The Aichi D3A (Codename 'Val') was the main dive bomber of the Japanese Navy during the early months of the Pacific Campaign in World War 2.
Neither especially large nor powerful, and in many respects obsolescent, the Imperial Navy's D3A dive bomber came as a most unpleasant shock to the Allies. On 7 December 1941 it was the ﬁrst type of Japanese aircraft to go into action against American targets, and it caused devastation at Pearl Harbor on that day. For almost a year it carried all before it, protected by the supposedly invincible A6IvI ‘Zero’ ﬁghters. During this period it wiped out most of the Allied surface vessels in the south-west Paciﬁc and Indian Ocean areas, achieving far more than even the Japanese commanders dared to hope. Then, quite suddenly, it was confronted by properly defended warships and formidable Allied ﬁghters, while replacement crews steadily deteriorated in quality and degree of training. The day of this once-feared aircraft was virtually over by mid-1943.
HistoryEditPrior to 1941 Allied intelligence on Japanese warplanes was almost non-existent. One of the few types known to exist — because of the fuss one caused in 1937 when it sank the US Navy gunboat Panay — was the Aichi D1A, a fabric-covered biplane derived from the German He 60. It was fondly thought that all Japanese combat aircraft were still of this general vintage in 1941, but in fact moves to replace the DlA had started in May 1936 with the drafting of an 11-Shi (meaning an experimental speciﬁcation in the 11th year of Emperor Hirohito's reign) for a new carrier-based dive bomber of stressed-skin monoplane design.The ultimate winner of an industry competition was again Aichi Tokei Denki, whose design team leader, Tokuhishiro Goake. was one of a number of Japanese fully experienced in the new form of all-metal construction. According to legend he adopted an elliptical wing plan because he was impressed by another earlier Heinkel type, the He YO. Like the Spitﬁre, the Aichi monoplane gained little from its curving wing shape which mainly had the effect of making it more difficult to construct. Goake decided against both internal bomb stowage and retractable landing gear, but did adopt a modern full-length engine cowling with cooling gills, a Hamilton type three-blade variable-pitch propeller and hydraulically powered ﬂaps and dive brakes, the latter being carried on three blade-pylons well below the underside of the wing and rotating 90" to limit speed in the dive. Only the tips of the wings folded to reduce stowage space when embarked.
The prototype flew in January 1938 and, after numerous improvements, the aircraft beat a rival from Nakajima, Aichi receiving a production contract in December 1939. The Navy designation was Type 99 Carrier Bomber Model ll, and the Allies bestowed the terse code-name Val, once the D3A had been positively identified. [N 1]
D3A carrier trials took place in autumn 1940, and an increasing number of the D3A1 version ﬂew operational missions in China and Indo-China from this time on, without the fact being appreciated in Washington. At Pearl Harbor 126 dive-bombers took part, and the number grew to over 250 by mid-1942. In April 1942 a small force placed from 82 to 87 per cent of their bombs on target in sinking the British carrier Hermes and heavy cruisers Dorsetshire and Cornwall. Altogether Aichi made 470 D3Als, followed by 815 of the more powerful and better streamlined D3A2, which replaced the earlier version on the company's assembly line in August 1942. A further 201 D3A2s were also constructed by the Japanese Showa company.
From mid-1942 losses were heavy, and by mid-1944 none were left in ﬁrst-line service except for the growing number of kamikaze suicide conversions.
Technical data on the Aichi D3A2Edit
- Powerplant: 1 × Mitsubishi Kinsei 54 14 cylinder radial, rated at 1300 hp (969.14 kW)
- Length: 33 ft 5.357 inch (10.19 m)
- Height: 12 ft 7.5 inch (3.85 m)
- Wing Span: 47 ft 2 inch (14.38 m)
- Wing Aspect ratio: 5.91
- Wing Area: 375.66 sq ft (34.9 m²)
- Empty weight: 5666 lb (2570 kg)
- Operational weight: 8047 lb (3650 kg) max
- Service ceiling: 34450 ft (10500 m)
- Maximum speed: 267 mph at 20340 ft (430 km/h at 6200 m)
- Cruising speed: 184 mph at (296 km/h) 9,845 ft (3,001 m)
- Initial climb rate: 9,845 ft (3,000 m) in 5 min 48 sec
- Range: 840 miles (1,352 km) typical
- Fuel capacity (internal): 237.35 Imp gal (285 US gal) 1079 liters
- Machine guns: 2 × 0.303 in (7.7 mm) fixed in upper nose, firing forward, 2 × 0.303 in (7.7 mm) flexible rearward firing in rear cockpit
- Bomb load: Up to 816 lb (370 kg) carried on three hardpoints: 1 × 551 lb (250 kg) under center line plus 2 × 132 lb (60 kg) under wings
- Crew: 2; pilot, radio operator/gunner
- First flight (prototype): August 1936
- Operational Service: 1940 - 1945
- Manufacturer: Aichi Tokei Denki KK
- Number produced: 1,016 this version out of 1,486 total.
- ↑ Code names were essential in order to report accurately aircraft whose true designation was seldom known and in any case difficult to remember. In general the policy was to assign a short and distinctive boy’s name to ﬁghters and reconnaissance seaplanes, names of trees to trainers, birds to gliders and girl's names to all other types.