 {| |} the blohm & voss ha 137 was a german ground-attack aircraft of the 1930s. it was blohm & voss' entry into the contest to equip the re-forming luftwaffe with its first purpose-built dive bomber. although the contest would eventually be won by the junkers ju 87, the ha 137 demonstrated that b&v's hamburger flugzeugbau, not even two years old at this point, had a truly capable design team of its own. it is of interest to note that one ha 137 single-seat prototype competed against the henschel hs 123 at rechlin. ==design and development== hamburger had already designed a biplane trainer of no particular distinction, the ha 135 under its first designer, reinhold mewes. mewes then left to join another small company, fieseler. in his place, hamburger hired richard vogt, who had been working for a decade with kawasaki aircraft and was looking to return to germany. before leaving japan, vogt had been working on a new design for building wing spars, using a single chrome-plated steel tube (often square or rectangular) that formed both the middle portion of the wing and also served as a primary fuel tank. when tenders were offered for the dive bomber program in 1934, hamburger was not even invited to submit an entry. nevertheless, vogt was convinced that his new construction method would deliver an aeroplane of the required strength with better performance than traditional designs, so he started work on projekt 6 and submitted it anyway. he also started work on a more conventional biplane design as projekt 7. thumb|blohm & voss ha 137 v-5. projekt 6 was essentially a scaled-up version of vogt's last design at kawasaki, the kawasaki ki-5. built entirely of metal and using a semi-monocoque fuselage, the design looked more like a fighter - specifically like the heinkel he 112 - than a dive bomber. the wing used the tubular spar system, the inner portion of which was sealed as a fuel tank holding 270&nbsp;l (70&nbsp;us gal). the design used fixed landing gear, so in order to reduce their length, and thus the drag, the wings featured a sharp inverted gull wing bend at about Â¼ span. the wheels were mo
Blohm_&_Voss_aircraft German_bomber_aircraft_1930a1939 Inverted_gull-wing_aircraft Low-wing_aircraft Single-engined_tractor_aircraft