Aichi Atsuta
Encyclopedia
The Aichi Kokuki KK AE1A Atsuta (Japanese:アツタ or 熱田) was a Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
ese licensed version of the German
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
Daimler-Benz DB 601
Daimler-Benz DB 601
|-See also:-Bibliography:* Mankau, Heinz and Peter Petrick. Messerschmitt Bf 110, Me 210, Me 410. Raumfahrt, Germany: Aviatic Verlag, 2001. ISBN 3-92550-562-8.* Neil Gregor Daimler-Benz in the Third Reich. Yale University Press, 1998-External links:...
A 12-cylinder liquid-cooled inverted-vee aircraft engine. The Atsuta powered only two models of Imperial Japanese Navy Air Service
Imperial Japanese Navy Air Service
The Imperial Japanese Navy Air Service was the air arm of the Imperial Japanese Navy during World War II, the organization was responsible for the operation of naval aircraft and the conduct of aerial warfare in the Pacific War.It was controlled by the Navy Staff of the Imperial Japanese Navy and...
(IJNAS) aircraft aircraft in World War II. The Imperial Japanese Army Air Service
Imperial Japanese Army Air Service
The , was the land-based aviation force of the Imperial Japanese Army. As with the IJA itself, the IJAAF was developed along the lines of Imperial German Army Aviation so its primary mission was to provide tactical close air support for ground troops while maintaining a limited air interdiction...
(IJAAS) used the same engine (manufactured by Kawasaki as the Ha-40
Kawasaki Ha-40
|-See also:-Bibliography:* Monogram Closeup 13. ISBN 0-914144-13-8.* Francillon, R. J., Japanese Aircraft of the Pacific War, Putnam, London, 1970 SBN 370 00033 1-External links:* * *...
) to power its Kawasaki Ki-61
Kawasaki Ki-61
The Kawasaki Ki-61 Hien was a Japanese World War II fighter aircraft used by the Imperial Japanese Army Air Force...
Hien (Allied reporting name "Tony") fighter. The IJNAS's Atsuta and its IJAAS cousin, the Ha-40 were based on the engine that powered Germany's Messerschmitt Bf 109
Messerschmitt Bf 109
The Messerschmitt Bf 109, often called Me 109, was a German World War II fighter aircraft designed by Willy Messerschmitt and Robert Lusser during the early to mid 1930s...
fighter.
Aichi receives Daimler-Benz DB 600 license
Daimler-Benz granted Aichi Kokuki KK, a part of the Aichi Clock and Electric Co. (Aichi Tokei Denki KK), a license to manufacture the DB 600A through D models in November, 1936. At that time the Aichi Aircraft Company was building only the Nakajima KotobukiNakajima Kotobuki
-References:...
9-cylinder air-cooled radial engine at its Atsuta Engine Plant, located in south central Nagoya. It was necessary to re-tool the factory for the production of the new Daimler-Benz engine. Two DB-600 series engines were imported that year and three the next, all to be used as production patterns.
Experimental status
It was the Imperial Japanese Navy's common practice to use a coded designation while an engine was in experimental or pre-production status. This engine was coded "AE1A", which decodes as follows:- A=Aichi Tokei Denki KK.
- E=Liquid-cooled
- 1=Aichi's first liquid-cooled engine model
- A=first version of that engine model
IJNAS engine naming method
It was the Imperial Japanese Navy's common practice to refer to its engines by name, while the Imperial Japanese Army referred to its engines by their engine (Japanese:Hatsudoki abbreviated Ha) model number. Ha numbers were assigned in sequence as the engine design was accepted.The Japanese method of identifying model numbers of aircraft engines is unique in that the model number always has two digits and may be followed by one or more letters. The first digit represents the major version of the engine and the second number represents the minor version of that model engine. The model number follows the name (IJNAS engines) or the Ha number (IJAAF engines).
The first model number assigned to an engine is always 11, meaning the first major design and first minor version of that design. A major change to the design increments the first number and resets the second number to one. A minor change to the engine model increments the second number by one. If a very minor change is made, suffix letters are added after the model number.
Engine accepted by IJN
When the AE1A engine was accepted by the IJNAS, its coded designation was dropped and a name was chosen. It is from the Atsuta factory that the engine name was derived.The first production engine was the Atsuta 12 rated at 1200 hp. The model number 12 indicates this was the first model with one minor change.
Aichi receives Daimler-Benz DB 601A license
By early 1938 the Japanese Navy had also acquired the German He 118 V4Heinkel He 118
-See also:-References:* Green, William. Warplanes of the Third Reich. New York: Doubleday, 1972. ISBN 0-385-05782-2....
two-seat dive bomber aircraft, along with its production rights. This aircraft was powered by the DB 601A. The Heinkel's spectacular performance impressed the IJN Naval Staff so much that the design of the Yokosuka D4Y
Yokosuka D4Y
The D4Y Navy Type 2 Carrier Dive bomber was operated by the Imperial Japanese Navy. Its Allied reporting name was "Judy". The D4Y was one of the fastest dive-bombers of the war, and only the delays in its development hindered its service, while its predecessor, the slower fixed gear Aichi D3A...
Suisei (Allied reporting name "Judy") carrier based dive bomber evolved from it.
By 1939, eleven of the more advanced model DB 601A engines were imported. Manufacturing rights were updated for Aichi and granted to Kawasaki to build this model. The new engine received AE1P as its experimental designation.
DB 601A becomes the Atsuta model 32
When the AE1P design was accepted, Aichi's version became the Atsuta 32 and Kawasaki's version became the Ha-40, which was to be used in IJAAS's Kawasaki Ki-61Kawasaki Ki-61
The Kawasaki Ki-61 Hien was a Japanese World War II fighter aircraft used by the Imperial Japanese Army Air Force...
Hien (Allied reporting name "Tony") fighter.
The Atsuta 12 rated at 1200 hp was chosen to power the Yokosuka D4Y1 when it went into production. The D4Y2 was powered by the 1400 hp Atsuta 32 when it became available. The success of both airplanes was attributed to the slender lines of the high powered liquid-cooled engine.
Aichi M6A gets the Atsuta engine
A new top-secret aircraft that was to be transported and launched from a large submarine was ordered by the IJN in the spring of 1942 as the 17-Shi Special Attack Bomber. That aircraft became the Aichi M6AAichi M6A
The Aichi M6A Seiran was a submarine-launched attack floatplane designed for the Imperial Japanese Navy during World War II...
Serian (Shisei-Seiran), along with its M6A1-K Ninzan (Shisei-Seiran Kai) land-based trainer version.
Four preproduction M6A aircraft were completed, a firsthand account stating that one had a 1,200 hp Atsuta 12 engine, while the others three had Atsuta 32's. The first aircraft's engine was later changed to an Atsuta 32.
Eighteen M6A1 Special Attack Bomber versions followed, and these had the Atsuta 32 engine as well. Lastly, two of the original M6A1 prototypes were converted into M6A1-K Nanzan land-based training aircraft.
Engine production
Aichi manufactured 873 Atsuta series engines during World War II. These were shared between the twenty-two M6A1/M6A1-K and all D4Y1/2 aircraft. Peak production of the Atsuta 32 engine was in May, 1944, when 107 engines were produced.Production problems
A serious problem with the Aichi and Kawasaki version of the Dailmer-Benz engine was that that of holding a close tolerance fit between the crankshaft and its bearings on this fairly long engine. The result was that the engine proved to be prone to crankshaft failure. Additionally, there was often great difficulties obtaining engine components which, along with repeated air attacks on the Atsuta engine plant, eventually brought engine production to a standstill.Atsuta production ends
Maintenance difficulties with the Atsuta and Ha-40 engines eventually led to the installation of the more reliable Mitsubishi Kinsei 62 radial engine for the D4Y3 model 33, and the Mitsubishi Ha-112 radial air-cooled engine for the Army's Kawasaki Ki-61, which then became known as the Ki-100 Type 5 Fighter. Such a modification was not possible for the M6A1 as it could only use the liquid-cooled inverted-vee type engine, as it had to fit the submarine's confined hangar. The M6A1 Seiran then became the only Japanese airplane that retained the inverted-vee engine installation throughout the war.Evaluation by ATSC
Postwar evaluation by the Air Technical Service Command's Foreign Aircraft Evaluation Center for the Air Force (located at Wright FieldWright Field
Wright Field was an airfield of the United States Army Air Corps and Air Forces near Riverside, Ohio. From 1927 to 1947 it was the research and development center for the Air Corps, and during World War II a flight test center....
and Freeman Army Airfield
Freeman Army Airfield
Freeman Army Airfield is an inactive United States Army Air Force base. It is located south-southwest of Seymour, Indiana.The base was established in 1942 as a pilot training airfield. It was also the first military helicopter pilot training airfield...
) found the Atsuta engine's standard of workmanship was not as good as that of the Army's Kawasaki Ha-40
Kawasaki Ha-40
|-See also:-Bibliography:* Monogram Closeup 13. ISBN 0-914144-13-8.* Francillon, R. J., Japanese Aircraft of the Pacific War, Putnam, London, 1970 SBN 370 00033 1-External links:* * *...
, and far worse than Mitsubishi and Nakajima.