Aviation of World War II

Home Russian

D-3A "Val" (99)

Aichi E13A Jake
  • Shipborne Assault Dive Bomber
  • First flight: 1937
  • Aichi

The D3A gained notoriety after the Japanese air raid on Pearl Harbor in December 1941. Double dive bomber type "99" company Aichi entered service in 1939. According to its scheme - a single-engine cantilever monoplane with a fixed landing gear, with an 1280 hp engine. With. and underwing brake flaps, it was close to the German Yu-87 already known to the whole world, and in terms of dive bombing accuracy, it may even have surpassed it.

The first prototype aircraft took to the air in January 1938, after which a series of 470 D3A1s with a 1000-horsepower Kinsei-43 or 1070-horsepower Kinsei-44 engine was produced in 1939. At the beginning of the Second World War, this aircraft was the main machine of the Japanese carrier-based aviation. In the autumn of 1942, its improved version D-3A2 appeared (1016 vehicles were produced). However, by this time the design of the aircraft was already outdated; from 1943, most of the remaining D3A2s were converted into training D3A2-Ks.

D3A Val, Rabaul 1943

D3A Val, Rabaul 1943

D-3A2 'Val' Specification
Crew 2
Wing span, m 14.37
Length, m 10.20
Height, m 3.85
PE "Kinsey-54" ("Mitsubishi"), hp 1300
Weight, kg:
Empty weight 2,570
Gross weight 4,120
Maximum speed, km/h 430
Time to 3000m, min 6
Service ceiling, m 10,500
Service range, km 1,350
7.7-mm machine guns in fuselage and in a rear cabin, pcs 2+1
External bomb load, kg 370

The D3A carrier-based dive bomber was produced at the Aichi (December 1939 - July 1944) and Owl (December 1942 - August 1945) factories almost until the end of the Pacific War. During this time, 1495 aircraft of this type were built with the following modifications:

D3A1 Model 11 - the first serial modification, produced until August 1942. 470 machines were manufactured, which practically did not differ from the aircraft of the pre-production batch, except that instead of the 1000-horsepower Mitsubishi Kinsei 43 engines, the Kinsei 44 engines with a capacity of 1070 liters were installed on later series bombers. With.

D3A2 Model 12 - built in June 1942 in a single copy of the aircraft of this version differed from its predecessors by the new Mitsubishi Kinsei 54 engine with a capacity of 1300 hp. With. Although thanks to the use of a more powerful power plant, its characteristics improved markedly (for example, the maximum speed increased from 386 to 430 km / h), it did not go into the series, since Kaigun Koku Hombu demanded that a number of additional changes be made to the design, designed to further increase combat machine quality.

D3A2 Model 22 - the most massive (815 aircraft produced at the Aichi plant in Funakata and 201 at the Owl plant in Tokyo) and the fastest (433 km/h) modification of the D3A. Bombers of this variant differed from the D3A2 Model 12 in the volume of fuel tanks increased by 79 liters, the presence of a propeller spinner and a new elongated cockpit canopy. The main goal pursued by the developers was to increase the flight range, but it was not possible to achieve it. On the contrary, due to the greater fuel consumption of the Kinsei 54 engine and the increased mass of the aircraft, the range decreased by 111 km.

At the end of his career, the already obsolete aircraft was used as a flying bomb, piloted by kamikaze suicide bombers.

Photo Description

Drawing D3A1 model 11

Drawing D3A2 model 22 "Val"

Aichi D3A1 (99) at the airfield.

Aichi D3A1 (99) in flight at summer 1941.

D3A Val


Nakajima D3N1
  • Dive Bomber
  • First flight: 1937
  • Nakajima

The success of the Japanese carrier-based dive bomber Aichi D3A "Val" in the first half of the war was so devastating that not even all Japanese aviation experts know that another aircraft could well have been in place of the "Val". Having a more progressive design, better flight data and a much larger reserve for development, a dive bomber developed by Nakajima would have achieved, in any case, no worse results. But, as it often happens, not everything is decided by the best quality level of competing designs. Often the status of a developer firm, as well as a "hairy paw" in the echelons of power, do their job no less efficiently than the brains of engineers.

When in 1936 the technical department of the Imperial Navy Aviation Headquarters Kaigun Koku Hombu formulated the requirements of specification 11-Shi for a new carrier-based dive bomber - according to the Japanese classification - "Carrier-based bomber" "Kanjo Bakugekiki" - to replace the D1A2 biplane in service, in Three companies were invited to participate in the competition: Aichi, as the developer of the aforementioned dive bomber; Nakajima, as the company that had the greatest, albeit unsuccessful, experience in the development of such machines, as well as, of course, Mitsubishi, the traditional supplier of marine aircraft.

Mitsubishi, however, assessing their strength, refused to participate in the competition, and the main struggle unfolded between the Nakajima and Aichi companies.

The Aichi project, eventually realized in the famous "Val", is well known. Structurally, he largely had the German influence of the designs of Ernst Heinkel, with whom the company had been closely cooperating for many years.

But Nakajima's plane was original. The development of the dive bomber Nakajima was headed by Ryozo Yamamoto. The project, which received the internal designation "DB", was distinguished by a number of original solutions. To ensure braking during a dive, unusual landing gear was used. Racks retracted into the wing had an interesting design. They had three positions - the usual, in the released position, when harvesting, they turned around their longitudinal vertical axis and retracted back into the wing niches. But they could also be fixed in the deployed position, so that the wheels were turned against the oncoming air flow, playing the role of brakes. Thus, the specified dive speed limit of 240 knots, about 440 km / h, was provided.

The first prototype, designated D3N1, was ready in March 1937, almost a year ahead of its competitor. And then inexplicable things begin. When the first Nakajima prototype went through almost the entire test cycle, showing very good data, there was no reaction at all from the naval leadership. The Aichi AM-17 prototype, which took off only in December 1937, turned out to be slightly larger in size, had only folding wingtips, while Nakajima's plane could completely fold not only all the consoles, but also the vertical tail. In addition, the Aichi prototype had a shorter range, rate of climb, service ceiling and higher landing speed - that is, those qualities that are usually put at the forefront in the development of deck vehicles. Only, having a more powerful engine, AM-17 developed a little more speed. In terms of armament and bomb load, the aircraft were identical. The very first tests of the AM-17 revealed the low thrust-to-weight ratio of the Aichi aircraft, poor handling and unreliable operation of the aerodynamic brakes. While the D3N was devoid of these shortcomings.

However, the decision of the Kaigun Koku Hombu was delayed ... While the Aichi firm built three prototypes one by one, experimenting with different wings and motors, practically copying the cockpit canopy from Nakajima, the fleet did not issue orders for new Nakajima prototypes.

At the end of 1938, suddenly there was a demand to reduce the previously indicated dive speed limit from 240 knots to 200 knots (364 km / h), surprisingly coinciding with the parameters shown by the AM-17. And at the same time, Nakajima received an order for the production of two more prototypes. Ryozo Yamamoto had to urgently make changes to the design. The extended landing gear could no longer ensure the deceleration of the aircraft to a predetermined value. Perforated brake grids appeared on the trailing edge of the wing, similar to those used on the American Douglas SBD. The slightly more powerful Nakajima "Hikari"-1 Kai engine with a takeoff power of 820 hp was installed on the second and third prototypes, while the D3A1 had already received a 1000 hp Mitsubishi "Kinsei" 43. In the spring of 1939, the Aichi aircraft was declared the winner and was adopted.

It's hard to say what was the reason for such obvious playing along with the Aichi project. The motivation that the D3A showed more speed with a more powerful engine hardly holds up to criticism.

The second prototype D3N1 was left on Nakajima and was used throughout the war as a test bed for different versions of the Sakae and Homare engines. It is curious that during the tests of the NK1F Sakae 21 engine with a power of 1115 hp, which was tested on the D1N1 in early 1941, the aircraft showed a speed of 436 km / h, while the later modification of the Aichi D3A2, equipped with an even more powerful engine 1300-horsepower Mitsubishi "Kinsei" 54 showed only 425 km / h. But it was impossible to change the decision.

The second prototype D3N1 managed to survive the war and was sent for remelting by the "new masters" of Japan only in the fall of 1945.

© Evgeny Aranov

D3N1 Specification
Crew 2
Wing plane, m 14.50
Wing area, m² 34.00
Length, m 8.80
Height, m 2.80
1 × PE Nakajima Hikari-1 Kai, power, hp 1 × 820
Weights, kg
Empty weight 1,800
Loaded weight 3,400
Maximum speed, km/h 344
Cruise speed, km/h 255
Rate of climb, m/min 375
Service ceiling, m 7,000
Service range, km 1,600

Armament. Two 7.7 mm Type 97 machine guns above the engine and one 7.7 mm Type 92 machine gun on the gunner's turret.

250 kg bomb on a trapezoid under the fuselage + two 30-60 kg under the wing.



  • Aichi B7A Ryusei /E Aranov./
  • Experimental Nakajima D3N1 deck dive bomber /Evgeny Aranov/
  • "Japan Aircraft of World War II." /Oleg Doroshkevich/
  • "Encyclopedia of military engineering" /Aerospace Publising/