The Mitsubishi A6M2 Zero’s Bastard Brother
Why would a hard-nosed organization (as the Japanese Navy certainly was) bother with ordering an airplane which performance was reduced to about 20% of its land and carrier-based version?
This question seems baffling enough until one looks at the size of the Japanese ruled or dominated part of the Pacific Ocean, the largest ocean on the planet.
In the spring of 1942, the Japanese armies had conquered the Philippines, Malaya and the Dutch East Indies. They were fighting their way into Burma and down to New-Guinea and its adjacent island groups. By that time, the Japanese dominated area was almost all that lay west of a line going straight north to south, from the Aleutian Islands to Rabaul. And though the Japanese Navy was equipped with no less than 12 aircraft carriers, they were not enough to secure such an immense area.
Another problem was the scarcity of suitable landing strips the Japanese forces needed during their island-hopping campaign. To solve this problem, the Japanese Navy fell back on a tradition already established in Japanese military aviation. They decided to use seaplanes in areas from which land based aircraft could not operate. They only had to look for either sheltered coastlines or lagoons and, if the water was calm enough, seaplanes could take off and land. There was no need for runways or carriers, just smooth waters and enough space to pitch tents for aircrew and ground crews.
When in 1940 the Japanese navy initiated the design of a new interceptor seaplane (the Kawanishi N1K1 Kyofu, or ‘Rex’), the need was also expressed for a stopgap aircraft and the Nakajima company was instructed in February 1941 to develop a float-equipped version of the excellent Mitsubishi A6M2 Zero naval interceptor.
Nakajima’s engineers added a large float beneath the fighter’s fuselage to allow the aircraft to operate from water while it housed a 330 liter fuel tank. Stabilizing floats had to be added beneath each wing. To counteract the negative effect of these floats on the aircraft’s aerodynamic properties, a new vertical tail plane had to be fitted to help to compensate for this. And a significant amount of strengthening and stiffening had to be added to the original lightweight design. The final result was a fighter which was not only slower and possibly less maneuverable, but also had a shorter range.
The ‘Rufe’ entered service with the Japanese Navy in 1942; in addition to the prototype another 326 examples entered service until production ceased in September 1943. From the Aleutians to the Solomans and to the Marshall Islands, the ‘Rufe’ was well known by allied aircrew in certain areas of the Pacific. It not only became a regular and unpredictable menace to allied bombers but was also used to attack light shipping and ground targets with its cannons and two 60kg bombs. ‘Rufe’s were able to break up enemy bomber formations and its pilots claimed a respectable number of kills. NA2/C Eitoku Matsunaga shot down 8 aircraft whilst flying the ‘Rufe’ and its replacement – the Kawanishi N1K1. Warrant Officer Kiyomi Katsuki claimed 16 kills during the Second World War; seven of these were scored whilst flying seaplane fighters.
However, despite some notable successes the ‘Rufe’s combat record was chequered. At a time when the more capable A6M2 was struggling against a newer breed of allied fighters, the float-hindered ‘Rufe’ was in an even worse position. On top of this, seaplanes stood little chance when violent tropical storms tore through the Pacific. An estimated 10% of all ‘Rufes’ were destroyed by storms.
A single ‘Rufe’ was discovered by the French forces when they returned to Indochina. They repaired the seaplane but it crashed on take-off for its first test flight.