Abstract: A gas turbine engine and method and control therefor particularly useful as the power plant for a ground vehicle. The gas turbine engine is of the free turbine type, and employs variable guide vanes to control the free turbine output. The guide vane control system is a combined hydromechanical and electronic control system to automatically regulate the guide vanes for both power regulation and braking modes.

Abstract: An electrohydraulic proportional actuator for converting an electrical input signal to proportional mechanical output. Fluid power may be derived from pressurized fuel or lubricating oil of an associated engine. The actuator may be used to drive any engine function requiring modulated control. The mechanical output is proportional to the electrical input. The actuator includes mechanical feedback to linearize the response function, thus eliminating the need for closed loop operation of the system in which the actuator is used. Both linear and rotary actuators are disclosed in various embodiments. Each type is capable of operation with either a proportional solenoid and valve or a force rebalance solenoid and valve.

Abstract: An electrohydraulic proportional actuator for converting an electrical input signal to proportional mechanical output. Fluid power may be derived from pressurized fuel or lubricating oil of an associated engine. The actuator may be used to drive any engine function requiring modulated control. The mechanical output is proportional to the electrical input. The actuator includes mechanical feedback to linearize the response function, thus eliminating the need for closed loop operation of the system in which the actuator is used. Both linear and rotary actuators are disclosed in various embodiments. Each type is capable of operation with either a proportional solenoid and valve or a force rebalance solenoid and valve.