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Yokosuka Ro-go Ko-gata

The Yokosuka Ro-go Ko-gata was a reconnaissance floatplane developed by the Japanese Navy Arsenal at Yokosuka during the First World War.

It was one of the earliest indigenous Japanese aircraft to enter production, with a total of 218 units built for the Imperial Japanese Navy.

The aircraft remained in service until 1928.

The Yokosuka Arsenal became involved in aircraft production in 1913, establishing an aeroplane factory that initially built several Maurice Farman and Curtiss Seaplanes.

The factory continued to build aircraft under license, including more Farman aircraft and several Short 184 seaplanes, as well as prototypes of its own designs.

In 1917, Chikuhei Nakajima, chief designer of the Yokosuka Arsenal aircraft factory, designed a new reconnaissance floatplane.

A prototype of this new design, powered by a 140 hp (104 kW) Salmson water-cooled radial engine, made its maiden flight early in 1918.

Test results were favorable, and the type was ordered into production as the Ro-go Ko-gata.

The Ro-go Ko-gata was a three-bay biplane of wood and fabric construction, with twin main floats and wings that folded backwards for storage.

Its crew of two sat in separate, closely spaced cockpits.

Initial production aircraft were powered by 200 hp (149 kW) Salmson engines, but the majority of production aircraft were fitted with 200–220 hp (149–164 kW) Mitsubishi-built Hispano-Suiza 8 V-8 engines.

A total of 218 aircraft were built, with production continuing until 1924.

The Ro-go Ko-gata was the first locally designed aircraft to be built in large numbers for the Japanese Navy.

Three of the early aircraft were modified in 1919 for making long-range flights, with one of the cockpits replaced by additional fuel storage.

This allowed a record flight of 1,300 km (808 mi) to be flown in 11 hours, 35 min on 20 April 1919.

The Ro-go Ko-gata, along with licensed built Hansa-Brandenburg W.29s, replaced the obsolete pusher Farmans in Japanese Navy service, remaining in large scale service until 1926, being re-designated Yokosho-Type Reconnaissance Seaplane in 1923.





10.16 m (33 ft 4 in)


15.692 m (51 ft 6 in)


3.666 m (12 ft 0 in)

Wing area

48.22 m2 (519.0 sq ft)

Empty weight

1,070 kg (2,359 lb)

Gross weight

1,628 kg (3,589 lb)


1 × Mitsubishi type Hi water-cooled V8 engine, 160 kW (220 hp)




Maximum speed

156 km/h (97 mph, 84 kn)


780 km (480 mi, 420 nmi)


5 hr

Time to altitude

4 min to 500 m (1,640 ft)



1× flexibly mounted 7.7 mm machine gun.


Japanese Aircraft, 1910-1941-Robert Mikesh & Shorzoe Abe

The Mainichi Newspapers Co Ltd

Yushukan War Memorial Museum


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