Yokosuka K4Y

Yokosuka Naval Air Technical Arsenal · Japan · first flew 1930 · light aircraft

The Yokosuka K4Y, or Navy Type 90 Seaplane Trainer, was a Japanese floatplane trainer of the 1930s. It was a single-engined two-seat biplane, and 211 were built between 1933 and 1940.

Recognition (WEFT)

W — Wings	Mid-mounted, straight
E — Engines	1 × piston, nose-mounted
F — Fuselage	Welded steel-tube fuselage
T — Tail	Conventional

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Spot it by:

Single-bay biplane with wooden wings
Welded steel-tube fuselage
Floatplane with a Gasuden Jimpu radial engine

It is a single-bay floatplane biplane with tandem seats for two crew. It is powered by a radial engine.

Specifications

The Yokosuka K4Y has a length of 9.05 m (30 ft).
It has a wingspan of 10.9 m (36 ft).
Its maximum speed is 163 km/h (101 mph).
Typical crew: 2.

Figures are for the representative variant described above; marks differ. See how AircraftIQ sources figures.

History

The Imperial Japanese Navy asked the First Naval Air Technical Arsenal at Yokosuka in 1930 to replace the K1Y trainer. The team led by Jiro Saha and Tamefumi Suzuki designed a single-bay biplane with a welded steel-tube fuselage and wooden wings, the first Japanese-designed aircraft with such a fuselage.

Variants

Two prototypes flew in 1930 with 90 hp Hatakaze four-cylinder inline engines. Production aircraft had a 130 hp Gasuden Jimpu radial and the short designation K4Y1.

Where you'll see it

Production began at Watanabe in May 1933, where 156 were built by 1939, and Nippon Hikoki built a further 53 in 1939 and 1940. It was the Navy's principal basic seaplane trainer throughout the Pacific war, and a few aircraft were released for civilian use.

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