Abstract: An aircraft landing gear shimmy damping device for aircraft landing gear with castering may include a centering cam engaged in a curvic slot in an internal diameter of an aircraft landing gear wheel spindle when the landing gear wheel is aligned with forward ground travel of the aircraft, engaging a landing gear wheel shimmy dampener. The centering cam may be pushed out of the curvic slot when the aircraft begins to turn, disengaging the landing gear wheel shimmy dampener, and may slide back into the curvic slot and (re)engage the shimmy dampener, when the landing gear wheel is realigned with forward ground travel of the aircraft.

Abstract: Embodiments are directed to operating a multi-engine aircraft during a cruise flight condition. A first engine is put off-line during flight while allowing a second engine to continue operating. The second engine provides sufficient power to maintain the multi-engine aircraft in the cruise flight condition. An outside air temperature, a first engine temperature, and/or an engine oil temperature is monitored and, when the temperature is below a predetermined threshold, the engine oil for the off-line first engine is warmed. The off-line engine oil may be warmed by continuously or periodically cranking the first engine without restarting the first engine. Alternatively, the engine oil may be warmed using a heat exchanger, such as an air-to-oil or oil-to-oil heat exchanger, or by using electronic heaters on an oil tank.

Abstract: Embodiments are directed to a blade lock comprising a fold lock adapted to prevent folding of a rotor blade in a fold-lock position and to allow folding of the rotor blade in a pitch-lock position. The blade lock further comprises a pitch lock adapted to allow pitch movement of a rotor blade in a fold-lock position and to prevent pitch movement of the rotor blade in the pitch-lock position. A spring-loaded link pivotally connects both the fold lock and the pitch lock and is adapted to provide passive, overcenter locking in the fold-lock position. An actuator is coupled to the pitch lock and is adapted to move the pitch lock and the fold lock between the fold-lock and pitch-lock positions.

Abstract: Various implementations described herein are related to an aircraft having a multi-engine configuration with multiple engines. The aircraft may have a flight control system coupled to the multiple engines with a multi-engine interface. The flight control system may be configured to reduce fuel consumption of at least one engine of the multiple engines during reduced-engine operation by pulse modulating fuel delivery to the at least one engine of the multiple engines.

Abstract: An aircraft is described and includes a fuselage; wings attached to the fuselage; and a torque box within the fuselage, the torque box including a side panel, the side panel comprising a composite laminate material including a plurality of stiffening beads integrated therewith.

Abstract: In certain embodiments, a rotorcraft includes a first engine, a second engine, a primary engine-start system for the first engine, a fast-start engine-start system for the first engine, and a computer system. The computer system is configured to detect a failure of the second engine during a reduced engine operation (REO) flight mode in which the first engine has been intentionally shut down inflight and the second engine is to remain operational, and to automatically initiate, in response to detecting the failure of the second engine during the REO flight mode, an automatic restart of the first engine using the fast-start engine-start system.

Abstract: Propeller restraint kits for turboprop aircraft are provided which include at least one, and preferably a pair, of propeller restraint systems. Each propeller restraint system will preferably include an open-ended propeller restraint boot that may be formed of a flexible and durable fabric material which is sized and configured for placement over the tip of a propeller blade. A cowling attachment assembly is provided in the kit and is adapted to being attached to an aircraft cowling skin. A propeller boot tether strap of predetermined length interconnects the propeller restraint boot and the cowling attachment assembly. The cowling attachment assembly includes (i) a quick disconnect (QD) pin assembly connected to a terminal end of the propeller boot tether strap, and (ii) a pin receiver adapted to being positionally attached to an interior portion of the aircraft cowling skin.

Abstract: A door management system on an aircraft includes a fuselage extending along a longitudinal axis in a fore-aft direction parallel to forward flight, an opening in a sidewall of the fuselage, a door mounted on the sidewall to slide in the fore-aft direction between a closed position covering the opening and an open position revealing the opening, a cable attached to the fuselage and the door and a speed governor operatively coupled to the cable to limit a velocity of the door as it moves between the open position and the closed position.

Abstract: An aircraft nacelle includes a forward cruise inlet, a forward-cruise-inlet conduit coupled to the forward cruise inlet and operable to supply air from the forward cruise inlet to an engine housed by the aircraft nacelle, an inlet barrier filter, an inlet-barrier-filter compartment coupled to the inlet barrier filter, a plurality of gills coupled between the inlet-barrier-filter compartment and the engine and operable to be in an open state and a closed state, a filter-purge door coupled to the inlet-barrier-filter compartment and operable to be in a closed state and an open state. When the plurality of gills are in the closed state and the filter-purge door is in the open state, air from the filter-purge door flows from the inlet-barrier-filter compartment through the inlet barrier filter.

Abstract: An aircraft comprising a fuselage; a vent disposed through a bottom surface of the fuselage; and a drainage system for transporting fluid leaked from a fluid source out of the fuselage via the vent in response to a first condition, the drainage system comprising a container having a top and a bottom; and a siphon tube within the container, the siphon tube having an inlet and an outlet and comprising a 180 degree bend between the inlet and the outlet.

Abstract: An improved compound planetary gear system. In embodiments, a compound planetary gear system includes at least one planet pinion including a main shaft having a first gear for meshing with a sun gear and a second gear for meshing with a ring gear, and a carrier for supporting the at least one planet pinion. Teeth of the first gear are configured with a first helical angle with respect to a longitudinal angle of the at least one planet pinion, teeth of the second gear are configured with a second helical angle with respect to the longitudinal angle of the at least one planet pinion, the first helical angle different from the second helical angle.

Abstract: A propulsion assembly for a rotorcraft. The propulsion assembly includes a mast having an internal ledge, a raceway station and an external ridge with at least a portion of the raceway station positioned axially between the internal ledge and the external ridge. A nonintegral raceway is receivable by the raceway station to form a press fit joint between the mast and the nonintegral raceway. A mast bearing assembly includes a plurality of bearings configured to engage an outer surface of the nonintegral raceway. The internal ledge is configured to generate a nonuniform normal force between the mast and the nonintegral raceway along the raceway station that axially biases the nonintegral raceway toward the external ridge, thereby securing the nonintegral raceway at the raceway station.

Abstract: A rotorcraft has a fuselage, an engine disposed substantially laterally centrally relative to the fuselage, and an air intake system (AIS). The AIS has a first duct configured to provide streamline air flow, a second duct configured to provide streamline air flow, and a combining section configured to receive streamline air flow from each of the first duct and the second duct. The combining section is further configured to output streamline air flow.

Abstract: A machining fixture counterbore bolt fitting includes a counterbore bolt, (SHCS) screw and jam nut. The counterbore bolt defines an axial bore therethrough, sized to location clearance or sliding fit receive the screw and a counterbore sized to running fit receive a head of the screw and of a depth for the head of the screw to bear on the bottom of the counterbore. The counterbore bolt is threaded through a machining fixture to bring a distal end of the bolt into contact with a surface of a part to be machined, with the axial bore around a screw-threaded bore in a fixture mating surface of the part. The screw is threaded into the screw-threaded bore, holding the part against movement with respect to the fixture. The head of the screw bears on the counterbore bottom, pulling the fixture mating surface against the bolt shaft threaded through the machining fixture.

Abstract: A fluid level sensing system includes a mounting strip and fluid sensing nodes coupled to the mounting strip. Each fluid sensing node is switchable between a fluid present state and a fluid absent state. Each fluid sensing node includes a prism, a photoemitter and a photoreceptor. The photoemitter and photoreceptor are interposed between the prism and the mounting strip. In the absence of fluid around the prism, the photoreceptor receives greater than a threshold amount of light from the photoemitter internally reflected by the prism to switch the fluid sensing node to the fluid absent state. When the prism is covered in fluid, the photoreceptor receives less than the threshold amount of light from the photoemitter to switch the fluid sensing node to the fluid present state. A processor determines a fluid level based on the fluid detection states of the fluid sensing nodes.

Abstract: An optical system for aligning various avionics sensors and displays includes an aircraft having a nose section, a forward fuselage section, and an aft fuselage section, and at least one of a sensor, a display, a sensor substitute, and a display substitute. A laser is attached to a side of the aft section of the fuselage, and is directed toward a corresponding laser target on a laser target board. The laser target board is mounted on a frame and is positioned a distance away from the aircraft, and includes a plurality of laser targets. Between the laser target board and the laser is a reference plate which includes an aperture through which a beam from the laser passes. With the laser aligned with its respective laser target, the relative position of the sensor, display, sensor substitute, or display substitute is determined relative to known positions on the aircraft.

Abstract: A heliport docking system provides automated transport, fueling, maintenance, and logistical management of VTOLs. The heliport docking system can include a plurality of helipads that can be autonomously transported from area-to-area to assist in the logistics of heliport management and control. The helipad system can include a surface on which a VTOL can land and a controller that can perform functions related to routing, maintenance, object detection, and transport, among others. The helipad system can releasably secure the VTOL to the helipad and transport the VTOL to different areas of the heliport system. The helipad system can also fuel the VTOL by providing, electricity, combustible fuel, or other suitable energy source, and perform a maintenance check of the VTOL and create maintenance crew of any VTOL irregularities.

Abstract: A multi-mode aircraft power-split-transmission system includes a rotational power input and a power-split transmission. The power-split transmission includes a sun gear, a planetary carrier, a ring gear, a first rotational power output, and a second rotational power output. The multi-mode aircraft power-split-transmission system also includes a first resistance device coupled to the first rotational power output and fixed to an airframe of the multi-mode aircraft and a second resistance device coupled to the second rotational power output and fixed to the airframe. Operation of the first resistance device causes power received from the rotational power input to be directed to the second rotational power output.

Abstract: Methods and systems for performing a validation process on a part to be processed are provided. An identifier associated with the part is received. A listing of at least one automated process based on the identifier is displayed. An indication of a selected automated process from the listing is received. First instructions are transmitted to an automated process device for performing an automated processing program in accordance with the selected automated process. Processing results associated with the part are received from the automated process device. Second instructions are transmitted to a validation process device for performing a validation program in accordance with a validation process associated with the selected automated process. Validation results associated with the part are received from the validation process device. The processing results and the validation results are stored in association with the identifier.