Nakajima Ki-84 Hayate (Frank)

The Nakajima Ki-84 Hayate (四式戦闘機「疾風」, "Gale"), codenamed "Frank" by the Allies, first flew in April 1943 and entered operational service in April 1944. Dubbed the "Greater East Asia Decisive Battle Fighter" (大東亜決戦機), it represented the pinnacle of Japanese Army fighter development.

Powered by the Nakajima Ha-45 (Homare) engine producing 1,900 hp, the Ki-84 achieved a maximum speed of 624 km/h and could climb to 5,000 meters in about six and a half minutes (6 minutes 26 seconds for the prototype). It was armed with two 20mm Ho-5 cannons and two 12.7mm Ho-103 machine guns, with provision for two 250 kg bombs. Crucially, it featured pilot armor and self-sealing fuel tanks.

The Ki-84 was the first Japanese Army fighter that could meet Allied fighters on equal terms at all altitudes. It served in the Philippines, China, and the Home Islands defense. However, quality control deteriorated as the war progressed, and engine reliability suffered from poor materials and rushed production. Total production reached 3,514 aircraft.