The Ki-5 was initially produced by Kawasaki Kōkūki Kōgyō K.K. in response to Japanese army specifications for a high-performance fighter to replace the existing Type 92. It was the first all-metal, cantilever monoplane fighter aircraft to be built in Japan. It was designed around the Kawasaki Ha-9, a Japanese development of the BMW IX aircraft engine, itself a development from the BMW VII A 7.3 liquid-cooled engine, with a nominal rating of 634-1NaN-1. It also had the innovation of using an inverted gull wing design, to improve downward visibility for the pilot and to be able to use a simple, short undercarriage.
However, the Ki-5 design quickly proved unsatisfactory in flight testing. Test pilots complained of stability and handling problems, and the engine was never able to produce enough power for the Ki-5 to attain its design speed parameter of 380-1NaN-1.
The project was cancelled on 9 September 1934, after a total of four units were produced. However, the design effort on the Ki-4 later paid off dividends with the designs for the future Ki-28, Ki-60 and Ki-61.
Japan