Intercept Officers Equipment Kit, Type I (Navigation Computer) 1943 Martin with an interesting history

with an interesting history

or patrol observer

Air Corps US Army Type C-13 (also AN-5760-1)

As airspeed increased

measuring vertical speed in a climb or descent from - 5 meters/second to + 5 meters/second

Intercept Officers Equipment Kit, Type I (Navigation Computer) 1943 Martin with an interesting historyThis is a WWII era navigation computer in a kit "Intercept Officers Equipment Type I. This example includes two 2 piece USAAF Ground Speed Timer Calculators (for map scales 1: 250,000 and 1: 500,000) and 2 USAAF Rulers. The bottom of the metal case contains a mechanical computer to solve the wind problem. It has a locking mechanism and a movable arm for drift, adjusted for air speed, interconnected to the heading tracker. The lid contains tables and a