Navigadget Mark I Flight Computer Battle but that is a guess

but that is a guess

Type IN-4D

000 Meters

and PBM Mariner

Power venturi tubes provide a source of vacuum for the operation of air-driven instruments such as directional gyros

Navigadget Mark I Flight Computer Battle but that is a guessThis highly unusual Navigadget Mark I Flight Computer is the first and only one of its kind that we've run across. Measuring 10 x 5. 25 inches and painted on aluminum, this device seem intended to be placed on a chart with a scale of 1. 25 inches = 10 miles, with the left "Miles" scale placed along the intended flight path. The center axis intersecting at the 40 Mile mark is the calculated ground speed, from 60 to 150 MPH. The aluminum semi circle