U.S. Navy. Via Francillon (1979)
Yokosuka D4Y1 “Judy”
| 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 |
| Powerplant | One Aichi AE1A Atsuta 12 12-cylinder radial 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 | 681 lb (310 kg) bombs plus two 72.6 gallon (275 liter) drop tanks |
| Range | 978 miles (1570km) normal 2417 miles (3890km) maximum |
| 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 1400hp Atsuta 32. The D4Y3 used a Mitsubishi MK8P Kinsei 62 14-cylinder engine. The D4Y4 was a single-seat suicide plane carrying 800kg of explosive. |
Known as the Suisei (Comet) to the Japanese,
the Judy was the response to a call for a two-seat long-range dive
bomber as
fast as the Zero.
The result was a plane that could
not operate effectively from light
carriers
due to high takeoff speed requirements, but which was otherwise an
excellent
dive bomber. It was about the same size as a Zero, making it small for a dive
bomber, and it lacked armor
protection or self-sealing fuel tanks.
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. 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 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.
References
The Pacific War Online Encyclopedia (c) 2007-2008 by Kent G. Budge. Index
