Abstract: Systems and methods are disclosed for controlling the pitch angle of a propeller and rotor assembly that selectively limit the pitch angle according to a selected mode of operation. The system comprises a fine stop collar defining a primary channel, an oil transfer bearing (OTB) extending across the fine stop collar, and an actuator piston engaged with a propeller blade crankshaft to vary propeller blade pitch, wherein the annular piston is positioned about the OTB in fluid communication with the primary channel.

Abstract: Systems and methods are disclosed for controlling the pitch angle of a propeller and rotor assembly that selectively limit the pitch angle according to a selected mode of operation. The system comprises a fine stop collar defining a primary channel, an oil transfer bearing (OTB) extending across the fine stop collar, and an actuator piston engaged with a propeller blade crankshaft to vary propeller blade pitch, wherein the annular piston is positioned about the OTB in fluid communication with the primary channel.

Abstract: A pitch control mechanism for an open rotor gas turbine engine is provided, the engine having a first rotor assembly and a second rotor assembly, with a plurality of airfoil blades circumferentially mounted on each rotor assembly and arranged in contra-rotational relationship to each other. The pitch control mechanism includes an actuator assembly configured to be secured to a non-rotating frame of the engine, the actuator assembly having a first actuator and a second actuator, with the actuator assembly being rotationally isolatable from and couplable to the first and second rotor assemblies such that, in use, an actuation signal from the first or second actuator induces a corresponding desired change in pitch of the airfoil blades of the respective first or second rotor assembly independently of the pitch of the airfoil blades of the second or first rotor assembly.

Abstract: A pitch control mechanism for an open rotor gas turbine engine is provided, the engine having a first rotor assembly and a second rotor assembly, with a plurality of airfoil blades circumferentially mounted on each rotor assembly, and arranged in contra-rotational relationship to each other. The pitch control mechanism includes an actuator assembly configured to be secured to a non-rotating frame of the engine, the actuator assembly having a first actuator and a second actuator, with the actuator assembly being rotationally isolatable from and couplable to the first and second rotor assemblies such that, in use, an actuation signal from the first or second actuator induces a corresponding desired change in pitch of the airfoil blades of the respective first or second rotor assembly independently of the pitch of the airfoil blades of the second or first rotor assembly.

Abstract: A pitch control mechanism for an open rotor gas turbine engine is provided, the engine having a first rotor assembly and a second rotor assembly, with a plurality of airfoil blades circumferentially mounted on each rotor assembly, and arranged in contra-rotational relationship to each other. The pitch control mechanism includes an actuator assembly configured to be secured to a non-rotating frame of the engine, the actuator assembly having a first actuator and a second actuator, with the actuator assembly being rotationally isolatable from and couplable to the first and second rotor assemblies such that, in use, an actuation signal from the first or second actuator induces a corresponding desired change in pitch of the airfoil blades of the respective first or second rotor assembly independently of the pitch of the airfoil blades of the second or first rotor assembly.