Nakajima Ki-84 Hayate

Last update: 8 December 2016

Nakajima Ki-84 Hayate


The Nakajima Ki-84 Hayate was a single-seat fighter used by the Imperial Japanese Army Air Service in World War II. The Allied reporting name was "Frank"; the Japanese Army designation was Army Type 4 Fighter.

Considered to be the best of all Japanese fighters available in quantity during the last year of the war, the Nakajima Ki-84 Hayate (gale) not only possessed an excellent performance and high maneuverability but (unusual among Japanese aircraft) carried a powerful armament that increased its lethality. It was able to match any Allied fighter, and to intercept the high-flying B-29 Superfortresses.

The Ki-84 first flew in March 1943 and deliveries from Nakajima's Ota factory commenced in April 1943. The Ki-84 met with immediate approval by Japanese army air force pilots, but was subjected to lengthy service trials which undoubtedly delayed its introduction to combat operations. Production got under way at Nakajima's Ota plant in April 1944, pre-production aircraft having equipped the 22nd Sentai in China the previous month. Immediately afterwards 10 sentais of the Ki-84-I, codenamed 'Frank' by the Allies, were deployed in the Philippines to confront the advancing American forces. In an effort to accelerate production of the excellent new fighter, Nakajima opened up a new line at its Otsonomiya plant, and as Boeing B-29 raids began to take their toll of Japanese cities a new 'bomber destroyer', the Ki-84-Ic, was produced with an armament of two nosemounted 20-mm cannon and two wingmounted 30-mm cannon. Some measure of the importance attached to the Ki-84 may be judged by the fact that in the last 17 months of war 3,382 aircraft were completed, this despite the tremendous havoc wrought by the B-29 raids and the fact that, owing to such damage at Musashi, Nakajima's engine plant had to be transferred elsewhere.

General Informations

Country of Origin:  Japan
First flight:1943
Total Production:3,514 
Number of wings:Low wing monoplane
Landing gear:Tailwheel (retractable)

Military Operators

Operators:4 countries
  •  People's Republic of China
  •  Republic of China
  •  Indonesia
  •  Japan


Variant: Nakajima Ki-84-Ia
Crew: 1
Length: 9.92 m (32 ft 7 in)
Height: 3385 m (11 ft 1 in)
Wing area: 21 m2 (226.041 sq ft)
Weight Empty: 2,660 kg (5,864 lb)
Weight Loaded: 3,602 kg (7,940 lb)
Max. takeoff weight: 4,170 kg (9,194 lb)
Model: Nakajima Ha-45-21 Homare
Type: 18-cylinder radial engine
Number: 1
Configuration: Tractor
Power: 1850 hp (17900 kW) at 17,900 ft
Max speed: 686.0 km/h (426.0 mph)
at 7,020 m (23,000 ft)
Max speed (altitude): ()
Max speed (sea level): ()
Range: 2,168 km (1,347 mi)
Service Ceiling: 11,826 m (38,800 ft)
Wing Loading: 171.47 kg/m2 (35.1 lb/ft2)
  • 2 x 12.7 mm Ho-103 machine guns in nose, 350 rounds/gun
  • 2 x 20 mm Ho-5 cannon in wings, 150 shells/cannon
  • 2 x 100 kg (220 lb) bombs
  • 2 x 250 kg (551 lb) bombs
Hardpoints: 58
  • 2 x 200 L (53 US gal) drop tanks


Evaluation model
Pre-production model
Ki-84-I Ko
Armed with 2 x 12.7 mm Ho-103 machine guns and 2 x 20mm Ho-5 cannons in wings (most widely produced version)
Ki-84-I Otsu
Armed with 4 x 20 mm Ho-5 cannons
Ki-84-I Hei
Armed with 2 x 20 mm Ho-5 cannons and 2 x 30 mm Ho-155 cannons in wings
Ki-84-I Tei
Night fighter variant of Ki-84 Otsu. Equipped with an additional Ho-5 20mm cannon (300 shells) placed at 45 degree angle behind the cockpit in Schr├Ąge Musik configuration. Rare variant, 2 built.
Ki-84-I Ko - Manshu Type
Manufactured in Manchukuo for Manshôkoku Hikôki Seizo KK by Nakajima License.
Similar to the models above (Ki-84 Ko, Otsu, Hei).
1st high-altitude interceptor variant of the Ki-84, with a 2500 hp Nakajima Ha-219 air cooled radial engine and with wing area increased to 249.19 square feet. The Ki-84-N production model was assigned to the Kitai 'Ki-117', both aircraft did not left design stage until the war's ended.
2nd high-altitude interceptor variant of the Ki-84, with a 2500 hp Nakajima Ha-219 air cooled radial engine and with wing area increased to 263.4 square feet. Cancelled in favor of further development of the Ki-84-R, which was proving to be a less ambiguous project.
3rd high-altitude interceptor variant of the Ki-84, with a 2000 hp Nakajima Ha-45-23 with a mechanically-driven two-stage three-speed supercharger. The prototype was 80% completed at war's end.
Prototype, constructed entirely out of wood. 3 Built.
Based on the Ki-84 Otsu, with certain steel components on different areas of the aircraft. The project was an attempt to sustain light alloys, which were becoming very scarce later in the war. It employed steel sheet skinning and the cockpit section, ribs, and bulkheads were made of carbon steel.
Evaluation model, equipped with a Mitsubishi Ha-112-II (Ha-33-62), 1,120 kW (1,500 hp). 1 Built.
Production designation of the Ki-84N.

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