Analysis of a Longitudinal Pilot-Induced Oscillation Experienced on the Approach and Landing Test of the Space Shuttle
Smith, John W. (1981) Analysis of a Longitudinal Pilot-Induced Oscillation Experienced on the Approach and Landing Test of the Space Shuttle. Technical Report NASA TM-81366, Research Engineering, NASA Dryden Flight Research Center.
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Abstract
During the final free flight (FF-5) of the shuttle's approach and landing tests, the vehicle experienced pilot-induced oscillations near touchdown. The flight test data showed that pilot inputs to the hand controller reached peak-to-peak amplitudes of 20 degrees at a frequency between 3 and 3.5 radians per second. The controller inputs were sufficient to exceed the priority rate limit set in the pitch axis. A nonlinear analytical study was conducted to investigate the combined effects of pilot input, rate limiting, and time delays. The frequency response of the total system is presented parametrically as a function of the three variables. In general, with no dead time, for controller inputs of 5 degrees or less, the total system behaves in a linear fashion. For 10 degrees of controller input, independent of the delay time, the elevon loop will be rate saturated above a frequency of 4 radians per second.
| EPrint Type: | NASA Technical Memorandum |
|---|---|
| Keywords: | Approach and landing tests (STS), Lateral control, Longitudinal stability, Oscillations, Pilot-induced oscillation |
| Subjects: | (01 - 09) Aeronautics: (08) Aircraft Stability And Control Aircraft/Project: Space Shuttle Orbiter |
| ID Code: | 1034 |
| Deposited On: | 01 August 2006 |
| Additional Information: | 45 pages. |
