Abstract: Compressor discharge pressure (CDP) in a gas turbine engine is sensed. A fall in CDP is interpreted as indicating compressor stall.

Abstract: An aircraft stall avoidance system uses flight measurements such as accelerations, aircraft configuration, engine power, atmospheric conditions, and other related characteristics in computing the speed at which a specific aircraft is likely to stall in real time. The indicator provides continuous stall avoidance information to the pilot along with positive warning signals when critical safety margins are broached.

Abstract: The approaching stall of an aircraft wing is predicted using an inherent characteristic of the airflow as the stall is approached. The airspeed over the wing is sensed at a predetermined location spaced above the top surface of the wing, input signals are produced representative of airspeed fluctuations caused by air turbulence, input signals are used to produce a signal representative of the ratio of the airspeed fluctuations to the average airspeed, and the ratio signal produces a signal indicating imminent stalling.

Abstract: An asymmetric thrust warning system for an aircraft having two gas turbine engines. The compressor discharge pressures of the two engines are compared to determine the engine providing the lower thrust and to provide a signal indicative of the actual difference in thrust. If the difference in thrust exceeds a prescribed value related to aircraft altitude, a low thrust warning lamp is illuminated. In addition, the positions of the two augmenter metering valves are compared. If their positions significantly differ, the warning light associated with the valve having the minimum opening will be illuminated. A stall warning circuit may also be included as a part of the system.

Abstract: An acceleration schedule, from which data is derived for use in calculating fuel flow during acceleration of a gas turbine engine, is modified each time the engine surges so as to avoid future surges.

Abstract: A method of predicting the approaching stall of an aircraft wing which is dependent on an inherent characteristic of the airflow as the stall is approached. The method described uses a hot-wire probe which measures the turbulence of the airflow at a predetermined location on the top surface of the wing. When the turbulence exceeds a threshold, which threshold is dependent on the air-speed, a signal is produced which indicates that a stall is imminent. The method can be particularly applied to an artificial stall warning device fitted to a transport aircraft.