The Günter brothers based their He 111 design on the proven He 70 Blitz. As a twin-engine version of its predecessor, the He 111 was often called the Doppel Blitz, or ‘Double Lightning’. The aircraft kept the elliptical wing design, although the surfaces were lengthened, and the extended fuselage could accommodate passengers and later a payload of bombs. The original BMW VI engines were deemed underpowered, giving way to the Daimler and then Junkers models. A single vertical fin was somewhat oversized for the aircraft’s profile; however, all surfaces were designed for maximum aerodynamics. The defensive machine guns were located in the nose and in flexible dorsal, ventral and lateral positions.
Factory workers labour to finish a He 111 on the floor of a facility in Germany. By 1944, the He 111 was largely obsolete but remained in service
Ernst Heinkel (right) with Siegfried Günter, working to perfect the design of the He 111