Air Position Indicator System Computer 12580-3-B & Manual T.O. 5N-3-1-31 PZL as used in the US

as used in the US Army Air Force's Boeing B-29 Superfortress (see photo of B-29 Flight Engineer's instrument panel with a red dot showing instrument location)

but comes with a replacement crank (the stem of the damaged crank remains on the shaft and we have elected not to try to remove it so as not to cause damage)

Included is the Eyebrow lamp bezel

The metal seal is in place in the lower right of the case

where the condition of the wings were monitored during flight

Air Position Indicator System Computer 12580-3-B & Manual T.O. 5N-3-1-31 PZL as used in the USThe Air Position Indicator System was an advanced navigational system introduced during WWII in later versions of the Boeing B 29 Superfortress Bomber by the US Army Air Force, including the Enola Gay (see API on navigator's panel). This electro mechanical system computed positions based on a series of dead reckoning inputs. The system maintained a continuous indication of the latitude and the longitude of the air position at any instant, as well as