Kyushu K10W

The Kyushu K10W Type 2 Land based intermediate trainer (Code Named Oak by the Allies) was a single engine low wing land monoplane trainer aircraft which served in the Imperial Japanese Navy Air Service in the latter part of World War II.

It was designed by the Kyushu Aircraft Company to the 14-Shi Intermediate Trainer specification of mid 1939 which required a design similar to the NA-16 following the Mitsubishi's purchase of an NA-16-4R and an NA-16-4RW on behalf of the Japanese Navy. Design work commenced in January 1940 and the first prototype was ready by April 1941 and was followed by no fewer that 16 test machines, possibly indicating development problems.

A total of 176 K10W1s were manufactured starting in February 1943 and running until August 1944, 26 under the Watanabe/Kyushu name (including the 17 prototypes) and the remaining 150 were built by the Nippon Hikoki K.K. (a small company that did a lot of subcontract work). The K10W1 was only used in small numbers and was not popular with crews possibly due to poor stall/spin behaviour and no Japanese records indicate any use as a Kamikaze or indeed for any other purpose, though a small number were definitely used as target tugs for gunnery training and as unit hacks attached to operational bases where they probably assisted in getting new pilots up to speed.

Design and development
The Japanese purchased two NA-16's and western sources have long believed that the K10W1 was a development of these, however a close study of the Oak, as it was code named by the Allies, shows that they shared nothing beyond a similar configuration.

Whereas the NA-16's featured a steel tube structure covered with metal or fabric panels, the K10W1 was of flush riveted stressed skin construction throughout (excepting the fabric covered control surfaces) with a much smaller wingspan, smaller chord wings, a longer fuselage and a higher aspect tailplane. The entire cockpit was further forward and the wings were swept forward rather than aft as on the NA-16.