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Flight-testing and frequency-domain analysis for rotorcraft handling qualitiesA demonstration of frequency-domain flight-testing techniques and analysis was performed on a U.S. Army OH-58D helicopter in support of the OH-58D Airworthiness and Flight Characteristics Evaluation and of the Army's development and ongoing review of Aeronautical Design Standard 33C, Handling Qualities Requirements for Military Rotorcraft. Hover and forward flight (60 kn) tests were conducted in 1 flight hour by Army experimental test pilots. Further processing of the hover data generated a complete database of velocity, angular-rate, and acceleration-frequency responses to control inputs. A joint effort was then undertaken by the Airworthiness Qualification Test Dirtectorate and the U.S. Army Aeroflightdynamics Directorate to derive handling-quality information from the frequency-domain database using a variety of approaches. This report documents numerous results that have been obtained from the simple frequency-domain tests; in many areas, these results provide more insight into the aircraft dynmamics that affect handling qualities than do traditional flight tests. The handling-quality results include ADS-33C bandwidth and phase-delay calculations, vibration spectral determinations, transfer-function models to examine single-axis results, and a six-degree-of-freedom fully coupled state-space model. The ability of this model to accurately predict responses was verified using data from pulse inputs. This report also documents the frequency-sweep flight-test technique and data analysis used to support the tests.
Document ID
19950058670
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Ham, Johnnie A.
(Edwards AFB CA, United States)
Gardner, Charles K.
(Edwards AFB CA, United States)
Tischler, Mark B.
(U.S. Army ATCOM, Moffett Field, CA United States)
Date Acquired
August 16, 2013
Publication Date
April 1, 1995
Publication Information
Publication: American Helicopter Society, Journal
Volume: 40
Issue: 2
ISSN: 0002-8711
Subject Category
Aircraft Stability And Control
Accession Number
95A90269
Distribution Limits
Public
Copyright
Other

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