Abstract: Stall is detected by monitoring the acceleration schedule of the engine's fuel control and an engine operating parameter, either compressor speed, compressor pressure and computing signals indicative of when both the fuel control is on or near the acceleration schedule and when (1) the compressor speed is decaying at a given rate or (2) compressor discharge or burner pressure is decaying at a given rate or (3) the pressure ratio of low compressor discharge to compressor inlet or burner pressure to compressor inlet is at a predetermined low level, an output signal will be manifested.

Abstract: A stall detector for a gas turbine engine is disclosed where detection is obtained by continuously monitoring turbine temperature and either compressor speed or bleed valve position and provide a stall signal solely when turbine temperature exceeds a predetermined value and the compressor speed decreases at a predetermined rate or when turbine temperature exceeds a predetermined value at the time that the compressor bleeds are in the opened position.

Abstract: Stall is detected by monitoring the minimum fuel flow schedule of a gas turbine engine fuel control and another parameter which includes (1) the fuel control acceleration schedule, (2) turbine temperature (inlet or exit) or (3) engine pressure (compressor discharge or burner) and computes these signals so that when both the control fuel metering valve is at its minimum stop position (minimum fuel flow) and one of the following conditions exists, (1) turbine temperature exceeds a predetermined level, (2) the rate of change of pressure exceeds a predetermined negative rate, or (3) the fuel control is on or in proximity to the acceleration schedule, an output will be manifested.