Abstract: Tubular members (22, 24) define a pressure chamber (26) and a reserve chamber (28) between them. A first variable metered hydraulic orifice area is provided between chambers (26, 28) by openings (32) in a metering tube (30). A second metered hydraulic orifice area is provided by fixed orifice (94). In a first mode of operation, both such areas are open during an initial retraction of members (22, 24). Control tube (34) is coaxial with metering tube (30) and has openings (36). In the first mode, latch (62) locks tubes (30, 34) together with openings (32, 36) aligned. Relative extension of members (22, 24) following the initial retraction causes pressure in chamber (28) to rise above pressure in chamber (26) and latch (62) to release control tube (34). Spring (40) moves tube (34) into a closed position in which it blocks openings (32). Shock absorber (20) then operates in its second mode in which fixed orifice (94) remains open and openings (32) remain closed.

Abstract: A relatively expensive, relatively heavy, and relatively nonflammable hydraulic fluid (chlorotrifluorethylene) is used in an aircraft ground wheel brake system between the piston (72) of a deboost device (68) and a set of wheel brakes (196). A relatively cheaper and relatively lighter, conventional hydraulic fluid (MIL-H-5606), which is also relatively flammable, is used in the remainder of the system. A replenish system for the relatively nonflammable fluid includes a reservoir divided into two chambers by a piston. One chamber contains a quantity of the relatively nonflammable fluid and the other chamber is connected to the system pressure. The deboost device includes a replenish valve which is opened in response to a position of the deboost piston. Replenishment only occurs when the brakes are applied and replenishment is necessary. At other times, all portions of the brake system are at return pressure.

Abstract: A control system for maintaining an aircraft within the lateral boundaries of a runway during landing rollout under conditions of combined crosswind and low runway friction is disclosed. An automatic mode of operation is provided wherein the system utilizes an input signal representative of the heading of the runway being utilized and signals provided by (or derivable from ) an inertial navigation system to exercise coordinated control of the aircraft rudder, steering and differential braking system. In a semiautomatic mode of operation, signals supplied by the inertial navigation system (or its equipment) are utilized in conjunction with a continuous command signal that is provided by the pilot to indicate the desired aircraft trajectory. An optional provision is included for limiting the aircraft ground velocity slip angle to a range wherein an increase in ground velocity slip angle results in increased lateral corrective force on the aircraft.