Military Aviation: 1918-1939

As the war drew to a close, the aircraft had proved its worth in combat, although many in positions of power in the military establishment were still sceptical. Britain's Royal Air Force (RAF) was formed in 1918 by the amalgamation of the Army's Royal Flying Corps (RFC) and the Royal Naval Air Service (RNAS). The RNAS had been responsible for the air defence of the United Kingdom until February 1916, when the RFC regained this responsibility. The German air force was disbanded by the Treaty of Versailles, while air power advocates in the victorious Allied nations struggled to prove that the aeroplane was the weapon of the future. The spectre of bomb attack from the air was raised regularly in the 1920s and 1930s by all sides in the debate, since the failure of night fighters in World War I seemed to suggest that there was no defence, and that civilian populations would be under attack.

Military aircraft technology evolved slowly after World War I. Biplane construction was standard, since the braced structure was strong, robust, and proven. In Britain, a series of fighters and bombers from Hawker, Bristol, and Gloster pushed biplane design to its limits, but the two wings remained the standard. By the 1930s, fast, smooth monoplane designs such as the de Havilland Comet and Supermarine S-6 floatplane were being built to contest air races like the Schneider Trophy, but these lessons had not been transferred into military aircraft design. In Germany, Hitler's rise to power and the elevation of ex-World War I pilots, like Hermann Goering, to positions of influence resulted in the design of a number of monoplane "airliners" and single-seaters. These monoplanes were rapidly to become the bombers and fighters with which the German Luftwaffe went to war five years later: the Heinkel He 111, the Dornier Do 17, and the Messerschmitt Bf 109.

Features such as retractable landing-gear, streamlining, and the use of metal for construction became the hallmarks of the new generation of aircraft. However, the RAF, the French Air Force, and even the United States Army Air Corps, the forerunner of the United States Army Air Force, were still largely equipped with wood-and-fabric biplanes. In addition, despite the fears about aerial bombardment, none was equipped with a genuinely heavy bomber.

Most of the genuine innovation in military aircraft construction between the wars came about as a result of unsolicited work in private companies.