Yokosuka E6Y

{{Infobox aircraft begin

|name= E6Y

|image=

|caption=

}}{{Infobox aircraft type

| type= Submarine-based reconnaissance aircraft

| national origin= Japan

| manufacturer= Yokosuka Naval Air Technical Arsenal

| designer=

| first flight= 1929

| introduced= 1933

| retired= 1943

| status= Retired

| primary user= Imperial Japanese Navy

| more users=

| produced=

| number built= 10

| program cost=

| unit cost=

| developed from=

| variants with their own articles=

}}

The Yokosuka E6Y (long designation: {{nihongo|Yokosuka Navy Type 91-1 Reconnaissance Seaplane|九一式水上偵察機}}) was a Japanese submarine-based reconnaissance seaplane developed at the Yokosuka Naval Air Technical Arsenal for the Imperial Japanese Navy during the 1920s. The prototype first flew as the Yokosho 2-Go (long designation: {{nihongo|Yokosuka Arsenal No. 2 Reconnaissance Seaplane|横廠式二号水上偵察機}}) in 1929.

The aircraft was a single-seat biplane 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 {{ship|Japanese submarine|I-5||2}}, {{ship|Japanese submarine|I-6||2}}, {{ship|Japanese submarine|I-7||2}} and {{ship|Japanese submarine|I-8||2}}. They saw limited action during the January 28 incident and the Second Sino-Japanese War, the last example being retired in 1943.

Development

The Imperial Japanese Navy 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.{{sfn|Polmar|2011|page=34}} By December 1922, Japan had completed Hōshō, which vies with {{HMS|Hermes|95|2}} as the first ship purpose-designed for aircraft operations.{{sfn|Polmar|2011|page=35}} 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 Navy was particularly looking at ways to improve their reconnaissance capability and saw submarine-based aircraft as a complement to land-based patrol.{{sfn| Geoghegan|2013|page=53}} They acquired a German Caspar U.1 from the United States and a Parnall Peto from Britain, both early submarine-based reconnaissance aircraft.{{sfn|Carpenter|Polmar|1986|page=6}} 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.{{sfn|Marriott|2006|page=154}}

Design

The {{nihongo|Yokosuka Naval Air Technical Arsenal|海軍航空技術廠|Yokosuka Kaigun Kōshō}}, which was abbreviated to Yokosho, developed the 2-Go as a smaller aircraft that the Peto. It was a biplane of mixed construction, with a steel frame and wooden-framed wings, covered in canvas.{{sfn|Mikesh|Abe|1990|page=279}} 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 five-cylinder radial engine, rated at {{convert|130|hp|kW|abbr=on}}, but manufactured under license by Mitsubishi.{{sfn|Mikesh|Abe|1990|page=279}}

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.{{sfn|Mikesh|Abe|1990|page=279}} The aircraft was fitted with a more powerful Japanese {{Interlanguage link|Gasuden Kamikaze|lt=Gasuden Jimpu|ja|神風 (エンジン)}} seven-cylinder radial, rated at {{convert|160|hp|kW|abbr=on}}, which gave a maximum speed of {{convert|105|mph|km/h|order=flip|abbr=on}} and four and a half hours endurance.{{sfn|Marriott|2006|page=154}}

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.{{sfn|Mikesh|Abe|1990|page=279}}

Operational history

File:Japanese submarine I-5 in 1932.jpg

The Navy took delivery of the 2-Go in May 1929 and initially tested it aboard the submarine {{ship|Japanese submarine|I-51||2}}.{{sfn|Volkov|2014}} Testing was completed by September 1931.{{sfn|Mikesh|Abe|1990|page=279}} The 2-Go Kai commenced testing in 1931 initially also on board I-51 and then subsequently the Junsen I Mod type submarine {{ship|Japanese submarine|I-5||2}}. 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.{{sfn|Volkov|2014}} 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.{{sfn|Geoghegan|2013|page=53}}

The first production E6Y entered service in 1933, and the eight aircraft were deployed to the three Junsen II and III submarines, {{ship|Japanese submarine|I-6||2}}, {{ship|Japanese submarine|I-7||2}} and {{ship|Japanese submarine|I-8||2}}.{{sfn|Volkov|2014}} The aircraft also saw surface ship use.{{sfn|Carpenter|Polmar|1986|page=6}} 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 Second Sino-Japanese War.{{sfn|Volkov|2014}} 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.{{sfn|Boyd|Yoshida|2002|page=54}} As the Japanese Navy introduced larger aircraft carrying submarines, the E6Y was superseded by the Watanabe E9W.{{sfn|Marriott|2006|page=154}} The last example retired in 1943.{{sfn|Volkov|2014}}

Variants

;Yokosho 2-Go

:First prototype equipped with a {{convert|130|hp|kW}} Mitsubishi-licensed Armstrong Siddeley Mongoose.{{sfn|Mikesh|Abe|1990|page=279}}

;Yokosho 2-Go Kai

:Second prototype equipped by a {{convert|160|hp|kW}} {{Interlanguage link|Gasuden Kamikaze|lt=Gasuden Jimpu|ja|神風 (エンジン)}}.{{sfn|Mikesh|Abe|1990|page=279}}

;E6Y1

:Production version of the 2-Go Kai manufactured by Kawanishi.{{sfn|Mikesh|Abe|1990|page=279}}

Operators

;{{JPN}}

Imperial Japanese Navy Air Service

Specifications (E6Y1)

{{Aircraft specs

|ref=Mikesh & Abe, 1990{{sfn|Mikesh|Abe|1990|page=279}}

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|height m=2.87

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|wing area sqm=26.70

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|empty weight kg=570

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|max takeoff weight kg=750

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|eng1 number=1

|eng1 name={{Interlanguage link|Gasuden Kamikaze|lt=Gasuden Jimpu|ja|神風 (エンジン)}}

|eng1 type=7-cylinder radial

|eng1 kw=

|eng1 hp=160

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|endurance=4.4 hours

|ceiling m=4800

|ceiling ft=

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|time to altitude={{convert|3000|m|ft|abbr=on}} in 20 minutes 14 seconds

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|power/mass={{convert|5.77|kg|lb|abbr=on}}/hp

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|armament= *None

|avionics=

}}

References

Bibliography

{{cite book|last1=Boyd|first1=Carl|last2=Yoshida|first2=Akihiko|title=The Japanese Submarine Force and World War II|location=Annapolis|publisher=Naval Institute Press|year=2002|isbn=978-1-55750-015-1}}
{{cite book|last1=Carpenter|first1=Dorr|first2=Norman|last2=Polmar|title=Submarines of the Imperial Japanese Navy|location=London|publisher=Conway Maritime Press|year=1986|isbn=978-0-851-77396-4}}
{{cite book|last=Geoghegan|first=John|title=Operation Storm: Japan's Top Secret Submarines and Its Plan to Change the Course of World War II|location=New York|publisher=Crown Publishers|year=2013|isbn=978-0-307-46480-4|url=https://books.google.com/books?id=t5NPN9V2u7oC|access-date=6 October 2018}}
{{cite book|last=Marriott|first=Leo|title=Catapult Aircraft: Seaplanes That Flew From Ships Without Flight Decks|place=Barnsley|publisher=Pen and Sword|year=2006|isbn=978-1-844-15419-7}}
{{cite book|last1=Mikesh|first1=Robert C.|first2=Shorzoe|last2=Abe|title=Japanese Aircraft 1910-1941|location=London|publisher=Putnam|year=1990|isbn=978-0-851-77840-2}}
{{cite journal |last1=Passingham|first1=Malcolm|title=Les hydravions embarqués sur sous-marins |journal=Avions: Toute l'aéronautique et son histoire |date=February 2000 |issue=83 |pages=7–17 |trans-title=Submarine-carried Seaplanes |language=French |issn=1243-8650}}
{{cite journal |last1=Passingham|first1=Malcolm|title=Les hydravions embarqués sur sous-marins |journal=Avions: Toute l'aéronautique et son histoire |date=March 2000 |issue=84 |pages=25–37 |trans-title= |language=French |issn=1243-8650}}
{{cite book|last=Polmar|first=Norman|title=Aircraft Carriers: A History of Carrier Aviation and Its Influence on World Events, Volume II: 1946-2006|location=Dulles|publisher=Potomac Books|year=2011|isbn=978-1-597-97343-4}}
{{cite web|last=Volkov|first=Dale|url=http://www.airwar.ru/enc/other1/e6y.html|title=E6Y|website=Уголок неба|year=2014|language=ru|access-date=7 October 2018}}