Nakajima Ki-43

The Nakajima Ki-43 Hayabusa (隼, "Peregrine Falcon") was a single-engine land-based tactical fighter used by the Imperial Japanese Army Air Force in World War II. The army designation was "Type 1 Fighter" (一式戦闘機); the Allied codename was "Oscar". Like the Mitsubishi Zero, which it resembled, the radial-engined Ki-43 was light, maneuverable and easy to fly. The Ki-43 was legendary for its combat performance in East Asia in the early years of the war. Its lightweight construction, lack of armour and limited firepower, however proved to be deficient in comparison to later, more powerful Allied fighters. Nevertheless, the Ki-43 shot down more Allied aircraft than any other Japanese fighter. Total production amounted to 5,919 aircraft.

Design and development

The Ki-43 was designed by Hideo Itokawa, who would later become famous as a pioneer of Japanese rocketry. The Ki-43 prototype was produced in response to a 1938 specification for a successor to the popular Nakajima Ki-27. The specification called for a top speed of 500 km/h, a climb rate of 5,000m in five minutes, and a range of 800 km.

When first flown in January 1939, the Ki-43 prototype was a disappointment. Japanese test pilots complained that it was less maneuverable than the Ki-27 and not much faster. Nakajima produced numerous revised prototypes through the summer of 1940. The 13th prototype introduced unique "butterfly" maneuvering flaps, which dramatically improved performance in tight turns.

The initial production version was given the designation Ki-43-I. Deliveries from Nakajima's Ota factory commenced in April 1941. In addition to outstanding maneuverability, the Ki-43-I had a very impressive rate of climb due to its light weight. Power was provided by the Nakajima Ha-25 engine turning a two bladed propeller. Top speed was 495 km/h (308 mph) at 4,000 m (13,160 ft). The Ki-43 was equipped with two cowling machine guns in various configurations, with either two 7.7 mm (.303 in) Type 97 machine guns, one 12.7 mm (.50 in) Ho-103 machine gun (machine cannon) and one 7.7 mm (.303 in) gun, or two 12.7 mm (.50 in) Ho-103 guns; the aircraft was given various sub-designations to reflect these differences. The configuration that appears to have been most prevalent at the outset of the war was the latter configuration with two 12.7 mm (.50 in) Ho-103 machine guns, sometimes given the official designation Ki-43-I (Mark Ic). The Ho-103 was often loaded with explosive ammunition to increase target effect; its penetrative effect against later Allied aircraft armor appears to have been marginal.

Prototypes for the Ki-43-II flew in early 1942. The Ha-25 engine was replaced by the more powerful Nakajima Ha-115 engine, which was installed in a longer-chord cowling. The new engine turned a three bladed propeller. The wing structure, which had suffered failures in the Ki-43-I, was strengthened and equipped with racks for drop tanks or bombs. The Ki-43-II was also fitted with 13-mm armor plate for the pilot's head and back. The pilot also enjoyed a slightly taller canopy and a reflector gunsight in place of the earlier telescopic gunsight. Nakajima commenced production of the Ki-43-II at its Ota factory in November 1942. Nakajima eventually ceased production in favor of the Ki-84, but the Tachikawa army arsenal continued to produce the Ki-43.

Tachikawa also produced the Ki-43-III, which utilized the more powerful Ha-115-II engine. Maximum speed increased to 358 mph. Tachikawa produced almost 1,100 Ki-43-III aircraft between October 1944 and June 1945.

The Ki-43 remained in production until the end of the war. Total production of all versions amounted to 5,919 aircraft.

Operational history

File:Chiran high school girls wave kamikaze pilot.jpg

A Ki-43 III-Ko, piloted by Second Lieutenant Toshio Anazawa and carrying a 250 kg (550 lb) bomb, sets off from a Japanese airfield for the Okinawa area, on a kamikaze mission, 12 April 1945. School girls wave goodbye in the foreground.

The Ki-43 was the most widely-used Army fighter, and equipped 30 sentai (groups) and 12 chutais (squadrons). The first version, Mark I, entered service in 1941, the Mark II in December 1942, the II-Kai in June 1943, and the Mark IIIa in summer 1944. The aircraft fought in China, Burma, the Malay Peninsula, New Guinea, the Philippines, South Pacific islands and the Japanese home islands.

Like the Zero, the Ki-43 initially enjoyed air superiority in the skies of Malaya, Netherlands East Indies, Burma and New Guinea. This was partly to do with the better performance of the Oscar and partly due to the relatively small numbers of combat-ready Allied fighters, mostly the P-36 Hawk, Curtiss P-40, Brewster Buffalo, Hawker Hurricane and Curtiss-Wright CW-21 in Asia and the Pacific during the first months of the war. As the war progressed, however, the fighter suffered from the same weaknesses as the "Nate" and the Zero; light armor and less-than-effective self-sealing fuel tanks, which caused high casualties in combat. Its armament of two machine guns also proved inadequate against the more heavily armoured Allied aircraft. As newer Allied aircraft were introduced, such as the P-47 Thunderbolt, P-38 Lightning, P-51 Mustang, F4U Corsair, F6F Hellcat and late-model Supermarine Spitfire/Seafire, the Japanese were forced into a defensive war and most aircraft were flown by inexperienced pilots. Towards the end of the war, many Hayabusas were expended in kamikaze raids.

The Ki-43 also served in an air defense role over Formosa, Okinawa and the Japanese home islands. Some examples were supplied to the pro-Japanese countries of Thailand, Manchukuo and Wang Jingwei Government as well. The Thai units sometimes fought against the USAAF in southern China.

File:Nakajima Ki-43-II.jpg

A Ki-43-II.

Hayabusas were well liked in the JAAF because of the pleasant flight characteristics and excellent manouevreability, and almost all JAAF fighter aces claimed victories with Hayabusa in some part of their career. At the end of the war, most Hayabusa units received Ki-84 Hayate "Frank" fighters, but some units flew the Hayabusa to the end of the war. The top-scoring Hayabusa pilot was Sergeant Satoshi Anabuki with 59 victories.

After the war, some examples served in limited numbers in the French Air Force in Indochina against communist rebels.

Variants

Ki-43

Prototypes and operative prototypes.

Ki-43-Ia

Variant armed with 2 × 7.7 mm (.303 in) Type 97 machine guns

Hayabusa Fighter Type 1 of Army (Mark 1).

Ki-43-Ib (Mark Ib)

Variant armed with one 12.7 mm (.50 in) Ho-103 machine gun and 1 × 7.7 mm (.303 in) Type 97

Ki-43-Ic (Mark Ic)

Variant armed with 2 × 12.7 mm (.50 in) Ho-103

Ki-43-II

Prototypes and evaluative models.

Ki-43-IIa (Mark 2a)

Ability to carry up to 500 kg (1,100 lb) of bombs

Ki-43-IIb (Mark 2b)

Radio equipment added

Ki-43-II-KAI

Fitted with ejector exhaust stacks

Ki-43-III

Prototypes powered by Nakajima Ha-115-II engine of 920 kW (1,230 hp)

2 × 170 L (45 gal) drop tanks (~3 hour full-throttle endurance)

Ki-43-IIIa (Mark 3a)

Series model

Ki-43-IIIb (Mark 3b)

Variant armed with 20 mm Type 99 cannons.

Ki-62 Project

Advanced interceptor version of Nakajima Ki-43 with a powerful engine and armed with 30 mm (1.18 in) or 40 mm (1.57 in) cannons.

Operators

Wartime

Template:JPN

• Imperial Japanese Army Air Force

Template:Country data Manchukuo

• Manchukuo Air Force

Template:THA

• Royal Thai Air Force

Postwar

Template:China as ROC

• Nationalist Chinese Air Force
  • 6^th Group
    • Two squadrons operated captured aircraft.

Template:PRC

• Chinese Communist Air Force captured five aircraft in 1946 from nationalists. Aircraft were operated until their retirement in 1952.

Template:FRA

• French Air Force operated captured aircraft in Indo-China.

Template:IDN

File:AURI Oscar.JPG

Captured Ki-43 used by the Indonesians

• Indonesian People's Security Force operated captured aircraft against Dutch colonial rule. On 29 July 1947, one aircraft from Maguwo Air Force Base, Yogyakarta was used for bombing Dutch strategic positions in Ambarawa, Salatiga and Semarang. However, Indonesia's Ki-43 failed to fly because of mechanical problems. One airplane saved as a display in Museum Dirgantara Udara Yogyakarta (near Adi Sucipto Airport).

Template:PRK

• North Korean Air Force operated captured aircraft after the war.

Survivors

There is currently only one airworthy Oscar located at the Tillamook Air Museum. There are six survivors in potentially flyable condition :

Ki-43

Owned by The Fighter Collection, Duxford UK and awaiting restoration.

Ki-43-Ib N750N

Owned by Paul Allen/Flying Heritage Collection, Arlington, USA. Former ZK-OSC restored to flying condition by Tim Wallis' Alpine Fighter Collection in the 1990s, not currently flying.

Ki-43-IIb

Seattle Museum of Flight

Ki-43-IIb

Pima Air Museum, static display in Hangar 4

Ki-43-IIIb

Four aircraft under restoration/rebuild at Texas Airplane Factory, Meacham Field, Fort Worth, Texas, USA.

Ki-43-IIIb

Tillamook Air Museum in Oregon.

Specifications (Ki-43-II)

General characteristics

• Crew: One
• Length: 8.92 m (29 ft 3 in)
• Wingspan: 10.84 m (35 ft 7 in)
• Height: 3.27 m (10 ft 8in)
• Wing area: 21.40 m² (230.35 ft²)
• Empty weight: 1,975 kg (4,355 lb)
• Loaded weight: 2,590 kg (5,710 lb)
• Powerplant: 1× Nakajima Ha-115 radial engine, 890 kW (1,130 hp)

Performance

• Maximum speed: 530 km/h (329 mph) at 4,000 m (13,125 ft)
• Range: 1,610 km (1,000 mi) combat, 2,575 km (1,600 mi) ferry ()
• Service ceiling: 11,200 m (36,750 ft)
• Rate of climb: 19.8 m/s (3,900 ft/min)
• Wing loading: 121 kgf/m² (1.1 kN/m²)

Armament

• Guns: 2 × fixed, forward-firing 12.7 mm (.50 in) Ho-103 machine guns in the cowl with 250 rpg (400 rpm rate each) or 1 × 12.7 mm (.50 in) and 1 × 7.7 mm (.303 in) Type 89 machine gun.
• Bombs: 2 × 250 kg (551 lb) bombs

See also

Related development

• Nakajima Ki-27
• Nakajima Ki-44
• Nakajima Ki-84

Comparable aircraft

• Macchi MC.200
• Mitsubishi A6M
• Polikarpov I-180

Related lists

• List of military aircraft of Japan

References

Notes

Bibliography

• Bueschel, Richard M. Nakajima Ki-43 Hayabusa I-III in Japanese Army Air Force RTAF-CAF-IPSF Service. Reading, Berkshire, UK: Osprey Publications, 1970. ISBN 0-85045-022-5.
• Bueschel, Richard M. Nakajima Ki-43 Hayabusa in Japanese Army Air Force RTAF-CAF-IPSF Service. Atglen, PA: Schiffer Books, 1995. ISBN 0-88740-804-4.
• Dorr, Robert F. and Chris Bishop. Vietnam Air War Debrief. London: Aerospace, 1996. ISBN 1-874023-78-6.
• Francillon, René J. Japanese Aircraft of the Pacific War. London: Putnam & Company, 1979. ISBN 0-370-30251-6.
• Glancey, Jonathan. Spitfire: The Illustrated Biography. London: Atlantic Books, 2006. ISBN 978-1-84354-528-6.
• Green, William. Warplanes of the Second World War, Volume Three: Fighters. London: Macdonald & Co. (Publishers) Ltd., 1961 (seventh impression 1973). ISBN 0-356-01447-9.
• Green, William and Gordon Swanborough. WW2 Aircraft Fact Files, Japanese Army Fighters, part 2. London, Macdonald and Janes's, 1977. ISBN 0-354-01068-9.
• Pajdosz, Waldemar, Mark T. Wlodarczyk and Adam Jarski. Nakajima Ki 43 Hayabusa "Oscar" (in Polish), Monografie Lotnicze 48. Gdańsk: AJ-Press, 1998. ISBN 83-86208-97-X.
• Skulski, Przemysław. Nakajima Ki 43 Hayabusa "Oscar", seria Pod Lupa no.11 (Polish/English). Wrocław: Ace Publications, 1999. ISBN 83-86153-98-9.
• Stanaway, John. Nakajima Ki.43 "Hayabusa" - Allied Code Name "Oscar". Bennington, VT: Merriam Press, 2003. ISBN 1-57638-141-2.
• Windrow, Martin C. and René J. Francillon. The Nakajima Ki-43 Hayabusa. Leatherhead, Surrey, UK: Profile Publications, 1965.

External links

• Nathan Sturman's Homepage
• Joe Baugher's Hayabusa files
• Nakajima Type 1 Model 1 Army Fighter (Ki 43-I) Armament - A Reassessment by Richard L. Dunn

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Nakajima Ki-43".