Messerschmitt Me 262

The Messerschmitt Me 262, nicknamed Schwalbe (German: "Swallow") in fighter versions, or Sturmvogel (German: "Storm Bird") in fighter-bomber versions, is a fighter aircraft and fighter-bomber that was designed and produced by the German aircraft manufacturer Messerschmitt. It was the world's first operational jet-powered fighter aircraft.

The design of what would become the Me 262 started in April 1939, before World War II. It made its maiden flight on 18 April 1941 with a piston engine, and its first jet-powered flight on 18 July 1942. Progress was delayed by problems with engines, metallurgy, and interference from Luftwaffe chief Hermann Göring and Adolf Hitler. The German leader demanded that the Me 262, conceived as a defensive interceptor, be redesigned as a ground-attack/bomber aircraft. The aircraft became operational with the Luftwaffe in mid-1944. The Me 262 was faster and more heavily armed than any Allied fighter, including the British jet-powered Gloster Meteor. The Allies countered by attacking the aircraft on the ground and during takeoff and landing.

One of the most advanced WWII combat aircraft, the Me 262 operated as a light bomber, reconnaissance, and experimental night fighter. The Me 262 proved an effective dogfighter against Allied fighters; German pilots claimed 542 Allied aircraft were shot down, although higher claims have sometimes been made. The aircraft had reliability problems because of strategic materials shortages and design compromises with its Junkers Jumo 004 axial-flow turbojet engines. Late-war Allied attacks on fuel supplies also reduced the aircraft's effectiveness. Armament production within Germany was focused on more easily manufactured aircraft. Ultimately, the Me 262 had little effect on the war because of its late introduction and the small numbers that entered service.

Although German use of the Me 262 ended with World War II, the Czechoslovak Air Force operated a small number until 1951. Also, Israel may have used between two and eight Me 262s. These were supposedly built by Avia and supplied covertly, and there have been no official confirmations of their use. The aircraft heavily influenced several prototype designs, such as the Sukhoi Su-9 (1946) and Nakajima Kikka. Many captured Me 262s were studied and flight-tested by the major powers, and influenced the designs of production aircraft such as the North American F-86 Sabre, MiG-15, and Boeing B-47 Stratojet. Several aircraft have survived on static display in museums. Some privately built flying reproductions have also been produced; these are usually powered by modern General Electric CJ610 engines.

Several years before World War II, the Germans saw the potential for aircraft powered by the jet engine constructed by Hans von Ohain in 1936. After the successful test flights of the world's first jet aircraft—the Heinkel He 178—within a week of the invasion of Poland which started the conflict, they adopted the jet engine for an advanced fighter aircraft. As a result, the Me 262 was already under development as Projekt 1065 (or P.1065) before the start of the war. The project had originated with a request by the Reichsluftfahrtministerium (RLM, Ministry of Aviation) for a jet aircraft capable of one hour's endurance and a speed of at least 850 km/h (530 mph; 460 kn). Woldemar Voigt headed the design team, with Messerschmitt's chief of development, Robert Lusser, overseeing.

During April 1939, initial plans were drawn up and, following their submission in June 1939, the original design was very different from the aircraft that eventually entered service. Specifically, it featured wing-root-mounted engines, rather than podded ones. The progression of the original design was delayed greatly by technical problems with the new jet engine. Originally designed with straight wings, problems arose when the long-delayed engines proved heavier than originally promised. While waiting for the engines, Messerschmitt moved the engines from the wing roots to underwing pods, allowing them to be changed more readily if needed. That turned out to be important, both for availability and maintenance.

When it became apparent that the BMW 003 jets would be significantly heavier than anticipated, on 1 March 1940, it was decided that instead of moving the wing backwards on its mount, the outer wing would be swept slightly rearwards to 18.5 degrees, to accommodate the change in the centre of gravity and to position the centre of lift properly relative to the centre of mass. (The original 35° sweep, proposed by Adolf Busemann, was not adopted.)

Initially, the inboard leading edge retained the straight profile as did the trailing edge of the midsection of the wing.

Based on data from the AVA Göttingen and wind tunnel results, the inboard section's leading edge (between the nacelle and wing root) was later swept to the same angle as the outer panels, from the "V6" sixth prototype onward throughout volume production.

The shallow leading edge sweep of 18.5° may have inadvertently provided an advantage by slightly increasing the critical Mach number however, its Tactical (useable) Mach number remained relatively modest at Mach 0.82 and both German and British test pilots found that it suffered severe controllability issues as it approached Mach 0.86.

The jet engine program was waylaid by a lack of funding, which was primarily due to a prevailing attitude amongst high-ranking officials that the conflict could be won easily with conventional aircraft. Among these was Hermann Göring, head of the Luftwaffe, who cut the engine development program to just 35 engineers in February 1940 (the month before the first wooden mock-up was completed). The aeronautical engineer Willy Messerschmitt sought to maintain mass production of the piston-powered, 1935-origin Bf 109 and the projected Me 209. Major General Adolf Galland had supported Messerschmitt through the early development years, flying the Me 262 himself on 22 April 1943. By that time, the problems with engine development had slowed the production of the aircraft considerably. One particularly acute problem was the lack of an alloy with a melting point high enough to endure the temperatures involved, a problem that had not been adequately resolved by the end of the war. After a November 1941 flight (with BMW 003s) ended in a double flameout, the aircraft made its first successful flight entirely on jet power on 18 July 1942, propelled by a pair of Jumo 004 engines.

Ludwig Bölkow was the principal aerodynamicist assigned to work on the design of the Me 262. He initially designed the wing using NACA airfoils modified with an elliptical nose section. Later in the design process, these were changed to AVL derivatives of NACA airfoils, the NACA 00011-0.825-35 being used at the root and the NACA 00009-1.1-40 at the tip. The elliptical nose derivatives of the NACA airfoils were used on the horizontal and vertical tail surfaces. Wings were of single-spar cantilever construction, with stressed skins, varying from 3 mm (0.12 in) skin thickness at the root to 1 mm (0.039 in) at the tip. To expedite construction, save weight, and use fewer strategic materials late in the war, the wing interiors were not painted. The wings were fastened to the fuselage at four points, using a pair of 20 mm (0.79 in) and forty-two 8 mm (0.31 in) bolts.

During mid-1943, Adolf Hitler envisioned the Me 262 as a ground-attack/bomber aircraft rather than a defensive interceptor. The configuration of a high-speed, light-payload Schnellbomber ("fast bomber") was intended to penetrate enemy airspace during the expected Allied invasion of France. His edict resulted in the development of (and concentration on) the Sturmvogel variant. Hitler's interference helped to extend the delay in bringing the Schwalbe into operation; (other factors contributed too; in particular, there were engine vibration problems which needed attention). In his memoirs, Albert Speer, then Minister of Armaments and War Production, claimed Hitler originally had blocked mass production of the Me 262, before agreeing in early 1944. Similar criticisms were voiced by Lieutenant General Adolf Galland. Hitler rejected arguments that the aircraft would be more effective as a fighter against the Allied bombers destroying large parts of Germany and wanted it as a bomber for revenge attacks. According to Speer, Hitler felt its superior speed compared to other fighters of the era meant it could not be attacked, and so preferred it for high-altitude straight flying.