Directional Gyro Control, US Air Force Type E-4 Autopilot/A,Original U.S. WWII US Navy Aircraft MK IV Autopilot Bank,289-1S-M AIM RMI Slaved Directional Gyro,Directional Gyro, RAF Mk IB, Ref 6A/1666 1945 NOS – AeroAntique,Vintage Sperry Gyroscope CO. INC. N.Y. Aircraft Directional