World War II

Aerial combat formed an important part of World War II military doctrine. The ability of aircraft to locate, harass, and interdict ground forces was an instrumental part of the German combined-arms doctrine, and their inability to achieve air superiority over Britain made a German invasion unfeasible. German Field Marshal Erwin Rommel noted the effect of airpower: "Anyone who has to fight, even with the most modern weapons, against an enemy in complete command of the air, fights like a savage against modern European troops, under the same handicaps and with the same chances of success." During the 1930s, two different streams of thought about air-to-air combat began to emerge, resulting in two different approaches to monoplane fighter development. In Japan and Italy especially, there continued to be a strong belief that lightly armed, highly maneuverable single-seat fighters would still play a primary role in air-to-air combat. Aircraft such as the Nakajima Ki-27, Nakajima Ki-43 and the Mitsubishi A6M Zero in Japan, and the Fiat G.50 and Macchi C.200 in Italy epitomized a generation of monoplanes designed to this concept. This Supermarine Spitfire XVI was typical of World War II fighters optimized for high level speeds and good climb rates The other stream of thought, which emerged primarily in Britain, Germany, the Soviet Union, and the United States was the belief that the high speeds of modern combat aircraft and the g-forces imposed by aerial combat meant that dogfighting in the classic WWI sense would be impossible. Fighters such as the Messerschmitt Bf 109, the Supermarine Spitfire, the Yakovlev Yak-1 and the Curtiss P-40 Warhawk were all designed for high level speeds and a good rate of climb. Good maneuverability was desirable, but it was not the primary objective. The 1939 Soviet-Japanese Battle of Khalkhyn Gol and the initial German invasion of Poland that same year were too brief to provide much feedback to the participants for further evolution of their respective fighter doctrines. During the Winter War, the greatly outnumbered Finnish Air Force, which had adopted the German finger-four formation, bloodied the noses of Russia's Red Air Force, which relied on the less effective tactic of a three-aircraft delta formation. [edit] European theater (Western Front) The Battle of France, however, gave the Germans ample opportunity to prove they had mastered the lessons learned from their experiences in the Spanish Civil War. The Luftwaffe, with more combat-experience pilots and the battle-tested Messerschmitt Bf 109 fighter operating in the flexible finger-four formation, proved superior to its British and French contemporaries relying on the close, three-fighter "vic" (or "V") and other formations, despite their flying fighters with comparable maneuver performance. The Battle of Britain was the first major military campaign to be fought entirely by air forces, and it offered further lessons for both sides. Foremost was the value of radar for detecting and tracking enemy aircraft formations, which allowed quick concentration of fighters to intercept them farther from their targets. As a defensive measure, this ground-controlled interception (GCI) approach allowed the Royal Air Force (RAF) to carefully marshal its limited fighter force for maximum effectiveness. At times, the RAF's Fighter Command achieved interception rates greater than 80%. In the summer of 1940, then Flight Lieutenant Adolph Malan introduced a variation of the German formation that he called the "fours in line astern", which spread into more general use throughout Fighter Command. In 1941, Squadron Leader Douglas Bader adopted the "finger-four" formation itself, giving it its English-language name. The Battle of Britain also revealed inadequacies of extant tactical fighters when used for long-range strategic attacks. The twin-engined heavy fighter concept was revealed as a failed concept as the Luftwaffe's heavily armed but poorly maneuverable Messerschmitt Bf 110s proved highly vulnerable to nimble Hurricanes and Spitfires; the Bf 110s were subsequently relegated to night fighter and fighter-bomber roles for which they proved better-suited. Furthermore, the Luftwaffe's Bf 109s, operating near the limits of their range, lacked endurance for prolonged dogfighting over Britain. When bomber losses induced Reichsmarschall Hermann Göring to assign most fighters to close-in escort duties, forcing them to fly and maneuver at reduced speeds, German fighter effectiveness fell and losses rose. Long-range escort fighters like this P-51D Mustang provided protection for Allied strategic bombers The Allies themselves, however, would not learn this latter lesson until they sustained heavy bomber losses of their own during daylight raids against Germany. Despite the early assertions of strategic bombing advocates that "the bomber will always get through", even heavily armed U.S. Army Air Force (USAAF) bombers like the Boeing B-17 Flying Fortress and Consolidated B-24 Liberator suffered such high losses to German fighters (such as the Focke-Wulf Fw 190 "bomber destroyer") and anti-aircraft artillery (AAA) that – following the second raid on Schweinfurt in August 1943 – the U.S. Eighth Air Force was forced to suspend unescorted bombing missions into Germany until longer-range fighters became available for escort. These would appear in the form of Lockheed P-38 Lightnings, Republic P-47 Thunderbolts and North American P-51 Mustangs. The use of drop tanks also became common, which further made the heavy twin-engine fighter designs redundant, as single-engine fighters could now cover a similar distance. Extra fuel was carried in lightweight aluminum tanks below the aircraft, and the tanks were discarded when empty. Such innovations allowed American fighters to range over Germany and Japan by 1944. As the war progressed, the growing numbers of these advanced, long-range fighters flown by pilots with increasing experience eventually overwhelmed their German opposition, despite the Luftwaffe's introduction of technological innovations like jet- and rocket-powered interceptors. The steady attrition of experienced pilots forced the Germans to more frequently dip into their training pool to make up numbers when casualties surged. While new Allied airmen in Europe were well-trained, new Luftwaffe pilots were seldom able to get effective training – particularly by the summer of 1944, when Allied fighters often loitered around their airfields. Luftwaffe training flights were additionally hampered by the increasingly acute fuel shortages that began in April 1944. [edit] European theater (Eastern Front) Soviet Air Force MiG-3s in winter camouflage. The slogan on the nearest aircraft reads "Za Rodinu" – "For the Motherland". On the Eastern Front, the strategic surprise of Operation Barbarossa demonstrated that Soviet air defense preparations were woefully inadequate, and the Great Purge rendered any lessons learned by the Red Air Force command from previous experience in Spain and Finland virtually useless. During the first few months of the invasion, Axis air forces were able to destroy large numbers of Red Air Force aircraft on the ground and in one-sided dogfights. However, by the winter of 1941–1942, the Red Air Force was able to put together a cohesive air defense of Moscow, successfully interdict attacks on Leningrad, and begin production of new aircraft types in the relocated semi-built factories in the Urals, Siberia, Central Asia and the Caucasus. These facilities produced more advanced monoplane fighters, such as the Yak-1, Yak-3, LaGG-3, and MiG-3, to wrest air superiority from the Luftwaffe. However, Soviet aircrew training was hasty in comparison to that provided to the Luftwaffe, so Soviet pilot losses continued to be disproportionate until a growing number of survivors were matched to more effective machines. Beginning in 1942, significant numbers of British, and later U.S., fighter aircraft were also supplied to aid the Soviet war effort, with the Bell P-39 Airacobra proving particularly effective in the lower-altitude combat typical of the Eastern Front. Also from that time, the Eastern Front became the largest arena of fighter aircraft use in the world; fighters were used in all of the roles typical of the period, including close air support, interdiction, escort and interception roles. Some aircraft were armed with weapons as large as 45 mm cannon (particularly for attacking enemy armored vehicles), and the Germans began installing additional smaller cannons in under-wing pods to assist with ground-attack missions.