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Yokosuka E1Y

The Yokosuka E1Y was a reconnaissance floatplane developed by the Yokosuka Naval Air Technical Arsenal for the Imperial Japanese Navy in the 1920s.

This single-engined biplane was designed to replace the Navy’s Yokosuka Ro-go Ko-gata floatplanes and was produced as the Type 14 Reconnaissance Seaplane, with 320 units entering service in 1925.

The E1Y remained in operational service until 1932.

The Type 10 Reconnaissance Seaplane was initially designed by a team led by a member of a visiting delegation from Short Brothers of the United Kingdom in 1921.

However, the two completed aircraft in 1923 showed poor performance due to being overweight.

A modified aircraft, the Type 10 Model A, flew in 1924, but only showed slight improvement.

A further revised prototype, the Model B, flew in 1925, which cured the aircraft’s weight problems while demonstrating better stability and control.

As a result, several pre-production Type Bs were built.

The revised design was accepted in January 1926 as the Type 14 Reconnaissance Seaplane, later receiving the short designation E1Y.

Two versions entered service in 1926, a two-seater and a three-seater with all-metal floats and a more powerful engine.

In 1928, the Type 14-2 was used as the basis for the Type 90-3 Reconnaissance Seaplane, of which about 20 were built as the Yokosuka E5Y1 and Kawanishi E5K1.

The E1Ys formed the main reconnaissance seaplane equipment of the fleet, operating from battleships and seaplane tenders.

They were operated from the seaplane tender Notoro during the Shanghai Incident of early 1932.

The E1Y remained in use until the early part of the Second Sino-Japanese War.

A total of 218 E1Y1 and E1Y2s were built by Yokosuka, Nakajima Aircraft Company, and Aichi, while 102 E1Y3s were built by Aichi.


Navy Type 10 Reconnaissance Seaplane 

Prototype reconnaissance seaplane, powered by 400 hp (298 kW) Lorraine-Dietrich 1 V-12 engine but overweight, Two built.

Navy Type 10 Model A Reconnaissance Seaplane 

Revised prototype, one built.

Navy Type 10 Model B Reconnaissance Seaplane 

Further modified prototype and pre-production aircraft.

Navy Type 14-1 Reconnaissance Seaplane (E1Y1)

Initial production version, powered by 400 hp (298 kW) Lorraine-Dietrich 1.

Navy Type 14-2 Reconnaissance Seaplane (E1Y2) 

Modified version, with new all metal floats and 450 hp (336 kW) Lorraine-Dietrich 2 W-engine.

Navy Experimental Type 14-2 Kai-1 Reconnaissance Seaplane 

An experimental version of the Type 14-2

Navy Type 14-3 Reconnaissance Seaplane (E1Y3)

Further improved version with new tail and improved performance.

Navy Type 14 Modified Transport Seaplane

Civil conversion.





10.59 m (34 ft 9 in)


14.22 m (46 ft 8 in)


4.15 m (13 ft 7 in)

Wing area

54.2 m2 (583 sq ft)

Empty weight

1,889 kg (4,165 lb)

Gross weight

2,750 kg (6,063 lb)


1 × Lorraine 2 W-12 water-cooled piston engine,

336 kW (451 hp)


Maximum speed

178 km/h (111 mph, 96 kn)

Cruise speed

130 km/h (81 mph, 70 kn)


1,156 km (718 mi, 624 nmi)


9 hours

Service ceiling

4,000 m (13,000 ft)

Time to altitude

3,000 m (9,843 ft) in 28 minutes 13 seconds

Wing loading

50.7 kg/m2 (10.4 lb/sq ft)


0.1226 kW/kg (0.0746 hp/lb)



1× flexibly mounted 7.7 mm machine gun


2× 110 kg (240 lb) or 4× 30 kg (66 lb) bombs.

Japanese Aircraft, 1910-1941-Robert Mikesh & Shorzoe Abe
The Mainichi Newspapers Co Ltd
Yushukan War Memorial Museum
Japanese Aircraft of the Pacific War-Rene Francillon,
Japanese Aircraft-John Stroud,
Japanese Military Aircraft Illustrated.


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