Abstract: A method of controlling a system is adapted to control flow to throat nozzle and vectoring nozzle actuators. The method comprises the steps of summing a plurality of signals representative of flow to the vectoring nozzle actuators with a signal representative of flow to the throat nozzle actuators to generate a total hydraulic flow signal. The total flow signal is then compared to a signal representative of total pump output to generate a reserve signal. Finally, a scaled rate limit signal is generated from the reserve signal and multiplied by predetermined ratio signals such that the ratio signals are limited by the difference between pump output and pump demand.

Abstract: A method of detecting hydraulic leaks from a high pressure fuel hydraulic system is useful in systems where a pump, actuators, and hydraulic lines are filled with engine fuel at high pressure. The method comprises the steps of calculating pump flow based on a core engine RPM and a pump displacement, and calculating actuator fluid flow. System condition signals are then generated to indicate whether the core engine RPM is constant and whether the actuators are quiescent. A servo flow value is then provided, typically at predetermined system conditions, as indicated by the system condition signals, using the pump flow calculation and the actuator fluid flow calculation. Finally, leak flow is determined based on the pump flow calculation, the actuator fluid flow calculation, and the servo flow value, and the leak flow is responded to accordingly.

Abstract: A method for controlling the amount of side load experienced by a gas turbine engine and associated airframe components is provided, where the gas turbine engine includes a thrust vectoring system which deflects thrust at a vector angle away from a centerline thereof. The method includes the steps of calculating engine thrust, calculating a side load vector angle limit as a function of the calculated engine thrust and a side load limit, and limiting the vector angle of the thrust vectoring system to the side load vector angle limit in order to maintain operation of the gas turbine engine within the side load limit.

Abstract: A method of controlling a system is adapted to control flow to throat nozzle and vectoring nozzle actuators. The method comprises the steps of summing a plurality of signals representative of flow to the vectoring nozzle actuators with a signal representative of flow to the throat nozzle actuators to generate a total hydraulic flow signal. The total flow signal is then compared to a signal representative of total pump output to generate a reserve signal. Finally, a scaled rate limit signal is generated from the reserve signal and multiplied by predetermined ratio signals such that the ratio signals are limited by the difference between pump output and pump demand.

Abstract: The reliability of a fluid multiplexed actuation system is increased by arranging a pair of fluidic multiplexers in a parallel fluid flow path between a selector valve and several fluid actuators. Position sensors associated with the fluidic multiplexers and with the fluid actuators provide feedback signals to a microprocessor. In the event the feedback signals identify a malfunction in the fluidic multiplexer currently supplying fluid to the actuators, the microprocessor will deactivate the malfunctioning fluidic multiplexer and activate a redundant or back-up fluidic multiplexer by actuating the selector valve.

Abstract: An electronic fuel control for a gas turbine engine monitors the mass density of the fuel. As the mass density of the fuel varies when the fuel temperature changes or when the fuel type changes, the electronic fuel control adjusts an initial mass density to a corrected value based on the most recent measurement of mass fuel flow that was taken when the mass fuel flow measurement was known to be accurate. Accurately controlling mass fuel flow permits gas turbine engine designers to reduce tolerances in moving parts which improves the efficiency of the gas turbine engine.

Abstract: An electronic fuel control for a gas turbine engine monitors the mass density of the fuel. As the mass density of the fuel varies when the fuel temperature changes or when the fuel type changes, the electronic fuel control adjusts an initial mass density to a corrected value based on the most recent measurement of mass fuel flow that was taken when the mass fuel flow measurement was known to be accurate. Accurately controlling mass fuel flow permits gas turbine engine designers to reduce tolerances in moving parts which improves the efficiency of the gas turbine engine.

Abstract: An improved synchrophasing system for synchrophasing fan spools and engine core spools of one or more "slave" turbofan engines to a "master" engine is disclosed. A fuel control means is provided for modulating the flow of fuel to the slave engines to first synchrophase the operation of the engine fan spools. A variable stator vane control means is provided for then modulating the position of variable stator vanes within the slave engines to synchrophase the operation of the engine core spools.

Abstract: An improved synchrophasing system for synchrophasing fan spools and engine core spools of one or more "slave" turbofan engines to a "master" engine is disclosed. A fuel control means is provided for modulating the flow of fuel to the slave engines to first synchrophase the operation of the engine fan spools. A variable stator vane control means is provided for then modulating the position of variable stator vanes within the slave engines to synchrophase the operation of the engine core spools.

Abstract: Control means and method for steering an aircraft is disclosed. The aircraft includes engines positioned on opposite sides of its longitudinal axis. The method comprises: selecting an aircraft heading; sensing a deviation from said heading; and varying the thrust of at least one engine in response to the sensed deviation.

Abstract: Control means and method for steering an aircraft is disclosed. The aircraft includes engines positioned on opposite sides of its longitudinal axis. The method comprises: selecting an aircraft heading; sensing a deviation from said heading; and varying the thrust of at least one engine in response to the sense deviation.

Abstract: In the present invention, fuel flow in an aircraft is modulated automatically in order to maintain a preselected altitude.

Abstract: A plurality of blocker door vanes are disposed in the bypass duct to selectively close off the bypass flow and increase the flow and pressure of the air flowing into the compressor. In this way, the compressor inlet pressure can be increased sufficiently to allow air starts without starter torque assist. The vanes may also be closed down during ground idle to reduce the thrust and increase the compressor bleed pressure and both the pressure and the temperature of the air to the combustor. Provision is made for the controlling of the blocker door vanes as a function of core speed.

Abstract: The angle of the variable blocker door vanes in the bypass duct of a turbofan engine is varied in response to the angle of the variable compressor vanes of the engine. A cam and linkage assembly interconnect the blocker doors with the actuation system of the variable stator vanes such that as the angle of the stator vanes is modulated through a first predetermined range, the angle of the blocker doors is modulated through a second predetermined range.

Abstract: A hydraulic pump and drive system is interconnected between the fan and compressor rotor of a turbofan engine such that the windmill speed of the core rotor can be boosted to a speed sufficient to allow a significantly increased in-flight start envelope by selectively extracting power from the windmilling fan prior to relight of the engine. Control logic is included to decouple the motor and pump whenever the engine is in the operating speed region and to selectively couple the fan-driven hydraulic pump to auxiliary machinery such as the nozzle actuators to obtain a dual-purpose function from the pump.

Abstract: A torque converter is interconnected between the fan and core rotor of a turbofan engine such that the speed of the core rotor can be boosted from windmill speed to a speed sufficient to allow an in-flight start by selectively extracting power from the windmilling fan during the start sequence of the engine. Control logic is included to automatically drain the oil from, and thereby unload, the torque converter whenever the engine is in the operating speed region. Further assurance is provided by an overrunning clutch which decouples the system when the core rotational speed exceeds the converter output.

Abstract: Fuel is selectively jettisoned through the engine of an aircraft by way of a normally closed, solenoid-operated jettison valve which is fed from the boost pump in the engine fuel system. The jettison valve is servo activated by the main fuel flow so that the engine must be running for the opening of the solenoid valve to occur. For an engine having an augmenter, other interlocks are provided to prevent the jettison of fuel when the augmenter is in use and to preclude the ignition function to the augmenter while fuel is being jettisoned.