In trials, it was discovered that the maximum dive angle was only 50°. In June 1936,
Ernst Udet took the He 118 on a test flight but after commencing his first dive from about 13,000 feet the
propeller suddenly feathered, shearing the reduction gears, and the He 118 disintegrated, leaving Udet to parachute to safety. The Ju 87 repeatedly demonstrated dives at 90 degrees with no trouble, and so won the contract. Heinkel complained in his biography that Udet ignored instructions and flew the aircraft beyond its limits. He suggests that the failure doomed his design, in spite of being unable to dive vertically like the Stuka. Of the 15 He 118s built, two went to Japan where they were designated
DXHe. However, the aircraft disintegrated during Japanese flight tests. The 13-Shi (1939) design specification that led to the
Yokosuka D4Y naval dive bomber may have been inspired by the He 118, but otherwise the two aircraft had little in common. Heinkel used another example as a flying testbed for the
Heinkel HeS 3 turbojet, with the jet engine slung under its fuselage. Although its pilot took off and landed using the He 118's piston engine, he started the turbojet engine in flight and flew under its power in July 1939, the first time an aircraft flew under jet power. The following month the similarly powered, fixed
conventional landing gear-fitted
Heinkel He 178 V1 would make the first flight powered entirely by a turbojet engine. ==Variants==