World War II Database

Contributor: C. Peter Chen

ww2dbaseThe D4Y Suisei ("Comet") dive bombers had their origins from the German He 118 dive bomber design. The maiden flight in Dec 1940 and the subsequent test flights were highly successful, but it was later discovered that the wings were not strong enough to withstand the stresses of a dive. As a result, initial models sent to the front lines in 1942 were mainly only used for reconnaissance. The structural problems were addressed by Mar 1943, and the design was given to Aichi Kokuki KK for production. Because the performance of D4Y aircraft was so impressive, despite the lack of armor and self-sealing fuel tanks some of them were converted to night fighters later in the war, aimed at intercepting the high flying American B-29 bombers. The conversion, however, did not fare well against American fighter escorts. The final version of this design, dated around Feb 1945, was the D4Y4 Special Strike Bomber Model 43; they were designed to each carry a single 800-kg bomb for special attack missions. By the end of the war, 2,038 D4Y aircraft were produced, mostly by Aichi Kokuki KK.

ww2dbaseAllied codename for this model was "Judy".

SPECIFICATIONS

D4Y2 Model 12

Machinery	One Aichi AE1P Atsuta 32 V-12 liquid-cooled engine rated at 1,400hp
Armament	2x7.7mm forward Type 97 machine guns, 1x7.92mm rear Type 1 machine gun, 560kg of bombs
Span	11.50 m
Length	10.22 m
Height	3.74 m
Wing Area	23.60 m²
Weight, Empty	2,635 kg
Weight, Loaded	3,835 kg
Weight, Maximum	4,623 kg
Speed, Maximum	580 km/h
Speed, Cruising	425 km/h
Service Ceiling	10,700 m
Range, Normal	1,463 km
Range, Maximum	3,602 km

D4Y1 Model 11

Machinery	One Aichi AE1A Atsuta 12 V-12 liquid-cooled engine rated at 1,200hp
Armament	2x7.7mm forward Type 97 machine guns, 1x7.92mm rear Type 1 machine gun, 560kg of bombs
Span	11.50 m
Length	10.22 m
Height	3.68 m
Wing Area	23.60 m²
Weight, Empty	2,440 kg
Weight, Loaded	3,650 kg
Weight, Maximum	4,250 kg
Speed, Maximum	552 km/h
Speed, Cruising	425 km/h
Service Ceiling	9,900 m
Range, Normal	1,574 km
Range, Maximum	3,889 km

D4Y3 Model 33

Machinery	One Mitsubishi MK8P Kinsei 62 14-cylinder air-cooled radial engine rated at 1,560hp
Armament	2x7.7mm forward Type 97 machine guns, 1x7.92mm rear Type 1 machine gun, 560kg of bombs
Span	11.50 m
Length	10.22 m
Height	3.74 m
Wing Area	23.60 m²
Weight, Empty	2,501 kg
Weight, Loaded	3,754 kg
Weight, Maximum	4,657 kg
Speed, Maximum	574 km/h
Speed, Cruising	333 km/h
Service Ceiling	10,500 m
Range, Normal	1,518 km
Range, Maximum	2,889 km

D4Y4 Model 43

Machinery	One Mitsubishi MK8P Kinsei 62 14-cylinder air-cooled radial engine rated at 1,560hp
Armament	2x7.7mm Type 97 machine guns, 800kg of bombs
Span	11.50 m
Length	10.22 m
Height	3.74 m
Wing Area	23.60 m²
Weight, Empty	2,635 kg
Weight, Loaded	4,542 kg
Weight, Maximum	4,746 kg
Speed, Maximum	563 km/h
Speed, Cruising	370 km/h
Service Ceiling	8,450 m
Range, Normal	1,648 km
Range, Maximum	2,593 km

Photographs

Visitor Submitted Comments

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1.  Bill says:
19 Feb 2009 03:03:41 PM

Yokosuka D4Y Suisei (Comet) code word Judy by the Allies. The Judy was armed with two 7.7mm machine-guns in the upper fuselage decking and one flexable rear-firing 7.92mm Type 1 machine-gun manned by the radio operator. Able to carry for short missions a max. warload of 1,234 lbs. Powered by a liquid-cooled engine. Another version was powered by a air-cooled engine. Judy was also used as a night-fighter armed with a fuselage-mounted oblique-firing 20mm cannon Type 99 Model 2 cannon. Lacking radar and having a slow climbing speed, the judy was an ineffective night-fighter. Like most japanese aircraft the Judy was used in Kamikaze attacks. Total Production: 2,033. On 15 August,1945 The last sortie of the Suisei was made when Admiral Ugaki led eleven aircraft in a final, but inconclusive kamikaze attack off Okinawa.

2.  Bill says:
19 Feb 2009 03:33:46 PM

Where are they now? A "Surviving Judy" that was recovered from Yap Island, in the Carolines was extensively restored at Kisarazu A.B. Japan in 1980. The restoration is a mix of D4Y2 parts on a basic D4Y1 airframe. The aircraft now resides at the Yasukuni Shrine, Tokyo. Tail number is of the 523rd. Kokutai.

3.  Bill says:
19 Feb 2009 03:44:54 PM

Another "Surviving Judy" Model D4Y Some basic components or needing major restoration location: Museum of Flying, Santa Monica, California U.S.A.