The Heinkel He 274 was a high altitude bomber developed from the Heinkel He 177, the heaviest bomber to see regular service with the Luftwaffe during the Second World War. Work began on the He 274 in 1941, under the designation He 177H. The RLM ordered six test aircraft in October 1941, with work to be split between Heinkel and Farman of Suresnes, Paris. Delivery was expected in July 1943.
The new aircraft abandoned the twinned DB 606 engines of the He 177 and instead used four DB 605 engines on a longer wing. The four-man crew were all located in a pressurized cabin in the nose, with the defensive guns remote controlled.
The development of the He 274 was slow. Sabotage in France, engine problems and design problems pushed the delivery date back into 1944. In April 1944 a proposed pre-production He 274A-0 was cancelled, but work continued on the prototypes. In July 1944 the first prototype was complete, but by then the allied armies were rapidly approaching Paris. An attempt to destroy the aircraft’s engines failed, and two prototypes were captured intact. More progress was made on the parallel plans to produce a four-engined He 177 under the designation He 277, but that too failed to produce a combat aircraft.
In the post-war reorganisation of the France aircraft industry, the Farman factory was renamed Atéliers Aéronautiques de Suresnes. One of their first jobs was to make the He 274 airworthy. On 27 December 1945 He 274 V1 made its maiden flight, under the new designation AAS 01. The test flights were successful and the aircraft was used to carry scale models of experimental French aircraft. The second prototype was completed with the addition of captured DB 603 engines and used as a flying test bed before being scrapped in 1953.
Engine: Daimler Benz DB 603A with turbo-superchargers on prototypes
Span: 144ft 8in
Length: 73ft 2 in
Full Weight: 79,564lb
Range: 3,602 miles
Ceiling: 46,905 ft
Speed: 363 mph at 36,000ft