Abstract: A leading edge flap system for an airplane includes a flap which is rotated about a single hinge point between (i) a retracted position, (ii) an intermediate extended position for high speed maneuvering, and (iii) a fully extended position for low speed maneuvering. In the high speed intermediate position, there is no slot between the flap and the wing leading edge. This position provides additional lift to improve the airplane's turning performance. On the other hand, in the low speed fully extended position, the flap is rotated a greater amount than in the intermediate extended position. In this position there is a slot between the flap and the fixed leading edge to permit air to flow from the bottom of the flap upward and over the upper surface of the leading edge. This improves the lateral stability of the airplane when in a sideslip during stall conditions.

Abstract: A system for controlling the tab (6) of an aircraft control surface (3) having a pair of position sensors (12 and 15) that supply information regarding the turning of the control surface (3) and the position of a jack (13), respectively, on the basis of signals generated by the sensors (12 and 15) as well as possibly on the basis of at least one parameter (p) originating from the aircraft, such as airspeed, positions of lift-augmenting devices, forces exerted by the pilot on a control, etc., and which formulates a command for the jack (13).

Abstract: A fault tolerant actuation system (12) for flight control systems is provided. The fault tolerant actuation system (12) includes a plurality of primary flight computers (14a, 14b, and 14c) with corresponding power control units (24a, 24b, and 24c). Each power control unit includes a remote electronic unit (18a, 18b, and 18c), an electro-hydraulic servo valve (26a, 26b, and 26c), and an actuator (28a, 28b, and 28c). The actuators are linked to a flight control surface (30) to control its position. The electro-hydraulic servo valves (26a, 26b, and 26c) and the actuators (28a, 28b, and 28c) include sensors that monitor their operation. Each RE (18a, 18b, and 18c) generates a control current (i.sub.1, i.sub.2, and i.sub.3) based upon commands of the corresponding primary flight computer as well as feedback data transmitted from the sensors of the corresponding electro-hydraulic servo valve and actuator only. The feedback data is transmitted along separate servo loops having separate compensations (66a, 70a).

Abstract: An aircraft control mechanism for a speed brake includes a shaft, an outer sleeve surrounding the shaft and a sprag clutch. The mechanism also includes input and output elements and a control element with the input element tied to the outer sleeve. The control element is tied to the shaft and the output is operatively connected to the output of the clutch. A control cable is connected to the output for moving a speed brake between a first and a second position. A manual input actuates the control element of the clutch. An automatic input is connected to the outer sleeve through a torsional dampening device which minimizes chatter or sticking due to high forces which are required to extricate the sprag clutch from a relatively high racked-in load.

Abstract: A method and apparatus for producing a dynamic thrust asymmetry airplane rudder compensation command with no direct thrust measurement is disclosed. An excess thrust estimate based on measured acceleration along the flight path of the airplane and measured vertical speed of the airplane is low pass filtered (11) to attenuate noise from the inertially derived data. The low pass filtered data is further filtered by a washout filter (15) to produce data that is sensitive only to changes in the excess thrust estimate. The input to the washout filter is frozen (13) and the output of the washout filter reduced to zero if the go-around or flare modes of the control system of the airplane are active or if the thrust asymmetry compensation feature of the primary flight computer is armed. The output of the washout filter is also zeroed when both engines are running, or multiplied by either -1 or +1 when one engine is out. Whether the multiplication is by -1 or +1 depends upon which engine is out.

Abstract: A method and apparatus for detecting oscillatory phenomena indicative of airflow separation or sensor common mode oscillatory failure is disclosed. The oscillations of a differential pressure transducer that senses the pressure difference on the opposite sides of an airfoil are bandpass filtered to remove oscillations lying outside of a band of interest. Oscillation peaks lying within the passband that exceed a positive or negative threshold produce pulses that are counted. The counter value is decremented each time an alternating peak is not detected within one-half cycle of a minimum frequency. If the allowable count threshold is exceeded, a latch is set. Setting the latch produces a command that can be used to inhibit the operation of systems that rely on data produced by the differential pressure transducer. An alternative path senses the position of a control element (e.g.

Abstract: A geared rotary actuator comprises at least two axially aligned compound epicyclic gear trains driven by an input shaft so that output ring gears in each train rotate relatively. Sun gears in adjacent gear trains are drivingly coupled to the input shaft through a differential device which permits limited rotational displacement between the sun gears. An element, for example an aircraft lift control surface, may be mounted on one set of the ring gears by means of spindles which extend normally of a plane which includes the axes of the ring gears, so that as a result of stresses therein the element may tilt locally about the spindles.

Abstract: An authority limiter includes an input shaft clutched to an output shaft. The output shaft is geared to a motor. Opto-sensors provide control signals to a current source supplying power to the motor. Different amounts of opposing torque are applied by the motor dependent upon the positioning of a disc, mechanically attached to the output shaft, effecting the optical path in the opto-sensors. In another embodiment, the opto-sensor control is replaced by an electro-mechanical mechanism which senses various thresholds corresponding to angular positions of the coupled input and output shafts.

Abstract: An aircraft flap sensing and control circuit for sensing and controlling the position of the flaps and for sensing and comparing the instantaneous movement and position of the flaps mounted on opposite wings of the aircraft.