Tri-Canyon Area (TCA) of the Wasatch Mountains, Utah, USA, we recorded 303 helicopter passes between 0 m and 3,000 m (horizontal distance) near >30 individual golden eagles (Aquila chrysaetos) in 22 nesting territories, through passive observation and active experimentation...

  4. 77 FR 41897 - Airworthiness Directives; PZL Swidnik S.A. Helicopters

    Science.gov (United States)

    2012-07-17

    ... Agency (EASA), which is the Technical Agent for the Member States of the European Union, has issued EASA...-045 widnik, Poland; telephone (+48 81) 468 09 01, 751 20 71; fax (+48 81) 468 09 19, 751 21 73; or at.... FAA's Determination These helicopters have been approved by the aviation authority of Poland and are...

  5. 14 CFR Appendix D to Part 60 - Qualification Performance Standards for Helicopter Flight Training Devices

    Science.gov (United States)

    2010-01-01

    ... control loading system, or the replacement of the IOS with a more capable unit) by requiring the “updated... operating station, and the normal functions and simulated malfunctions of the simulated helicopter systems... one operating system. Air/ground logic is required (no aerodynamic programming required). All displays...

  6. Physician-staffed emergency helicopter reduces transportation time from alarm call to highly specialized centre

    DEFF Research Database (Denmark)

    Fjaeldstad, A.

    2013-01-01

    INTRODUCTION: Since 2007, the number of Danish emergency departments has decreased from 44 to 21. Longer distances to specialized treatment have increased the demand for advanced prehospital treatment. A Danish 24/7 Helicopter Emergency Medical System (HEMS) project in western Denmark was initiated...

  7. Identification method for helicopter flight dynamics modeling with rotor degrees of freedom

    Directory of Open Access Journals (Sweden)

    Wu Wei

    2014-12-01

    Full Text Available A comprehensive method based on system identification theory for helicopter flight dynamics modeling with rotor degrees of freedom is developed. A fully parameterized rotor flapping equation for identification purpose is derived without using any theoretical model, so the confidence of the identified model is increased, and then the 6 degrees of freedom rigid body model is extended to 9 degrees of freedom high-order model. Bode sensitivity function is derived to increase the accuracy of frequency spectra calculation which influences the accuracy of model parameter identification. Then a frequency domain identification algorithm is established. Acceleration technique is developed furthermore to increase calculation efficiency, and the total identification time is reduced by more than 50% using this technique. A comprehensive two-step method is established for helicopter high-order flight dynamics model identification which increases the numerical stability of model identification compared with single step algorithm. Application of the developed method to identify the flight dynamics model of BO 105 helicopter based on flight test data is implemented. A comparative study between the high-order model and rigid body model is performed at last. The results show that the developed method can be used for helicopter high-order flight dynamics model identification with high accuracy as well as efficiency, and the advantage of identified high-order model is very obvious compared with low-order model.

  8. Helicopter and aircraft detection and classification using adaptive beamforming and tracking techniques

    NARCIS (Netherlands)

    Koersel, A.C. van; Beerens, S.P.

    2002-01-01

    Measurements of different types of aircraft are performed and used to obtain information on target characteristics and develop an algorithm to perform classification between jet aircraft, propeller aircraft and helicopters. To obtain a larger detection range, reduce background noise and to reduce

  9. Design of a Slowed-Rotor Compound Helicopter for Future Joint Service Missions

    Science.gov (United States)

    Silva, Christopher; Yeo, Hyeonsoo; Johnson, Wayne R.

    2010-01-01

    A slowed-rotor compound helicopter has been synthesized using the NASA Design and Analysis of Rotorcraft (NDARC) conceptual design software. An overview of the design process and the capabilities of NDARC are presented. The benefits of trading rotor speed, wing-rotor lift share, and trim strategies are presented for an example set of sizing conditions and missions.

  10. Integrated Flight Path Planning System and Flight Control System for Unmanned Helicopters

    Directory of Open Access Journals (Sweden)

    Yu-Hsiang Lin

    2011-07-01

    Full Text Available This paper focuses on the design of an integrated navigation and guidance system for unmanned helicopters. The integrated navigation system comprises two systems: the Flight Path Planning System (FPPS and the Flight Control System (FCS. The FPPS finds the shortest flight path by the A-Star (A* algorithm in an adaptive manner for different flight conditions, and the FPPS can add a forbidden zone to stop the unmanned helicopter from crossing over into dangerous areas. In this paper, the FPPS computation time is reduced by the multi-resolution scheme, and the flight path quality is improved by the path smoothing methods. Meanwhile, the FCS includes the fuzzy inference systems (FISs based on the fuzzy logic. By using expert knowledge and experience to train the FIS, the controller can operate the unmanned helicopter without dynamic models. The integrated system of the FPPS and the FCS is aimed at providing navigation and guidance to the mission destination and it is implemented by coupling the flight simulation software, X-Plane, and the computing software, MATLAB. Simulations are performed and shown in real time three-dimensional animations. Finally, the integrated system is demonstrated to work successfully in controlling the unmanned helicopter to operate in various terrains of a digital elevation model (DEM.

  11. Velocity-Aided Attitude Estimation for Helicopter Aircraft Using Microelectromechanical System Inertial-Measurement Units.

    Science.gov (United States)

    Lee, Sang Cheol; Hong, Sung Kyung

    2016-12-11

    This paper presents an algorithm for velocity-aided attitude estimation for helicopter aircraft using a microelectromechanical system inertial-measurement unit. In general, high- performance gyroscopes are used for estimating the attitude of a helicopter, but this type of sensor is very expensive. When designing a cost-effective attitude system, attitude can be estimated by fusing a low cost accelerometer and a gyro, but the disadvantage of this method is its relatively low accuracy. The accelerometer output includes a component that occurs primarily as the aircraft turns, as well as the gravitational acceleration. When estimating attitude, the accelerometer measurement terms other than gravitational ones can be considered as disturbances. Therefore, errors increase in accordance with the flight dynamics. The proposed algorithm is designed for using velocity as an aid for high accuracy at low cost. It effectively eliminates the disturbances of accelerometer measurements using the airspeed. The algorithm was verified using helicopter experimental data. The algorithm performance was confirmed through a comparison with an attitude estimate obtained from an attitude heading reference system based on a high accuracy optic gyro, which was employed as core attitude equipment in the helicopter.

  12. 76 FR 45225 - Information Collection; Airplane Pilot Qualifications and Approval Record, Helicopter Pilot...

    Science.gov (United States)

    2011-07-28

    .... Information collected on these forms includes: Name. Address. Certification numbers. Employment history. Medical Certification. Airplane/helicopter certifications and specifications. Accident/violation history... and assumptions used; (3) ways to enhance the quality, utility, and clarity of the information to be...

  13. Hummingbird wing efficacy depends on aspect ratio and compares with helicopter rotors

    NARCIS (Netherlands)

    Kruyt, J.W.; Quicazan Rubio, E.M.; Heijst, van G.J.F.; Altshuler, D.L.; Lentink, D.

    2014-01-01

    Hummingbirds are the only birds that can sustain hovering. This unique flight behaviour comes, however, at high energetic cost. Based on helicopter and aeroplane design theory, we expect that hummingbird wing aspect ratio (AR), which ranges from about 3.0 to 4.5, determines aerodynamic efficacy.

  14. A helicopter emergency medical service may allow faster access to highly specialised care

    DEFF Research Database (Denmark)

    Afzali, Monika; Hesselfeldt, Rasmus; Steinmetz, Jacob

    2013-01-01

    Centralization of the hospital system entails longer transport for some patients. A physician-staffed helicopter may provide effective triage, advanced management and fast transport to highly specialized treatment for time-critical patients. The aim of this study was to describe activity and poss...

  15. 78 FR 26715 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2013-05-08

    ... Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). SUMMARY: We propose to adopt a new airworthiness directive (AD) for Eurocopter Deutschland... Deutschland GmbH: Docket No. FAA-2013-0398; Directorate Identifier 2011-SW-065-AD. (a) Applicability This AD...

  16. 77 FR 52265 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2012-08-29

    ... Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ] ACTION: Notice of proposed rulemaking (NPRM). SUMMARY: We propose to adopt a new airworthiness directive (AD) for Eurocopter Deutschland... Eurocopter Deutschland (Germany). The proposed actions are intended to detect corrosion and thread damage in...

  17. 78 FR 52410 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2013-08-23

    ... Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for Eurocopter Deutschland GmbH (ECD) Model BO... Deutschland (Germany). Comments We gave the public the opportunity to participate in developing this AD, but...

  18. 78 FR 48599 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2013-08-09

    ...-17544; AD 2013-16-06] RIN 2120-AA64 Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters... airworthiness directive (AD) for Eurocopter Deutschland GmbH (Eurocopter) Model BO-105A, BO-105C, BO- 105LS A-1...): 2013-16-06 Eurocopter Deutschland GmbH: Amendment 39-17544; Docket No. FAA-2011-1285; Directorate...

  19. 77 FR 75073 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2012-12-19

    ... Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Supplemental notice... proposed airworthiness directive (AD) for Eurocopter Deutschland GmbH (Eurocopter) Model BO-105A, BO- 105C... airworthiness directive (AD): Eurocopter Deutschland GmbH: Docket No. FAA-2011-1285; Directorate Identifier 2010...

  20. 78 FR 40053 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2013-07-03

    ... Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). SUMMARY: We propose to adopt a new airworthiness directive (AD) for Eurocopter Deutschland.... 39.13 by adding the following new airworthiness directive (AD): Eurocopter Deutschland GmbH...

  1. 78 FR 54383 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2013-09-04

    ... Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for all Eurocopter Deutschland GmbH (ECD) EC 135... Deutschland GmbH: Amendment 39-17552; Docket No. FAA-2013-0239; Directorate Identifier 2010-SW-087-AD. (a...

  2. 78 FR 56597 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2013-09-13

    ... Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for Eurocopter Deutschland GmbH (ECD) Model... Deutschland GmbH: Amendment 39-17578; Docket No. FAA-2013-0398; Directorate Identifier 2011-SW-065-AD. (a...

  3. 78 FR 65169 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2013-10-31

    ... Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for Eurocopter Deutschland GmbH (Eurocopter) Model...): 2013-21-05 Eurocopter Deutschland GmbH: Amendment 39-17629; Docket No. FAA-2013-0446; Directorate...

  4. 78 FR 37446 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2013-06-21

    ... Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for Eurocopter Deutschland GmbH (Eurocopter) Model... airworthiness directive (AD): 2013-11-15 Eurocopter Deutschland GmbH: Amendment 39-17475; Docket No. FAA-2012...

  5. 78 FR 2223 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2013-01-10

    ... Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). SUMMARY: We propose to adopt a new airworthiness directive (AD) for Eurocopter Deutschland... directive (AD): Eurocopter Deutschland GmbH: Docket No. FAA-2012-1305; Directorate Identifier 2010-SW-041-AD...

  6. 77 FR 37790 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2012-06-25

    ... Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT...) that supersedes an existing Emergency Airworthiness Directive (EAD) for certain Eurocopter Deutschland...): 2012-11-02 Eurocopter Deutschland GmbH: Amendment 39-17065; Docket No. FAA-2012-0566; Directorate...

  7. 78 FR 22209 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2013-04-15

    ... Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). SUMMARY: We propose to adopt a new airworthiness directive (AD) for Eurocopter Deutschland.... 39.13 by adding the following new airworthiness directive (AD): Eurocopter Deutschland GmbH...

  8. 75 FR 56487 - Airworthiness Directives; Erickson Air-Crane Incorporated Model S-64F Helicopters

    Science.gov (United States)

    2010-09-16

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Erickson Air-Crane... Air-Crane Incorporated (Erickson Air-Crane) Model S- 64F helicopters. The AD would require, at... the service information identified in this proposed AD from Erickson Air-Crane Incorporated, 3100...

  9. 78 FR 40063 - Airworthiness Directives; Erickson Air-Crane Incorporated Helicopters (Type Certificate...

    Science.gov (United States)

    2013-07-03

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Erickson Air-Crane... helicopter has been transferred to Erickson Air-Crane Incorporated (Erickson), and expand the applicability... Air-Crane Incorporated, ATTN: Chris Erickson/Compliance Officer, 3100 Willow Springs Rd., PO Box 3247...

  10. 75 FR 42340 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Model S-92A Helicopters

    Science.gov (United States)

    2010-07-21

    ... gearbox housing and replacing any main gearbox housing that exceeds the life limit. This proposal is prompted by a fatigue analysis conducted after a helicopter was found with a severed main gearbox mounting... to prevent failure of the main gearbox mounting housing foot pad, loss of the main gearbox, and...

  11. 77 FR 64699 - Airworthiness Directives; Agusta S.p.A. Helicopters

    Science.gov (United States)

    2012-10-23

    ...- 711133; fax 39-0331-711180; or at http://www.agustawestland.com/technical-bullettins . You may review the... incorporated-by-reference service information, the economic evaluation, any comments received, and other..., and subsequent loss of control of the helicopter. The European Aviation Safety Agency (EASA), which is...

  12. 77 FR 44116 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2012-07-27

    ... frame for overhaul of the operator handle. Comments We gave the public the opportunity to participate in... one half-hour to complete. At $85 per work-hour, the labor cost will total about $43. No parts will be needed, so we estimate the total cost per helicopter to be $43, or $516 for the fleet. Option 2: Remove...

  13. Nine Years of Cooperation: The US-German Memorandum of Understanding (MoU) on Helicopter Aeromechanics 2003-2012

    Science.gov (United States)

    2013-12-01

    complementary facilities available on both sides with respect to a variety of flying helicopter test beds ( RASCAL , BO105, EC135) and test facilities (model...helicopter and in the U.S,, this entails flight tests on AFDD’s RASCAL variable-stability helicopter. In addition, the NASA-Ames ground-based Vertical... RASCAL , and with a side-stick on DLR’s EC 135 ACT/FHS. Based on the results of these test, the following conclusions are drawn: 1. The effect of cyclic

  14. A New Framework For Helicopter Vibration Suppression; Time-Periodic System Identification and Controller Design

    Science.gov (United States)

    Ulker, Fatma Demet

    In forward flight, helicopter rotor blades function within a highly complex aerodynamic environment that includes both near-blade and far-blade aerodynamic phenomena. These aerodynamic phenomena cause fluctuating aerodynamic loads on the rotor blades. These loads when coupled with the dynamic characteristics and elastic motion of the blade create excessive amount of vibration. These vibrations degrade helicopter performance, passenger comfort and contributes to high cost maintenance problems. In an effort to suppress helicopter vibration, recent studies have developed active control strategies using active pitch links, flaps, twist actuation and higher harmonic control of the swash plate. In active helicopter vibration control, designing a controller in a computationally efficient way requires accurate reduced-order models of complex helicopter aeroelasticity. In previous studies, controllers were designed using aeroelastic models that were obtained by coupling independently reduced aerodynamic and structural dynamic models. Unfortunately, these controllers could not satisfy stability and performance criteria when implemented in high-fidelity computer simulations or real-time experiments. In this thesis, we present a novel approach that provides accurate time-periodic reduced-order models and time-periodic H2 and H infinity controllers that satisfy the stability and performance criteria. Computational efficiency and the necessity of using the approach were validated by implementing an actively controlled flap strategy. In this proposed approach, the reduced-order models were directly identified from high-fidelity coupled aeroelastic analysis by using the time-periodic subspace identification method. Time-periodic H2 and Hinfinity controllers that update the control actuation at every time step were designed. The control synthesis problem was solved using Linear Matrix Inequality and periodic Riccati Equation based formulations, for which an in-house periodic

  15. Flight State Information Inference with Application to Helicopter Cockpit Video Data Analysis Using Data Mining Techniques

    Science.gov (United States)

    Shin, Sanghyun

    The National Transportation Safety Board (NTSB) has recently emphasized the importance of analyzing flight data as one of the most effective methods to improve eciency and safety of helicopter operations. By analyzing flight data with Flight Data Monitoring (FDM) programs, the safety and performance of helicopter operations can be evaluated and improved. In spite of the NTSB's effort, the safety of helicopter operations has not improved at the same rate as the safety of worldwide airlines, and the accident rate of helicopters continues to be much higher than that of fixed-wing aircraft. One of the main reasons is that the participation rates of the rotorcraft industry in the FDM programs are low due to the high costs of the Flight Data Recorder (FDR), the need of a special readout device to decode the FDR, anxiety of punitive action, etc. Since a video camera is easily installed, accessible, and inexpensively maintained, cockpit video data could complement the FDR in the presence of the FDR or possibly replace the role of the FDR in the absence of the FDR. Cockpit video data is composed of image and audio data: image data contains outside views through cockpit windows and activities on the flight instrument panels, whereas audio data contains sounds of the alarms within the cockpit. The goal of this research is to develop, test, and demonstrate a cockpit video data analysis algorithm based on data mining and signal processing techniques that can help better understand situations in the cockpit and the state of a helicopter by efficiently and accurately inferring the useful flight information from cockpit video data. Image processing algorithms based on data mining techniques are proposed to estimate a helicopter's attitude such as the bank and pitch angles, identify indicators from a flight instrument panel, and read the gauges and the numbers in the analogue gauge indicators and digital displays from cockpit image data. In addition, an audio processing algorithm

  16. Design of fault tolerant control system for individual blade control helicopters

    Science.gov (United States)

    Tamayo, Sergio

    This dissertation presents the development of a fault tolerant control scheme for helicopters fitted with individually controlled blades. This novel approach attempts to improve fault tolerant capabilities of helicopter control system by increasing control redundancy using additional actuators for individual blade input and software re-mixing to obtain nominal or close to nominal conditions under failure. An advanced interactive simulation environment has been developed including modeling of sensor failure, swashplate actuator failure, individual blade actuator failure, and blade delamination to support the design, testing, and evaluation of the control laws. This simulation environment is based on the blade element theory for the calculation of forces and moments generated by the main rotor. This discretized model allows for individual blade analysis, which in turn allows measuring the consequences of a stuck blade, or loss of the surface area of the blade itself, with respect to the dynamics of the whole helicopter. The control laws are based on non-linear dynamic inversion and artificial neural network augmentation, which is a mix of linear and nonlinear methods that compensates for model inaccuracies due to linearization or failure. A stability analysis based on the Lyapunov function approach has shown that bounded tracking error is guaranteed, and under specific circumstances, global stability is guaranteed as well. An analysis over the degrees of freedom of the mechanical system and its impact over the helicopter handling qualities is also performed to measure the degree of redundancy achieved with the addition of individual blade actuators as compared to a classic swashplate helicopter configuration. Mathematical analysis and numerical simulation, using reconfiguration of the individual blade control under failure have shown that this control architecture can potentially improve the survivability of the aircraft and reduce pilot workload under failure

  17. Hearing loss in civilian airline and helicopter pilots compared to air traffic control personnel.

    Science.gov (United States)

    Wagstaff, Anthony S; Arva, Per

    2009-10-01

    In order to investigate possible hearing loss as a consequence of aviation noise, a comparative analysis of audiometric data from Norwegian Air Traffic Control (ATC) personnel, airline (fixed-wing) pilots, and helicopter pilots was performed. The results may be of use in giving advice regarding preventive measures. Male ATC, airline, and helicopter pilots were selected randomly from the Civil Aviation Authority (CAA) medical files. There were 182 subjects included in the study: 50, 81, and 51 subjects for ATC, helicopter, and airline pilots, respectively. Two audiograms with a 2-3-yr interval were analyzed for each individual. Age correction was performed using data from ISO 7129. Threshold changes per year for the frequencies 3, 4, and 6 kHz were examined in particular after age correction. For all three groups, mean hearing threshold levels were above (worse than) ISO 7129 predictions for most frequencies. As expected, hearing thresholds increased with age in the group as a whole. Looking at the 3-, 4-, and 6-kHz frequencies in particular, all groups had small but highly significant increases in hearing thresholds at 4 kHz between the first and second audiogram. The mean hearing thresholds for this group of aviation personnel are higher than International Standard ISO-7129 would predict according to age. Highly significant changes in hearing threshold after age correction, indicating possible noise-induced hearing loss, were found in all groups at 4 kHz. The fact that helicopter pilots had similar hearing loss to their other aviation colleagues indicates that current hearing protection for these pilots is effective in counteracting the increased noise levels in helicopters.

  18. Active structural acoustic control of helicopter interior multifrequency noise using input-output-based hybrid control

    Science.gov (United States)

    Ma, Xunjun; Lu, Yang; Wang, Fengjiao

    2017-09-01

    This paper presents the recent advances in reduction of multifrequency noise inside helicopter cabin using an active structural acoustic control system, which is based on active gearbox struts technical approach. To attenuate the multifrequency gearbox vibrations and resulting noise, a new scheme of discrete model predictive sliding mode control has been proposed based on controlled auto-regressive moving average model. Its implementation only needs input/output data, hence a broader frequency range of controlled system is modelled and the burden on the state observer design is released. Furthermore, a new iteration form of the algorithm is designed, improving the developing efficiency and run speed. To verify the algorithm's effectiveness and self-adaptability, experiments of real-time active control are performed on a newly developed helicopter model system. The helicopter model can generate gear meshing vibration/noise similar to a real helicopter with specially designed gearbox and active struts. The algorithm's control abilities are sufficiently checked by single-input single-output and multiple-input multiple-output experiments via different feedback strategies progressively: (1) control gear meshing noise through attenuating vibrations at the key points on the transmission path, (2) directly control the gear meshing noise in the cabin using the actuators. Results confirm that the active control system is practical for cancelling multifrequency helicopter interior noise, which also weakens the frequency-modulation of the tones. For many cases, the attenuations of the measured noise exceed the level of 15 dB, with maximum reduction reaching 31 dB. Also, the control process is demonstrated to be smoother and faster.

  19. Implementation and Analysis of the Chromakey Augmented Virtual Environment (ChrAVE) Version 3.0 and Virtual Environment Helicopter (VEHELO) Version 2.0 in Simulated Helicopter Training

    National Research Council Canada - National Science Library

    Hahn, M. E

    2005-01-01

    The Chromakey Augmented Virtual Environment (ChrAVE) 3.0 System is a training system created to augment initial, refresher, and proficiency training in helicopter aviation using accurate simulation...

  20. 76 FR 20490 - Special Conditions: Eurocopter France Model AS350B Series, AS350D, and EC130 Helicopters...

    Science.gov (United States)

    2011-04-13

    ... operation. These helicopter models are capable of carrying up to six passengers with one pilot, and have a... features include a 3- blade, fully articulated main rotor, an anti-torque tail rotor system, a skid landing...

  1. The NASA/industry Design Analysis Methods for Vibrations (DAMVIBS) program: McDonnell-Douglas Helicopter Company achievements

    Science.gov (United States)

    Toossi, Mostafa; Weisenburger, Richard; Hashemi-Kia, Mostafa

    1993-01-01

    This paper presents a summary of some of the work performed by McDonnell Douglas Helicopter Company under NASA Langley-sponsored rotorcraft structural dynamics program known as DAMVIBS (Design Analysis Methods for VIBrationS). A set of guidelines which is applicable to dynamic modeling, analysis, testing, and correlation of both helicopter airframes and a large variety of structural finite element models is presented. Utilization of these guidelines and the key features of their applications to vibration modeling of helicopter airframes are discussed. Correlation studies with the test data, together with the development and applications of a set of efficient finite element model checkout procedures, are demonstrated on a large helicopter airframe finite element model. Finally, the lessons learned and the benefits resulting from this program are summarized.

  2. Closed-Loop Behavior of an Autonomous Helicopter Equipped with a Robotic Arm for Aerial Manipulation Tasks

    Directory of Open Access Journals (Sweden)

    Konstantin Kondak

    2013-02-01

    Full Text Available This paper is devoted to the control of aerial robots interacting physically with objects in the environment and with other aerial robots. The paper presents a controller for the particular case of a small-scaled autonomous helicopter equipped with a robotic arm for aerial manipulation. Two types of influences are imposed on the helicopter from a manipulator: coherent and non-coherent influence. In the former case, the forces and torques imposed on the helicopter by the manipulator change with frequencies close to those of the helicopter movement. The paper shows that even small interaction forces imposed on the fuselage periodically in proper phase could yield to low frequency instabilities and oscillations, so-called phase circles.

  3. 75 FR 48617 - Airworthiness Directives; Eurocopter Deutschland GmbH (ECD) Model MBB-BK 117 C-2 Helicopters

    Science.gov (United States)

    2010-08-11

    ... Deutschland GmbH (ECD) Model MBB-BK 117 C-2 Helicopters AGENCY: Federal Aviation Administration (FAA), DOT...) and adding the following new AD: Eurocopter Deutschland GmbH: Docket No. FAA-2010-0780; Directorate...

  4. 76 FR 68299 - Airworthiness Directives; Eurocopter Deutschland GmbH (ECD) Model MBB-BK 117 C-2 Helicopters

    Science.gov (United States)

    2011-11-04

    ... Deutschland GmbH (ECD) Model MBB-BK 117 C-2 Helicopters AGENCY: Federal Aviation Administration, DOT. ACTION... directive to read as follows: 2011-21-13 EUROCOPTER DEUTSCHLAND GmbH (ECD): ] Amendment 39-16836; Docket No...

  5. System Research Of Multi-Barrel Machine Guns Installed On Board Of The Helicopter Of Mi-17 Type

    Directory of Open Access Journals (Sweden)

    Bęczkowski Grzegorz

    2015-08-01

    Full Text Available This article presents tests of a multi-barreled machine gun system built on board of a helicopter. The described weapon system consists of three 7.62 mm M-134G multi-barreled machine guns built on the designed frames of shooting positions located in the escape hatch window, the side doors and the rear doors of the transport cabin of the Mi-17-1V helicopter.

  6. Vision based control of unmanned aerial vehicles with applications to an autonomous four-rotor helicopter, quadrotor

    Science.gov (United States)

    Altug, Erdinc

    Our work proposes a vision-based stabilization and output tracking control method for a model helicopter. This is a part of our effort to produce a rotorcraft based autonomous Unmanned Aerial Vehicle (UAV). Due to the desired maneuvering ability, a four-rotor helicopter has been chosen as the testbed. On previous research on flying vehicles, vision is usually used as a secondary sensor. Unlike previous research, our goal is to use visual feedback as the main sensor, which is not only responsible for detecting where the ground objects are but also for helicopter localization. A novel two-camera method has been introduced for estimating the full six degrees of freedom (DOF) pose of the helicopter. This two-camera system consists of a pan-tilt ground camera and an onboard camera. The pose estimation algorithm is compared through simulation to other methods, such as four-point, and stereo method and is shown to be less sensitive to feature detection errors. Helicopters are highly unstable flying vehicles; although this is good for agility, it makes the control harder. To build an autonomous helicopter, two methods of control are studied---one using a series of mode-based, feedback linearizing controllers and the other using a back-stepping control law. Various simulations with 2D and 3D models demonstrate the implementation of these controllers. We also show global convergence of the 3D quadrotor controller even with large calibration errors or presence of large errors on the image plane. Finally, we present initial flight experiments where the proposed pose estimation algorithm and non-linear control techniques have been implemented on a remote-controlled helicopter. The helicopter was restricted with a tether to vertical, yaw motions and limited x and y translations.

  7. Capability of State-of-the-Art Navier-Stokes Solvers for the Prediction of Helicopter Fuselage Aerodynamics

    DEFF Research Database (Denmark)

    N., Kroll; P., Renzoni; M., Amato

    1998-01-01

    The purpose of this paper is to describe the influence of different Navier-Stokes solvers and grids on the prediction of the global coefficients for a simplified geometry of a helicopter fuselage.......The purpose of this paper is to describe the influence of different Navier-Stokes solvers and grids on the prediction of the global coefficients for a simplified geometry of a helicopter fuselage....

  8. Estimation of Rice Crop Quality and Harvest Amount from Helicopter Mounted NIR Camera Data and Remote Sensing Satellite Data

    OpenAIRE

    Kohei Arai; Masanoori Sakashita; Osamu Shigetomi; Yuko Miura

    2015-01-01

    Estimation of rice crop quality and harvest amount in paddy fields with the different rice stump density derived from helicopter mounted NIR camera and remote sensing satellite data is made. Using the intensive study site of rice paddy fields with managing, estimation of protein content in rice crop and nitrogen content in rice leaves through regression analysis with Normalized Difference Vegetation Index: NDVI derived from camera mounted on a radio-control helicopter is made together with ha...

  9. Black Hawk down? Establishing helicopter parenting as a distinct construct from other forms of parental control during emerging adulthood.

    Science.gov (United States)

    Padilla-Walker, Laura M; Nelson, Larry J

    2012-10-01

    The purpose of the current study was to establish a measure of helicopter parenting that was distinct from other forms of parental control, and to examine parental and behavioral correlates of helicopter parenting. Participants included 438 undergraduate students from four universities in the United States (M(age) = 19.65, SD = 2.00, range = 18-29; 320 women, 118 men), and at least one of their parents. Analyses revealed that helicopter parenting loaded on a separate factor from both behavioral and psychological control, and that helicopter parenting was positively associated with behavioral and psychological control, but not at levels suggesting complete overlap. Results also revealed that helicopter parenting was positively associated with parental involvement and with other positive aspects of the parent-child relationship; but negatively associated with parental autonomy granting and school engagement. Discussion focuses on the implications of helicopter parenting for healthy development during emerging adulthood. Copyright © 2012 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

  10. 75 FR 79988 - Airworthiness Directives; Eurocopter France Model AS350B, B1, B2, B3, BA, and EC130 B4 Helicopters

    Science.gov (United States)

    2010-12-21

    ... France Model AS350B, B1, B2, B3, BA, and EC130 B4 Helicopters AGENCY: Federal Aviation Administration..., Revision 1, dated February 6, 2009, for the Model EC130 B4 helicopter (80A003). The Model AS350 BB... Model AS350B, B1, B2, B3, BA, and EC130 B4 helicopters with ARRIEL engines with Aircraft Parts...

  11. The Adaptive Neural Network Control of Quadrotor Helicopter

    Directory of Open Access Journals (Sweden)

    A. S. Yushenko

    2017-01-01

    Full Text Available The current steady-rising interest in using the unmanned multi-rotor aerial vehicles (UMAV designed to solve a wide range of tasks is, mainly, due to their simple design and high weight-carrying capacity as compared to classical helicopter options. Unfortunately, to solve a problem of multi-copter control is complicated because of essential nonlinearity and environmental perturbations. The most widely spread PID controllers and linear-quadratic regulators do not quite well cope with this task. The need arises for the prompt adjustment of PID controller coefficients in the course of operation or their complete re-tuning in cases of changing parameters of the control object.One of the control methods under changing conditions is the use of the sliding mode. This technology enables us to reach the stabilization and proper operation of the controlled system even under accidental external exposures and when there is a lack of the reasonably accurate mathematical model of the control object. The sliding principle is to ensure the system motion in the immediate vicinity of the sliding surface in the phase space. On the other hand, the sliding mode has some essential disadvantages. The most significant one is the high-frequency jitter of the system near the sliding surface. The sliding mode also implies the complete knowledge of the system dynamics. Various methods have been proposed to eliminate these drawbacks. For example, A.G. Aissaoui’s, H. Abid’s and M. Abid’s paper describes the application of fuzzy logic to control a drive and in Lon-Chen Hung’s and Hung-Yuan Chung’s paper an artificial neural network is used for the manipulator control.This paper presents a method of the quad-copter control with the aid of a neural network controller. This method enables us to control the system without a priori information on parameters of the dynamic model of the controlled object. The main neural network is a MIMO (“Multiple Input Multiple

  12. Lead-Lag Control for Helicopter Vibration and Noise Reduction

    Science.gov (United States)

    Gandhi, Farhan

    1995-01-01

    As a helicopter transitions from hover to forward flight, the main rotor blades experience an asymmetry in flow field around the azimuth, with the blade section tangential velocities increasing on the advancing side and decreasing on the retreating side. To compensate for the reduced dynamic pressure on the retreating side, the blade pitch angles over this part of the rotor disk are increased. Eventually, a high enough forward speed is attained to produce compressibility effects on the advancing side of the rotor disk and stall on the retreating side. The onset of these two phenomena drastically increases the rotor vibratory loads and power requirements, thereby effectively establishing a limit on the maximum achievable forward speed. The alleviation of compressibility and stall (and the associated decrease in vibratory loads and power) would potentially result in an increased maximum forward speed. In the past, several methods have been examined and implemented to reduce the vibratory hub loads. Some of these methods are aimed specifically at alleviating vibration at very high flight speeds and increasing the maximum flight speed, while others focus on vibration reduction within the conventional flight envelope. Among the later are several types passive as well as active schemes. Passive schemes include a variety of vibration absorbers such as mechanical springs, pendulums, and bifilar absorbers. These mechanism are easy to design and maintain, but incur significant weight and drag penalties. Among the popular active control schemes in consideration are Higher Harmonic Control (HHC) and Individual Blade Control (IBC). HHC uses a conventional swash plate to generate a multi-cyclic pitch input to the blade. This requires actuators capable of sufficiently high power and bandwidth, increasing the cost and weight of the aircraft. IBC places actuators in the rotating reference frame, requiring the use of slip rings capable of transferring enough power to the actuators

  13. Association between helicopter with physician versus ground emergency medical services and survival of adults with major trauma in Japan.

    Science.gov (United States)

    Abe, Toshikazu; Takahashi, Osamu; Saitoh, Daizoh; Tokuda, Yasuharu

    2014-07-09

    Helicopter emergency medical services with a physician (HEMS) has been provided in Japan since 2001. However, HEMS and its possible effect on outcomes for severe trauma patients have still been debated as helicopter services require expensive and limited resources. Our aim was to analyze the association between the use of helicopters with a physician versus ground services and survival among adults with serious traumatic injuries. This multicenter prospective observational study involved 24,293 patients. All patients were older than 15 years of age, had sustained blunt or penetrating trauma and had an Injury Severity Score (ISS) higher than 15. All of the patient data were recorded between 2004 and 2011 in the Japan Trauma Data Bank, which includes data from 114 major emergency hospitals in Japan. The primary outcome was survival to discharge from hospitals. The intervention was either transport by helicopter with a physician or ground emergency services. A total of 2,090 patients in the sample were transported by helicopter, and 22,203 were transported by ground. Overall, 546 patients (26.1%) transported by helicopter died compared to 5,765 patients (26.0%) transported by ground emergency services. Patients transported by helicopter had higher ISSs than those transported by ground. In multivariable logistic regression, helicopter transport had an odds ratio (OR) for survival to discharge of 1.277 (95% confidence interval (CI), 1.049 to 1.556) after adjusting for age, sex, mechanism of injury, type of trauma, initial vital signs (including systolic blood pressure, heart rate and respiratory rate), ISS and prehospital treatment (including intubation, airway protection maneuver and intravenous fluid). In the propensity score-matched cohort, helicopter transport was associated with improved odds of survival compared to ground transport (OR, 1.446; 95% CI, 1.220 to 1.714). In conditional logistic regression, after adjusting for prehospital treatment (including

  14. Actuator Fault Estimation and Reconfiguration Control for the Quad-Rotor Helicopter

    Directory of Open Access Journals (Sweden)

    Fuyang Chen

    2016-02-01

    Full Text Available In this paper, an improved reconfiguration control scheme via an H∞ fault observer and adaptive control is studied for the quad-rotor helicopter with actuator faults. The bilinear problem is eliminated by constructing fault compensation and control law reconfiguration in the adaptive controller. Fault estimation is achieved by designing the fault observer with an H∞ performance index, which is applied to evaluate the ‘locking in place’ fault of the actuator in a quad-rotor helicopter. By drawing the H∞ performance index into the adaptive fault observer, an asymptotically convergent estimated error can be attained and the burden of the adaptive controller is alleviated. Some simulation and experimental results confirm the availability of the reconfiguration control scheme.

  15. Impact of structural optimization with aeroelastic/multidisciplinary constraints on helicopter rotor design

    Science.gov (United States)

    Friedmann, Peretz P.

    1992-01-01

    This paper presents a review of the state-of-the-art in the field of structural optimization when applied to vibration reduction of helicopters in forward flight with aeroelastic and multidisciplinary constraints. It emphasizes the application of the modern approach where the optimization is formulated as a mathematical programming problem and the objective function consists of the vibration levels at the hub and behavior constraints are imposed on the blade frequencies, aeroelastic stability margins as well as on a number of additional ingredients which can have a significant effect on the overall performance and flight mechanics of the helicopter. It is shown that the integrated multidisciplinary optimization of rotorcraft offers the potential for substantial improvements which can be achieved by careful preliminary design and analysis without requiring additional hardware such as rotor vibration absorbers or isolation systems.

  16. Backstepping control for a 3DOF model helicopter with input and output constraints

    Directory of Open Access Journals (Sweden)

    Rong Mei

    2016-02-01

    Full Text Available In this article, a backstepping control scheme is developed for the motion control of a Three degrees of freedom (3DOF model helicopter with unknown external disturbance, modelling uncertainties and input and output constraints. In the developed robust control scheme, augmented state observers are applied to estimate the unknown states, unknown external disturbance and modelling uncertainties. Auxiliary systems are designed to deal with input saturation. A barrier Lyapunov function is employed to handle the output saturation. The stability of closed-loop system is proved by the Lyapunov method. Simulation results show that the designed control scheme is effective at dealing with the motion control of a 3DOF model helicopter in the presence of unknown external disturbance and modelling uncertainties, and input and output saturation.

  17. Robust Control for Lateral and Longitudinal Channels of Small-Scale Unmanned Helicopters

    Directory of Open Access Journals (Sweden)

    Bao Feng

    2015-01-01

    Full Text Available Lateral and longitudinal channels are two closely related channels whose control stability influences flight performance of small-scale unmanned helicopters directly. This paper presents a robust control approach for lateral and longitudinal channels in the presence of parameter uncertainties and exogenous disturbances. The proposed control approach is performed by two steps. First, by performing system identification in frequency domain, system model of lateral and longitudinal channels can be accurately identified. Then, a robust H∞ state feedback controller is designed to stabilize the helicopter in lateral and longitudinal channels simultaneously under extraneous disturbances situation. The proposed approach takes advantages that it reduces order of the controller by preestimating some parameters (like flapping angles without sacrificing control accuracy. Numerical results show the reliability and effectiveness of the proposed method.

  18. Design of a Stability Augmentation System for an Unmanned Helicopter Based on Adaptive Control Techniques

    Directory of Open Access Journals (Sweden)

    Shouzhao Sheng

    2015-09-01

    Full Text Available The task of control of unmanned helicopters is rather complicated in the presence of parametric uncertainties and measurement noises. This paper presents an adaptive model feedback control algorithm for an unmanned helicopter stability augmentation system. The proposed algorithm can achieve a guaranteed model reference tracking performance and speed up the convergence rates of adjustable parameters, even when the plant parameters vary rapidly. Moreover, the model feedback strategy in the algorithm further contributes to the improvement in the control quality of the stability augmentation system in the case of low signal to noise ratios, mainly because the model feedback path is noise free. The effectiveness and superiority of the proposed algorithm are demonstrated through a series of tests.

  19. Direct self-repairing control for a helicopter via quantum multi-model and disturbance observer

    Science.gov (United States)

    Chen, Fuyang; Cai, Ling; Jiang, Bin; Tao, Gang

    2016-02-01

    In this paper, a new direct self-repairing control scheme is developed for a helicopter flight control system with unknown actuator faults and external disturbance. The design of multi-model-based adaptive control is used to accommodate the faulty system under different fault conditions. By appropriate switching based on quantum information technique, the system can be converted to the best model and the corresponding controller. Asymptotic model following performance and system stability is guaranteed. A disturbance observer is introduced to observe the disturbance of the system, which can produce corresponding control signals according to the disturbance. The results including a numerical simulation and a semi-physical verification demonstrate the effectiveness of the proposed self-repairing control approach for the helicopter flight control system.

  20. Mach number scaling of helicopter rotor blade/vortex interaction noise

    Science.gov (United States)

    Leighton, Kenneth P.; Harris, Wesley L.

    1985-01-01

    A parametric study of model helicopter rotor blade slap due to blade vortex interaction (BVI) was conducted in a 5 by 7.5-foot anechoic wind tunnel using model helicopter rotors with two, three, and four blades. The results were compared with a previously developed Mach number scaling theory. Three- and four-bladed rotor configurations were found to show very good agreement with the Mach number to the sixth power law for all conditions tested. A reduction of conditions for which BVI blade slap is detected was observed for three-bladed rotors when compared to the two-bladed baseline. The advance ratio boundaries of the four-bladed rotor exhibited an angular dependence not present for the two-bladed configuration. The upper limits for the advance ratio boundaries of the four-bladed rotors increased with increasing rotational speed.