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D4Y “Judy”, Japanese Carrier Dive Bomber


Photograph of D4Y "Judy"

U.S. Navy. Via Francillon (1979)

3-view diagram of D4Y "Judy"

U.S. Army. Via ibiblio.org


Yokosuka D4Y1 Suisei ("Comet") "Judy"


Specifications:


Crew 2
Dimensions 37’9” by 33’7” by 12’0"
11.51m by 10.24m by 3.66m
Wing area 254 square feet
23.6 square meters
Weight 5379-9370 lbs
2440-4250 kg
Maximum speed       343 mph at 15,585 feet
552 km/h at 4750 meters
Cruising speed 265 mph at 9845 feet
426 km/h at 3000 meters
Climb rate 31 feet per second
9.4 meters per second
Service ceiling 32,480 feet
9900 meters
Power plant One 1200 hp (895 kW) Aichi AE1A Atsuta 12 12-cylinder inverted-vee liquid-cooled engine driving a three-blade constant-speed metal propeller
Armament Two fuselage-mounted 7.7 mm Type 97 machine-guns
One rear-firing flexible 7.92 mm Type 1 machine-gun
External stores       One 500 kg (1102 lb) bomb plus two 30 kg (66 lb) bombs or one 310 kg (681 lb) bomb plus two 330 liter (72.6 gallon) drop tanks
Range 978 miles (1570km) normal
2417 miles (3890km) maximum
Fuel
280 gallons (1060 liters) internal
Production Aichi Kokuki K.K., at the Eitoku Plant, Nagoya
  660 D4Y1 production aircraft (spring 1942-Apr 1944)
  326 D4Y2 production aircraft (Apr 1944-Aug 1944)
  536 D4Y3 production aircraft (May 1944-Feb 1944)
  296 D4Y4 production aircraft (Feb 1945-Aug 1945)  

Dai-Juichi Kaigun Kokusho at Hiro:
 215 D4Y1, D4Y2 and D4Y3 production aircraft (Apr 1944-July 1945)
Variants The D4Y1-C added a camera in the rear fuselage for photoreconnaissance.
The D4Y2 upgraded the engine to a 1400 hp (1044 kW) Atsuta 32.
The D4Y3 used a 1560 hp (1163 kW) Mitsubishi MK8P Kinsei 62 14-cylinder radial engine.
The D4Y4 was a single-seat suicide plane carrying 800kg of explosives.


"Judy" was the response to a call for a two-seat long-range dive bomber as fast as the Zero. The result was the fastest dive bomber of the Second World War, which could not operate effectively from light carriers due to high takeoff speed requirements. It was otherwise an excellent light bomber. It was about the same size as a Zero, making it small for a dive bomber. Because of its relatively short wing span, it did not have folding wings.

The design dated from late 1938, when Aichi acquired manufacturing rights for the German DB 601A engine. A Yokosuka design team led by Yamana Masao began work on a derivative of the German He 118V4 and completed a prototype by November 1940. The aircraft exceeded all expectations and was rushed into production in the spring of 1942.

The initial production run suffered from wing flutter problems during steep dives. Because of their range and speed, these aircraft were deployed as the D4Y1-C reconnaissance aircraft, also known as the Type 2 Carrier Reconnaissance Aircraft. One of these aircraft was with 1 Air Fleet at the battle of Midway. The flutter problem was solved by strengthening the wing spars and redesigning the dive brakes, and the aircraft went into full production in March 1943 as a dive bomber.

Late-production D4Y3s were equipped with rocket-assisted takeoff units to allow them to operate from smaller carriers. This technology carried over to the D4Y4 suicide version as a way to boost the speed during the final dive.

Like many Japanese aircraft, the D4Y lacked armor protection or self-sealing fuel tanks. However, the aircraft had an internal bomb bay for its typical loadout of a single 500 kg bomb, and it could carry either two smaller bombs or two 330 liter drop tanks under its wings.

Photo Gallery


Captured D4Y Judy

U.S. Navy

Side view of D4Y Judy

SDASM

Front view of D4Y Judy

Wikimedia

Commons

Cockpit of D4Y Judy

Wikimedia

Commons


References

Francillon (1979)

Wilson (1998)


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