A compound harmonic drive assembly includes a ring gear assembly, a wave generator, a flex spline, and a rolling element. The wave generator is received within the ring gear assembly along the rotational axis. The wave generator has a body that extends radially between an exterior surface and an interior surface. The body defines at least one groove that extends radially from the exterior surface towards the interior surface. The flex spline is disposed between the ring gear assembly and the wave generator. The rolling element is disposed between the wave generator and the flex spline.

A compound harmonic drive assembly includes a ring gear assembly, a wave generator, a flex spline, and a rolling element. The wave generator is received within the ring gear assembly along the rotational axis. The wave generator has a body that extends radially between an exterior surface and an interior surface. The body defines at least one groove that extends radially from the exterior surface towards the interior surface. The flex spline is disposed between the ring gear assembly and the wave generator. The rolling element is disposed between the wave generator and the flex spline.

A monitoring system includes a movable surface of an aircraft, an actuation system for the movable surface of an aircraft including actuators, a first position sensor adapted to measure a position of a first actuator of the actuators and a second position sensor adapted to measure a position of a second actuator of the actuators. The monitoring system also includes a first force sensor adapted to measure forces passing through the first actuator of the actuators and a second force sensor of the at least two force sensors being adapted to measure forces passing through the second actuator of the actuators. The monitoring system also includes a calculator configured to detect skew of the movable surface and excess force passing through the first and/or second actuator from the position obtained by the at least two position sensors and the force measured by the at least two force sensors.

An aircraft, a control surface arrangement, and a method of assembling an aircraft are disclosed herein. In an exemplary embodiment, the aircraft includes, but is not limited to, an airframe, a control surface, and a rotary actuator. The rotary actuator rotatably mounts the control surface to the airframe. The rotary actuator supports the control surface on the airframe and is configured to rotate the control surface with respect to the airframe when the rotary actuator is actuated. The rotary actuator is further configured to deliver torque to the control surface from a longitudinally intermediate portion of the rotary actuator.

An aircraft, a control surface arrangement, and a method of assembling an aircraft are disclosed herein. In an exemplary embodiment, the aircraft includes, but is not limited to, an airframe, a control surface, and a rotary actuator. The rotary actuator rotatably mounts the control surface to the airframe. The rotary actuator supports the control surface on the airframe and is configured to rotate the control surface with respect to the airframe when the rotary actuator is actuated. The rotary actuator is further configured to deliver torque to the control surface from a longitudinally intermediate portion of the rotary actuator.

A combined active stick and control boost actuator system for a control surface has a control stick engaged to a mechanical flight control structure with a linkage configured to move a control surface. A mechanical interconnect engages the linkage and has a control stick connection. An integrated actuator is separably connected to the mechanical interconnect intermediate the control stick connection and the linkage. A stick force sensor is configured to provide a stick force signal. A flight control system receives the stick force signal and provides an actuator position control signal to the integrated actuator. The integrated actuator moves to a prescribed position in accordance with a force feel profile providing pilot variable tactile cueing and power boost to reduce both fatigue and workload.

A wing (5) for an aircraft (1) and include a fixed wing (7), a high lift system (9) including a high lift surface (27) movably mounted to the fixed wing (7), and a high lift actuation system (29) for moving the high lift surface (27) relative to the fixed wing (7) between a retracted position and at least one deployed position, a foldable wing tip portion (11) mounted to the fixed wing (7) pivotally about an axis of rotation (35) between an extended position and a folded position, a tip actuation unit (13) for moving the foldable wing tip portion (11) between the extended position and the folded position. The object to provide a simple, cost-efficient and light-weight wing, is achieved in that the high lift actuation system (29) is drivingly coupled to the tip actuation unit (13) to provide power to the tip actuation unit (13)

A method of prognostic health monitoring is provided for use with an aircraft. The method includes generating torque for controlling positions of controllable surfaces at right- and left-hand-sides (RHS and LHS) of the aircraft in a power drive unit (PDU) based on torque-limiter (TL) thresholds, performing real-time monitoring of the torque at the RHS and LHS of the aircraft, generating RHS and LHS torque information from results of the performing of the real-time monitoring, analyzing the RHS and LHS torque information and controlling operations of the PDU based on results of the analysis by at least one of modifying, tuning and defining the TL thresholds.

Underwing-mounted trailing edge bifold flaps for wings of aircraft are disclosed. A bifold flap pivotally coupled to the wing is movable between a stowed position located along a lower surface of the wing and a deployed position located rearward of a trailing edge of the wing. The bifold flap includes a forward panel and an aft panel. The aft panel is pivotally coupled to the forward panel and foldable relative thereto. The aft panel is folded toward the forward panel when the bifold flap is in the stowed position. The aft panel is unfolded from the forward panel when the bifold flap is in the deployed position. A bullnose pivotally coupled to the forward panel pivots relative to the bifold flap as the bifold flap moves between the stowed and deployed positions.

Described herein is a system that includes an actuator with a movable input, a first summing mechanism with an input, a first output, and a second output. The input of the first summing mechanism is movably driven by the movable input of the actuator and the first output of the first summing mechanism is movably coupled to a first actuatable element. The system also includes an end mechanism with an input and a first output. The input of the end mechanism is movably driven by the second output and the first output of the end mechanism is movably coupled to a second actuatable element. The system further includes a sensor that senses a position of the rotational input of the actuator. A status of the first and second actuatable elements is based on a sensed position of the movable input of the actuator.