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Nakajima Ki-43 Hayabusa (Oscar) Fighter Aircraft (1942)

Authored By Martin Foray | Last Updated: 8/25/2014

The Nakajima Ki-43 Hayabusa rivaled only the Japanese Navy's A6M Zero series as the most produced Japanese fighter of World War 2.

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By 1937, it became apparent to the Imperial Japanese Army (IJA) that a more modern replacement for the Nakajima Ki-27 was needed. The Ki-27 (Allied codename of "Nate") began a private venture design by Hideo Nakajima himself, after an invitation by the IJA to supply a modern fighter in 1935 with all-metal stressed skin. The type was of a monoplane design with an enclosed cockpit and lightweight yet was fielded with a fixed undercarriage and a tail skid, no pilot armoring nor self-sealing fuel tanks and required an external unit for starting. At the time of its inception, the Ki-27 became the first Japanese monoplane to achieve operational service with the military. While fighting on until the end of the war in 1945, Nates were quickly withdrawn from direct contact against the more modern Western fighters as they were wholly outclassed.

The IJA went straight to the Nakajima Aircraft Company once more and Mr. Nakajima took on the new requirement and delivered a promising prototype. As in the Ki-27 "Nate" before it, the new design was kept lightweight to make for a more maneuverable mount. As such, important facets such as pilot armor and self-sealing fuel tanks were once again dropped from the equation. Armament consisted of just a pairing of 2 x 7.7mm Type 97 machine guns firing from the upper engine cowl and synchronized to fire through the spinning propeller blades. 250 rounds of ammunition were afforded to a machine gun. Flight tests of the new fighter began in 1939 but soon proved the overall design something of a disappointment, forcing a halt to all further development for the time being. It was not until 1941 that the design was revisited and revised to make up for the inherent deficiencies. The wing surface area was enlarged and the addition of combat flaps helped in maneuverability to the point that the modified airframe proved to have excellent turning capabilities, promising to content with the best Allied fighters that could be fielded. The fighter was formally designated as the Ki-43 "Hayabusa" (meaning "Peregrine Falcon") and accepted into service with the IJA. Serial production of the new mount occurred in June of 1941 and the type entered service shortly thereafter as the Ki-43-Ia.

Outwardly, the Ki-43 was a highly conventional aircraft and, in some ways, decidedly Japanese in origin. She sported fine contoured lines making for an elegant design. The engine was fitted well-forward in the thin fuselage and covered over in a nicely rounded cowling. The spinner was noticeably protruding from the engine compartment and powered a three-bladed propeller system. The cockpit sat just behind the engine and just ahead of amidships. The fuselage tapered off to a point and the empennage was highly conventional in its use of a single vertical tail fin and applicable horizontal planes - all well-rounded at the edges. Wings were set ahead of amidships and initially rounded at the tips. The undercarriage was wholly retractable and featured two main landing gear legs and a diminutive tail wheel (the tail wheel remained exposed in flight). The main legs retracted inwards towards centerline under each wing near the wing roots and were exposed to the elements along one side (the main legs were not covered over by door panels in flight).

Once in service, the Ki-43 proved a capable adversary despite the lack of formidable firepower. In true Allied fashion, the fighter was assigned the codename of "Oscar" to follow suit with other Japanese aircraft names ("Nate", "Sally", "Zeke", etc.... Her turning capability ensured the aircraft would become one of the most feared of the Japanese fighters for a portion of the Pacific War. Her inherent success extended beyond the machine itself for the Ki-43 would go on to produce many of the admired Japanese aces of her time. The ki-43-Ia was followed into service by the Ki-43-Ib which was interestingly armed with 1 x 12.7mm Ho-103 heavy machine gun and 1 x 7.7mm Type 97 machine gun. The Ki-43-Ic came next and was fittingly armed with 2 x 12.7mm Ho-103 heavy machine guns.


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Specifications for the
Nakajima Ki-43 Hayabusa (Oscar)
Fighter Aircraft


Focus Model: Nakajima Ki-43-II Hayabusa (Oscar)
Country of Origin: Imperial Japan
Manufacturer: Nakajima - Imperial Japan
Initial Year of Service: 1942
Production: 5,919


Crew: 1


Length: 29.27 ft (8.92 m)
Width: 35.56 ft (10.84 m)
Height: 10.73ft (3.27 m)
Weight (Empty): 4,211 lb (1,910 kg)
Weight (MTOW): 6,449 lb (2,925 kg)


Powerplant: 1 x Nakajima Ha-115 air-cooled radial piston engine developing 1,150hp.


Maximum Speed: 329 mph (530kmh; 286 kts)
Maximum Range: 1,094 miles (1,760km)
Service Ceiling: 36,745 ft (11,200 m; 7.0 miles)
Rate-of-Climb: 3,900 feet-per-minute (1,189 m/min)


Hardpoints: 2
Armament Suite:
STANDARD:
2 x 7.7mm Type 97 machine guns (Ki-43-Ia)
1 x 12.7mm Ho-103 and 1 x 7.7mm Type 97 machine gun (Ki-43Ib).
2 x 12.7mm Ho-103 machine guns (Ki-43-Ic)
2 x 20mm cannons (Ki-43-IIIb)

OPTIONAL:
2 x 550lb bombs (Ki-43-IIa)


Variants:
Ki-43 - Designation for prototypes and evaluation models.


Ki-43-Ia - Fitted with 2 x 7.7mm Type 97 machine guns.

Ki-43-Ib - Fitted with 1 x 12.7mm Ho-103 machine gun and 1 x 7.7mm Type 97 machine gun.

Ki-43-Ic - Fitted with 2 x 12.7mm Ho-103 machine guns.

Ki-43-II - Designation used for improved prototype and developmental models.

Ki-43-IIa - Provision added for 500kg of external ordnance.

Ki-43-IIb - Equipped with Radio Communications Capability.

Ki-43-II-KAI - Modified Ki-43-II series with ejector exhaust stacks.

Ki-43-III - Prototype Models fitted with Nakajima Ha-115-II powerplants of 1,230 horsepower.

Ki-43-IIIa - Main Production Designation

Ki-43-IIIb - Fitted with 20mm cannons

Ki-62 (Project) - Advanced Interceptor Model; improved powerplant; 40mm cannons.

Mark I - Japanese Army Designation of Ki-43-Ia model series.

Mark Ib - Japanese Army Designation of Ki-43-Ib model series.

Mark Ic - Japanese Army Designation of Ki-43-Ic model series.

Mark 2a - Japanese Army Designation of Ki-43-IIa model series.

Mark 2b - Japanese Army Designation of Ki-43-IIb model series.

Mark 3a - Japanese Army Designation of Ki-43-III model series.


Operators:
China; France; Indonesia; Imperial Japan; Manchukuo; Thailand; North Korea