The Kawanishi H6K was an

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 ...

flying boat A flying boat is a type of fixed-winged seaplane with a hull, allowing it to land on water. It differs from a floatplane in that a flying boat's fuselage is purpose-designed for floatation and contains a hull, while floatplanes rely on fusela ...

produced by the

Kawanishi Aircraft Company was a Japanese aircraft manufacturer during World War II. History The company was founded as Kawanishi Engineering Works in 1920 in Hyōgo Prefecture as an outgrowth of the Kawanishi conglomerate, which had been funding the Nakajima Aircraft Co ...

and used during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

for

maritime patrol {{Unreferenced, date=March 2008 Maritime patrol is the task of monitoring areas of water. Generally conducted by military and law enforcement agencies, maritime patrol is usually aimed at identifying human activities. Maritime patrol refers to ac ...

duties. The Allied reporting name for the type was Mavis; the Navy designation was .

Design and development

Kawanishi H6K Type 97 Transport Flying Boat Mavis H6K-16s

The aircraft was designed in response to a Navy requirement of 1934 for a long-range flying boat and incorporated knowledge gleaned by a Kawanishi team that visited the

Short Brothers Short Brothers plc, usually referred to as Shorts or Short, is an aerospace company based in Belfast, Northern Ireland. Shorts was founded in 1908 in London, and was the first company in the world to make production aeroplanes. It was particu ...

factory in the UK, at that time one of the world's leading producers of flying boats, and from building the

Kawanishi H3K The Kawanishi H3K, also known as Navy Type 90-2 Flying Boat (九〇式二号飛行艇), was a Japanese biplane military flying boat from the interwar period. The H3K was a development of the Short S.8/8 Rangoon. The first of the H3Ks was built ...

, a license-built, enlarged version of the Short Rangoon. The "Type S", as Kawanishi called it, was a large, four-engined

monoplane A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes. A monoplane has inherently the highest efficiency and lowest drag of any wing confi ...

with

twin tail A twin tail is a specific type of vertical stabilizer arrangement found on the empennage of some aircraft. Two vertical stabilizers—often smaller on their own than a single conventional tail would be—are mounted at the outside of the aircra ...

s, and a hull suspended beneath the

parasol wing A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes. A monoplane has inherently the highest efficiency and lowest drag of any wing confi ...

by a network of struts. Three

prototype A prototype is an early sample, model, or release of a product built to test a concept or process. It is a term used in a variety of contexts, including semantics, design, electronics, and Software prototyping, software programming. A prototyp ...

s were constructed, each one making gradual refinements to the machine's handling both in the water and in the air, and finally fitting more powerful engines. The first of these flew on 14 July 1936 and was originally designated "Navy Type 97 Flying Boat", later H6K. Eventually, 217 were built.

Operational history

H6Ks were deployed from 1938 onwards, first seeing service in the Sino-Japanese War and were in widespread use by the time the full-scale

Pacific War The Pacific War, sometimes called the Asia–Pacific War, was the theater of World War II that was fought in Asia, the Pacific Ocean, the Indian Ocean, and Oceania. It was geographically the largest theater of the war, including the vast ...

erupted, in December 1941. At that time of the war, four ''

Kōkūtai A ''Kōkūtai'' () was a term used by the Imperial Japanese Navy Air Service (IJNAS) to designate a military aviation unit, similar to the Air Groups in other air arms and services of the time. (''Group'' in the British Royal Air Force, ''Gruppe ...

'' (air groups) operated a total of 66 H6K4s. The type had some success over

South East Asia Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical south-eastern region of Asia, consisting of the regions that are situated south of mainland ...

and the

South West Pacific Oceania (, , ) is a geographical region that includes Australasia, Melanesia, Micronesia, and Polynesia. Spanning the Eastern and Western hemispheres, Oceania is estimated to have a land area of and a population of around 44.5 million as of ...

. H6Ks had excellent endurance, being able to undertake 24-hour patrols, and were often used for long-range reconnaissance and bombing missions. From bases in the

Dutch East Indies The Dutch East Indies, also known as the Netherlands East Indies ( nl, Nederlands(ch)-Indië; ), was a Dutch colony consisting of what is now Indonesia. It was formed from the nationalised trading posts of the Dutch East India Company, which ...

, they were able to undertake missions over a large portion of Australia. However, the H6K became vulnerable to a newer generation of more heavily armed and faster fighters. It continued in service throughout the war, in areas where the risk of interception was low. In front-line service, it was replaced by the

Kawanishi H8K The Kawanishi H8K was a flying boat used by the Imperial Japanese Navy Air Service during World War II for maritime patrol duties. The Allied reporting name for the type was "Emily". The Kawanishi H8K was a large, four-engine aircraft designed ...

Variants

Kawanishi H6K Type 97 Transport Flying Boat Mavis H6K-8s

; H6K1 :Evaluation

s with four

Nakajima Hikari The Nakajima Hikari (Japanese: 光 "Light") was a nine-cylinder, air-cooled, radial aircraft engine developed in Japan for Navy use during World War II by the Nakajima Aircraft Company. It was a development of the Nakajima Kotobuki and Wright ...

2 engines, four built. ; H6K1 (navy flying boat Type 97 Model 1) :Prototypes with 746 kW (1,000 hp)

Mitsubishi Kinsei The was a 14-cylinder, air-cooled, twin-row radial aircraft engine developed by Mitsubishi Heavy Industries in Japan in 1934 for the Imperial Japanese Navy. The Mitsubishi model designation for this engine was A8 while it was an experimental p ...

43 engines, three converted from the original H6K1 prototypes ; H6K2 Model 11 :First production model. Includes two H6K2-L officer transport modification, 10 built. ; H6K2-L (navy transport flying boat Type 97) :Unarmed transport version of H6K2 powered by Mitsubishi Kinsei 43 engines, 16 built ; H6K3 Model 21 :Modified transport version of H6K2 for VIPs and high-ranking officers, 2 built ; H6K4 Model 22 :Major production version, modified H6K2 with revised weapons, some with 694 kW (930 hp) Mitsubishi Kinsei 46 engines. Fuel capacity increased from 7,764 L (1,708 Imp gal) to 13,410 L (2,950 Imp gal). Includes two H6K4-L transport versions, 100 to 127 (if other numbers are all correct) built. ; H6K4-L :Transport version of H6K4, similar to H6K2-L, but with Mitsubishi Kinsei 46 engines, 20 built and another two converted from the H6K4 ; H6K5 Model 23 :Fitted with 969 kW (1,300 hp) Mitsubishi Kinsei 51 or 53 engines and new upper turret replacing the open position, 36 built

Operators

; * Air Service Volunteer Corps - A single H6K5 flying boat was restored to flight by Indonesian forces during the

Indonesian War of Independence The Indonesian National Revolution, or the Indonesian War of Independence, was an armed conflict and diplomatic struggle between the Republic of Indonesia and the Dutch Empire and an internal social revolution during postwar and postcoloni ...

.''Air Enthusiast Quarterley'' 1976, p. 156. ; *

Imperial Japanese Navy Air Service The was the Naval aviation, 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 air ...

Imperial Japanese Airways was the national airline of the Empire of Japan during World War II. History With the start of the Second Sino-Japanese War, there was a tremendous need for air transport capability by the Japanese military, which had traditionally drawn on th ...

: Used on the routes Yokohama-Saipan-Koror (Palau)-Timor, Saigon-Bangkok and Saipan- Truk-Ponape-Jaluit

Specifications (H6K4 Model 22)

Notes

Bibliography

* Doubilet, David. "The Flying Boat". ''Sport Diver Magazine''. Volume 15, Number 8, September 2007. * (new edition 1987 by Putnam Aeronautical Books, .) * * * "Pentagon Over The Islands...The Thirty Year History of Indonesian Military Aviation". '' Air Enthusiast Quarterly''. No. 2, n.d. pp. 154–162. * Richards, M.C. "Kawanishi 4-Motor Flying-Boats (H6K 'Mavis' and H8K 'Emily')". ''Aircraft in Profile Volume 11''. Windsor, Berkshire, UK: Profile Publications Ltd., 1972. * Van der Klaauw, Bart. ''Water- en Transportvliegtuigen Wereldoorlog II'' (in Dutch). Alkmaar, the Netherlands: Uitgeverij de Alk. .

External links

Duel between an HK6 and 2 B-17s
{{DEFAULTSORT:Kawanishi H6k H6K H6K, Kawanishi Flying boats Four-engined tractor aircraft Parasol-wing aircraft World War II Japanese patrol aircraft Aircraft first flown in 1936 Four-engined piston aircraft