Flight-Test Results of Propulsion-Only Emergency Control System on MD-11 Airplane

Burken, John J. and Burcham Jr., Frank W. (1997) Flight-Test Results of Propulsion-Only Emergency Control System on MD-11 Airplane. Journal of Guidance, Control, and Dynamics 20(5):980-987.

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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 four landings without any aerodynamic flight control surface movement were demonstrated; however, only one landing is presented. Results that show satisfactory performance of the PCA system in the longitudinal axis are presented. 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:	Journal Article (Technical)
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:	1846
Deposited On:	07 March 2008
Additional Information:	8 pages. In Journal of Guidance, Control, and Dynamics, Vol. 20, No. 5, September-October, 1997. Burken, Burcham Jr., NASA Dryden Flight Research Center.