Air Position Indicator System Computer 12580-1-B DC-7 Measures 3 inches diameter and

Measures 3 inches diameter and 1 inch deep

and the bubble is full and intact within the glass chamber

and the fill port on the bottom has a small crack

000 ft to align with the line markings outside of the window

Air Position Indicator System Computer 12580-1-B DC-7 Measures 3 inches diameter andThe 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