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Japan Nakajima B-5N Ki-27 Ki-43 Ki-44 Ki-84 J1N Photos & Drawings

Ki-84 "Hayate"



The Ki-84 of 104-th Sentai, the airplane was seized by the Soviet armies on one of airfield in Manchdzuria, August, 1945 © Michael Bykov

The Ki-84 of 104-th Sentai, the airplane was seized by the Soviet armies on one of airfield in Manchdzuria, August, 1945

A conventional low-wing cantilever monoplane, the Ki.84 had a flush-riveted semi-monocoque light alloy fuselage structure of oval section and a single-spar wing with light alloy stressed skinning. The structural design followed the common Japanese practice of building the wing integral with the centre fuselage in order to save the weight of heavy attachment points, hut the Ki.84 was very much sturdier than any of its predecessors. Of particular interest was the heavy mainspar built up of half-inch extruded AI angles into an I-beam design. The wing carried metal-framed fabric-covered ailerons and hidraulically-operated Fowler-type flaps with a maximum deflection of 35 deg. The fuselage centre section embodied two firewals between which was mounted a 35 Imp gal (160 l) water-methanol tank, and 162 Imp gal (737 l) of fuel was distributed between the main tank aft of the cockpit, a pair of wing tanks in board of the main undercarriage members and two outboard wing leading edge tanks. The windscreen incorporated 65-mm armourglass, the pilot was provided with 13-mm head and back armour, and the paired synchronized Ho-103 machine guns m the forward fuselage had 350 rpg while the two wing-mounted Ho-5 cannon each had 150 rounds. From the outset provision was made for underwing racks capable of lifting two bombs of up to 551 lb (250 kg) weight or 44 Imp gal (200 l) drop tanks. The initial Army version of the Homare installed in the prototypes, the Ha-45-11. offered a take-off rating of 1.800 hp at sea level and drove an electrically-operated four-blade constant-speed Pe-32 propeller.

A batch of no fewer than 83 service trials aircraft was initiated in the early summer of 1943. immediately upon confirmation by Army test pilots at the Tachikawa Air Arsenal of the Nakajima test pilot's enthusiastic report on the capabilities of the Ki.84. the first of these pre-production lighters following closely on the heels of the second Ki.84 prototype from the Ota plani in August 1943. Allhough in some respects performance fell short of that requested by the specification, the capabilities of Nakajima's new warplane were undoubtedly impressive, and one of the Army lest pilots at Tachikawa. Li Funabashi, attained a maximum level speed of 394 mph (634 km h) at 21.800 ft (6.645 m) in me second pre-production example which embodied the various minor modifications resulting from the prototype test programme. During diving trials, the aircraft attained a speed of 496 mph (798 km h). at which point the test pilot experienced difficulty with his oxygen supply, necessitating termination of the test.

The pre-production aircraft were largely hand-built, despite the quantity involved, and differed one from another in minor details, these including various detail changes to the vertical tail surfaces, the application of different types of ejector exhausts and the provision of a centreline rack for a drop tank. Individual aircraft were tested with longer-span wings and at least two of the pre-production examples were evaluated with retractable skis in Hokkaido during the winter of 1943-44, A total of 24 pre-production fighters had left the Ota line by the end of 1943, a service trials Chutai being formed with a number of these in October of that year, but the primary factor governing deliveries was at this time, availability of Ha-45 engine.

Crew 1
Wing span 36ft 2in (11.24m)
Length 32ft 6in (9.92m)
Height 11ft 1in (3.38m)
Wing area 226.04 sq ft (21.0m2)
One Nakajima (Ha-45-21) Army Type 4 Model 21, 18-cylinder radial air-cooled engine for take-off 2000 hp
Weight, kg:
Empty weight 5.864 lb (2660 kg)
Loaded weight 8.192 lb (3716 kg)
Maximum takeoff weight 9.195 lb (4171 kg)
Maximum speed at sea level 325 mph (523 km/h)
Maximum speed at altitude 9840ft (3000m) 362 mph (582 km/h)
Time to 16.405ft (5000m) 6.42min
Service ceiling 36.090ft (11000m)
Range (full internal fuel) at 1640 ft (5000m) 1.025mls (1650km)
2x13-mm Ho-103 machine guns with 350 rpg and 2x 20-mm Ho-5 cannon with 150rpg 2 + 2
Bombs on underwing racks 2x551-lb (250-kg)
Photo Description

Drawing Ki-84

Ki-84, Nakajima

Ki-84, Nakajima

Ki-84, Nakajima


  • "Encyclopedia of military engineering" /Aerospace Publising/
  • "50 best fighters of World War II" /Gennadiy Kornukhin/