Abstract: A mechanism (10) for limiting rotation of a rotatably mounted first shaft (12) in accordance with the invention includes a housing (28) in which the first shaft is rotatably supported; a torque input (14) coupled to the first shaft; and a torque output (18) coupled to the first shaft; a second shaft (30) rotatably supported by the housing and movable between a first axial position in which the second shaft does not engage the first shaft and a second axial position in which the second shaft engages the first shaft; at least one member (32) attached to the second shaft which projects radially from the second shaft; and the housing having an inner cavity (42) with at least one surface (70) which engages the at least one member which projects radially at first and second angular positions of the shafts to provide for a limited degree of angular rotation of the shafts when the second shaft is in the second axial position.

Abstract: A locking device made of two interfitting parts that holds the throttle control levers of an aircraft in their closed position when the parts are interfit. A key activated locking mechanism holds the two parts together. The throttle control levers are sandwiched between an upper transverse bar and the locking mechanism that secures the two parts to one another. An inclined surface formed mid-length of the upper transverse bar is inclined at the same angle as the throttle control levers when in their throttle closed position to confine the levers to the smallest possible space. A hemispherical-in-configuration cutaway is formed in the lower transverse bar and accommodates the yoke of the aircraft and restricts its movement.

Abstract: An aircraft pitch control system which includes a movable tail composed of a powered stabilizer which is angularly movable about a first axis, and elevators mounted on the rear end of the stabilizer which are angularly rotatable about a second axis displaced from the first axis. The stabilizer is controlled by an electric, pneumatic or hydraulically powered actuator, and the elevators are controlled manually through appropriate cables or mechanical linkage. The stabilizer actuator is controlled by movements of the elevators through an appropriate servo mechanism, so that angular movement of the stabilizer follows angular movement of the elevators. In the event of failure of the stabilizer actuator, the stabilizer is locked in a selected position by an automatic lock, and the pitch of the aircraft is controlled manually by the elevators alone.

Abstract: An automatic neutral position locking system for a control surface of an aircraft. A hydraulic prime mover is provided for moving the control surface. A locking device is capable of locking the control surface against movement. A ratchet-and-pawl device is operatively associated with a rotary drive train between the prime mover and the control surface for actuating the locking device in response to the control surface reaching a neutral position. The ratchet-and-pawl device normally is maintained in inactive condition when hydraulic pressure exists in the prime mover. A pneumatic piston-and-cylinder device, when under pressure, maintains the ratchet-and-pawl device in normally inactive condition. With a loss of hydraulic pressure, the ratchet-and-pawl device is effective to actuate the locking device in response to the control surface itself reaching the neutral position as the control surface moves under external loads.

Abstract: A shield of rigid sheet metal is of a size and shape to substantially cover the instrument panel of an aircraft. A pair of shrouds on the bottom of the shield are spaced so that each fits over one of the control columns of the aircraft, and aligned holes in each shroud are adapted to receive a padlock to lock the shield in place. The shrouds are of a length to fit closely over the control columns when fully extended to prevent any significant movement of the control column axially and pins, which are secured to the shield, extent through openings in the control columns to prevent any accidental or unauthorized turning. A cylindrical housing open at one end is received over the throttle control, and a lock stem extending vertically from the housing is received in a tube, which is fixed to the shield, when the shield is possitioned on the instrument panel so that there can be no manipulation of the throttle.

Abstract: A retainer for an aircraft rudder for holding stable such rudder during storage but which retainer will automatically remove itselt from the airplane should the airplane be taxied from its storage position without the retainer first being removed from the rudder.

Abstract: An aircraft flight control surface actuator that prevents against overtravel is provided with a lock which includes a pin (76) that is urged by spring (b 74) toward the wall (68) that is part of control gear (56) which travels along the axis of a threaded shaft (42) in response to rotation of main shaft (16). An aperture (70) in the wall (68) is aligned with pin (76) only at a neutral position of the flight control surface (12). Lever (80) depresses pin (76) against the force of spring (74) only so long as hydraulic system pressure for the actuator is supplied to cylinder (84).

Abstract: A device useful for verifying and setting the minimal resistive force setting of a collective stick in an aircraft using a collective stick is disclosed. The device is permanently attached to the collective stick and may be used by the pilot at any time. A method of setting the minimal resistive force setting on an aircraft using a collective stick is also disclosed.

Abstract: An actuator system for controlling the position of an aerodynamic control surface of an aircraft is disclosed. The actuator system (10) comprises a rotary actuator (12) rotatably mounted to the aircraft structure (20) with the actuator having an output member (22) adapted to be coupled to the control surface. A latch assembly (37) is provided which is mounted to the structure which releasably engages the actuator. Preferably, the latch assembly (37) comprises a grooved flange (38) mounted on the actuator (12) and a solenoid (47) mounted to the aircraft structure which is adapted to move a locking pin (44) from a first position in engagement with the grooved flange (38) to a second position out of engagement with the groove. In a second embodiment, a second rotary actuator (114) is mounted to the aircraft structure and is adapted to rotate the actuator (81) upon its failure and after the latch assembly is activated.

Abstract: A hydraulic actuator including a piston rod having a centering mechanism associated therewith which, upon actuation, will return the piston rod to a predetermined position even against loads and lock it in that position and hold it there even without the presence of hydraulic power. The centering and locking mechanism includes a drive mechanism and cam surfaces on the piston rod which are engaged by drive surfaces on the driving mechanism. The drive and cam surfaces are opposed ramps with one of the ramps on the drive mechanism always disposed opposite one of the ramps on the actuator, such that at any position of the stroke of the actuator piston rod the centering and locking mechanism may be actuated and is operable to return the actuator to the predetermined position and lock it in place. The cam surfaces are infinitely variable as to their position on the piston rod within the limits of the dimensions of the drive mechanism.

Abstract: A control surface lock (10) for flutter constraint of a control surface (14) of an aircraft in cooperative combination with an hydraulic actuator (12), wherein system pressure on the actuator maintains the lock in a dynamically bypassed configuration and loss of system pressure causes the lock to assume a constraint configuration providing a stiff link with the control surface, is comprised of a locking piston (82) secured to the control surface and disposed for reciprocable movement in a locking cylinder (90) upon actuation of the surface, first and second charged locking chambers (92, 94) within the cylinder disposed for series flow of fluid from one to the other upon movement of the locking piston through a bypass valve (100) biased to an open position and a flow splitter (74) having a parallel flow path from the actuator to serve for fluid exchange; wherein loss of system pressure interrupts the series flow and locks the piston in the constraint configuration for flutter protection of the control surface.

Abstract: A device for protecting the navigational instruments and radio equipment mounted on an instrument panel in the cockpit of an aircraft against theft. The device includes a protective cover mounted immediately adjacent the instrument panel and means for locking the potective cover to the control column of the aircraft in a manner such that the aircraft controls will not be damaged in the event that the protective cover is tampered with.

Abstract: The invention relates to a control column (2) for a copilot of an aircraft, coupled for control of roll and pitch by a linkage (5) to the pilot's control column (1). This linkage comprises two parallel rods (6,7) pivoted on the one hand to the column (1) and on the other hand to a member (13) connected to the column (2) by a double universal joint (14, 17). When operative, the column (2) is locked to the member (13) by a lock bolt (19). This control column can be put out of action by releasing the said bolt and can be secured by hooking to a fixed point, in which case the double universal joint (14, 17) ensures its disconnection from the column (1) and thus prevents any misoperation.

Abstract: To provide the pilot with the "feel" that he is inadvertently moving his cyclic control stick from its midposition when the helicopter is on the ground, and thereby possibly changing the rotor plane from a safe to an unsafe position for ground personnel, a restraint member is provided which includes an over-center spring, and which may be pivoted from its stowed position into an operable position where it bears against the cyclic stick so midpositioned. The over-center spring thereof offers resistance to cyclic stick motion if the pilot inadvertently begins to move the stick forward or laterally of its midposition, but the spring biasing force can readily be overcome by the pilot by manually pushing the cyclic stick forward and thereby cause the restraint member to move to its stowed position.

Abstract: A rudder gust control lock device is disclosed for securing the rudder and vertical stabilizer of single and twin engine airplanes to each other. The device includes a partial collet having a substantially U-shaped cross section and paired opposed flanges that extend from the extremities of the collet in a direction transverse to its longitudinal dimension. The collet is adapted to receive a leading edge of the rudder, and the flanges are adapted to slidably engage the adjacent surfaces of the stabilizer when the device is shifted along the rudder. A handle is included, that is attached to one of the flanges and extends in substantially the same direction as that flange, to enable the operator to grasp the device during installation and removal. A flag is also included, attached to the handle, to serve as a warning and reminder to the operator that the device is in position.

Abstract: Disclosed is a lock to lock open the speed brake doors of an aircraft to facilitate servicing the brake mechanism. The lock cooperates with lightening holes in the internal stiffening structure of the speed brake. The lock is adjustable to provide different amounts of brake opening. Surfaces of the lock that contact the aircraft speed brake structure are fabricated of resilient material to protect the aircraft.

Abstract: A device for locking the ailerons and elevators of an aircraft controlled by a wheel-operated longitudinally shiftable and rotatable control column, and, at the same time preventing theft of the navigational instruments and radio equipment mounted on the instrument panel in the cockpit of the plane. The protective device takes the form of a cover formed of two overlapping plates having an arrangement for adjusting the overall width. The adjusted cover is mounted immediately adjacent the instrument panel by means of upper and lower clamping blocks secured about the control column in such a manner as to prevent unauthorized movements of the column and access to the instruments on the panel. The blocks have complementary semi-cylindrical grooves which clamp about the control column, and one block is fixed to the cover plate while the other is hinged to the first for ready uncoupling and coupling movements.

Abstract: The device retains the ejection seat arm/dearm lever in safe position to allow the seat to be tilted safely for required maintenance and repair work. A bolt positioned through a clearance hole in an inverted U-shaped base member engages threads in the ejection seat structure. An upstanding brace extends upward from one end of the base member at an angle to abut the seat ejection arming lever to physically block and prevent its movement into the armed position. The bolt is retained in the base member by a cotter pin through the body of the bolt under the head to allow turning while preventing separation from the base.

Abstract: A device for locking the ailerons and elevators of an aircraft controlled by a wheel-operated longitudinally shiftable and rotatable control column, and, at the same time preventing theft of the navigational instruments and radio equipment mounted on the instrument panel in the cockpit of the plane. The protective device takes the form of a cover plate mounted immediately adjacent the instrument panel by means of upper and lower clamping blocks secured about the control column in such a manner as to prevent unauthorized movements of the column and access to the instruments on the panel. The blocks have complementary semi-cylindrical grooves which clamp about the control column, and one block is fixed to the cover plate while the other has sliding, tongue and groove engagement to couple with said one block and clamp the control column against movement. The pair of blocks are held in clamped arrangement by a padlock whose shackle passes through aligned apertures in the blocks.

Abstract: Means for inter-locking the two control wheels of an airplane to prevent movement or vibration of the ailerons and horizontal stabilizer when the plane is parked. Such means is in the form of a loop of cord which is looped snugly about each inboard upright arm of the two control wheels to prevent movement of the ailerons. An integral straight cord portion pulls the control wheels rearwardly sufficiently so as to raise the horizontal stabilizer and prevent it also from moving. The straight cord is anchored on the floor of the aircraft between the seats of the pilot and co-pilot.