Historical information

The navigational computer was a circular slide rule used for calculating height and air speed corrections when flying an aircraft. The front cover lifts to reveal a further calculator used to solve vector triangles and plot course alterations. The device was intended to be strapped to a pilot's leg. The instrument was made by White and Gillespie (Melbourne) Pty Ltd c 1940 for the RAAF and used during WW2.

Physical description

Black metal box with silver metal flap top cover affixed with rotating circular rule . Two adjustable belts are affixed to the base of black box. A small spiral bound note book is contained beneath the flap top.

Inscriptions & markings

RAAF Computer Navigational system MK. III. D. Serial No WG 2833