Propulsion - Controlled Aircraft
Product Profile:
Engineers at Dryden Flight Research Center have developed an emergency flight control system, the Propulsion-Controlled Aircraft (PCA) system, for controlling the flight of multi-engine aircraft in the case of catastrophic failure of the main hydraulic control system. The PCA system provides emergency flight control using only the thrust of the aircraft engines. PCA takes pilot commands, airplane measurements, computes the needed thrust from each engine to satisfy the pilot's commands, and sends the thrust commands to the engines. PCA has been successfully flight tested on the F-15 airplane and on an MD-11.
Technical Basics
The PCA control system uses the aircraft engines instead of the ailerons,
trim tabs, elevators, and rudders to adjust altitude, pitch, and roll rate
for flight control of the airplane in emergency situations. The system
is based on the use of a computer-controlled feedback system in which parameters
such as flightpath angle, pitch rate, bank angle, and yaw rate are measured
and used to keep the airplane under control and on the correct flightpath.
The PCA system is comprised of an input device for generating a control
command from the pilot indicative of a desired flightpath, a feedback sensor
for generating a feedback signal indicating the pitch rate, pitch attitude,
roll rate, and roll attitude of the airplane, and a control device for
changing the output power of one or more of the main drive engines on each
side of the airplane in response to the feedback signal. The thrust control
achieved in this way allows the pilot to maintain sufficient maneuverability
to be able to maintain the specified flightpath and land the aircraft.
The PCA system can be incorporated into existing and future aircraft that
have digital control systems, in some cases adding little or no weight
to the airplane.
Contact Information
For more information regarding how this technology can help your company, pleasecontact the Far West Regional Transfer Center either via e-mail to nasa@usc.edu or phone at 213-743-2353 or 800-642-2872.
