Development of Handling Qualities Criteria for Rotorcraft with Externally Slung Loads PDF Download
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Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781721153381
Category :
Languages : en
Pages : 174
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Book Description
Piloted simulations were performed on the NASA-Ames Vertical Motion Simulator (VMS) to explore handling qualities issues for large cargo helicopters, particularly focusing on external slung load operations. The purpose of this work was based upon the need to include handling qualities criteria for cargo helicopters in an upgrade to the U.S. Army's rotorcraft handling qualities specification, Aeronautical Design Standard-33 (ADS-33E-PRF). From the VMS results, handling qualities criteria were developed fro cargo helicopters carrying external slung loads in the degraded visual environment (DVE). If satisfied, these criteria provide assurance that the handling quality rating (HQR) will be 4 or better for operations in the DVE, and with a load mass ratio of 0.33 or less. For lighter loads, flying qualities were found to be less dependent on the load geometry and therefore the significance of the criteria is less. For heavier loads, meeting the criteria ensures the best possible handling qualities, albeit Level 2 for load mass ratios greater than 0.33. Hoh, Roger H. and Heffley, Robert K. and Mitchell, David G. Ames Research Center NAS2-14360
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781721153381
Category :
Languages : en
Pages : 174
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Book Description
Piloted simulations were performed on the NASA-Ames Vertical Motion Simulator (VMS) to explore handling qualities issues for large cargo helicopters, particularly focusing on external slung load operations. The purpose of this work was based upon the need to include handling qualities criteria for cargo helicopters in an upgrade to the U.S. Army's rotorcraft handling qualities specification, Aeronautical Design Standard-33 (ADS-33E-PRF). From the VMS results, handling qualities criteria were developed fro cargo helicopters carrying external slung loads in the degraded visual environment (DVE). If satisfied, these criteria provide assurance that the handling quality rating (HQR) will be 4 or better for operations in the DVE, and with a load mass ratio of 0.33 or less. For lighter loads, flying qualities were found to be less dependent on the load geometry and therefore the significance of the criteria is less. For heavier loads, meeting the criteria ensures the best possible handling qualities, albeit Level 2 for load mass ratios greater than 0.33. Hoh, Roger H. and Heffley, Robert K. and Mitchell, David G. Ames Research Center NAS2-14360
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 174
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Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 174
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Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
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Book Description
This report presents the results of a study to develop airworthiness requirements for rotorcraft with external sling loads. The report starts with a review of the various phenomena that limit external sling load operations. Specifically discussed are the rotorcraft-load aeroservoelastic stability, load-on handling qualities, effects of automatic flight control system failure, load suspension system failure, and load stability at speed. Based on past experience and treatment of these phenomena, criteria are proposed to form a package for airworthiness qualification. The desired end objective is a set of operational flight envelopes for the rotorcraft with intended loads that can be provided to the user to guide operations in the field. The specific criteria proposed are parts of ADS-33E-PRF; MIL-F-9490D, and MIL-STD-913A all applied in the context of external sling loads. The study was performed for the Directorate of Engineering, U.S. Army Aviation and Missile Command (AMCOM), as part of the contract monitored by the Aerothermodynamics Directorate, U.S. Army AMCOM.
Author:
Publisher:
ISBN:
Category : Military research
Languages : en
Pages : 676
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Book Description
Author: Gareth D. Padfield
Publisher: John Wiley & Sons
ISBN: 111940102X
Category : Technology & Engineering
Languages : en
Pages : 856
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Book Description
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.
Author: Seth B. Anderson
Publisher:
ISBN:
Category : Flight control
Languages : en
Pages : 56
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Book Description
A study has been undertaken to define hand-ling qualities criteria for V/STOL aircraft. With the current military requirements for helicopters and airplanes as a framework, modifications and additions were made for conversion to a preliminary set of V/STOL requirements using a broad background of flight experience and pilots' comments from VTOL and STOL aircraft, BLC (boundary-layer-control) equipped aircraft, variable stability aircraft, flight simulators and landing approach studies. The report contains a discussion of the reasoning behind and the sources of information leading to suggested requirements. The results of the study indicate that the majority of V/STOL requirements can be defined by modifications to the helicopter and/or airplane requirements by appropriate definition of reference speeds. Areas where a requirement is included but where the information is felt to be inadequate to establish a firm quantitative requirement include the following: Control power and damping relationships about all axes for various sizes and types of aircraft; control power, sensitivity, d-amping and response for height control; dynamic longitudinal and dynamic lateral- directional stability in the transition region, including emergency operation; hovering steadiness; acceleration and deceleration in transition; descent rates and flight-path angles in steep approaches, and thrust margin for approach.
Author: Tom Berger
Publisher:
ISBN:
Category :
Languages : en
Pages :
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Book Description
The U.S. Department of Defense has established the Future Vertical Lift initiative to develop a family of next-generation vertical lift aircraft that will fly farther, faster, and more efficiently than the current fleet of rotorcraft. To accomplish these goals, advanced rotorcraft configurations beyond the single main rotor/tail rotor design must be considered. Two advanced configurations currently being flight tested in a technology demonstrator program are a lift offset coaxial rotorcraft with a pusher propeller and a tiltrotor. The U.S. Army Aviation Development Directorate has developed generic, high-fidelity flight-dynamics models of these two configurations to provide the government with independent control-system design, handling-qualities analysis, and simulation research capabilities for these types of aircraft in support of the Future Vertical Lift initiative.In an effort to begin defining high-speed handling qualities requirements for these types of advanced rotorcraft configurations, full flight envelope inner-loop explicit model following control systems were designed for both configurations using a multi-objective optimization approach to meet a comprehensive set of stability, handling qualities, and performance requirements. The requirements were chosen from both helicopter and fixed-wing criteria. The control laws for both aircraft were evaluated in a piloted simulation experiment at the NASA Ames Vertical Motion Simulator using a series of high-speed handling qualities demonstration maneuvers. The results from the simulation experiment show overall assigned Level 1 handling qualities for both aircraft which correlates well with the predicted Level 1 handling qualities they were designed to, thus supporting the choice of handling qualities requirements selected during the design process.In addition, outer-loop control laws were also developed for both aircraft in an effort to improve handling qualities and reduce pilot workload. A dynamic inversion control law architecture was used for the outer loops, and again a comprehensive set of stability, handling qualities, and performance requirements was used to optimize the parameters of the control laws. The outer-loop control laws for both aircraft were evaluated in a piloted simulation experiment at the Pennsylvania State University Flight Simulator facility using a subset of the high-speed handling qualities demonstration maneuvers used in the first evaluation. Overall, the outer-loop control laws provided Level 1 handling qualities for the Break Turn and High-Speed Acceleration/Deceleration maneuvers, with improvements seen over the inner-loop control laws. In addition, the outer-loop control laws improved performance and reduced workload during a formation flying task that was developed for this project. However, for pitch attitude capture and tracking tasks, the outer-loop control laws degraded handling qualities as compared to the inner-loop control laws. This was due to the pitch attitude dropback behavior of the outer-loops, even though they were tuned to meet the dropback specification. The results suggest that the amount of allowable dropback should be decreased for high-speed rotorcraft and the outer-loop functionality might be provided as a selectable mode. The set of handling qualities criteria used to optimize the inner- and outer-loop control systems presented here are proposed as a set of requirements to tune high-speed rotorcraft control systems to achieve Level 1 handling qualities.
Author: John Kroll (Jr.)
Publisher:
ISBN:
Category : Helicopters
Languages : en
Pages : 76
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Book Description
"This report presents a series of discussions on selected topics related to the development of VTOL flying qualities criteria. The topics were chosen on the basis of their importance to flying qualities and the potential significance to the Air Force VTOL Integrated Flight Control System (VIFCS) program. The treatment given to the selected topics was aimed at identifying those areas that require further study and research within the scope of the VIFCS program. -- page iii.
Author:
Publisher:
ISBN:
Category : Military research
Languages : en
Pages : 678
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