Attitude Indicator, 5" Type B-1A Lear USAF SMAMA, F-94, B-50, C-130 Aerial Refueling A (-) negative reading indicates

A (-) negative reading indicates current flowing away from the battery (discharge)

B-52 Stratofortress (see photo of RMI on B-52 instrument panel)

and Martin P5M Marlin Floatplane of the US Navy

Removing a small cover at the rear reveals three vacuum tubes (one of the cover's metal tabs is broken)

B-25 Mitchell

Attitude Indicator, 5" Type B-1A Lear USAF SMAMA, F-94, B-50, C-130 Aerial Refueling A (-) negative reading indicatesThis is an Attitude Indicator, Type B 1A, made by Lear PN 62160 01 MIL I 6501A. It has a service stamp SMAMA (USAF Sacramento Air Materiel Area at McClellan AFB, California) dated Nov 19, 1962. As of 1969, SMAMA managed the logistics support for the F 111A variable sweep wing fighter, as well as the F 100, F 104, F 105, F 84, F 86, T 28, A 1, T 6, and EC 121 aircraft, and is the repair activity on the F I06 fighter interceptor. We have not been able