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)

where the condition of the wings were monitored during flight

This indicator has a label of Cherry Point

It was also used in versions of US Army Air Corps WWII fighters P-38

as is the glass inclinometer

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