Abstract: A clip for an airplane stringer supports wires, conduits and the like which are located in the fuselage. The clip has several embodiments for attachment to S-shaped or Z-shaped stringers. Those embodiments of the clip which are attached to S-shaped stringers each have a left end which fits over and around one end of the stringer, and a right end which includes a slot for receiving therein the opposite end of the stringer. The width of the slot is controlled by various mechanisms. The stringer end is retained inside the slot by a ledge or lip portion of the clip which lies over the stringer above the slot. The embodiment of the clip which is attached to Z-shaped stringers includes an upper element which is connected to a separate lower element by a bolt. The upper and lower elements fit about one end of the stringer in an interference fit.

Abstract: A controller for automatically controlling aircraft thrust during a noise abatement climb operates so as to smoothly reduce aircraft thrust during a reduction in aircraft climb angle at the noise abatement altitude so as to maintain a selected noise abatement climb gradient dependent upon the pilot maintaining a recommended climb airspeed. The selected noise abatement climb gradient is compared with a measured climb gradient to generate an error term. The measured climb gradient is adjusted by a acceleration correction term in order to make the resulting measured climb gradient term independent of airspeed changes. The climb gradient error term is added to the selected climb gradient to generate a commanded climb gradient which is converted to an equivalent thrust (noise abatement thrust). The resulting noise abatement thrust is compared with measured engine thrust to generate an error term for controlling engine thrust so that the aircraft follows the noise abatement climb gradient.

Abstract: Apparatus for stabilizing a test specimen in a compression/tension testing machine. The apparatus supports the test piece along its lengthwise edge or edges to prevent unwanted Euler buckling, however in a manner so as not to prevent sublaminate buckling. In one embodiment the apparatus supports the test piece along both of its lengthwise edges while engaged between the grips of the test machine. In a second embodiment, the apparatus supports the test piece along only one of its lengthwise edges. In a third embodiment, the apparatus includes grip plates which are mounted to the test machine and which engage a portion of the test specimen while the remainder of the specimen is supported along its lengthwise edges by stabilizer plates.

Abstract: A liquid level sensor system for a tank includes a stillwell having a transducer assembly positioned in the bottom of the stillwell. A guide conduit surrounds a flexible plastic coated wire bus which extends through a sidewall of the tank and which connects the transducer assembly to an indicator assembly located outside the tank. The conduit includes an end cap which secures the wire bus within the conduit. Installation and removal of the transducer assembly and wire bus is accomplished at a location outside the tank by removing the end cap and pulling or pushing the transducer assembly through the conduit by means of the wire bus.

Abstract: The time constant of an adaptive digital filter is regulated as a function of the magnitude of the rate of change of the input signal to the filter. When the input signal has a large step input or it changes rapidly, the time constant is shortened; however when the input signal has a small step input or it changes more slowly, the time constant of the filter is increased.

Abstract: A grille for an aircraft mounted on the cabin sidewall includes apertures to allow return airflow from the air conditioning system. In a preferred embodiment, the grille apertures are covered by resilient baffles which are resiliently folded into semicircular configurations and held in place between adjacent ribs of the grille by the force exerted by the folded baffles. One end of each baffle is affixed to upper and lower rods of the grille, while an opposite end of each baffle is releasably inserted over the rods. During a sudden decompression of the cargo compartment, the releasable ends of the baffles are dislodged from the rods and unbend into a flat shape in a manner parallel to the airstream. This permits rapid pressure equalization between the cargo and passenger compartments.

Abstract: An aircraft toilet system includes a holding tank and a discharge pipe which extends to a service panel located near the skin of the aircraft. A poppet valve is located near the outlet end of the discharge pipe. Leakage of fluids past the poppet valve is corrected in a first embodiment by pressurized cabin air which is ported to a downstream side of the poppet valve and by venting the upstream side of the valve to the atmosphere. In a second embodiment, high pressure air from the aircraft's environment control system is ported to the downstream side of the valve. The resulting pressure differential holds the valve against its seat, and prevents fluid leakage in the event of a damaged valve seal.

Abstract: A fluid ejector for discharging gases and fluids from an aircraft. The fluid ejector is fastened to an exterior surface of the aircraft and includes an air tube which is spaced apart from the exterior surface of the aircraft by a mast. Unwanted fluids and gases are evacuated from the aircraft through a conduit located inside the drain mast and are expelled from an outlet located in the side of the air tube. In this manner, the liquid or gases present at the outlet are discharged in a rearward direction away from the downstream portion of the aircraft by the airstream through the tube.

Abstract: A tester simulates high energy pulses typically present at the inputs to an avionics device after an aircraft carrying the avionics device has been struck by lightning. The tester is used to assist in determining whether the avionics device is sufficiently protected against the effects of a lightning strike on the aircraft. The tester includes a trigger circuit for generating trigger signals at fixed or random intervals so that the pulses which make up each burst as well as the bursts themselves are generated at fixed or random intervals. A number of individual pulse generating circuits are provided to generate high energy pulses which are output to the avionics device under test. A sequencing circuit feeds the trigger signals to the pulse generating circuits so as the generate the high energy pulses and bursts at the selected fixed or random intervals.

Abstract: A controller for generating a bank angle limit for an aircraft during takeoff with an nonoperational engine. The controller operates so that there are minimum and maximum bank angle limits. Between these minimum and maximums, there is a linear relationship between aircraft airspeed and bank angle limit. However, before there is a change in aircraft airspeed from an increasing mode to a decreasing mode or vice versa, the bank angle limit remains constant until the change in aircraft airspeed is greater than or equal to a predetermined airspeed differential.

Abstract: Apparatus for supporting parts to allow the parts to manipulated such as for application of protective coatings and paint. The apparatus includes a support rack and at least one flexible wire-like clamp. In an exemplary embodiment, the clamp includes an engaging end which support the part configured as a pair of helical rings which support the part against an edge of the rack. The opposite end of the clamp includes a pair of opposing rings which engage opposing faces of the support rack. In some embodiments, the clamp may be rotated to adjust the distance between the engaging rings and the support rack edge in order to accomodate parts of different sizes and configurations. The clamp includes a finger which is inserted within a selected one of a plurality of holes in the support rack so as to prevent unwanted rotation of the clamp and thereby maintain it in a selected position.

Abstract: Apparatus for latching a thrust reverser cowl to an engine includes a hooking mechanism which is attached to the thrust reverser cowl and a receiver mechanism which is attached to the engine fan case. When the thrust reverser cowl is inserted about the engine, a hook portion of the hooking mechanism engages a U-ring portion of the receiver mechanism to hold the clamshells of the thrust reverser cowl in place. The receiver mechanism includes a slotted base which supports a slidable bar therein. The slidable bar has the U-ring attached to one end and a threaded shaft attached to its opposite end. The position of the slidable bar along the base is maintained by the location of the nut on the shaft which engages a keeper mounted to the end of the base.

Abstract: A system for forming an I-section workpiece includes a transporter having a pair of mandrels onto which two unformed charges are placed. The transporter carries the mandrels to a forming station which includes a pair of forming enclosures which contain heating elements and compliant material therein. By insertion of the mandrels into the compliant material, the charges are caused to bend around the mandrels thereby generating a pair of formed elements having channel shaped cross-sections. The elements are then carried by the transporter to a cure station where they are joined together by heated mandrels so that a one piece I-section workpiece is formed.

Abstract: A reuseable panel for equalizing pressure between adjacent compartments includes a frame and a movable floor which is releasably sandwiched within the frame on three sides. When there is a sufficiently large pressure differential between the compartments, the three sides of the door are dislodged from the frame (blowout) thereby exposing an opening to allow the pressure between the compartments to equalize. In order to provide additional control over the pressure at which door blowout occurs, one end of a flexible strap is fixedly attached to the door while the other end is removably connected to an attachment bracket which is fixed to the frame. By adjusting (i) the configuration of the attachment bracket, (ii) the depth at which the door is sandwiched within the frame, (iii) the number of attachment brackets, (iv) the position of the attachment brackets, and (v) the side of the frame on which the attachment brackets are mounted, the pressure differential at which door blowout occurs can be adjusted.

Abstract: When an aircraft is operating in an asymmetrical flight condition, such as during a landing decrab maneuver or during inflight engine out, the pilot is normally required to make precise compensatory roll control inputs to keep the aircraft moving along its original track angle. The pilot is relieved of this compensatory roll control task by providing a control system which automatically banks the aircraft to maintain the flight of the aircraft along the selected track angle while in the asymmetrical flight condition. Further adjustments in the bank angle of the aircraft are made automatically by a track angle feedback control system so that the aircraft remains on the selected track angle even when subject to external disturbances such as crosswind gusts and shear.

Abstract: A device for preventing aircraft wing flutter causes the port and starboard wings of the aircraft to oscillate at different frequencies. In an exemplary embodiment, engine nacelles are suspended from the port and starboard wings by strut assemblies in a manner that the port and starboard engine nacelles have different oscillation frequencies when subjected to a displacing force. The port and starboard strut assemblies each include a pair of flexible beams whose dimensions and composition may be adjusted to change its stiffness. In this manner, the oscillation frequency of the attached engine nacelle is adjusted in a known manner.

Abstract: A single-size interior cabin sidewall panel fits aircraft of different sizes. The panel is fabricated so that in its "relaxed" state it has a curved configuration which requires the panel to be unbended to fit in the aircraft. Larger aircraft require more unbending of the panel than do smaller aircraft. This results in a uniform pressure across the panel which promotes a close fit between adjacent overlapping sidewall panels.

Abstract: A throttle controller includes a manual mode where engine output is a function of throttle lever angle, and an alternatively selectable Speed Hold/Thrust Hold mode which is initiated when the throttle is placed in a center Hold position. Throttle operation during the Speed Hold mode is governed by (i) a selected speed entered at a mode control panel, or (ii) a speed existing when the lever was placed in the Hold detent, given that no speed is entered and selected at that mode control panel or (iii) a selected speed/thrust designated in a flight plan entered into the aircraft's flight management computer. During the Thrust Hold mode, the throttle controller maintains the level of thrust which existed when the throttle lever was placed in the Hold detent. When out of the Hold detent, the controller operates to control output thrust as a function of Throttle Lever Angle (TLA).

Abstract: A hubcap for an aircraft wheel includes an internal spider which engages an anti-skid transducer located in the wheel hub. The hubcap is constructed of one piece and has a conical configuration to provide increased strength as well as increased airflow inside the hubcap for improved heat dissipation.

Abstract: There is provided a controller for aiding a pilot to control an airplane's track over the ground. While the airplane is in the air, a lateral control subsystem is provided for automatically holding the aircraft aligned with a desired track angle. Control is initiated when the pilot places the airplane in a wings level condition and centers his roll axis controller (e.g., wheel or stick). An in-air track rate control subsystem is also provided. While the airplane is on the ground, a directional control subsystem is provided which enables the pilot to command track rate or heading rate with rudder pedal inputs. The track/heading rate commands are integrated to generate track/heading angle commands. Feedback control is used to position the rudder and nosewheel steering as required to make the airplane's actual track/heading follow the track/heading commands. Provisions are made to initialize the in-air lateral and on-ground directional control subsystems to provide smooth transitions during takeoff and landing.