The inverted gull wing, bent downward to keep the gear legs short and the huge prop clear of the ground, made the F4U Corsair instantly recognizable. Other airplanes, however, had used this feature before the Corsair, particularly during the era of fixed gears enveloped in voluminous fairings or “pants.” An early example was the Ha 137. Ha stands for Hamburger Flugzeugbau — Hamburg Airplane Factory — a subsidiary of the great German shipbuilding firm of Blohm & Voss. A dark horse in a Luftwaffe dive bomber competition, the sleek 137 lost out to the famous Junkers Stuka, which also had an inverted gull wing as well as its own built-in air-raid siren and the ability to dive perfectly vertically.
The designer of the Ha 137 was named Richard Vogt. A protégé of Claudius Dornier, whose designs were manufactured under license by Kawasaki, Vogt worked in Japan in the 1920s, then returned to Germany in 1933 to become head of aircraft design for Blohm & Voss. He remained there until the end of the war.
