The Kawanishi K-7 Transport Seaplane was a

Japanese Japanese may refer to: * Something from or related to Japan, an island country in East Asia * Japanese language, spoken mainly in Japan * Japanese people, the ethnic group that identifies with Japan through ancestry or culture ** Japanese diaspor ...

single-engined

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 ...

floatplane A floatplane is a type of seaplane with one or more slender floats mounted under the fuselage to provide buoyancy. By contrast, a flying boat uses its fuselage for buoyancy. Either type of seaplane may also have landing gear suitable for land, ...

of the 1920s. Eleven were built from 1924 to 1927, being used to carry passengers and

airmail Airmail (or air mail) is a mail transport service branded and sold on the basis of at least one leg of its journey being by air. Airmail items typically arrive more quickly than surface mail, and usually cost more to send. Airmail may be the ...

Design and development

In December 1923, Eiji Sekiguchi, chief designer of the aircraft department of ''Kawanishi Kikai Setsakuho'' (Kawanishi Machinery Manufacturing Works), started design of a new high speed transport

to equip ''Nippon Koku KK'' (Japan Aviation Co. Ltd.), an airline subsidiary of Kawanishi. Sekiguchi designed a single-engined

sesquiplane 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 ...

(i.e. a

with the lower wing much smaller than the upper wing) of all-wooden construction. Seating for four passengers was provided in an enclosed cabin, while the aircraft's two pilots sat in individual open tandem cockpits aft of the passenger cabin. The aircraft was powered by a single

Maybach Mb.IVa The Maybach Mb IVa was a water-cooled aircraft and airship straight-six engine developed in Germany during World War I by '' Maybach-Motorenbau GmbH'', a subsidiary of Zeppelin. It was one of the world's first series-produced engines designed sp ...

water-cooled inline-engine providing 305 hp (228 kW), an engine type usually used to power

Zeppelins A Zeppelin is a type of rigid airship named after the German inventor Count Ferdinand von Zeppelin () who pioneered rigid airship development at the beginning of the 20th century. Zeppelin's notions were first formulated in 1874Eckener 1938, pp ...

or ''

Riesenflugzeug A ''Riesenflugzeug'' (plural ''Riesenflugzeuge'', German for "giant aircraft"), sometimes colloquially referred to in English as an R-plane, was any member of a class of large World War I German bombers, possessing at least three aircraft engines ...

'' like the

Zeppelin-Staaken R.VI The Zeppelin-Staaken R.VI was a four-engined Imperial Germany, German biplane strategic bomber of World War I, and the only ''Riesenflugzeug'' ("giant aircraft") design built in any quantity.Gray, P and Thetford, O ''German Aircraft of the First ...

, received as part of

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reparations Reparation(s) may refer to: Christianity * Restitution (theology), the Christian doctrine calling for reparation * Acts of reparation, prayers for repairing the damages of sin History *War reparations **World War I reparations, made from G ...

to Japan after the end of the

First World War World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

. The first example of the new aircraft, the K-7A Transport Seaplane was completed in November 1924, demonstrating both good performance and handling. A further nine K-7As were built by the time production ended in 1927, together with a single example of the K-7B Mail-Carrying Aircraft, a modified version that could be operated either on floats or with a

tailwheel undercarriage Conventional landing gear, or tailwheel-type landing gear, is an aircraft An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynami ...

Operational history

The K-7A entered service on ''Nippon Kokus service between

Osaka is a designated city in the Kansai region of Honshu in Japan. It is the capital of and most populous city in Osaka Prefecture, and the third most populous city in Japan, following Special wards of Tokyo and Yokohama. With a population of 2. ...

and

Fukuoka is the sixth-largest city in Japan, the second-largest port city after Yokohama, and the capital city of Fukuoka Prefecture, Japan. The city is built along the shores of Hakata Bay, and has been a center of international commerce since ancie ...

in January 1925, mainly carrying

rather than passengers. The K-7A proved successful in service, one carrying mail from Fukuoka and

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, a distance of over in May 1926, while the K-7B was used together with the Kawanishi K-10 Transport to operate an airmail route between Osaka and the Japanese occupied city of

Dalian Dalian () is a major sub-provincial port city in Liaoning province, People's Republic of China, and is Liaoning's second largest city (after the provincial capital Shenyang) and the third-most populous city of Northeast China. Located on the ...

in September 1926. The K-7A continued in use until 1929, when ''Nippon Koku'' was forced to be disbanded, with its routes transferred to the government owned ''Nihon Koko Yuso KK'' (

Japan Air Transport was the national airline of the Empire of Japan from 1928 to 1938. History Commercial aviation began in Japan with the privately held Japan Air Transport Institute, which pioneered passenger service between Sakai, Osaka and Tokushima on Shikok ...

).History
ShinMaywa Industries via http://www.shinmaywa.co.jp. Retrieved 7 June 2010.

Variants

; K-7A Transport Seaplane :Six-seat airliner/transport floatplane, powered by Maybach MIVa engine. Ten built. ; K-7B Mail-carrying Aircraft :Modified version of K-7A, capable of operating with a fixed tailwheel undercarriage or floats, powered by 440 hp (328 kW) Lorraine 1

V12 engine A V12 engine is a twelve-cylinder piston engine where two banks of six cylinders are arranged in a V configuration around a common crankshaft. V12 engines are more common than V10 engines. However, they are less common than V8 engines. The fi ...

. One built in 1925.

Operators

; * Dai Nippon Kōkū Kabushiki Kaisha The Imperial Japanese Airways, in short Nippon Koku KK.

Specifications (K-7A)

References

;Notes ;Bibliography * {{Kawanishi aircraft 1920s Japanese airliners Floatplanes K-7 Sesquiplanes Single-engined tractor aircraft Aircraft first flown in 1924