"At a meeting held at the Royal Aircraft Establishment, Farnborough, on February 17, 1941, the Air Ministry asked that a Spitfire should be provided with a pressurized cabin capable of maintaining a differential pressure of 11 lbs. per square inch at 40,000ft. The Marshall blower was to be used, and it was agreed that the sliding hood could be eliminated, provided that arrangements were made to allow the new hood to be jettisoned".
These words were the opening statement at a meeting where the Air Staff determined it had a need for a high altitude fighter. A Mk V Spitfire, serial R7120 was pulled from the production line and modified to accept 2 airtight bulkheads, a specially designed canopy made from 5/16" perspex as well as the elimination of the pilot's side door and the sliding hood rails. All seams, bolts and fasteners leading to the cockpit were covered with an airtight rubber compound. The Spitfire was fitted with a Marshall blower and was flight tested at 40,000 ft. The test results concluded that there were no insurmountable problems in pressurizing the cockpit. Following these and subsequent tests, an order was given by the Air Ministry to commence production of the Mk VI in January, 1942.
The original intent of the Mk VI was for high-altitude interception of German reconnaissance aircraft over England. A total of five Mk VIs were shipped to the Middle East to bolster the modified high altitude Mk Vs assigned to No. 252 Wing. The Mk VIs were assigned serial numbers BS106, 124, 134, 149 and an unknown machine. Little is known of the camouflage schemes or markings given to these aircraft.
The last production Mk VI, serial number EN189 came of the assembly line in November of 1942 and was immediately sent to Worthy Down for testing. In general the Mk VI did not meet all expectations, and consequently the majority of the Mk VIs were relegated to training roles with all armament and pressurization removed. They were also retro-fitted with normal Mk I wingtips.
Supermarine's records indicate that a total of 100 Mk VIs were delivered yet the RAF records account for only 97.
The subject of this review is an aircraft from the fifth production batch, serial number BS111, airframe number 3130. It was a Mk V, converted to Mk VI standards and ferried to number 33 Maintenance Unit where the Sky fuselage band was applied. After which it was assigned to No. 616 squadron on August 1, 1942 while they were stationed at Great Sampford, England. In February 1944 it was allocated to No. 519 squadron and finally struck off charge on January 29, 1945.