Autopilot Slaved Gyro Magnetic Compass, USAF E-4 System, 667258-21 P-39 The indicator displayed airspeed from

The indicator displayed airspeed from 60-850 knots

M6 periscopes in each late model Sherman

This is a dual engine Intercooler Flap Position Indicator as appeared on the US Air Force's Korean War-era Boeing B-50 Superfortress

German (Luftwaffe) Sensitive Altimeter Dated Dec 1938

Autopilot Slaved Gyro Magnetic Compass, USAF E-4 System, 667258-21 P-39 The indicator displayed airspeed fromThis is an example of an Autopilot Slaved Gyro Magnetic Compass, Type V 3, for the USAF Autopilot Type E 4 (aka as the Sperry A 12 Gyrosyn Automatic Pilot System). The E 4 System was used in the late 1940 1950's and was still in use in some 1960's aircraft. Lockheed C 130 Hercules and C 121 Constellation transports used this system, as well as civilian aircraft such as DC 3 and DC 6. The Indicator is in reasonable condition for its age. The glass is