Model Variants (Including Prototypes)
Ki-44 - Used for both prototype designation and preproduction evaluation models.
Ki-44 Type I - Fitted with Nakajima Ha-41 engine of 1,250 horsepower; 2 x 7.7mm Type 89 machine guns and 2 x 12.7mm Ho-103 machine guns.
Ki-44 Type II - Fitted with Nakajima Ha-109 engine of 1,440 horsepower; 4 x 12.7mm Type I machine guns.
Ki-44 II - Prototype Model; fitted with Nakajima Ha-109 engine of 1,520 horsepower.
Ki-44 IIa - Mark 2a Series Designation
Ki-44 IIc - Fitted with 4 x 20mm Ho-3 cannons OR 2 x 12.7mm Ho-103 machine guns and 2 x 40mm Ho-301 cannons.
Ki-44 IIIa - Mark 3a Series Designation; fitted with 2,000 horsepower powerplant; armament of 4 x 20mm Ho-5 cannons.
Ki-44 IIIb - Fitted with 2 x 20mm Ho-5 cannons and 2 x 37mm Ho-203 cannons.