Supermarine Spitfire Mk I
Although it was only a front line fighter for eighteen months, the Spitfire I earned one of the most enduring reputations of any aircraft. Its sleek lines, graceful appearance and impressive performance combined with its role in the battle of Britain to make it a British icon. The Mk I Spitfire was in constant development during its production run. Amongst the pre-war changes the most visually obvious was the replacement of the level cockpit of the prototype with the instantly familiar curved bubble cockpit. Of perhaps more importance to the pilot, armour plating was added behind the engine and a bullet proof windscreen was fitted. From the 78th aircraft the two blade wooden propeller was replaced by a de Havilland two-speed 3-blade propeller. From the 175th aircraft the engine was changed from the 1030 hp Merlin II to the similar Merlin III, which could take either the de Havilland propeller or a more advanced Rotol propeller. These changes increased the performance of the Spitfire at different speeds, as the angle of the propeller blade could be altered to suit high or low speed situations. The maximum speed of the Mk I was reduced from 363 mph at 18,500 in early version to 353 mph at 20,000 feet after the new armour and other extra equipment was added, but the decrease would have much more significant without the new propellers. The de Havilland propeller had increased the maximum speed by 10 mph; the Rotol propeller had a huge impact on rate of climb. One change that did not work out was an attempt to install two 20mm cannon in the Spitfire I. The cannon were unreliable and prone to jam, and would not enter front line service in the Spitfire until the IIb. Production began slowly. The first production aircraft was completed in June 1938. In August No. 19 Squadron became the first one to receive the new aircraft, when it converted from Gloster Gauntlets. By the outbreak of war on 3 September 1939, 306 Spitfires had been delivered (of which 36 had already been written off!). The RAF went into the war with only eight Spitfire squadrons. Over the next nine months the most important battles facing the Spitfire were the battle of production and the political battle to keep them out of France. The production battle was slowly won -- in all 1566 Spitfire Is were produced before the type was phased out in favour of the Mk V. At the end of the Dunkirk evacuations the RAF had 19 Spitfire squadrons. The Hurricane was still being produced quicker, and despite heavy losses in France was still more numerous during the battle of Britain. Just as crucial was the political battle. As the battle in France developed into a crisis, the RAF came under intense pressure to sent Spitfire squadrons to France. Fortunately Air Marshal Hugh Dowding, the head of Fighter Command, was able to resist this pressure, and the Spitfires were retained for home defence. The Spitfire I's first major contribution to the fighting in France came over Dunkirk. Here, home based squadrons could reach the beaches, admittedly at extreme range. Their presence changed the balance of the fighting in the air. The Hurricane squadrons had suffered heavily in France, partly because of the rapid German advance, so it was over Dunkirk that the Bf 109 finally met an equal. Dunkirk stands as the Luftwaffe's first defeat. Worse would soon follow. At the start of the battle of Britain the Spitfire I represented just under half of Fighter Command's available aircraft (321 out of 848 in July 1940, 372 out of 1081 on 30 August 1940). With the help of the home defence chain of radar stations, and a brilliantly designed control system, the Spitfire and the Hurricane defeated the Luftwaffe's daytime offensive during the battle of Britain. In fairness one must remember that the Hurricane was responsible for the majority of German losses, but it was the Spitfire that captured the imagination. Even German pilots were said to suffer from "Spitfire snobbery" -- at least one Hurricane pilot, when meeting with German airmen he had personally shot down, found the Luftwaffe pilot quite convinced he had been shot down by a Spitfire! The Spitfire did perform better against the Bf 109, accounting for 180 of the around 330 Bf 109s shot down by the two types of British fighters. Copyright © 2011 Malcolm Auld This video and audio material may not be reproduced in any form (except as an embedded video on any other website), without written permission.