The Yokosuka D3Y Myojo (Venus) was originally intended to be a wooden version of the Aichi D3A2-K bomber trainer, but the design was modified while the aircraft was under development. A suicide attack version was also developed, but the prototype of this version was unfinished at the end of the Second World War.
The Aichi D3A2-K Navy Type 99 Bomber Trainer was a training version of the D3A 'Val', one of the main Japanese bombers early in the Pacific War. By 1943 Japan was beginning to run short of the light alloys needed for high performance aircraft, and a programme was put in place to produce aircraft using non-strategic materials.
The Naval Arsenal at Yokosuka was given the task of producing a wooden version of the D3A2-K. A number of chances to the design had to be made to make it suitable for construction in wood by semi-skilled workers. The elliptical wings and curved tails of the Val were replaced with simple straight edged tapered wings. The fuselage was lengthened. It retained the fixed undercarriage of the Val. The D3Y was powered by a 1,300 Mitsubishi Kinsei 54 fourteen-cylinder radial engine.
Two prototypes of the D3Y1-K trainer were produced in July-August 1944. The aircraft proved to be heavier than expected and had to be redesigned, delaying production. Production of the final version was given to Matsushita, but only three had been completed by the end of the war.
At the start of 1945 work began on a suicide attack version. The prototype was designated as the D3Y2-K, although production aircraft would have been the D5Y1. The D3Y2-K had a more powerful version of the Kinsei engine, a jettisonable undercarriage, and would have been armed with two 20mm cannon and a 1,764lb. The prototype was still under construction at the end of the war.
D3Y1-K Bomber Trainer
Engine: Mitsubishi Kinsei 54 fourteen-cylinder air-cooled radial
Power: 1,300hp at take-off; 1,200hp at 9,845ft; 1,100hp at 20,340ft
Span: 45ft 11 3/16in
Length: 36ft 9 17/32in
Height: 13ft 8 3/4in
Empty weight: 7,055lb
Loaded weight: 9,259lb
Max speed: 280mph at 20,340ft
Climb Rate: 13min 23sec to 19,685ft
D3Y2-K Suicide Bomber
Engine: Mitsubishi Kinsei 62 fourteen-cylinder air-cooled radial
Power: 1,560hp at take-off; 1,340hp at 9,845ft; 1,190hp at 20,340ft
Span: 45ft 11 3/16in
Length: 37ft 9 11/32in
Height: 13ft 9 11/32in––
Empty weight: 6,725lb
Loaded weight: 10,207lb
Max speed: 292mph at 16,405ft
Climb Rate: 11min 45sec to 19,685ft
Service ceiling: 30,350ft
Range: 915 miles
Armament: Two 20mm Type 99 Model 1 cannon
Bomb load: 1,764lb