U.S. Patent Specifications

In an aircraft control system, aileron means and a reversible motor therefor, a variable resistor operated by said motor, a roll gyro and a variable resistor operated thereby, said variable resistors being arranged in a bridge circuit, a polarized relay responsive to the potential across the output terminals of said bridge circuit and arranged to control said motor for operation in either direction, a variable resistor arranged to apply a potential of either polarity across said bridge output terminals, a yaw gyro and a reversible motor arranged to differentially operate the last mentioned variable resistor to respectively impose automatic yaw control and selection of heading upon the aileron operating system, a pair of polarized relays arranged in parallel to control said last‐men‐tioned motor for operation in either direction, a second bridge circuit comprising a circular resistor having two pairs of contacts rotatable thereon, one of said pairs constituting the input terminals of the bridge circuit and the other of said pairs the output terminals thereof, one of said pair of relays being connected across said output terminals of the second bridge circuit, one of said pairs of contacts being rotatable by said last‐mentioned motor, stepping means for rotating the other one of said pairs of contacts, and means of selectively operating said stepping means and the other of said pair of relays to thereby selectively cause incremental turns and continuous turns of the aircraft.