Abstract: An apparatus that includes a single event latchup (SEL) recovery circuit, a microprocessor operatively connected with the SEL recovery circuit, and an output maintenance circuit that maintains a state of the microprocessor prior to a power cycle of the microprocessor. The apparatus is configured to detect a SEL event or other fault via a watchdog circuit, initiate a power cycle of the microprocessor, retain a latch state from the microprocessor, and determine whether the microprocessor was restarted due to an SEL event. Responsive to determining that the microprocessor has failed to restart due to a persistent fault, the apparatus determines whether a prepower cycle limit is reached within a predetermined span of time, and selectively provide power to a load based on the latch state and the power cycle limit determination.

Abstract: An air turbine starter includes a transfer tube having a lubrication inlet and a lubrication outlet configured to allow fluid to flow therethrough. A valve is positioned within the transfer tube including a spring. The spring is configured to selectively allow fluid flow within the transfer tube based on fluid pressure differential across the valve. The spring can have three positions: a first position configured to prevent flow within the transfer tube, an intermediate position configured to allow free flow of fluid within the transfer tube, and a compressed positioned to prevent flow to the lubrication outlet.

Abstract: A hydraulic unit includes a housing, a pump located in the housing, and a motor located in the housing and operably connected to the pump such that the motor is driven in response to fluid pressure delivered to the motor from the pump. An output shaft is operably connected to and driven by the motor and includes a body having a first end and a second opposite end, and a first flange and a substantially identical second flange integrally formed with the body of the shaft adjacent the second end. A relief is formed about a circumference of the body. A plurality of first splines are integrally formed with an exterior of the body between the second portion and the third portion, and a plurality of second splines are integrally formed with an interior surface of the body adjacent the second end.

Abstract: A splined muff is provided for use with a ram air turbine (RAT). The splined muff includes a body formed of plastic material that acts as an insulator during a lightning strike. The body is formed to define an aperture and includes an interior facing spline for engagement with a complementary exterior facing spline; and an exterior facing spline for engagement with a complementary interior facing spline.

Abstract: A ram air turbine is provided that utilizes a one-piece strut. The strut includes an integral gearbox section and an integral drive section. Within the strut, a turbine shaft and a bevel gear engages a driveshaft and a pinion gear, which transfers rotation from the turbine to a generator. The strut may be machined from a single piece of metal, such as aluminum.

Abstract: An example method of fuel delivery to a turbomachine includes reaching a light-off speed of a turbomachine and delivering fuel to a combustor of the turbomachine at a first rate. The method also increases the rate of the delivery. The combustor achieves light-off at a fuel flow rate on or in-between the first rate and a second rate that is greater than the first rate. An example turbomachine fuel delivery assembly includes a fuel delivery component and a controller configured to adjust the fuel pump to increase a rate of fuel delivery from a fuel supply to a combustor of a turbomachine.

Abstract: A sealing washer assembly includes a main washer with a bottom annular groove for a removable O-ring and a top recess for a sealing washer. A fastener such as a screw or bolt passes through the sealing washer and the main washer, into a hole in a mounting surface. When the fastener is tightened, the main washer is clamped to the mounting surface to create a metal-to-metal seal, the O-ring is deformed to create a seal between the main washer and the mounting surface, and the sealing washer is deformed to create a seal between the fastener and the main washer.

Abstract: A solid state power control includes a sensor to detect when the power control is not connected to a power source. Disconnecting the power source turns off an output stage in the power control. If the power control receives a command to turn on its output stage while the power source is disconnected from the power control or otherwise not present, logic in the power control prevents the command from reaching the output stage. When the power source is connected or reconnected to the power control, the output stage remains off until the logic detects a zero crossing in the power source, thereby preventing high inrush currents into the power control. Suppressing high inrush currents caused by power source reconnection ensures that any current trip circuitry in the power control will be activated only by short circuit conditions and not by abnormal inrush currents.

Abstract: A core assembly for an electric motor includes a heat exchanger comprising a plurality of fins. The fins define a plurality of cooling air passages that include offset fins that disrupt cooling air flow to reduce the formation of boundary layers and improve heat transfer capacity.