1936 Air Ministry RAF Mark XIII Height Indicator / Altitude Meter 6A/445 Made By Short And Mason

1936 Air Ministry RAF Mark XIII Height Indicator / Altitude Meter 6A/445 Made By Short And Mason This vintage aircraft cockpit gauge is a 1936 Air Ministry RAF Mark XIII Height Indicator / Altitude Meter 6A/445 Made By Short And Mason. The aneroid based 'simple altimeter' XIII was introduced in 1930s aircraft just prior to WW2, and during WW2 in the Fleet Air Arm including training aircraft, and early versions of warbirds including the Supermarine Spitfire, Fairey Light Bomber and the Sunderland Stirling. In very good cosmetic condition, with some minor surface blemishes, it has not been tested. Approximate Size: Face Diameter: 9cm Depth: 7cm (excluding knob and fittings) Marked:- 6A/445 (where 6A is the RAF stores number for Aircraft Engine and Flying Instruments, Accessories and Spares) Mark XIII (probably XIIIC) Maximum Height- 30,000 Feet AM (Air Ministry) No. 8529/36 The XIII meter relied on height difference between the outward and inward aerodromes in flight, as opposed to early in WW2 when it changed to altitude as this measurement is less dependent on correcting for temperature and pressure. The MkXIIIB variant measured from 0 to 20,000 ft, and the MkXIIIC measured 0 to 30,000 ft. Please click on the following link for more vintage aircraft spares.