Abstract: A method for controlling an aircraft engine using a control system enables an engine to be operated at low power while hail is ingested. The control system includes a processor coupled to the aircraft engine. The method comprises receiving a plurality of sensed inputs from the aircraft engine, receiving current engine environmental operating conditions, determining a reference value for a controlled variable from a fuel flow schedule, generating a fuel-air-ratio for the reference value based on current engine environmental operating conditions, and enriching combustor fuel staging in response to the fuel-air-ratio.

Abstract: An exemplary embodiment of the invention is directed to a fuel flow control system for use with a fuel distribution system having a plurality of zones each including a servovalve. The fuel flow control system includes a fluidic multiplexer having a plurality of pressure ports and a plurality of servoflow ports. The fluidic multiplexer sequentially receives pressure from each zone and sequentially provides servo fluid to each servovalve. A pressure sensor is fluidly coupled to the pressure ports and generates a pressure signal for each zone. A controller receives the pressure signal and generates a control signal. A driver receives the control signal and increases or decreases flow through the servoflow ports in response to the control signal.

Abstract: A control circuit adapted to receive at least first, second and third input signals. The first input signal is a signal representative of the fuel pressure at the output of a pump. The second signal is a signal representative of the fuel pressure in the manifold of fuel disbursement means which is supplied through a controllable valve, by the fuel pump. The third signal is a signal representative of the pressure at the inlet to the pump. The control circuit further includes a feedback path for continuously circulating fuel from the manifold to the pump inlet. In one arrangement of the fuel supply system, there is an aperture in parallel with the controllable valve and an aperture in the feedback path.

Abstract: An improved augmentor fuel supply system including a fuel source, a pump for pressurizing the fuel, a flow control means for controlling the flow and pressure of fuel to a fuel disbursement means (e.g., an augmentor) and a return path for recirculating unburned fuel. The flow control means includes a restrictor means such as a small orifice in parallel with a controllable valve. The restrictor means allows fuel to flow to the fuel disbursement means when the controllable valve is shut off. Further, according to the present invention, a second restrictor means, such as a small orifice is included in the return path. Finally, a check valve is included in the return path to ensure that fuel does not flow into the augmentor through the return path.

Abstract: A control circuit adapted to receive at least first, second and third input signals. The first input signal is a signal representative of the fuel pressure at the output of a pump. The second signal is a signal representative of the fuel pressure in the manifold of fuel disbursement means which is supplied through a controllable valve, by the fuel pump. The third signal is a signal representative of the pressure at the inlet to the pump. The control circuit further includes a feedback path for continuously circulating fuel from the manifold to the pump inlet. In one arrangement of the fuel supply system, there is an aperture in parallel with the controllable valve and an aperture in the feedback path.