Based on the Mk V airframe, the HF Mk VI was the first Spitfire specifically intended for high altitude combat, rather than reconnaissance duties. Fitted with a pressurized cockpit and powered by a Merlin 47 of 1415 hp, it had increased span ‘c’ wings of 40 ft. 2 in. Although intended for use in England, No.124 Spdn receiving its first example in February 1941, five were shipped to the Middle East to replace the Special Performance Flight Mk Vs. In the event, the Mk VI’s performance fell short of expectations and only 97 were completed; it did not prove as good as the modified SPF Mk Vs overseas, being unable to reach Ju 86P-2 flights then operating at 50,000 ft. The most serious drawback was the fact that the canopy had to be locked down to allow pressurization and was not intended to be opened in flight, although it could be jettisoned in an emergency. Relegated to second-line and training duties, the majority of Mk VIs had their pointed wingtips replaced by standard tips and armament removed. Length: 9.12m Wing span: 12.24m Max weight: 3,084kg Max speed (at 8535m): 586km/h Service ceiling: 12,190m Range: 764km Armament: 7.7mm gun×4 20mm cannon×2