Heinkel He 274

The Heinkel He 274 was a German heavy bomber with pressurized crew accommodation, developed during the Second World War for high-altitude bombing. It grew out of the He 177 programme: on 17 November 1938 Ernst Heinkel asked the air ministry to set aside two He 177 prototype airframes for a trial of four separate Junkers Jumo 211 engines, and on 27 April 1939 Heinkel's engineers presented the first proposal for a high-altitude version. By December 1940 the specification for a high-altitude He 177A-2 called for a four-person crew in two pressurized compartments. Because of the Allied advance through north-west Europe, the prototypes were abandoned at the factory in German-occupied France where they were being built. The French completed them after the war and used them for high-altitude research.