The Nakajima Ki-84 Hayate (疾風, "Hurricane") was a single-seat fighter used by the Japanese Imperial Army in World War II. It was the last in Nakajima's line of classic fighters and considered one the best-performing craft from any country. The Allied codename was "Frank"; the Army designation was "Type 4 Fighter" (四式戦闘機).

The Ki-84 first flew in March 1943. While the design was solid, a shortage of fuel and construction materials, poor production quality, and lack of skilled pilots kept it from reaching its potential. After the war, a captured example was tested by the U.S. Army using high-octane fuel and achieved a speed of 689 km/h. A total of 3,449 were produced.

The Ki-84 was the only army fighter with a four-bladed propeller; this was chosen to reduce the diameter and provide ground clearance. Several interesting experimental variants of the Ki-84 were produced: the wooden Ki-103 , the steel (rather than duralumin) Ki-113 , and the Ki-116, with the Nakajima Ha-45 engine replaced by a Mitsubishi Ha-112 -II.

Specifications (Ki-84-Ia)

General Characteristics

• Crew: one, pilot
• Length: 9.93 m (32 ft 7 in)
• Wingspan: 11.23 m (36 ft 10 in)
• Height: 3.38 m (11 ft 1 in)
• Wing area: 21 m² (226 ft²)
• Empty: 2,665 kg (5,864 lb)
• Loaded: 3,616 kg (7,955 lb)
• Maximum takeoff: 3,898 kg (8,576 lb)
• Powerplant: 1x Nakajima Ha-45-21 18-cylinder radial, 1,485 kW (1,990 hp)

Performance

• Maximum speed: 627 km/h (392 mph)
• Range: 2,155 km (1,347 miles)
• Service ceiling: 10,500 m (34,450 ft)
• Rate of climb: 833 m/min (2,734 ft/min)
• Wing loading: 172 kg/m² (35 lb/ft²)
• Power/Mass: 0.41 kW/kg (0.25 hp/lb)

Armament

• 2x 12.7 mm Type 1 machine guns in fuselage
• 2x 20 mm Ho-5 cannon in wings
• 2x 250 kg (551 lb) bombs

Related content

Related development: Tachikawa Ki-103 - Nakajima Ki-113 - Nakajima Ki-116

Comparable aircraft:

Designation sequence: Ki-81 - Ki-82 - Ki-83 - Ki-84 - Ki-85 - Ki-86 - Ki-87