Manual/auto brake valve

A manual/automatic brake modulating valve for an aircraft braking system having a hydraulic pressure source and a means for providing at least one servo command pressure responsive to an aircraft deceleration rate control signal, comprising:

• a housing having a bore, an input port connected to said hydraulic pressure source, at least one servo command port connected to said aircraft deceleration rate control signal and an output port connected to said aircraft braking system;
• a metering spool slideably contained in said bore in said housing and responsive to said aircraft deceleration rate control signal;
• a means for manual actuation of said metering spool;
• a means for generating a feel force during manual actuation of said valve;
• and
• at least one servo piston and cylinder arranged to act between said metering spool and said means for generating a feel force having a stroke at least as great as the stroke of said metering spool, oriented with said cylinder reacting against said metering spool and said piston reacting against said means for generating a feel force so that said feel force and said displacement of said means for manual actuation of said metering spool are essentially independent of spool displacement as a result of said servo pressure while said feel force is directly responsive to displacement of said means for manual actuation of said metering spool, whereby said output may be responsive exclusively to said servo command pressure or responsive exclusively to said manual actuation.