Abstract: An electric motor adapted to apply torque to a drive shaft rotatable about an axis, the electric motor includes a stator, a rotor adapted to rotate relative to the stator, a primary bearing interoperably coupled to the stator and adapted to provide bearing support between the stator and the rotor, an auxiliary bearing interoperably coupled to the drive shaft, an annular shear adapter connected to the primary bearing and the auxiliary bearing, and a shear pin interoperably coupled to the primary bearing via the annular shear adapter and configured to break responsive to torque between the annular shear adapter and the drive shaft exceeding a predetermined torque threshold.

Abstract: A spinner is described that can provide aerodynamic advantages for vertical takeoff and landing (VTOL) aircraft. The spinner can be shaped with multiple faces divided by chines. The chines can run down the edge of the spinner to fairings that can cover rotor blades and/or couplings between rotor blades and the rotor hubs of the aircraft. During forward flight the rotor blades can be folded down into recesses on the spinner. The spinner and fairings can provide aerodynamic advantages in addition to protection for sensitive components within the rotor and blades apparatus. This improves efficiency and allows the aircraft to fly faster.

Abstract: A method of simulating an aircraft one-engine inoperative (“OEI”) event includes operating a supplemental power unit (“SPU”) at a first SPU power level less than an SPU contingency power rating, operating a primary engine at a first primary-engine power level, reducing the primary-engine power level to less than the first primary-engine power level, and maintaining a sum of the primary-engine power level and the SPU power level at a power level substantially equal to the SPU contingency power rating.

Abstract: A control system for a multi-rotor aircraft is described that results in lower operating noise. Allowing blades to flap during flight reduces aerodynamic interference as blades pass by other aircraft components, such as wings or the fuselage. Pitch links coupled to a rotational swashplate can be used to allow flapping during flight. The swashplates can allow the canting of the rotors to change a rotational or out-of-plane angle of the blades to decrease noise.

Abstract: Embodiments are directed to systems and methods for estimating wear in aircraft rotor systems. Data associated with loads and motions of a swashplate actuator is collected. The swashplate actuator drives a swashplate and at least one control link is coupled to the swashplate. The loads and motions of the at least one control link is estimated based upon the loads and motions of the swashplate actuator. Using a wear model, the current wear of control link components is estimated due to the loads and motions of the at least one control link. Wear estimates for the components are aggregated across multiple flights and used to determine when maintenance actions should occur.

Abstract: A retractable cargo hook for aircraft is described. The cargo hook comprises a torsion spring allowing rotatable attachment to an aircraft body. An optional recessed portion of the aircraft body can house and receive the cargo hook. This can protect interior components from crashes which can push the cargo hook into the aircraft fuselage, damaging components.

Abstract: A system for monitoring of elastomeric bearings is described. A pattern or shape can be applied to a joint comprising elastomeric material. A camera can be disposed such that it can capture photographs or video of the pattern and how it deforms under torque and other stresses. Actual deformation of the shape/pattern can be compared to an expected deformation to gauge levels of degradation of the elastomeric material or other joint components.

Abstract: A torque measurement system determines torque on a shaft by monitoring angular deflection of the shaft under load using phase shift measurements. Calibration of the system uses a defined offset that is determined using a reference operating condition. The offset calibration value is determined for a rotorcraft using the following steps: defining a reference operational condition in which the shaft is rotating, estimating the torque at the reference condition based on aerodynamic knowledge of the rotors coupled to the shaft, operating the shaft at the reference operational condition, capturing sensor data to determine the phase difference at the operational condition, and associating the phase difference and an estimated torque as a calibration value to enable calculation of torque in the torque measurement system.

Abstract: Tail rotor control system is described for helicopters. A pedal position sensor operable by a pilot yields greater tail rotor RPM relative to the main rotor RPM, giving the pilot increased control over the vehicle. This proves especially useful in certain situations, such as high altitude, where increasing tail rotor speed from main rotor speed can give a pilot increased maneuverability and stability.

Abstract: A method and system for controlling a fluid valve are described that avoid the effects of hysteresis. In hysteresis, the power signals associated with a valve position are different on the upstroke and downstroke. As a result, predicting the valve position can be difficult if you only know the current power signal. Instead of using upstrokes and downstrokes, a valve can momentarily be set to zero power, or a rest position when receiving a new command signal. This way the command signal is applied from a zero power or rest position, making the valve position more predictable and accurate.

Abstract: A safety system for aircraft passenger seats is described. A pallet that can be removably coupled to seats can also be removably coupled to the aircraft floor and one or more brackets, tension fittings, or machined straps that can be coupled to structural beams or components in an aircraft. A keel tension fitting can be attached to a keel beam and then be coupled to the pallet and thereby the seats. By attaching to the keel beam the safety system allows the seating arrangement (pallet and seats) to withstand greater stresses and forces, resulting in increased safety.

Abstract: An aircraft thermal hydraulic active-warming system includes an active thermal-warming valve interoperably coupled between a hydraulic pressure line and a hydraulic low-pressure return line and a hydraulic actuator arranged in parallel with the active thermal-warming valve between the hydraulic pressure line and the hydraulic low-pressure return line.

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: 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: 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: 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: 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: 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 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.