Abstract: A turboprop engine system for an aircraft includes an engine, a propeller, and a gear train coupled to and configured to provide power from the engine to the propeller at a predetermined gear reduction. The engine system also includes a gearbox that houses at least part of the gear train. The gearbox includes a gearbox flow structure and an inlet flow structure that is removably attached to the gearbox. The inlet flow structure and the gearbox flow structure cooperate to define an inlet flow passage to the engine. The inlet flow passage has an upstream end and a downstream end that are cooperatively defined by the inlet flow structure and the gearbox flow structure. The upstream end is configured to receive an airstream that is directed along the inlet flow passage to the downstream end and toward the engine.

Abstract: A turboprop engine system for an aircraft includes an engine, a propeller, and a gear train coupled to and configured to provide power from the engine to the propeller at a predetermined gear reduction. The engine system also includes a gearbox that houses at least part of the gear train. The gearbox includes a gearbox flow structure and an inlet flow structure that is removably attached to the gearbox. The inlet flow structure and the gearbox flow structure cooperate to define an inlet flow passage to the engine. The inlet flow passage has an upstream end and a downstream end that are cooperatively defined by the inlet flow structure and the gearbox flow structure. The upstream end is configured to receive an airstream that is directed along the inlet flow passage to the downstream end and toward the engine.

Abstract: An afterburner nozzle actuation system includes a case, an actuation structure, a plurality of cam plates, a plurality of nozzle flaps and seals, and a plurality of rollers. The actuation structure surrounds at least a portion of the case and includes an aft end that has a polygonal cross section shape. The cam plates are removably coupled to an inner surface of the actuation structure, and each includes a cam surface. The nozzle flaps are rotationally coupled to the case and extend at least partially from the actuation structure aft end. Each nozzle flap is movably coupled to a different one of the cam plates. The rollers are each rotationally mounted on a different one of the nozzle flaps and engage the cam surface of one of the cam plates.

Abstract: A retention structure includes a center body including an outer surface, an enclosed end, an open end, and a contact section, the outer surface adapted to define a first portion of a flowpath, and the contact section extending radially outwardly from a centerline and located on the enclosed end and configured to reduce a radial and a torsional component of a first load that exceeds a first threshold applied to the contact section, when the turbine rotates and applies the first load to the contact section and an energy absorber coupled to the center body, disposed adjacent to the contact section, and having an outer surface adapted to define a second portion of the flowpath, the energy absorber further adapted to collapse, when the turbine rotates and contacts the energy absorber and applies a second load that exceeds a second threshold to the energy absorber.

Abstract: A retention structure includes a center body including an outer surface, an enclosed end, an open end, and a contact section, the outer surface adapted to define a first portion of a flowpath, and the contact section extending radially outwardly from a centerline and located on the enclosed end and configured to reduce a radial and a torsional component of a first load that exceeds a first threshold applied to the contact section, when the turbine rotates and applies the first load to the contact section and an energy absorber coupled to the center body, disposed adjacent to the contact section, and having an outer surface adapted to define a second portion of the flowpath, the energy absorber further adapted to collapse, when the turbine rotates and contacts the energy absorber and applies a second load that exceeds a second threshold to the energy absorber.

Abstract: A torque limiting includes first and second rotational plates, first and second springs, and a slip device. The first rotational plate is coupled to a torque input device. The second rotational plate is coupled to a drive shaft, and is configured to be movable along an axial direction thereof. The first spring has a first free length, and exerts a first spring force against the second rotational plate toward the first rotational plate. The second spring has a second free length, smaller than the first free length, and selectively exerts a second spring force against the second rotational plate toward the first rotational plate. The slip device, disposed at least partially within or between the first and second rotational plates, causes relative motion between the first and second rotational plates when torque overcomes the combined first and second spring forces exerted against the second rotational plate.

Abstract: A torque limiting includes first and second rotational plates, first and second springs, and a slip device. The first rotational plate is coupled to a torque input device. The second rotational plate is coupled to a drive shaft, and is configured to be movable along an axial direction thereof. The first spring has a first free length, and exerts a first spring force against the second rotational plate toward the first rotational plate. The second spring has a second free length, smaller than the first free length, and selectively exerts a second spring force against the second rotational plate toward the first rotational plate. The slip device, disposed at least partially within or between the first and second rotational plates, causes relative motion between the first and second rotational plates when torque overcomes the combined first and second spring forces exerted against the second rotational plate.