Issued by the Royal Air Force during World War II, the Navigational Computor Mark III D* (Stores Ref. 6B/180) was a vital dead-reckoning flight instrument used by pilot-navigators to solve complex vector triangles, wind drift, speed, and altitude calculations in flight. Constructed with a metal outer frame and a Bakelite housing, this model features an I.C.A.N. calibration scale on the top hinged lid and a scrollable internal paper grid viewable through a circular glass compass bezel. Originally designed as an early form of wearable aviation technology, it included fittings for straps to be worn directly on the pilot's thigh for easy access in cramped cockpits. The top plate features a integrated circular slide rule alongside speed and altitude correction dials. Measuring 16cm x 12.5cm, this piece carries Serial No. 4213 and represents an exceptional piece of WWII military aviation heritage.

Condition
The item is in good vintage condition showing age-appropriate light surface wear, minor scuffs, and natural patina to the metal casing and dials.