Heinkel He 280
He 280 V1
When work on the He 178 was discontinued in the autumn of 1939, effort was transferred to a more advanced twin-engined design which was to be powered by pairs of two new Heinkel turbojets, the HeS 8 and HeS 30. Design of the He 280, which started before the end of 1939, included a low wing with twin underslung turbojets tricycle landing gear and twin fins and rudders. Neither engine was ready for flight when the Heinkel He 280 prototype airframe was itself complete and first trial flights, which began on 22 September 1940, were unpowered, the aircraft being towed to release height behind a Heinkel He 111.
Despite the obvious need for low-diameter engines, Dr von Ohain succeeded in developing the centrifugal-flow HeS 8 (or 109-001) to produce 700-kg (1,543-1b) thrust installed in March 1941, and a pair of these engines powered the He 280 VI on its first powered flight on 2 April l941. For this first flight the engines were kept uncovered as during test runs fuel had gathered in the cowlings.
Fritz Schafer piloted the first powered flight, and the engines were producing little more than 500kg thrust, however, and although available thrust had risen to some 600kg by early 1943 when the second and third prototypes were flown, in April of that year BMW 109-003 engines were adopted.
A total of nine prototypes flew, includ-ing the He 280 V2 and He 280 V3 with HeS 8 engines (the former also being re-engined with Jumo 109-004s). The He 280 V4 had BMW 109-003s and la-ter with six Argus 109-014 pulsejets. The He 280 V5 flew first with HeS 8s and later with 109-003s. The He 280 V6 (as well as the V5) with three MG 151 20-mm can-non, the He 280 V7 with 109-004s (and later tested as a high-speed glider for aerodynamic research), the He 280 V8 with 109-004s and a V-type tail unit, and the He 280 V9 with 109-003s.
Although production of the He 280 was planned, recurring complaints (which included structural weakness in the tail, together with tail flutter, and in-adequate fuel and armament provi-sion) caused the design to be aban-doned in favour of the Messerschmitt Me 262,
It was from the He 280 V1 that the first-ever bale-out using an ejector seat was made when Argus test pilot Schenk abandoned the aircraft on 13 January 1942 when his controls locked from icing-up during a towed test flight. This seat was powered by compressed air.
He 280 V5
Engines: two 750-kg (1,653-1b) thrust HeS 8A (109-001A) turbojets
Maximum short-burst speed 900 kph (559 mph) at 6000 m (19,685 ft)
Normal max-speed 820 km/h
Initial climb rate 1145 m (3,755 ft) per minute
Estimated service ceiling 11500 m (37,730ft)
Range 650 km (404 miles)
Empty weight 3215 kg (7,088 lb)
Maximum take-off weight 4310 kg (9,502 lb)
Wing span 12.20 m (40 ft 0 in)
Length 10.40 m (34 ft 1.5 in)
Height 3.06 m (10 ft 0.5 in)
Wing area 21.50 sq.m (231.5 sq ft).
Armament: three nose-mounted 20-mm MG 151 cannon.