Download or read book An Investigation of the Effects of Pitch Roll De Coupling on Helicopter Handling Qualities written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-17 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: An extensive investigation of the effects of pitch-roll coupling on helicopter handling qualities was performed by the U.S. Army and Deutsche Forschungsanstalt fur Luft- und Raumfahrt (DLR), using a NASA ground-based and a DLR in-flight simulator. Over 90 different coupling configurations were evaluated using a high gain 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 is 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, shows excellent consistency, and has the additional benefit that compliance testing data are obtained from the bandwidth/phase delay tests, so that no additional flight testing is needed. Blanken, C. L. and Pausder, H. J. and Ockier, C. J. Ames Research Center CONTROLLABILITY; COUPLING; DECOUPLING; FLIGHT CONTROL; HELICOPTER CONTROL; HELICOPTER PERFORMANCE; HELICOPTERS; PITCH (INCLINATION); ROLL; AERODYNAMIC STABILITY; AIRCRAFT SAFETY; CONTROL STABILITY; HIGH GAIN; LATERAL CONTROL; LONGITUDINAL CONTROL; SIMULATION; TRACKING (POSITION)...

Download or read book An Investigation of the Effects of Pitch roll de coupling on Helicopter Handling Qualities written by Carl J. Ockier and published by . This book was released on 1995 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An investigation of the effects of pitch roll de coupling on helicopter handling qualities written by Carl J. Ockier and published by . This book was released on 1995 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book In Flight Simulation Investigation of Rotorcraft Pitch Roll Cross Coupling written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-10-26 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: An in-flight simulation experiment investigating the handling qualities effects of the pitch-roll cross-coupling characteristic of single-main-rotor helicopters is described. The experiment was conducted using the NASA/Army CH-47B variable stability helicopter with an explicit-model-following control system. The research is an extension of an earlier ground-based investigation conducted on the NASA Ames Research Center's Vertical Motion Simulator. The model developed for the experiment is for an unaugmented helicopter with cross-coupling implemented using physical rotor parameters. The details of converting the model from the simulation to use in flight are described. A frequency-domain comparison of the model and actual aircraft responses showing the fidelity of the in-flight simulation is described. The evaluation task was representative of nap-of-the-Earth maneuvering flight. The results indicate that task demands are important in determining allowable levels of coupling. In addition, on-axis damping characteristics influence the frequency-dependent characteristics of coupling and affect the handling qualities. Pilot technique, in terms of learned control crossfeeds, can improve performance and lower workload for particular types of coupling. The results obtained in flight corroborated the simulation results. Watson, Douglas C. and Hindson, William S. Ames Research Center RTOP 505-66-51

Download or read book Effects of Coupling Between Pitch and Roll Control Inputs on the Handling Qualities of VTOL Aircraft written by John F. Garren and published by . This book was released on 1962 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Helicopter Flight Investigation of Roll control Sensitivity Damping and Cross Coupling in a Low Altitude Lateral Maneuvering Task written by and published by . This book was released on 1983 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: A helicopter in-flight simulation was conducted to determine the effects of variations in roll damping, roll sensitivity, and pitch- and roll-rate cross-coupling on helicopter flying qualities in a low-altitude maneuver. The experiment utilized the Ames UH-1H helicopter in-flight simulator, which is equipped with the V/STOLAND avionics system. The response envelope of this vehicle allowed simulation of configurations with low-to-moderate damping and sensitivity. A visual, low-level slalom course was set up, consisting of constant-speed and constant-altitude S-turns around the 1000-ft markers of an 8000-ft runway. Results are shown in terms of Cooper-Harper pilot ratings, pilot commentary, and statistical and frequency analyses of the lateral characteristics. These results show good consistency with previous ground-simulator results and are compared with existing flying-qualities criteria, such as those set forth in MIL-F-83300 and MIL-H-8501A. (Author).

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Download or read book In flight Simulation Investigation of Rotorcraft Pitch roll Cross Coupling written by and published by . This book was released on 1988 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Piloted Simulator Investigation of Static Stability and Stability control Augmentation Effects on Helicopter Handling Qualities for Instrument Approach written by and published by . This book was released on 1980 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: A motion-base simulator was used to compare the flying qualities of three generic single-rotor helicopters during a full-attention-to-flight control task. Terminal-area VOR instrument approaches were flown with and without turbulence. The objective of this NASA/FAA study was to investigate the influence of helicopter static stability in terms of the values of cockpit control gradients as specified in the existing airworthiness criteria, and to examine the effectiveness of several types of stability control augmentation systems in improving the instrument-flight-rules capability of helicopters with reduced static stability. Two levels of static stability in the pitch, roll, and yaw axes were examined for a hingeless-rotor configuration; the variations were stable and neutral static stability in pitch and roll, and two levels of stability in yaw. For the lower level of static stability, four types of stability and control augmentation were also examined for helicopters with three rotor types: hingeless, articulated, and teetering. Pilot rating results indicate the acceptability of neutral static stability longitudinally and laterally and the need for pitch-roll attitude augmentation to achieve a satisfactory system. (Author).

Download or read book A Pilot s Assessment of Helicopter Handling quality Factors Common to Both Agility and Instrument Flying Tasks written by and published by . This book was released on 1980 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Helicopter Flight Dynamics written by Gareth D. Padfield and published by John Wiley & Sons. This book was released on 2018-09-07 with total page 856 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Book The behaviour of helicopters and tiltrotor aircraft is so complex that understanding the physical mechanisms at work in trim, stability and response, and thus the prediction of Flying Qualities, requires a framework of analytical and numerical modelling and simulation. Good Flying Qualities are vital for ensuring that mission performance is achievable with safety and, in the first and second editions of Helicopter Flight Dynamics, a comprehensive treatment of design criteria was presented, relating to both normal and degraded Flying Qualities. Fully embracing the consequences of Degraded Flying Qualities during the design phase will contribute positively to safety. In this third edition, two new Chapters are included. Chapter 9 takes the reader on a journey from the origins of the story of Flying Qualities, tracing key contributions to the developing maturity and to the current position. Chapter 10 provides a comprehensive treatment of the Flight Dynamics of tiltrotor aircraft; informed by research activities and the limited data on operational aircraft. Many of the unique behavioural characteristics of tiltrotors are revealed for the first time in this book. The accurate prediction and assessment of Flying Qualities draws on the modelling and simulation discipline on the one hand and testing practice on the other. Checking predictions in flight requires clearly defined mission tasks, derived from realistic performance requirements. High fidelity simulations also form the basis for the design of stability and control augmentation systems, essential for conferring Level 1 Flying Qualities. The integrated description of flight dynamic modelling, simulation and flying qualities of rotorcraft forms the subject of this book, which will be of interest to engineers practising and honing their skills in research laboratories, academia and manufacturing industries, test pilots and flight test engineers, and as a reference for graduate and postgraduate students in aerospace engineering.

Download or read book The Effects of Pilot Stress Factors on Handling Quality Assessments During US German Helicopter Agility Flight Tests written by and published by . This book was released on 1982 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Piloted Simulation of Helicopter Air Combat to Investigate Effects of Variations in Selected Performance and Control Response Characteristics written by Michael S. Lewis and published by . This book was released on 1987 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Rotor Parameter Variations on Handling Qualities of Unaugmented Helicopters in Simulated Terrain Flight written by Peter D. Talbot and published by . This book was released on 1980 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Helicopter Handling Qualities written by and published by . This book was released on 1982 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Coupling Between Pitch and Roll Control Inputs on the Handling Qualities of Vtol Aircraft written by John F. Garren (Jr.) and published by . This book was released on 1962 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Simulation Investigation of the Effects of Engine and Thrust response Characteristics on Helicopter Handling Qualities written by and published by . This book was released on 1983 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: A program is being conducted to study the effects of engine response, rotor inertia, rpm control, excess power, and vertical damping on specific maneuvers included in nap-of-the-Earth (NOE) operations. Specifically, this study concentrates on the helicopter configuration with an rpm-governed gas-turbine engine and expands on handling qualities-criteria data by focusing on aspects peculiar to rotary-wing and NOE operations. This paper summarizes results of three moving-based piloted simulation studies and explores the frequency characteristics of helicopter thrust response which set it apart from other VTOL types. Power-system response is affected by both the engine governor response and the level of rotor inertia. However, results indicate that, with unlimited power, variations in engine response can have a significant effect on pilot rating, whereas changes in rotor inertia, in general, do not. Results also show that any pilot interaction required to maintain proper rpm control can significantly degrade handling qualities. Data for variations in vertical damping and collective sensitivity are compared with existing handling-qualities specifications, MIL-F-83300 and AGARD 577, and show a need for higher minimums for both damping and sensitivity for the bob-up task.