Classic Military Aircraft
The Yokosuka D4Y Suisei was a Dive bomber operated by the Imperial Japanese Navy. Known as ‘Judy’ to the Allied forces. The D4Y was one of the fastest dive-bombers of the war and replace the slower Aichi D3A, after delays in production.
Development of the aircraft began in 1938, it was powered by a liquid-cooled inverted V12 ‘Atsuta’ engine, a licensed copy of a German aircraft engine and was fitted with a three-blade propeller. This gave the aircraft a maximum speed of 342 mph with a range of 910 miles and a ceiling height of 35,105 feet.
The aircraft had a crew of two, pilot and a navigator who was also the radio-operator / gunner, the maiden flight took place in December 1940. Bombs could be carried under the wings and in an internal fuselage bomb bay. It could carried one 1,100 lb bomb or two 550 lb bombs. The aircraft was armed with two 7.7 mm machine guns in the nose and a 7.92 mm machine gun in the rear of the cockpit. Later this was replaced by a 13 mm machine gun. To save weight the aircraft was not fitted with self-sealing fuel tanks or armour, this made it vulnerable to Allied fighters and anti aircraft fire, it tended to catch fire when hit.
The D4Y proved difficult to keep operational because the Atsuta engines tended to be unreliable. The aircraft’s engine was replaced with an air-cooled 14-cylinder two-row radial engine, the tried and trusted Mitsubishi MK8P. The new model was known as the Yokosuka D4Y3 Model 33.
As well as being used as a dive bomber the aircraft was also used as a reconnaissance aircraft, and later for kamikaze missions. The kamikaze version, the D4Y4 was fitted with a fixed 1760 lb bomb. They also begun installing rocket boosters on some aircraft to increase speed near the target.