Automatic direction stabilization system

Claim 1

An automatic direction stabilization system for aircraft, especially for the landing run after touchdown, comprising sensor means (1) responding to changes in the travel direction of the aircraft to provide a measured signal, transducer and comparator means (2) operatively connected to said sensor means to receive said measured signal, control means (3) providing a rated control signal, said transducer and comparator means (2) being also operatively connected to said control means to receive said rated control signal in addition to said measured signal for comparing the measured signal and the rated control signal to produce a corrected difference control signal, said transducer and comparator means (2) having output means providing said corrected difference control signal, and steering performing means operatively connected to said output means of said transducer and comparator means (2) for responding to said difference control signal whereby a pilot caused steering action is automatically corrected to provide a steering action required for substantially eliminating the effects of disturbing yaw moments, said steering performing means comprising wheel steering means as well as left wheel brake means and right wheel brake means, amplifier means operatively interconnecting said transducer output means and said wheel steering means, selector switch means operatively connecting said transducer output means to said left or right wheel brake means, said selector switch means being responsive to the polarity sign of said difference control signal, whereby the braking action of the controlled wheel brake means is varied by varying the hydraulic brake pressure in the respective brake means in an increasing or decreasing manner without exceeding a given maximum brake pressure.