AICHI D3A1 VAL

Navy single-engined two-seat carrier-based dive bomber.

                      
Der Aichi D3A1, Typ 99, Serie II wurde 1936 nach japanischen Marinespezitikationen für einen neuen Bomber gebaut, der auf Flugzeugträgern stationiert wurde. Er war der Ersatz des Aichi DIA2-Zweideckers und das erste Flugzeug, das die amerikanischen Ziele bei Pearl Harbour am 7. Dezember 1941 bombardierte. Das Design war teilweise vom Heinkel 70 inspiriert, d.h., die Tragflächen hatten eine ähnliche Form, aber beim Aichi-Design wurde das feste Fahrgestell beibehalten. Der Prototyp flog erstmals im Januar 1938, war aber nicht hochtourig genug, und manche Teile waren anfällig. Beim zweiten Prototyp wurden diese Probleme jedoch gelöst. Im Wettbewerb mit anderen Herstellern bekam Aichi 1939 den Auftrag, sechs Probe- und 470 Serienflugzeuge für die Marine zu bauen. Ihre Tragflächen hatten eine etwas reduzierte Spannweite und Fläche. Trotz der Größe und des Gewichtes hatte das Flugzeug nach dem Einbau der Seitenflosse die Wendigkeit eines Jägers. Nach Probeflügen von Flugzeugträgern flogen die D3A1 zum ersten Male 1940 im Krieg zwischen China und Japan. Später haben ca. 126 D3A1 an den Angriffen auf Pearl Harbour teilgenommen, Sie waren auch mit allen bedeutenden Flugzeugträgereinsätzen für die nächsten 10 Monate verwickelt. Zuerst erzielten sie eine sehr hohe Bombardierpräzision. Die Vals (der alliierte Deckname) mußten schwere Verluste in den großen Schlachten hinnehmen, die im Korallenmeer, bei Midway, Guadalcanal und den Solomonen stattfanden. Dies lag teilweise an der verbesserten Leistung der alliierten Kampfjäger und den erfahrenen Piloten sowie auch an den Verlusten der japanischen Flugzeugträger. Viele Vals mußten von Landstützpunkten fliegen, deshalb produzierte Aichi die verbesserten Langstrecken-Vals D3A2, die mit den ständig größeren Entfernungen im Pazifik fertig werden sollten. Sie verdrängten Ende 1942 die frühere Version beim Fronteinsatz. Als die vielen von Aichi produzierten Yokosuka-D4Y2-Suisei-Stukas 1943 den Dienst antraten, wurden die Vals zu den kleineren Begleitflugzeugträgern oder Landstützpunkten als Trainingsflugzeuge relegiert. Ihr Schwanengesang kam im letzten Kriegsjahr, als viele ältere Vals wieder an der Front eingesetzt werden mußten, diesmal aber als die ziemlich erfolglosen und sehr anfälligen Kamikaze-Flugzeuge. Die ersten Vals D3A1 hatten einen 1000PS Mitsubishi-Kinsei 14-Zylindersternmotor und eine Höchstgeschwindigkeit von 386km/h (240mph) bei 2.998m (9.845 Fuß). Sie waren mit zwei vorwärts und einem rückwärts schießenden 7.7mm Maschinengewehren bewaffnet und konnten eine 250kg (551 Pfund) Bombe unter dem Rumpf und zwei 60kg (132 Pfund) Bomben unter den Tragflächen tragen. Designed to specifications issued by the Japanese Navy in 1936 for a new carrier-borne bomber to replace the Aichi DIA2 biplane, the Aichi D3A1 Type 99 Carrier Bomber Model II was destined to be the first Japanese type to bomb American targets at Pearl Harbour an 7 December 1941. The design was partially inspired by the German Heinkel 70, the wing shapes being very similar, although the Aichi design retained a fixed undercarriage. The prototype first flew in January 1938, and proved to be underpowered and suffering from some unstable characteristics, although these problems were solved in the second prototype. In competition with other types during 1939, Aichi won an order to build six trials and 470 production aircraft for the Navy; these featured wings of slightly reduced span and area. Despite its size and weight, when the dorsal fin was fitted the aircraft had fighter-style maneuverability; following carrier trials, the first operational D3A1s undertook combat missions in 1940 from the Chinese mainland during the war with that country. Later some 126 D3A1s took part in the Pearl Harbour attack, and the type was involved in all major carrier operations for the next 10 months, achieving very high bombing accuracies in the early days. Code-named VAL by the allies, it began to suffer heavy losses in the huge battles which occurred in the Coral Sea, at Midway, Guadalcanal and in the Solomon Islands; this was due in part to the improved performances of allied fighter aircraft and the experience of the their pilots, and also to the losses amongst the Japanese carrier forces. Many Vals were forced to operate from shore bases, and to cope with the ever-increasing. distances involved in the Pacific theatre Aichi produced the improved longer range D3A2 Val. These supplanted the earlier version in front line use by the end of 1942, and when the Yokosuka D4Y2 Suisei dive bomber - many of which were produced by Aichi - entered service from 1943, Vals were increasingly relegated to the smaller escort carriers or to land bases as trainers. Their swan song came during the final year of the war when many elderly Vals were again pressed into front line service, but this time as not very effective and very vulnerable kamikaze bombers. Powered by a 1,000 hp Mitsubishi Kinsei 14-cylinder radial engine, the early D3A1 Val had a maximum speed of 386km/h (240mph) at 2,998m (9,845ft).1t was armed with two forward-firing and one rearward-firing 7.7mm machine guns and could carry one 250kg (5511b) bomb under the fuselage and two 60kg (1321b) bombs under the wings.
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This plane played an important role in the beginning of the Pacific War as a dive-bomber. Like it's illustrious German counterpart the "Stuka" it was designed in the mid 1930's (1936 to be precise). The Val and Stuka share a number of similarities: both are 2-seaters with fixed forward firing guns and a single flexible rearfiring gun. Also the landing gear is non-retractable. The Val however was carrier based, whereas the Stuka was only landbased. Also did the Stuka have a more powerfull engine, and the typically gull-shaped wings

 

Technical data on the Aichi D3A2
Powerplant 1 × Mitsubishi Kinsei 54 14 cylinder radial, rated at 1300 hp (969.14 kW)   Role during war
bulletDive Bomber
Length 33 ft 5.357 inch   Height 12 ft 7.5 inch
Empty weight 5666 lb   Operational weight 8047 lb max
Wing Span 47 ft 2 inch   Wing Aspect ratio 5.91
Wing Area 375.66 sq ft   Service ceiling 34450 ft
Maximum speed 267 mph at 20340 ft   Cruising speed 184 mph at 9845 ft
Initial climb rate 9845 ft in 5 min 48 sec   Range 840 miles typical
Fuel capacity internal 237.35 Imp gal (285 US gal)   Fuel capacity external -
Machine guns 2 × 0.303 in fixed forward firing in upper nose,
2 × 0.303 in flexible rearward firing in rear cockpit		   Cannons -
Bomb load Up tot 816 lb carried on three hardpoints:
bullet1 × 551 lb under center line
bullet2 × 132 lb under wings
   Torpedoes/rockets -
Crew 2: pilot, radio operator/gunner   Naval or ground based Naval
First flight (prototype) August 1936   Operational Service 1940 - 1945
Manufacturer Aichi Tokei Denki KK   Number produced 1486 total, 1016 this version
Metric system
Length 10.19 m   Height 3.85 m
Empty weight 2570 kg   Operational weight 3650 kg max
Wing Span 14.38 m   Wing Aspect ratio 5.91
Wing Area 34.9 m²   Service ceiling 10500 m
Maximum speed 430 km/h at 6200 m   Cruising speed 296 km/h at 3001 m
Initial climb rate 3000 m in 5 min 48 sec   Range 1352 km typical
Fuel capacity internal 1079 liters   Fuel capacity external -
Machine guns 2 × 7.7 mm fixed forward firing in upper nose,
2 × 7.7 mm flexible rearward firing in rear cockpit		   Cannons -
Bomb load Up tot 370 kg carried on three hardpoints:
bullet1 × 250 kg under center line
bullet2 × 60 kg under wings
   Torpedoes/rockets -

 

Here is a quick overview of all different versions, without the full technical specifications:

Different versions of the Aichi D3A  Val
Aichi D3A1 The D3A1 was the first production version of the "Val". It differed form the D3A2 with it's powerplant: either 1 × Mitsubishi Kinsei 43 14 cylinder, rated at 1,000 hp (745 Kw), or 1 × Mitsubishi Kinsei 44 14 cylinder, rated at 1,075 hp (801 Kw).
Number built: 470
Aichi D3A2 Improved version of the Aichi D3A1. For details see above
Number built: 1,016

 

Remarks:

The Val was initially very successfull, and sunk a number of ships during the attack on Pearl Harbor in 1941. They sunk more Allied ships then any other type during World War 2. In the beginning of the war they had a hit ratio of over 80%, also due to the well trained crews. In the year 1942 however the weaknesses started to show: due to the slow speed they proved very vulnerable and were taken out of active duty from 1943 on. In 1945 the leftovers made a dubious comeback, this time as kamikaze planes. Even in this last role they were ineffective due to the firm air superiority the allied forces had gained.

Strengths

bulletGood maneuverability
bulletGood stability and handling during the dive
bulletGood structural strength, capable of taking damage

 

Weaknesses

bulletSlow speed
bulletInsufficient fixed armament, unable to pose a threat in dogfights