The Yokosuka D4Y "Judy": From Dive Bomber to Special Attack Aircraft
The Yokosuka D4Y Suisei (Japanese for "Comet"), known to the Allies by the reporting name "Judy," was a two-seat carrier-based dive bomber operated by the Imperial Japanese Navy during the Second World War. Developed by the Yokosuka Naval Air Technical Arsenal and making its first flight in December 1940, the D4Y was designed to replace the aging Aichi D3A. It was an exceptionally sleek and aerodynamic aircraft, originally powered by a licensed copy of the German Daimler-Benz DB 601 liquid-cooled V12 engine. This streamlined design made the Suisei one of the fastest dive bombers of the entire war, capable of outpacing even the famous Mitsubishi A6M Zero fighter in certain flight regimes.
Despite its impressive speed and maneuverability, the early D4Y variants suffered from the chronic unreliability of their inline engines and a lack of defensive armor or self-sealing fuel tanks. To address the powerplant issues, later models, such as the D4Y3, were fitted with the more dependable Mitsubishi Kinsei radial engine. While primarily a dive bomber, the aircraft's high speed and long range allowed it to be adapted for various roles throughout the conflict, including reconnaissance and night fighting. The D4Y proved its lethal capability in conventional attacks late in the war; notably, lone Suisei bombers were responsible for sinking the light carrier USS Princeton at the Battle of Leyte Gulf in October 1944 and severely damaging the fleet carrier USS Franklin in March 1945.
As the strategic situation deteriorated for Japan in the final year of the Pacific War, the Imperial Japanese Navy increasingly turned to tokko (special attack) or kamikaze tactics. The D4Y emerged as an almost ideal platform for these suicide missions due to its unmatched combination of speed, range, and payload capacity. In February 1945, production began on the D4Y4 Special Strike Bomber, a purpose-built kamikaze variant. This final iteration was modified to carry a massive 800-kilogram (1,760-pound) bomb semi-recessed in the fuselage and was equipped with three tail-mounted rocket boosters designed to accelerate the aircraft during its terminal dive, making it incredibly difficult for Allied anti-aircraft gunners to intercept.
The D4Y4 was also the first variant to finally incorporate bulletproof glass and armor protection for the crew and fuel tanks, ensuring the pilot could survive long enough to strike his target. The Suisei was heavily utilized during the massed kikusui kamikaze raids off Okinawa, diving on American radar pickets and escort carriers. In a poignant and grim footnote to the aircraft's history, Vice Admiral Matome Ugaki, commander of the IJN's 5th Air Fleet, flew his final, unauthorized kamikaze mission in a D4Y hours after Emperor Hirohito had already announced Japan's surrender on August 15, 1945.
Ron Cole regards this composition of his as one of his personal favorites, depicting an almost otherworldly environment that's in contrast to his other work.
