Birkland, Henry (Flight Lieutenant)

Source: Harold A Skaarup Web Page (DND Photo)
Supermarine Spitfire Mk. VI, RCAF (Serial No. X4492), in flight, 26 Feb 1944.

The Supermarine Spitfire is a British single-seat fighter aircraft that was used by the Royal Air Force and other Allied countries before, during, and after World War II. Many variants of the Spitfire were built, using several wing configurations, and it was produced in greater numbers than any other British aircraft. It was also the only British fighter produced continuously throughout the war. The Spitfire continues to be popular among enthusiasts; around 70 remain airworthy, and many more are static exhibits in aviation museums throughout the world.

The Spitfire was designed as a short-range, high-performance interceptor aircraft by R. J. Mitchell, chief designer at Supermarine Aviation Works, which operated as a subsidiary of Vickers-Armstrong from 1928. Mitchell pushed the Spitfire's distinctive elliptical wing with cutting-edge sunken rivets (designed by Beverley Shenstone) to have the thinnest possible cross-section, helping give the aircraft a higher top speed than several contemporary fighters, including the Hawker Hurricane.

The Spitfire had detachable wing tips which were secured by two mounting points at the end of each main wing assembly. When the Spitfire took on a role as a high-altitude fighter (Marks VI and VII and some early Mk VIIIs), the standard wing tips were replaced by extended, "pointed" tips which increased the wingspan from 36 ft 10 in (11.23 m) to 40 ft 2 in (12.24 m). The other wing-tip variation, used by several Spitfire variants, was the "clipped" wing; the standard wing tips were replaced by wooden fairings which reduced the span by 3 ft 6 in (1.07 m). The wing tips used spruce formers for most of the internal structure with a light alloy skin attached using brass screws.

Due to a shortage of Brownings, which had been selected as the new standard rifle calibre machine gun for the RAF in 1934, early Spitfires were fitted with only four guns, with the other four fitted later. Early tests showed that, while the guns worked perfectly on the ground and at low altitudes, they tended to freeze at high altitude, especially the outer wing guns, because the RAF's Brownings had been modified to fire from an open bolt. While this prevented overheating of the cordite used in British ammunition, it allowed cold air to flow through the barrel unhindered. Supermarine did not fix the problem until October 1938, when they added hot air ducts from the rear of the wing-mounted radiators to the guns, and bulkheads around the gunbays to trap the hot air in the wing. Red fabric patches were doped over the gun ports to protect the guns from cold, dirt, and moisture until they were fired.

The first Rolls-Royce Griffon-engined Mk XII flew in August 1942, and first flew operationally with 41 Squadron in April 1943. This mark could nudge 400 mph (640 km/h) in level flight and climb to an altitude of 33,000 ft (10,000 m) in under nine minutes. As American fighters took over the long-range escorting of USAAF daylight bombing raids, the Griffon-engined Spitfires progressively took up the tactical air superiority role, and played a major role in intercepting V-1 flying bombs, while the Merlin-engined variants (mainly the Mk IX and the Packard-engined Mk XVI) were adapted to the fighter-bomber role. Although the later Griffon-engined marks lost some of the favourable handling characteristics of their Merlin-powered predecessors, they could still outmanoeuvre their main German foes and other, later American and British-designed fighters.Wikipedia

Wikipedia Supermarine Spitfire

Harold A Skaarup Web Page

YouTube How the Spitfire Became an Aviation Masterpiece

RCAF Supermarine Spitfire Serials - Kestrel Publications