Abstract: A rotorcraft has a drive system including a main rotor coupled to a main rotor gearbox to rotate the main rotor at a rotor speed, a main engine coupled to the drive system to provide a first power, a supplemental engine coupled, when a first clutch is engaged, to the drive system to provide a second power additive to the first power, and a control system operable to control the main engine and the supplemental engine to provide a total power demand, where the main engine is controlled based on variations in rotor speed and a power compensation command to produce the first power, and the supplemental engine is controlled to produce the second power in response to a supplemental power demand.

Abstract: A method of operating an aircraft includes providing a fuel cell system to power the aircraft, providing an airflow path through the fuel cell system, sensing a change mass air flow rate supplied to a compressor of the fuel cell system, and at least one of adjusting a restriction of airflow entering the airflow path in response to the sensed change in mass air flow rate, adjusting a restriction of airflow exiting the airflow path in response to the sensed change in mass air flow rate, and adjusting an air scoop to gather a different amount of air into the airflow path. A method of operating an aircraft includes sensing a change in ambient pressure supplied to an airflow path and adjusting a restriction of airflow exiting the airflow path in response to a sensed change in ambient pressure.

Abstract: An electric tandem rotorcraft is disclosed. The tandem rotorcraft can include a forward and an aft electric rotor assembly operably coupled to a fuselage of the rotor craft. The aft rotor assembly can be coupled to the fuselage via a tail structure. The rotorcraft can include a wing assembly that can be operably rotatable between a vertical lift configuration and a horizontal flight configuration. The wing assembly can be disposed between and/or below planes of rotation of the forward and aft rotor assemblies. The forward and aft rotor assemblies can have planes of rotation that overlap one another and may or may not intermesh. The forward and aft rotor assemblies can also be distanced such that their respective planes of rotation do not overlap.

Abstract: In an embodiment, a method of automatically generating an inspection program includes receiving input data related to an object to be inspected. The input data includes geometric dimensioning and tolerancing data for the object. The method also includes, for each of a plurality of surfaces of the object, generating at least one inspection direction and a plurality of inspection points based, at least in part, on the geometric dimensioning and tolerancing data. The method also includes generating transitional motions for an inspection machine to inspect the plurality of surfaces according to the inspection directions and the inspection points. The method also includes storing, at a destination, machine-readable code for inspecting the object according to the at least one inspection direction of each of the plurality of surfaces, the inspection points of each of the plurality of surfaces, and the transitional motions.

Abstract: In an embodiment, a method for automatically generating object inspections includes generating a preliminary list of inspection directions for an object to be inspected. The method also includes checking a compatibility of the preliminary list of inspection directions with each of a plurality of surfaces of the object. The method also includes creating a master set of direction-surface pairs responsive to the checking. The method also includes selecting candidate inspection points for each direction-surface pair in the master set of direction-surface pairs. The method also includes, responsive to a determination that the plurality of surfaces each have at least one compatible inspection direction indicated in the master set of direction-surface pairs, generating an optimized set of direction-surface pairs using a minimization algorithm. The method also includes returning the optimized set of direction-surface pairs and corresponding inspection points.

Abstract: A method of constructing a fuel cell system includes providing an open cell structure to form a first end plate, filling at least part of the open cell structure with a stiffening material, disposing a fuel cell stack between the first end plate and a second end plate, and compressing the fuel cell stack by moving the first end plate toward the second end plate. A fuel cell system includes a first end plate comprising an open cell structure, a second end plate, and a fuel cell stack compressed between the first end plate and the second end plate.

Abstract: A gimbaled rotor assembly for an aircraft. The gimbaled rotor assembly including a static mast; a spherical bearing comprising an inner component and an outer component pivotable relative to each other about a bearing focus, the inner component fixedly coupled to the static mast; a rotor hub rotatably coupled to the outer component, allowing for relative rotation of the rotor hub about a rotor axis and for pivoting together with the outer component about the bearing focus; and a primary hub spring coupling the outer component to the static mast and configured for opposing pivoting of the rotor hub about the bearing focus from a neutral position.

Abstract: A battery cell assembly, including a cell having a first electrode and a second electrode rolled together to form a cylindrical shape; a first end cap disposed on a first end of the cell and contacting the first electrode; a second end cap disposed on a second end of the cell and contacting the second electrode; and a jacket configured to couple the first end cap and the second end cap to the cell, the jacket made from a non-conductive material.

Abstract: A fitting for securing a rotor blade in pivotable engagement with a yoke that is coupled to a mast of an aircraft for rotation therewith about a mast axis has a body that extends from an inboard end to an outboard end. The body of the fitting has an opening that extends into the body from the outboard end and that is adapted to receive a root end of the blade. The body further has a first bearing race that is defined along an outer surface of the body and is located between the inboard and outboard ends. The body further has an array of apertures that is located between the inboard end and the first bearing race, each aperture adapted to receive a respective fastener for retaining the blade within the opening.

Abstract: A battery cell assembly, including a rolled cell formed from a first electrode and a second electrode rolled together about a longitudinal axis. The rolled cell includes a primary section in which the first electrode and the second electrode overlap in a radial direction from the longitudinal axis, and a first extension end extending from a first longitudinal end of the primary section and formed from a first edge section of the first electrode. The first edge section includes a first folded portion folded to contact an adjacent portion of the first edge section. The battery cell assembly further includes a first end cap coupled to the rolled cell and contacting the first folded portion.

Abstract: Embodiments are directed to systems and methods for utilizing a two-degree-of-freedom model-following control law within an architecture of nested loop functions. This allows for the separation of command and feedback path requirements and enables the restrictions of the inner loops to be applied to the outer loop feedbacks. This method of restriction allows a better allocation of coordinated authority between the loops.

Abstract: A system for optimizing engine air-mass-flow intake of an aircraft includes a forward-facing airframe-inlet duct interoperably coupled to an inlet of an engine of the aircraft, an air-mass-flow bypass mechanism coupled to the forward-facing airframe-inlet duct and adjustable to allow a selected amount of air entering an inlet of the forward-facing airframe-inlet duct to bypass the inlet of the engine, and an air-pressure sensor arranged in the forward-facing airframe-inlet duct adjacent to the inlet of the engine. A measured value (“PT1”) from the air-pressure sensor is used to determine a degree to which the air-mass-flow bypass mechanism is to be opened.

Abstract: A method of optimizing engine air-mass-flow intake of an aircraft includes determining air mass flow (“M1”) at a forward-facing airframe inlet duct. The forward-facing airframe inlet duct includes an air-mass-flow bypass mechanism. The method also includes determining required air mass flow (“MR”) of an engine coupled to the forward-facing airframe inlet duct, determining an air-mass-flow difference (“M3”) between M1 and MR, and adjusting the air-mass-flow bypass mechanism to pass M3 such that at least a portion of M3 does not reach the engine.

Abstract: A rotorcraft includes a substantially rigid structural body. The structural body has an internal cavity and an aperture extending entirely through the structural body. The rotorcraft further includes at least one of a tail boom and a fuselage. The rotorcraft further includes a propulsion device disposed at least partially within the internal cavity and at least partially within the aperture. The propulsion device is carried by the structural body so that forces are transferred from the propulsion device to at least one of the tail boom and the fuselage via the structural body.

Abstract: An exemplary rotorcraft lockout system includes a main rotor lockout comprising a base operable to be attached to a bottom surface of a fuselage and a first and a second tension arm operable to be connected to the base and a main rotor hub, and a tail rotor lockout including a clamp operable to connect to a horizontal stabilizer, a rotor arm connector operable to connect to a tail rotor hub, and a tail rotor tension arm operable to interconnect the clamp and the rotor arm connector in tension.

Abstract: An exemplary aircraft transport jack includes a vertical structure having a vertical axis, a bottom end, and a top end, a connector above the bottom end operable to detachably secure the vertical structure to an aircraft member, a wheel assembly with wheels positioned on opposing sides of the vertical structure, and an actuator coupled to the vertical structure and the wheel assembly and operable to move the wheel assembly axially relative to the vertical structure between a lowered position with the wheels on a ground and a raised position with the bottom end on the ground and the wheels above the ground.

Abstract: An exemplary pitch link centering tool includes a rod having a longitudinal axis, a front face, a rear face, a first rod end and a second rod end, the first rod end having a first aperture with a first rotational axis, the second rod end having a second aperture with a second rotational axis, a first connector coupled to the first rod end, the first connector having a first slot extending in a first radial direction relative to the longitudinal axis and a second connector coupled to the second rod end, the second connector having a second slot extending in a second radial direction relative to the longitudinal axis different from the first radial direction.

Abstract: An off-highway recreational vehicle includes side-by-side passenger and driver seats held within a chassis. The seats sit low in the chassis and are covered by a roll-over protection system (ROPS). The vehicle is powered by an engine rearward of the seats that utilizes a continuously variable transmission (CVT) to provide power to the ground engaging members, wherein the CVT is cooled via air captured by a CVT intake body located adjacent the driver-side seat, between the frame and external panels of the utility vehicle.

Abstract: A method of adjusting a directional movement ability in an aircraft having two or more rotors includes receiving a desired thrust demand for each rotor of the two or more rotors, comparing the desired thrust demands to determine a maximum thrust demand, determining whether the maximum thrust demand exceeds a maximum thrust limit of the two or more rotors, and adjusting each desired thrust demand based on whether the maximum thrust demand exceeds the maximum thrust limit to provide an adjusted thrust demand for each rotor of the two or more rotors. Each rotor can be operated based on a respective adjusted thrust demand.

Abstract: A blade pitch adjustment mechanism includes a pitch cylinder having a first face and pitch slots extending longitudinally from the first face, a blade sleeve having a second face and a blade slot extending longitudinally from the second face, the blade sleeve is configured to be rotationally positioned in the pitch cylinder with the second face located with the first face, wherein the blade slot and the pitch slots are cooperative to form keyway, corresponding to a discrete blade pitch, when the blade slot is aligned with a pitch slot.