Aichi D3A Val

Designed to supersede the D1A, the Aichi D3A became far better known than its predecessor. Of low-wing monoplane configuration, the prototype had elliptical wings similar to those of the Heinkel He 70, a conventional tail unit, and a circular-section fuselage. Construction was basically all-metal. Non-retractable tailwheel landing gear incorporated main units with large speed fairings, and the prototype's powerplant was the 730 hp (544 kW) Hikari 1 radial that had powered the D1A2. Testing showed that the aircraft was underpowered, had a tendency to snap roll in tight turns, and had ineffective dive brakes. The second prototype incorporated modifications to overcome these shortcomings, including increased wing span, changed outboard wing section leading edges to over-come the roll problem, strengthened dive brakes, and an 840 hp (626 kW) Mitsubishi Kinsei 3 radial engine. In this form the type proved superior to Nakajima's contender for this requirement, and in December 1939 was ordered into production under the designation Navy Type 99 Carrier Bomber Model 11 (Aichi D3A1).

Production aircraft differed from the second prototype by having a small decrease in wing span, and directional stability was improved by the addition of a long dorsal fin. Power was again increased, with the introduction of a 1,000 hp (746 kW) Mitsubishi Kinsei 43 engine on early production models. In this form the D3A1 completed carrier trials aboard the Kaga and Akagi, and entered operational service with the navy in China and Indo-China. A total of 129 of these dive-bombers was carried by the task force that launched the attack on Pearl Harbor, and it was a force of D3A1s that sank the British aircraft carrier HMS Hermes, and the cruisers HMS Comwall and HMS Dorsetshire, in April 1942. At this time, the Aichi D3A enjoyed a bombing accuracy of 80 - 82 percent, and after releasing their bombs they were still effective dogfighters. This changed in late 1943, when the loss of skilled pilots saw the bombing accuracy drop below 10 percent, and this aircraft type ceased to be an effective threat.

Identified by the Allies under the codename 'Val', a total of 1,495 D3As of different versions was built. These included the two prototypes, plus six service trials and 470 D3A1 production aircraft. Then followed a single prototype of an improved D3A2 Model 12 which, first flown in June 1942, differed by having a modified rear canopy, a 1,300 hp (969 kW) Mitsubishi Kinsei 54 radial engine driving a propeller with spinner, and increased fuel capacity to cater for the more powerful engine. Duly ordered as the D3A2 Model 22, this was the major production version, a total of 1,016 being built by Aichi (815) and Showa (201). With a maximum take-off weight of 8,378 lbs (3800 kg), the D3A2 had a maximum speed of 267 mph (430 km/h) at 20,340 ft (6200 m) and service ceiling of 34,450 ft (10500 m). Final variant was the D3A2-K bomber trainer, of which an unspecified number of conversions were made from D3A2s late in the war after the type had been relegated to second-line duties. With the appearance of the Yokosuka D4Y Suisei, the Aichi D3A was relegated to lesser important operations. Nevertheless, D3As remained in service from beginning to end of the Pacific war, serving finally in kamikaze roles. Nakajima developed a smaller version of this aircraft with retractable landing gear (D3N1), but the type was never adopted.


An Aichi D3A1 "Val" of the Japanese Imperial Navy - Modern Day Replica

Variants

Aichi D3A2 Model 12 - A single prototype of an improved version with a 1,300 hp (969 kW) Mitsubishi Kinsei 54 engine, increased fuel capacity, a modified rear canopy and introducing a propeller spinner.

Aichi D3A2 Model 22 - A production version of the single Model 12 prototype. Maximum level speed 267 mph (430 km/h) at 20,340 ft (6200 m). Service ceiling 34,450 ft (10500 m). An empty weight of 5,666 lbs (2570 kg) with a maximum take-off weight of 8,378 lbs (3800 kg). A total of 1,016 of this type were built.

Aichi D3A2-K - A late war conversion of an unknown number of aircraft for use as a trainer. 

(Navy Type 99 Carrier Bomber Model 11 - Aichi D3A1)

Allied Codename: Val

Type: Two Seat Carrier or Land Based Dive Bomber

Design: Aichi Tokei Denki KK Design Team

Manufacturer: Aichi Tokei Denki KK (D3A2 - 815 aircraft) & Showa Hikoki Kogyo KK (D3A2 - 201 aircraft)

Powerplant: (D3A1) One 1,070 hp (798 kW) Mitsubishi Kinsei 44 14-cylinder radial engine. (D3A2) One 1,300 hp (969 kW) Mitsubishi Kinsei 54 radial engine.

Performance: (D3A1) Maximum speed 242 mph (389 km/h) at 9,845 ft (3000 m); cruising speed 183 mph (295 km/h) at 9,845 ft (3000 m); service ceiling 30,510 ft (9300 m). (D3A2) Maximum speed 267 mph (430 km/h) at 20,340 ft (6200 m); service ceiling 34,450 ft (10500 m).

Range: 913 miles (1470 km) on internal fuel with a single 551 lbs (250 kg) bomb.

Weight: Empty 5,309 lbs (2408 kg) with a maximum take-off weight of 8,047 lbs (3650 kg).

Dimensions: Span 47 ft 1 1/2 in (14.36 m); length 33 ft 5 1/4 in (10.19 m); height 12 ft 7 1/2 in (3.85 m); wing area 375.67 sq ft
(34.90 sq m).

Armament: Two fixed forward firing 7.7 mm (0.303 in) Type 97 machine guns, one 7.7 mm (0.303 in) Type 92 machine gun on a trainable mount in rear cockpit plus one 551 lbs (250 kg) centerline bomb and two 132 lbs (60 kg) of bombs on under wing racks.
Variants: D3A1, D3A2 Model 12 (single prototype), D3A2 Model 12, D3A2-K (trainer conversion).

Avionics: None.

History: First flight August 1936; first flight (D3A2) June 1942; termination of production (D3A2) January 1944.