Flight Test of a Propulsion-Based Emergency Control System on the MD-11 Airplane With Emphasis on the Lateral Axis

Burken, John J. and Burcham Jr., Frank W. and Maine, Trindel A. and Feather, John and Goldthorpe, Steven and Kahler, Jeffrey A. (1996) Flight Test of a Propulsion-Based Emergency Control System on the MD-11 Airplane With Emphasis on the Lateral Axis. Technical Report NASA TM-4746, Research Engineering, NASA Dryden Flight Research Center.

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Abstract

A large, civilian, multiengine transport MD-11 airplane control system was recently modified to perform as an emergency backup controller using engine thrust only. The emergency backup system, referred to as the propulsion-controlled aircraft (PCA) system, would be used if a major primary flight control system fails. To allow for longitudinal and lateral–directional control, the PCA system requires at least two engines and is implemented through software modifications. A flight-test program was conducted to evaluate the PCA system high-altitude flying characteristics and to demonstrate its capacity to perform safe landings. The cruise flight conditions, several low approaches and one landing without any aerodynamic flight control surface movement, were demonstrated. This paper presents results that show satisfactory performance of the PCA system in the longitudinal axis. Test results indicate that the lateral–directional axis of the system performed well at high altitude but was sluggish and prone to thermal upsets during landing approaches. Flight-test experiences and test techniques are also discussed with emphasis on the lateral–directional axis because of the difficulties encountered in flight test.

EPrint Type:	NASA Technical Memorandum
Keywords:	Control system failure, Emergency controller using thrust, Hydraulic system failure, MD-11 airplane, Propulsion-only control
Subjects:	Aircraft/Project: MD-11 (01 - 09) Aeronautics: (08) Aircraft Stability And Control
ID Code:	195
Deposited On:	16 July 2004
Additional Information:	18 pages. Presented as AIAA 96-3919 at the AIAA Guidance, Navigation, and Control Conference, San Diego, California, July 29–31, 1996.