Abstract: A system is provided for reducing ice mass on an aircraft engine. A compressor inlet temperature and pressure sensor measures total temperature and total pressure at the inlet to the engine compressor. An ice shield is provided, wherein a plurality of wedge portions has multiple protrusions for promoting ice formation in multiple locations. The ice shield is separable from the sensor with which it interfaces. The ice shield comprises straight angle wedge shapes and curved surfaces to separate and minimize ice accretion in desired locations. The mass of each resultant ice formation is reduced to a size that the compressor inlet blades can withstand without deformation.

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.

Abstract: The invention relates to a control system which controls the diameter of a turbine shroud which surrounds a turbine in a gas turbine aircraft engine. The invention seeks to minimize the clearance between the turbine rotor and the shroud. Air is bled from the compressor in the engine and ducted to the shroud in order to heat or cool the shroud in order to, respectively, either expand or shrink the shroud to a proper diameter. The air temperature which is required is computed based on compressor speed and other engine parameters, but not upon directly measured rotor temperature, despite the fact that rotor temperature has a significant influence upon rotor diameter, and thus upon shroud diameter needed. Air at two different temperatures is bled from two different compressor stages in the engine and mixed together in a ratio which is determined according to flight conditions, in order to provide air of the required temperature for the shroud, and then ducted to the shroud in order to modify shroud size.