Description
Spitfire Mk. VI (H.F. VI)
Dimensions:
Span 40ft 2 in. (12.24m) length overall 29 ft. 11 in.(9,12m) height 9 ft. 11 in.(3.02)
Weights: Loaded 6,797 lb. (3083kg)
Performance: Maximum speed 364 mph (586 km/h) Stalling speed flaps down 73 mph (114 km/h), Max ceiling: 40,000 ft.(12.190 m).
Propeller: 4-blade Rotol.
Power plant: Rolls-Royce Merlin 47 (1,415 hp.))
The Spitfire Mk VI was the first special high-flying model. 100 was build. Basically an Mk V with a pressurized cabin and the Marshall IXs blower to give a cabin-pressure of 20.000 ft. at 40.000 ft. Also special bulkheads fore and aft of the cockpit and no cockpit access flap, an airtight hood that couldn’t slide and sealing of all moving control wires and enlarge wing tips for more lift at high attitude.
It was normally fitted with the extended wing an production was by taking from the Mk V production line, it was intended for home service only, but due to high-flying enemy aircraft in the middle-east five was shipped out in October 1942.
A distinct flying characteristic for the Mk. VI was that it like all Spitfires was generally stable, it become increasingly longitude unstable as high increased and the controls was rather heavier due to cabin sealing.
I remember that Pierre Clostermann in his book “The Big Show” made high-altitude interdiction over the Royal Navy's Scapa Flow base and he told that the hood was bolted on to make it airtight, nobody mentioned how to get out in an emergency.
From "Spitfire - the story of a famous fighter" by Bruce Robertson