Abstract: An integrated engine control-autothrottle control system for controlling changes in the thrust of a jet aircraft engine during transients (i.e., changes in speed) in a manner that prevents throttle lead and overshoot (i.e., exceeds the response capability of the engine) is disclosed. The system uses the engine control to continuously monitor current fuel flow (WF), burner pressure (PB), high rotor speed (N2) and engine thrust (EPR), manipulates the signals and produces limiting fuel flow transient error (WFPBERR) and rotor speed transient error (N2DOTERR) signals for both acceleration and deceleration. The lower parameter transient error signal is selected as the controlling limit signal during acceleration and the higher parameter transient error signal is selected as the controlling limit signal during deceleration. The controlling limit signals are used to produce limiting throttle lever angle rate of change signals--+TRADOT for acceleration and -TRADOT for deceleration.

Abstract: A method and apparatus for quickly adjusting the coolant flow in a tuned, low-flow coolant system to maintain the temperature of air leaving an aftercooler at a desired temperature and for maintaining the temperature of an engine block within a predetermined range, during various engine loads and ambient temperatures. The invention employs a quick-acting, proportional radiator shuttle valve to mix hot coolant from the radiator input with cool coolant from the radiator output for application to the aftercooler and a quick-acting aftercooler shuttle valve to mix cool coolant from the radiator output with coolant from the aftercooler for application to the engine block.

Abstract: A control system and method for utilizing the rotational speed of the high-speed spool in a multi-spool turbofan engine to stabilize changes in engine operation which affect the thrust output of the engine. Signals representing the actual rotational speed of the high-speed spool, the actual value of the selected engine pressures which provide an accurate measure of engine thrust, and a commanded value of the selected engine pressures are processed; and an error signal is provided in response to these three signals which is a function of all three signals. The error signal is then used to control the rate of fuel flow to the engine which, in turn, controls engine thrust. In one embodiment the error signal is a function of the rotational speed of the high-speed spool and the actual and commanded values of engine pressure ratio, and in another embodiment the error signal is a function of the rotational speed of the high-speed spool and the actual and commanded values of integrated engine pressure ratio.

Abstract: A fan spool stabilization loop which improves the stability of the low speed or fan spool in a two spool turbofan engine. In a preferred embodiment, the actual rate of rotation of the high speed spool is compared with the desired rate of rotation determined by integrating the difference between the desired rate of rotation of the fan spool and the actual rate of rotation. The difference therebetween controls the flow of fuel to the turbofan engine. In an alternate preferred embodiment of the invention, the rate of change of rotation of the high speed spool is added to the actual rate of rotation of the fan spool and the result is compared with the desired rate of rotation of the fan spool. The difference therebetween is utilized to control the flow of fuel to the turbofan engine.

Abstract: A fan spool stabilization loop which improves the stability of the low speed or fan spool in a two spool turbofan engine. In a preferred embodiment, the actual rate of rotation of the high speed spool is compared with the desired rate of rotation determined by integrating the difference between the desired rate of rotation of the fan spool and the actual rate of rotation. The difference therebetween controls the flow of fuel to the turbofan engine. In an alternate preferred embodiment of the invention, the rate of change of rotation of the high speed spool is added to the actual rate of rotation of the fan spool and the result is compared with the desired rate of rotation of the fan spool. The difference therebetween is utilized to control the flow of fuel to the turbofan engine.