The Heinkel He 280 was the first jet powered fighter aircraft to take to the skies, although it never entered mass production. The Heinkel He 178, the first aircraft to fly solely on jet power, had been powered by a single jet engine built into the fuselage, but the German Air Ministry believed that the fuselage mounted engine presented too many problems, and so work moved on twin-engined aircraft, with the engines mounted outside the fuselage, in most cases in nacelles carried below the wings.
The Heinkel He 178 had been powered by the HeS 3 and HeS 6 engines, designed by Dr Hans Joachim Pabst von Ohain. His next engine was the HeS 8, a centrifugal flow engine based on his earlier designed which was expected to produce 1,540lb of static thrust. He was now joined at Heinkel by Max A. Mueller, who was working on a axial flow engine, the HeS 30 of 1,760lb thrust. The two engines were also given official Air Ministry designations - 109-006 for the HeS 30 and 109-001 for the HeS 8. Heinkel intended to test both engines in the new He 280. A number of other companies were also working on jet engines, amongst them BMW, whose 109-003 would be suggested for production versions of the He 280.
The new aircraft was an all metal mid-wing monoplane with a streamlined fuselage. The cockpit was mounted just in front of the wings, and was given a sliding canopy. The wing had a straight leading edge and curved trailing edge, a design that would limit the speed of the aircraft. A tricycle undercarriage was used, with the nose wheel retracting backwards into the fuselage and the main wheels retracting inwards. The tail carried twin rudders. One genuinely revolutionary aspect of the design was the inclusion of a compressed-air powered ejection seat, which would soon come into use.
The aircraft was ready before the first of the new generation of Heinkel engines, and so its first test flight, on 22 September 1940, was an unpowered gliding test. The He 280 V1 was towed to altitude by a Heinkel He 111B, and then released. By March 1940 forty unpowered flights had been made, proving that the basic design of the aircraft was sound.
The first powered flight followed on 2 April 1941, and saw the V1 take to the air powered by two HeS 8 engines, each providing 1,102lb of static thrust, but with their cowling removed. This was followed by a demonstration flight in front of Luftwaffe and Air Ministry officials on 5 April, which led to approval being given for Heinkel to develop a new general of jet engines.
The He 280 was in direct competition with the Me 262 for a production order. When powered by the same engines the smaller lighter He 280 was faster, had a faster rate of climb, and a higher maximum ceiling, but it suffered some problems with its tail, had a shorter range than the Me 262 (Heinkel had underestimated the fuel consumption of their engines, and as a result the fuel tanks were too small), and was under-armed compared to the Me 262. In 1943 work on developing the Heinkel design as a production fighter aircraft came to an end, although the aircraft continued to be used for development work and to test new engines.
The He 280A-1 was the first design for a production version of the aircraft. It was to have been powered by Heinkel engines, and armed with three forward firing MG 151/15 machine guns. The A-1 didn't carry enough fuel, limiting its range, and so Heinkel produced the B-1 design.
In an attempt to solve the fuel problems the He 280B-1 was to have been 2ft 7in longer than the A-1 and prototype aircraft. It would have been powered by the BMW 003 engine, and armed with 20mm or 30mm cannon - some sources say three cannon, while others go as high as six. Despite these changes the He 280B-1 was not accepted for production.
After its first unpowered flights the He 280 V1 was finally given engines early in 1941. It made its maiden powered flight on 2 April 1941, using two HeS 8A engines. The V1 was then used to test the Argus 109-014 pulse-jet. It was equipped with four of these engines, and on 13 January 1943 was towed to altitude by a pair of Messerschmitt Bf 110s, before being released. This was to be a short-lived experiment, for during the first flight the aircraft iced up, and the Argus test pilot Schenk had to make the first ever use of an ejector seat in flight to escape from the aircraft.
The He 280 V2 made its first flights during 1941 with two prototype HeS 8 engines. Over the next two years the power provided by these engines rose from 500kg to 720kg of thrust, but higher powered engines were still needed, and in April 1943 the V2 was given a pair of Junkers Jumo 109-004 engines. Its maiden flight with the new engines came on 16 March 1943, but the aircraft was destroyed during landing on 26 June 1943.
The V3 made its maiden flight on 5 July 1943, powered by the He S8A engine. It made at least fifteen flights during 1942, but was damaged during a heavy landing in February 1943.
The V4 was built around a pair of BMW 109-003 engines, and made its maiden flight on 15 August 1943. Soon after this it was taken to Rechlin, where it was used to test the Argus 109-014, replacing the V1. The V4 was given six engines, and unlike the V1 survived the tests, but by the end of the year had been placed into storage at Hörsching near Linz.
The V5 was originally powered by HeS 8 engines, before being given a pair of BMW 109-003s. It was later used in armament trials, and possibly in mock combats against the Fw 190.
The V6 was powered by the BMW 109-003 engine.
The V7 was originally flown in April 1943, when it was powered by the Junkers Jumo 109-004. It was then taken to Ainring, Bavaria, where it was used for aerodynamic trails. The engines were removed, and experimental equipment added. The aircraft would be towed to height by a Heinkel He 111H-6 and then released. It was able to reach very high speed in fives, peaking at 578mph. At least 100 test flights were made between August 1944 and early 1945. Some of the experiments were made in an attempt to solve some of the problems of high speed flight, and some to test a new 'vee' shaped tail that was being designed for the He 162 and Me 262.
The V8 made its maiden flight on 30 June 1943, powered by two Junkers Jumo 109-004 engines. It was then given the new 'vee' shaped tail, and made its maiden flight in the new configuration on 29 September 1944.
The V9 was a test-bed for the BMW 109-003, and made its maiden flight on 31 August 1943.
Engine: Two Heinkel HeS 8A turbojets
Power: 1,650lb static thrust each
Wing span: 40ft
Length: 34ft 1 ½ in
Height: 10ft 0 ½ in
Empty weight: 7,073lb
Loaded weight: 9,482lb
Max Speed: 559mph for 30 seconds, 510mph maintained speed
Service Ceiling: 37,720ft (estimated)
Range: 404 miles at 19,680ft
Armament: Three MG 151 20m cannon