The Nakajima Ki-84 Hayate was a single-seat fighter that was used by Japan during World War II. It had a Nakajima Ha-45 engine that was capable of propelling it at speeds of up to 687 km/h. The Ki-84's armament consisted of two 20 mm autocannons and two 12.7 mm MGs. Up to two 250 kg bombs could be added if necessary.
The total weight of the Ki-84 system was about 2,660 kg while its total length was 9.92 meters. The service ceiling of the Ki-84 was approximately 10,000 meters while the maximum range of the Hayate was 2,100 kilometers.
Design work on the Ki-84 began in 1942 with the intention of creating a replacement for the Ki-43. Its prototype first flew in early 1943, and production began in April 1944, a month after pre-production aircraft entered service with the 22nd Sentai. Hayates were used in many of the final battles of the Pacific Theater, including over the Philippines and the Japanese home islands. 3,514 were built before Japan surrendered.
- Ki-84-Ia: Most common version; armed with 2 machine guns and 2 autocannons in wings.
- Ki-84-Ib: Version with four autocannons, built in very limited numbers.
- Ki-84-Ic: Bomber destroyer version armed with 4 autocannons.
- Ki-84-II: Built with a wooden rear fuselage.
- Ki-106: All wood version.
- Ki-113: Had a stronger airframe built from steel.
- Ki-116: Used a lighter Ha-32 engine.
- Ki-117: Interceptor version.