Japanese Dive-bombers - the D3A and D4Y
Aichi D3A1 Val dive-bomber - Profile drawing
AichiD3A 'Val'

The Aichi D3A - Allied reporting-name 'Val' -  was the standard Japanese carrier-based dive-bomber during the opening stages of the Pacific War, operating with great effect in the Pearl Harbor attack and in the great carrier battles of 1942, but also suffering heavy losses in those battles.

Despite its importance in these engagements the D3A was produced in only relatively small numbers - 478 of the D3A1 and 816 of the more streamlined D3A2.

The Yokosuka D4Y Suisei  ('Comet') - Allied reporting-name 'Judy' - was the D3A's replacement, and by late 1944 relatively few Vals were left in service.

The D4Y had been designed to a demanding specification of 1937,  which called for a two-seat dive-bomber as fast as the A6M Zero-Sen fighter.   It was one of the few Japanese aircraft to go into production with a liquid-cooled engine.

The supposedly lower drag of the in-line motor was one means of meeting the demand for high speed,  but the Daimler-Benz 601 had an unsuccessful history in Japanese service. In 1943 the main problems with the Judy were eliminated by replacing the 601 with the reliable and smooth-running Kinsei 62 radial. After the Battle for Leyte Gulf battle the D4Y was extensively employed as a kamikaze aircraft carrying 800 kg (1,764 lb) of explosives.

Total production of the Judy was 2,038.

   

Aichi D3A - the 'Val'

Origin: Aichi Tokei Denki KK

Type:  Two-seat shipborne dive-bomber

Dimensions:  Span (D3A1) 47' 2" (D3A2) 47' 8" -  Length 33' 6" to 33' 7" -  Height 11' 0."

Weight:  (D3A1) 5,309 lb empty,  8,047 lb loaded  -  (D3A2)  5,772 lb empty,  8,378 lb loaded

Engine: (D3A1) One 1,075 hp Mitsubishi Kinsei 44 14-cylinder radial (D3A2) One 1,200 hp Kinsei 54

Performance:  Maximum speed (D3A1):  242 mph  -  (D3A2)  281 mph
                         Service ceiling (D3A1):   31,170 feet  -  (D3A2)  35,700 feet
                         Range Loaded (D3A1):  1,131 miles  -  (D3A2)  969 miles

 Armament: Two fixed forward-firing 7.7 mm machine-guns in wings
                    One 7.7 mm manually-aimed machine-gun in rear cockpit
                    One 250 kg bomb under fuselage plus (D3A1) two 30 kg bombs
   or (D3A2) two 60 kg bombs under wings

Yokosuka D4Y Suisei - the 'Judy'

Origin
Dai-Ichi Kaigun Koku Gijitsusho, Yokosuka;
 Production aircraft built by Aichi Kokuki KK and Dai-Juichi Kaigun Kokusho

Type
 Two-seat carrier dive-bomber
(D4Y1-c and D4Y2-c reconnaisance / D4Y2-s night-fighter / D4Y4 single-seat kamikaze aircraft)

Dimensions
Span 37' 9" -  Length 33' 6" -  Height (D4Y1, D4Y2) 12' 1" (D4Y3, D4Y4) 12' 3"

Weight
(D4Y1) 5,650 lb empty - 9,615 lb loaded

Engine
(D4Y1)  One 1,200 hp Aichi Atsuta-21 in-line inverted-V12 , liquid-cooled (Daimler-Benz 601)
(D4Y2)  One 1,400 hp Atsuta-32 in-line
             (D4Y3, D4Y4)  One 1,560 hp Mitsubishi Kinsei 62 14-cylinder two-row radial

Maximum Speed
(D4Y1) 339 mph  -  (D4Y2) 360 mph -  (D4Y3) 356 mph.

Initial Climb
D4Y1) 1,970 feet per minute (Other Versions) 2,700 feet per minute.

  Service Ceiling (typical)  34,500 feet

Range
(D4Y2) 749 miles(D4Y3) 945 miles.

Normal Armament
2 x 7.7 mm fixed forward-firing machine-guns above engine
1 x 7.7 mm manually-aimed 7.7 mm machine-gun in rear cockpit
1 x 250 kg (551 lb) bomb in internal fuselage bay
2 x 30 kg bombs - one under each wing