Abstract: In some examples, gases are vented out of a battery compartment through an exit port defined by an antenna housing. For example, a vent line may be disposed between the battery compartment and the exit port, defining a passageway through which gases in the battery compartment can exit the battery compartment. In some examples, the battery compartment is located in an aircraft and the antenna housing is at least partially disposed an exterior of the aircraft.

Abstract: A valve assembly having a position control characteristic that is represented by an N-th order polynomial equation includes a valve housing a valve element, and a valve characterization circuit. The valve housing has at least a fluid inlet, a fluid outlet, and a flow passage between the fluid inlet and fluid outlet. The valve element is mounted on the valve housing, is disposed at least partially within the valve housing flow passage, and is movable between a closed position and an open position. The valve characteristic circuit is mounted on the valve housing, and includes a plurality of resistors. Each resistor has a resistance value representative of at least one digit in the N-th order polynomial equation.

Abstract: A turbofan gas turbine propulsion engine includes a system to transfer power from the low pressure turbine to the high pressure turbine and/or extract additional load from the low pressure turbine during certain turbofan engine operational conditions. The systems include a hydrostatic power transfer system that includes a hydraulic pump and a hydraulic motor coupled to the low pressure and high pressure turbine, respectively. The systems additionally include a mechanical and electrical load shifting/loading sharing systems that use clutches and gear assemblies to share and/or shift load between the turbines.

Abstract: The present invention provides a relatively simple way to automatically turn on and off the fuel to a starter/generator cooling system during engine start. The present invention takes advantage of a fuel pressure rise provided by an engine fuel boost pump during the period from engine start to engine idle conditions. This pressure rise is used to stroke a shutoff valve in a fuel return to tank valve (FRTTV), which shuts off the starter generator cooling fuel flow. This shutoff occurs automatically with no other external input from, for example, an engine controller. A check valve is also included that prevents back flow through the FRTTV in the event of an engine start with no aircraft pumps running.

Abstract: The present invention discloses a relatively simple system and method to reduce fuel system pumping by automatically turning on and off servo flow to various non-needed devices or “start lockout” servos during engine start. The invention takes advantage of a fuel pressure rise provided by the fuel pump during the period from engine start until the pump speed is greater than windmill. This pressure rise is used to move a pressure activated piston in a servo shutoff valve from a normally closed position to an open position, which at higher pressures allow servo flow to the “start lockout” servos through the servo lockout valve. When the pressure is reduce, the piston return to a normally closed position due to a biasing spring closing the servo lockout valve. This opening and closing of the servo lockout valve occurs automatically with no other external input.