Abstract: The invention provides a system and method for making the braking action more sensitive to pilot control, to provide a smooth stopping response to foot pedal movement by the pilot. A port control member (48) of a first stage metering valve (44) is mechanically connected to a pilot operated foot pedal (50). A pilot applied force on the foot pedal (50) moves the member (48) in a direction causing flow through the valve (44) from a supply pressure to a control pressure chamber in a second stage metering valve (46) to produce a force on a second port control member (76), for moving it in response to foot pedal (50) movement, to meter flow and pressure through the second stage metering valve (46), from a supply pressure to the brake applying device of an aircraft wheel. The output pressure of the first stage metering valve is used as a feedback pressure to move the first stage port control member (48) into a null position in opposition to the foot pedal force.

Abstract: A port control member (24) of a metering valve (10) is mechanically connected to a pilot operated foot pedal (38). Foot pedal (38) movement of this member (24) meters fluid pressure to a second electrically controlled metering valve (108, 110, 112). Pressure from the second metering valve (108, 110, 112) is delivered to one end of a port control member (126) of a third metering valve (126, 136, 138, 140). The third metering valve (126, 136, 138, 140) meters pressure and flow from a supply pressure to wheel brakes (50). Feedback pressure from the brakes (142) is applied to the port control member (126) in opposition to the command pressure (124). The command pressure (108, 110, 112) is fed back to act on the port control member (24) of the first stage valve (10) in opposite relation to the pilot developed pedal force.

Abstract: In an aircraft having an alternate gear extension system as a backup for use by the pilot in the event of failure of the main gear extension system, a ground-crew operated subsystem is integrated with the pilot's alternate gear extension equipment for enabling the ground-crew to open and close the gear door by controls accessible on the underside of the aircraft fuselage. The integration of these two functions involves dual use of certain of the electrical and hydraulic components so that frequent and scheduled operation of the door opening function by ground-crew personnel automatically exercises the alternate gear extension mode to ensure its operability as a safety backup to the main gear extension system.