A helicopter autopilot system includes an inner loop for attitude hold for the flight of the helicopter including a given level of redundancy applied to the inner loop. An outer loop is configured for providing a navigation function with respect to the flight of the helicopter including a different level of redundancy than the inner loop. An actuator provides a braking force on a linkage that serves to stabilize the flight of the helicopter during a power failure. The actuator is electromechanical and receives electrical drive signals to provide automatic flight control of the helicopter without requiring a hydraulic assistance system in the helicopter. The autopilot can operate the helicopter in a failed mode of the hydraulic assistance system. A number of flight modes are described with associated sensor inputs including rate based and true attitude modes.

An actuation system for a control surface for an aircraft includes a first, second, third and fourth actuator, a first and second bell crank, and at least one push pull rod system. Each of the first and second bell cranks comprises a first and a second crank arm, the first and second crank arms intersect with and are joined to each other at an intersection, the first and second crank arms extend from the intersection at an angle to each other, the first bell crank is pivotally connected to the sub-structure by a first pivot extending through the first bell crank's intersection, and the second bell crank is pivotally connected to the sub-structure by a second pivot extending through the second bell crank's intersection.

Various flight control components can be operated through gearbox driven rotary actuators. In the event of a jam occurring the gearbox, the gearbox can be decoupled from a surrounding support housing to enable free-trailing or limited motion relative to the support housing. The motion may or may not be damped. Decoupling the gearbox enables the flight control component to move to a neutral or non-interfering position even when user control over the component has been lost.

An assembly comprising a first part and a second part, the assembly comprising a disconnectable coupling system provided with a mechanical fuse for securing the first part and the second part according to an axis of movement up to a breaking threshold. The assembly comprises at least one single-use friction brake interposed between the first part and the second part, the friction brake braking a movement of the first part with respect to the second part after the mechanical fuse has broken.

An actuator system for actuating movement of a control surface of an aircraft wing includes a common input rail connectable to a means for providing movement to said input rail. The system also includes: a plurality of rotary geared actuators “RGAs”; a common output rail connectable to said control surface; wherein each of said plurality of RGAs is connected to said input rail by an individual input clutch and also connected to said output rail by an individual output clutch, and wherein the input clutch functions independently of the output clutch.

Example flap actuation systems and related methods are disclosed herein. An example flap actuation system includes a first actuator, a second actuator, a first drive arm coupled to the first actuator and to a flap, a second drive arm coupled to the second actuator and to the flap, a first cam, and a first output shaft. The first cam is to couple to the first drive to enable the first actuator to actuate the flap via the first drive arm. The example flap actuation system includes a second cam and a second output shaft. The first cam is to be uncoupled from the first drive arm in response to a failure of the first actuator. The second actuator is to actuate the flap via the first drive arm and the second drive arm in response to the failure of the first actuator.

An actuator assembly includes a primary load path for tightly coupling an actuated surface to a reference structure, and a secondary load path having a backlash portion for coupling the actuated surface to the reference structure with backlash, wherein the secondary load path is unloaded during an operative state of the primary load path and loaded during a failure state of the primary load path. A first sensor is configured to sense relative displacement between a portion of the primary load path and a portion of the secondary load path. A controller is operatively coupled to the first sensor, the controller configured to determine a load on the primary load path based on relative displacement sensed by the first sensor.

Example flap actuation systems and related methods are disclosed herein. An example control surface actuation system includes processor circuitry to cause a first actuator to generate an output to operatively couple the first actuator to a first drive arm; cause a second actuator to generate an output to operatively couple the second actuator to a second drive arm; cause the first actuator and the second actuator to move a control surface when the first actuator and the second actuator are in an operative state; detect the first actuator as in a failed state; and in response to the first actuator being in the failed state, cause first actuator to refrain from generating the output to disrupt the operative coupling between the first actuator and the first drive arm; and cause the second actuator to move the control surface via the first drive arm and the second drive arm.

An actuator for aviation applications, in particular for adjusting rotor blades in a helicopter, may include an electromechanical drive assembly connected to an output drive via a downstream transmission, where the drive assembly is divided into sub-drives that can be operated independently, and where at least two sub-drives are spatially separated from one another in that the transmission is placed between these sub-drives. The transmission may include at least two harmonic gearings coupled to one another by at least one first coupling element, where a first harmonic gearing is located inside a non-rotating first housing, where a second harmonic gearing is located inside a rotating second housing, and where the second housing is connected to the output drive.

A linear electromechanical actuator with a main screw-nut assembly driven by a main motion device and having a hollow screw with an abutting surface; an anti-jamming piston arranged coaxially within the screw and shiftable between an engaged position in which locking dogs interfere with the abutting surface and a disengaged position in which the piston is free to slide within the screw; and actuating elements configured to shift the piston from the engaged to the disengaged position upon electrical or mechanical failure of the actuator. The actuating elements include a key axially movable between the engaged and disengaged positions and having a locking section, configured to bias the locking dogs into interference with the abutting surface in the engaged position, and an unlocking section, configured to allow free sliding of the piston within the screw in the disengaged position. An anti-jamming device for operating a critical flight control surface.