This aircraft was powered initially by a 930 kW (1,250 hp) Nakajima Ha-41 engine, and had a maximum speed of 580 km/h (363 mph). Updated to a 1,074 kW (1,440 hp) Nakajima Ha-109 engine allowed a top speed of 604 km/h (378 mph.
In contrast to its predecessor, the nimble Ki-43, the Ki-44 was designed for speed and climbing ability and was used to intercept high flying B-29 Superfortress bombers. However with its poor visibility on the ground, weak armament, and high landing speed, it was generally disliked by pilots.
Initial armament consisted of two 7.7 mm (.303 in) Type 89 machine guns and two 12.7 mm (.50 in) Ho-103 machine guns placed in each wing