The Kawanishi E7K 'Alf' was a long range reconnaissance floatplane that was obsolescent by the start of the Pacific War, but that remained in front line service until 1943.
Work on the E7K began in March 1932 in response to a 7-Shi specification issued by the Japanese Navy. The new aircraft was expected to replace the earlier Kawanishi E5K, which had only been produced in very small numbers.
Kawanishi responded with the Model J, a twin-float biplane, powered by a 500hp Hiro Type 91 engine. The aircraft was armed with one fixed forward firing machine gun and two rear-firing flexibly mounted guns, one above and one below the fuselage. It could carry two 66lb or two 132lb bombs under the wing centre section (between the floats), and carried a crew of three, each with their own separate open cockpit.
The Kawanishi Model J was ready early in 1933 and made its maiden flight on 6 February. IT then went for competitive tests against the Aichi AB-6, coming out the clear winner. A second prototype was produced during 1933, and then in May 1934 the aircraft was ordered into production as the Kawanishi E7K1 Navy Type 94 Reconnaissance Seaplane Model 1. Kawanishi built 183 aircraft, while Nippon Hikoki K.K. built 57 aircraft in total, although that includes the E7K2.
The E7K1 was used as a maritime reconnaissance and coastal patrol aircraft, operating from coastal bases, dedicated seaplane tenders and a large number of cruisers. It was a popular aircraft, with good handling, but the Hiro engine was something of a weak link.
In 1937 Kawanishi suggested fitting the aircraft with a Mitsubishi Zuisei 11 fourteen-cylinder air cooled radial. The Navy approved this design, and the first E7K2 made its maiden flight in August 1938. It entered production in November 1938 as the Navy Type 94 Reconnaissance Seaplane Model 2 (this was soon changed to Model 12, to indicate 1st airframe and 2nd engine). The new engine was more reliable, and also lifted the aircraft's top speed from 148mph to 171mph.
At the start of the Pacific War the E7K1 was withdrawn to training duties, but the E7K2 served in the front line until 1943. It was one of the older aircraft types used to protect the Japanese merchant marine, and performed convoy escort and anti-submarine duties, but the Japanese didn't take these tasks seriously until most of their merchant fleet had been sunk. After being withdrawn from the front line the E7K2s were used as liaison and training aircraft. They were also used to control the MXY4 radio-controlled target plane.
Engine: Mitsubishi Zuisei 11 radial engine
Wing span: 45ft 11 1/4in
Length: 34ft 5 1/2in
Height: 15ft 10 1/2in
Empty Weight: 4,630lb
Maximum take-off Weight: 7,275lb
Max Speed: 171mph at 6,560ft
Service Ceiling: 23,165ft
Endurance: 11 hours 30 minutes
Armament: Three 0.303in machine guns
Bomb-load: 265lb bomb load