Abstract: The present invention provides a door operating system for opening and closing a door covering an exit opening of an aircraft. More particularly, the present invention provides a door operating system for opening and closing a plug type door typically located on the lower passenger deck of an aircraft. The door operating system includes a frame that is connected to the door of the aircraft and defines a pivot for the door. Connected to the frame is a torque drum and linkage system. The door operating system also includes a motor and a cable drum attached to the opposite end of the track. A cable is connected to the cable drum, the torque drum, and the frame. When opening the door, the motor turns the cable drum, which thereby pulls the cable. The cable rotates the drive torque drum and causes the door to be rotated about the pivot thereby moving the door upwardly and inwardly away from the exit opening.

Abstract: A robust mechanical reversion system which provides the ability to fly and land in the absence of any fly-by-wire controls and which is transparent to the pilot during normal operation. The described invention provides a mechanism which includes redundant linear variable differential transmitters (LVDT) which generates a transmitted signal in proportion to the displacement of the control apparatus in the cockpit. The signal is fed to the flight control computer which determines the magnitude of the change represented by the signal and in turn, commands both the control surface servo actuators as well as an electrical mechanical servo actuator (EMA) located in close proximity to the flight compartment and coupled to the mechanical system to move in proportion to the change.

Abstract: In a mechanically redundant actuator system, the actuator has a structurally redundant members for attaching it between a stationary anchor point to a movable control surface. Specifically the actuator consists of a cylinder body, a double action piston with a piston rod attached to the control surface at one end and a swivel bar at the other end. Single or multiple tie rods are attached between the swivel bar and the movable control surface. Each tie rod can withstand one half the load of the piston rod. Also, trunnion links attach the cylinder body to the structure. Each trunnion links can withstand the full limit load with or without any load factors. The trunnion fittings can be any configuration that provides a structural reaction, and provides a dual load path and freedom of movement in at least two axes. At least two of these actuator units are required per surface. Also, a dual tandem control valve with a hydraulic compensator for each actuator is required.

Abstract: In an aircraft control system a standby cable system which does not significantly affect existing control system friction, but detects when the primary cables are severed and actuates an alternative elevator control mechanism. The standby cable loop of the instant invention consists of two similar type mechanisms located outside the uncontained rotor or propeller shrapnel area. One mechanism attaches to the primary cables and is located forward of the engine and the other is located aft. Each mechanism operates such that negligible friction is added because during normal control motions the standby cable loop does not move, only individual elements input cranks are in motion. The primary cables are provided with an index cable that is routed close to and parallel to the primary cables. In the event the engine shrapnel cuts the primary cables, the index cable will also be cut because of its close proximity to the primary cables and due to the fact it is of smaller size.

Abstract: A drive system for high-lift devices on aircraft having two power drive units, one at each end of the connecting torque tube system, so as to force sum the outputs. A one-way brake always insures against inadvertent retraction of the device but allows extension. An asymmetrical protective device prevents the high-lift device from an asymmetrical condition even after a combined power loss and mechanical failure of the torque tube. The power drive units consist of hydraulic motors driving through a gear box and a no-back brake combination and are controlled by a servo valve.

Abstract: A mechanical power transmission apparatus, of the differential gear type, for actuating an airplane control surface requiring two independent actuator inputs to a single control surface. Asymmetric loading to the control surface is accommodated by a mechanical fuse link. The fuse link is provided by employing a shear pin to attach the pinion gear to the pinion shaft, designed to fail at a predetermined differential torque between the two driven bevel gears. Positive disengagement of the gears is provided following fuse link release.