Blohm & Voss Ha-137
Blohm & Voss Ha-137 Dive Bomber
The dive bomber Blohm & Voss Ha-137 was designed in 1935 by Richard Vogt, who had been working for a decade with Kawasaki and was looking to return to Germany. The singleseat, low-wing, cantilever monoplane aircraft had a length of 9.46 m (31 ft), a span of 11.15 m (36 ft 7 in) and an empty weight of 1,814 kg (4,000 lbs). The all-metal design used fixed, faired landing gear, so in order to reduce their length, and thus the drag, the wings featured a sharp, reverse-gull bend at about 1/4 span.
The wheels were mounted on two shock absorbers each, so the fairing around the gear was large enough to allow the mounting of a 7.92-mm MG 17 machine gun for testing, and a 20-mm MG FF cannon if required. Two additional MG 17 machine guns were mounted in the fuselage decking above the engine cowl. Four 50-kg (110-lb) bombs were carried on underwing racks. The dive bomber was originally powered by one BMW XV engine, then by a 650hp Pratt & Whitney Hornet, licensed for production in Germany as the BMW 132. Three prototypes were built and the Ha 137V1 first flew in April 1935, followed the next month by prototype V2. It quickly became apparent that the Hornet engine was so large that the visibility during diving was greatly affected.
Fitted with a 610hp Jumo 210 engine, three new Ha 137 prototypes were built and tested. The aircraft was sturdy and welldesigned; it would probably have been a tough and maneuverable close-support fighter/dive bomber. It had a speed of 330 km/h (205 mph) and a range of 580 km (360 miles) but the Reichsluftfahrministerium (RLM—State Ministry of Aviation) chose the two-seat Junkers Ju-87 as standard Luftwaffe Stuka. The Ha 137 was thus excluded, and the project was dropped in 1936. The existing planes were maintained in flying condition as testbeds for experimental tasks, e.g., test firing of air-to-air rockets. There was a plan to produce a naval seaplane version of the design, known as Projekt 11. However the additional weight of the floats dramatically reduced performances and made the design untenable.