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Watanabe E9W

The Watanabe E9W was a reconnaissance seaplane that was launched from a Japanese submarine.

It was the first aircraft to be designed by Watanabe Ironworks.

In January 1934, the Imperial Japanese Navy expressed a need for a two-seat reconnaissance seaplane that could be operated from its J-3 type submarines.

Consequently, they commissioned Watanabe to design and develop an aircraft that would meet this requirement.

The first of three prototypes was flown in February 1935.

The E9W was a two-seat, single-engine, twin-float, unequal-span seaplane that was designed to be easily dismantled for hangar stowage on a submarine.

It could be reassembled in two minutes and thirty seconds and disassembled in one minute and thirty seconds.

The observer operated a 7.7 mm (0.303 in) machine gun, and the aircraft was armed.

After successful testing of one of the prototypes on the submarine I-5, an order for a production batch of 32 aircraft, designated E9W1, was placed.

The aircraft entered service in 1938 with the Imperial Japanese Navy Air Service as the Navy Type 96 Small Reconnaissance Seaplane.

The last of these planes was delivered in 1940.

Although it was in the process of being replaced by the Yokosuka E14Y monoplane, it was still in frontline service at the time of the Japanese attack on Pearl Harbor.

It remained in service until July 1942, being used to direct their parent submarines onto Chinese ships attempting to pass the Japanese blockade of the South China Sea.




8.00 m (26 ft 3 in)


9.91 m (32 ft 9.5 in)


3.71 m (12 ft 2 in)

Wing area

23.51 m2 (252.95 sq ft)

Empty weight

882 kg (1,940 lb)

Gross weight

1,253 kg (2,756 lb)


1 × Hitachi Tempu II radial engine,

224 kW (300 hp)


Maximum speed

232 km/h (144 mph, 125 kn)

Cruise speed

148 km/h (92 mph, 80 kn)


731 km (454 mi, 395 nmi)


4.9 hours

Service ceiling

6,740 m (22,100 ft)


1 x 7.7mm (0.303in) machine gun.

Watanabe E9W- Bartholomei Timothe Crispinus.
Imperial Japanese Navy Reconnaissance Seaplanes-Bunrin Do.
The Illustrated Encyclopedia of Aircraft-David Mondey.
Japanese Aircraft 1910–1914-Robert Mikesh & Shorzoe Abe.



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