The Yokosuka E6Y (long designation: ) was a Japanese submarine-based reconnaissance seaplane developed at the

Yokosuka Naval Air Technical Arsenal had many names, each depending on the period of its existence, and the circumstances at that time. Many of the names were acronyms that were derived from its military name or designation, which changed from time to time. The arsenal was sometim ...

for the

Imperial Japanese Navy The Imperial Japanese Navy (IJN; Kyūjitai: Shinjitai: ' 'Navy of the Greater Japanese Empire', or ''Nippon Kaigun'', 'Japanese Navy') was the navy of the Empire of Japan from 1868 to 1945, when it was dissolved following Japan's surrender ...

during the 1920s. The prototype first flew as the Yokosho 2-Go (long designation: ) in 1929. The aircraft was a single-seat

biplane A biplane is a fixed-wing aircraft with two main wings stacked one above the other. The first powered, controlled aeroplane to fly, the Wright Flyer, used a biplane wing arrangement, as did many aircraft in the early years of aviation. While a ...

that could be quickly assembled and disassembled so that it could be stored on board a submarine. Two prototypes were built that differed in power plant and design details. Eight production machines followed with the designation E6Y built by Kawanishi in the 1930s and served with the Japanese submarine aircraft carriers , , and . They saw limited action during the January 28 incident and the

Second Sino-Japanese War The Second Sino-Japanese War (1937–1945) or War of Resistance (Chinese term) was a military conflict that was primarily waged between the Republic of China and the Empire of Japan. The war made up the Chinese theater of the wider Pacific T ...

, the last example being retired in 1943.

Development

The

was a pioneer in naval aviation, starting as early as 1912 with the purchase of two floatplanes from Britain and one from the United States. By December 1922, Japan had completed '' Hōshō'', which vies with as the first ship purpose-designed for aircraft operations. Alongside that development, the Navy also looked at aircraft as a way to extend the operational reach of their large submarine force. Aware of the challenge of operations in the large expanse of the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the conti ...

, the Navy was particularly looking at ways to improve their reconnaissance capability and saw submarine-based aircraft as a complement to land--based patrol. They acquired a German Caspar U.1 from the United States and a Parnall Peto from Britain, both early submarine-based reconnaissance aircraft. The two aircraft formed the basis for two prototype Japanese aircraft built for submarine-based reconnaissance, the 1-Go based on the former, while the latter heavily influenced the 2-Go.

Design

The , which was abbreviated to Yokosho, developed the 2-Go as a smaller aircraft that the Peto. It was a

of mixed construction, with a steel frame and wooden-framed wings, covered in canvas. The wings were designed to detach for storage, as was the twin float assembly, which was also wooden. The first prototype was powered by the same engine as the Peto, an

Armstrong Siddeley Mongoose The Armstrong Siddeley Mongoose is a British five-cylinder radial aero engine produced by Armstrong Siddeley. Developed in the mid-1920s it was used in the Hawker Tomtit trainer and Parnall Peto seaplane amongst others. With a displacement of ...

five-cylinder

radial engine The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders "radiate" outward from a central crankcase like the spokes of a wheel. It resembles a stylized star when viewed from the front, and is ...

, rated at , but manufactured under license by

Mitsubishi The is a group of autonomous Japanese multinational companies in a variety of industries. Founded by Yatarō Iwasaki in 1870, the Mitsubishi Group historically descended from the Mitsubishi zaibatsu, a unified company which existed from 1870 ...

. The second prototype, designated 2-Go Kai, differed in a number of details. Lateral stability issues were resolved by increasing the tail fin and rudder, extending them upward. The aircraft was fitted with a more powerful Japanese seven-cylinder radial, rated at , which gave a maximum speed of and four and a half hours endurance. In 1931, the Kawanishi Aircraft Company was commissioned to produce eight production machines, designated E6Y1, based on the 2-Go Kai, which were built between 1932 and 1934.

Operational history

The Navy took delivery of the 2-Go in May 1929 and initially tested it aboard the submarine . Testing was completed by September 1931. The 2-Go Kai commenced testing in 1931 initially also on board ''I-51'' and then subsequently the Junsen I Mod type submarine . ''I-5'' was not fitted with a hangar, but rather the aircraft was disassembled and stored in two cylindrical containers, one for the fuselage and the other for the wings, stored on the deck. Launch was initially from the water, but a catapult was fitted to ''I-5'' in 1933 and this was found more satisfactory. All subsequent Japanese aircraft-carrying submarines used catapults. The first production E6Y entered service in 1933, and the eight aircraft were deployed to the three Junsen II and III submarines, , and . The aircraft also saw surface ship use. They saw limited service during the January 28 incident in 1932, providing reconnaissance, and subsequently there are reports that they served on submarines that operated during the

. Between 1937 and 1938, submarines ''I-5'' and ''I-6'' were assigned to the Third Fleet (China Theatre Fleet) based at Hong Kong to patrol and blockade the central and southern Chinese coasts. As the Japanese Navy introduced larger aircraft carrying submarines, the E6Y was superseded by the

Watanabe E9W The Watanabe E9W was a Japanese submarine-borne reconnaissance seaplane, the first aircraft designed by Watanabe Ironworks. Development and design In January 1934, the Imperial Japanese Navy had a requirement for a two-seat reconnaissance s ...

. The last example retired in 1943.

Variants

;Yokosho 2-Go :First prototype equipped with a

-licensed

. ;Yokosho 2-Go Kai :Second prototype equipped by a . ;E6Y1 :Production version of the 2-Go Kai manufactured by Kawanishi.

Operators

; *

Imperial Japanese Navy Air Service The was the air arm of the Imperial Japanese Navy (IJN). The organization was responsible for the operation of naval aircraft and the conduct of aerial warfare in the Pacific War. The Japanese military acquired their first aircraft in 1910 ...

Specifications (E6Y1)

References

Bibliography

* * * * * * * * *

External links

Multiplan view of the aircraft
*

Photo A photograph (also known as a photo, image, or picture) is an image created by light falling on a photosensitive surface, usually photographic film or an electronic image sensor, such as a CCD or a CMOS chip. Most photographs are now crea ...

{{Japanese Navy short aircraft designations Aircraft first flown in 1929 Floatplanes Kawanishi aircraft 1920s Japanese military reconnaissance aircraft Single-engined tractor aircraft Submarine-borne aircraft E6Y