The first flight of the prototype was in August 1940, until the end of production in the year 1944, 1,223 aircraft were built. Diverging from the Japanese doctrine of high manoeuvreability, the Ki-44 was designed as an Interceptor aircraft with a good rate of climb and a high speed. Even if the flight performance had priority, the manoeuvreability was comparable to western fighters. U.S. fighters were also designed to have good flight performance but because of the Shoki's small size and light weight it was competitive, if not superior. Even though the Ki-44 prevailed in combat against many fighters of the USAAF because