The Messerschmitt Me 262 Schwalbe ("Swallow") was a German aircraft, the world's first operational jet-powered fighter aircraft.^[5] It was produced in World War II and saw action starting in 1944 as a multi-role fighter/bomber/reconnaissance/interceptor warplane for the Luftwaffe. The Me 262 claimed a total of 509 Allied kills^[6] (although higher claims are sometimes made^{[Notes 1]}) against the loss of about 100 Me 262s. The Me 262 is considered to be the most advanced German aviation design in operational use^[8] and according to some Allied historians it was an aircraft that might have won air supremacy back for the Luftwaffe. Nevertheless, the Me 262 had a negligible impact on the course of the war due to its late introduction and the small numbers that were deployed in operational service.^[9] The Me 262 influenced the designs of post-war aircraft such as the North American F-86 and Boeing B-47.^[8]

The Me 262 was already being developed as Projekt P.1065 before the start of World War II. Plans were first drawn up in April 1939, and the original design was very similar to the plane that eventually entered service. The progression of the original design into service was delayed greatly by technical issues involving the new jet engines. Funding for the jet program was also initially lacking as many high-ranking officials thought the war could easily be won with conventional aircraft. Among those was Hermann Göring, head of the Luftwaffe, who cut back the engine development program to just 35 engineers in February 1940, Willy Messerschmitt, who desired to maintain mass production of the Bf 109 and the projected Me 209, and Major General Adolf Galland, who supported Messerschmitt through the early development years, flying the Me 262 himself on 22 April 1943. By that time problems with engine development had slowed production of the aircraft considerably.^[10]

In mid-1943 Adolf Hitler envisioned the Me 262 as an offensive ground-attack/bomber rather than a defensive interceptor, as a high speed, light payload Schnellbomber ("Fast Bomber"), to penetrate Allied air superiority during the expected invasion of France. His edict resulted in the development of (and concentration on) the Sturmvogel variant. It is debatable to what extent Hitler's interference extended the delay in bringing the Schwalbe into operation.^[11][12] Albert Speer, then Minister of Armaments and War Production, claimed in his memoirs that Hitler originally blocked mass-production of the Me 262 before agreeing to production in early 1944. He rejected arguments that the plane would be more effective as a fighter against Allied bombers then destroying large parts of Germany and wanted it as a bomber for revenge attacks. According to Speer Hitler had felt that its superior speed compared to other fighters of the era meant that it couldn't be attacked and so had preferred it for high altitude straight flying.^[13]

Although it is often stated the Me 262 is a "swept wing" design, the production Me 262 had a leading edge sweep of only 18.5°. This was done after the initial design of the aircraft, when the engines proved to be heavier than originally expected, primarily to position the center of lift properly relative to the centre of mass, not for the aerodynamic benefit of increasing the critical Mach number of the wing, where the sweep was too slight to achieve any significant advantage.^[14] On 1 March 1940, instead of moving the wing forward on its mount, the outer wing was repositioned slightly aft. The trailing edge of the mid-section of the wing remained unswept.^[15]. Based on data from the AVA Göttingen and windtunnel results, the middle section's leading edge was later swept to the same angle as the outer panels.^[16]

The first test flights began on 18 April 1941, with the Me 262 V1 example, bearing its Stammkennzeichen radio code letters of PC+UA, but since its intended BMW 003 turbojets were not ready for fitting, a conventional Junkers Jumo 210 engine was mounted in the V1 prototype's nose, driving a propeller, to test the Me 262 V1 airframe. When the BMW 003 engines were finally installed, the Jumo was retained for safety, which proved wise as both 003s failed during the first flight and the pilot had to land using the nose mounted engine alone.^[1]

The V3 third prototype airframe, with the code PC+UC, became a true "jet" when it flew on 18 July 1942 in Leipheim near Günzburg, Germany, piloted by Fritz Wendel.^[17] This was almost nine months ahead of the British Gloster Meteor's first flight on 5 March 1943. The conventional gear, forcing a tail-down attitude on the ground, of the Me 262 V3 caused its jet exhaust to deflect off the runway, with the wing's turbulence negating the effects of the elevators in the tail-down attitude, and the first attempt was cut short. On the second attempt, Wendel solved the problem by tapping the aircraft's brakes at takeoff speed, lifting the horizontal tail above and out of the wing's turbulence.^[18]

The aircraft was originally designed with a tailwheel undercarriage and the first four prototypes (Me 262 V1-V4) were built with this configuration, but it was discovered on an early test run that the engines and wings "blanked" the stabilizers, giving almost no control on the ground, as well as serious runway surface damage from the hot jet exhaust. Changing to a tricycle undercarriage arrangement, initially a fixed undercarriage on the "V5" fifth prototype, then fully retractable on the sixth (V6, with Stammkennzeichen code VI+AA) and succeeding aircraft, corrected this problem.

The BMW 003 jet engines, which were proving unreliable, were replaced by the newly available Junkers Jumo 004. Test flights continued over the next year, but the engines continued to be unreliable. Airframe modifications were complete by 1942, but hampered by the lack of engines, serial production did not begin until 1944, but deliveries were low with 28 Me 262s in June, 59 in July, but only 20 in August.^[8] This delay in engine availability was in part due to the shortage of strategic materials, especially metals and alloys able to handle the extreme temperatures produced by the jet engine. Even when the engines were completed, they had an expected operational lifetime of approximately 50 continuous flight hours; in fact, most 004s lasted just 12 hours, even with adequate maintenance. A pilot familiar with the Me 262 and its engines could expect approximately 20–25 hours of life from the 004s. Changing a 004 engine was intended to require three hours, but this typically took eight to nine due to poorly made parts and inadequate training of ground crews.

Turbojet engines have less thrust at low speed than propellers, and as a result, low-speed acceleration is relatively poor. It was more noticeable for the Me 262 as early jet engines (before the invention of afterburners) responded slowly to throttle changes. The introduction of a primitive autothrottle late in the war only helped slightly. Conversely, the higher power of jet engines at higher speeds meant the Me 262 enjoyed a much higher rate of climb. Used tactically, this gave the jet fighter an even greater speed advantage in climb rate than level flight at top speed.

With one engine out, the Me 262 still flew well, with speeds of 450–500 km/h (280-310 mph), but pilots were warned never to fly slower than 300 km/h (190 mph) on one engine, as the asymmetrical thrust would cause serious problems.

Operationally, the Me 262 had an endurance of 60 to 90 minutes.

By January 1945, Jagdgeschwader 7 (JG 7) had been formed as a pure jet fighter wing, although it would be several weeks before it was operational. In the meantime, a bomber unit — I Gruppe, Kampfgeschwader 54 (KG 54) — had re-equipped with the Me 262 A-2a fighter-bomber for use in a ground-attack role. However, the unit lost 12 jets in action in two weeks for minimal returns.

Jagdverband 44 (JV 44) was another Me 262 fighter unit, of Staffel (squadron) size given the low numbers of available personnel, formed in February 1945 by Lieutenant General Adolf Galland, who had recently been dismissed as Inspector of Fighters. Galland was able to draw into the unit many of the most experienced and decorated Luftwaffe fighter pilots from other units grounded by lack of fuel.

During March, Me 262 fighter units were able, for the first time, to mount large scale attacks on Allied bomber formations. On 18 March 1945, 37 Me 262s of JG 7 intercepted a force of 1,221 bombers and 632 escorting fighters. They shot down 12 bombers and one fighter for the loss of three Me 262s. Although a 4:1 ratio was exactly what the Luftwaffe would have needed to make an impact on the war, the absolute scale of their success was minor, as it represented only one per cent of the attacking force. In 1943 and early 1944, the USAAF had been able to keep up offensive operations despite loss ratios of 5% and more, and the few available Me 262s could not inflict sufficient losses to hamper their operations.

Despite its deficiencies, the Me 262 clearly signaled the beginning of the end of piston-engined aircraft as effective fighting machines. Once airborne, it could accelerate to speeds well over 800 km/h (500 mph), over 150 km/h (90 mph) faster than any Allied fighter operational in the European Theater of Operations.

The Me 262's top ace^{[Notes 2]} was probably Hauptmann Franz Schall with 17 kills which included six four-engine bombers and ten P-51 Mustang fighters, although night fighter ace Oberleutnant Kurt Welter claimed 25 Mosquitos and two four-engine bombers shot down by night and two further Mosquitos by day flying the Me 262. Most of Welter's claimed night kills were achieved in standard radar-less aircraft, even though Welter had tested a prototype Me 262 fitted with FuG 218 Neptun radar. Another candidate for top ace on the aircraft was Oberstleutnant Heinrich Bär, who claimed 16 enemy aircraft while flying the Me 262.

The Me 262 was so fast that new tactics had to be devised to attack American bombers. In the head on attack, the closing speed of about 350 yds per second was too high for accurate shooting. Even from astern the closing speed was too great for the short-ranged 30 mm cannon to be used to maximum effect. Therefore, a roller-coaster attack was devised. The 262s approached from astern and about 6,000 ft higher than the bombers. From about three miles behind they went into a shallow dive that took them through the escort fighters with little risk of interception. When they were about a mile astern and 1,500 ft below the bombers they pulled up sharply to reduce their excess speed. On levelling off, they were 1,000 yds astern and overtaking the bombers at about 100 mph, well placed to attack them.^[23] Since 30 mm cannon were not accurate above 650 yd (590 m), and since it was necessary to break off at 200 yd (180 m) to avoid colliding with the target, Me 262 pilots would normally commence firing at 550 m (600 yd).^[24] Allied bomber gunners found their electric gun turrets had problems tracking the jets. Target acquisition was difficult because the jets closed into firing range quickly and had to remain in firing position only briefly using their standard attack profile.

Eventually, new combat tactics were developed to counter the Allied bombers' defences. Me 262s equipped with R4M rockets would approach from the side of a bomber formation, where their silhouettes were widest, and while still out of range of the 12.7 mm (.50 in) guns, fire a salvo of rockets. The high explosive warhead of only one or two of these rockets was capable of downing even the famously rugged B-17; a strike on an enemy aircraft meant its total annihilation.^[25] Although this tactic was effective, it came too late to have a real effect on the war. This method of attacking bombers became the standard until the invention and mass deployment of guided missiles. Some nicknamed this tactic the "Luftwaffe's Wolf Pack", as the fighters would often make runs in groups of two or three, fire their rockets, then return to base.

On 1 September 1944, USAAF General Carl Spaatz expressed the fear that if greater numbers of German jets appeared, they could inflict losses heavy enough to force cancellation of the Allied daylight bombing offensive.