Japanese “Army Zero” – Nakajima Ki-43 in 27 Photos

The Japanese Nakajima Ki-43 Hayabusa was a relatively slow, lightly armed, and fragile land-based tactical fighter plane, but it became legendary for its performance in East Asia during the early years of the Second World War, and was famous for its extraordinary maneuverability and climb rate during its service with the Imperial Japanese Army Air Service.

Although the Ki-43 was officially reported as Oscar by the Allies, it was often referred to as the “Army Zero” by American pilots, owing to the fact that its layout and lines, Nakajima Sakae radial engine, round cowlings, and bubble-type canopy were features very similar to the Mitsubishi A6M Zero long-range fighter, which served with the Japanese Navy.

Propeller, Nakajima Ki-43-II Hayabusa in the “Great Patriotic War Museum”. Photo: Mike1979 Russia CC BY-SA 3.0

Hideo Itokawa was the designer of the Ki-43, and his achievements would later earn him fame as the pioneer of Japanese rocketry. It is important to note that the Ki-43 story did not start out as a success story.

Front view of a Japanese Nakajima Ki-43 Hayabusa (隼 Peregrine Falcon), designated as an Army Type 1 Fighter, and referred to by Allied forces as “Oscar”.

The first flown prototype in early January 1939 was a disappointment as it did not offer better maneuverability than the Ki-27, the purpose for which the Ki-43 had been made.

Hideo Itokawa – a pioneer of Japanese rocketry, popularly known as “Dr. Rocket,” and described in the media as the father of Japan’s space development.

To correct the manueverability problems, subsequent prototypes were produced between 1939 and 1940. Major changes were made and many field tests were executed. Experimental changes included a slimmer fuselage, a new canopy, and the introduction of Fowler flaps to improve the lift of the plane’s wings at a certain speed. The Fowler flap was implemented on the 11th prototype and brought about a dramatically enhanced performance in tight turns.

Ki-43 Hayabusa Cockpit (1944)

The 13th prototype combined all these changes, and tests conducted with this aircraft ended satisfactorily. Thus, the Nakajima Aircraft Company was instructed to place that prototype, which was designated Ki-43-I, into production.

Nakajima Ki-43-I Hayabusa aircraft in flight over Brisbane, Queensland (Australia) in 1943.

The Ki-43-I had an amazing maneuverability and remarkable climb rate owing to its light weight. It was powered by a Nakajima Ha-25 engine, and its maximum speed was 307.5 mph at 13,160 ft.

A Japanese Nakajima Ki-43-I Hayabusa (s n 750) in dense jungle 6 km from Vunakanau airfield, Rabaul, in September 1945.

Prototypes for the Ki-43-II had their maiden flights in February 1942. They came with the more powerful Nakajima Ha-115 fourteen cylinder air-cooled radial engine, which was an upgrade from the Ki-43-I’s engine. The wing structure of the Ki-43-I was strengthened in the Ki-43-II, and racks were added to the wings for drop tanks or bombs. Its speed also increased to 333 mph and its climb rate to 3,900 feet per minute.

Nakajima Ki43 II, P-5017, Chinese Air Force

It was equipped with an armament consisting of two fixed, forward-firing 12.7 mm Ho-103 machine guns in the cowl, and two 551 lb bombs.

12.7 mm Ho-103 machine gun.Photo Sturmvogel 66 CC BY-SA 3.0

It had a self-sealing fuel tank and a .5″ armor plate to protect the pilot’s head and back. Its canopy was slightly taller, and a reflector gunsight replaced the telescopic gunsight of the earlier prototype.

By November 1942, production of the Ki-43-II began at Nakajima’s Ota factory.

Nakajima Ki-43 type2 – at Pima Air Space Museum

The Nakajima was the most widely used fighter in the Japanese Army Air Force (JAAF) and fully equipped both the 30 Sentai Flight Regiment and 12 Chutais Independent Squadron. The first unit to be equipped with them was the 59th Flight Regiment, whose Ki-43s made their debut operational sorties across the skies of Hengyang on 29 October 1941.

Japanese Army Air Force fighter plane active in the Pacific throughout the war. The Japanese name for this aircraft was “Peregrine Falcon” and the Allied code name was “Oscar”.Photo Stumanusa CC BY 3.0

Ki-43s fought over the skies of the Japanese home islands, China, the Malay Peninsula, Burma, the Philippines, New Guinea, and other South Pacific islands.

A captured Japanese Nakajima Ki-43 Hayabusa (Allied code name “Oscar”) fighter at Clark Field, Luzon (Philippines), in 1945.

During their first combat experiences, the Ki-43 exerted some aerial superiority in Malaya, Netherlands East Indies, Burma and New Guinea just as the Zero did, but as the war got more intense, its light armor and less efficient self-sealing fuel tanks would be its weaknesses, causing several losses and casualties. Its machine guns could barely penetrate the heavily armored Allied planes.

Captured Ki-43 Hayabusa on Munda Field 14 June 1944

From October to December 1944, 17 Ki-43s were downed, but to their credit, they scored a total of 25 kills, claiming the fall of Allied aircraft such as the C-47, B-24 Liberator, Spitfire, Beaufighter, Mosquito, F4U Corsair, B-29 Superfortress, F6F Hellcat, P-38, and B-25.

US Ki-43-II Otsu code XJ005 Hollandia 1944

Towards the end of their time, several Ki-43s, just like many other Japanese aircraft, were expended in kamikaze strikes.

Nakajima, Ki-43, Hayabusa ‘Peregrine Falcon’ Oscar ‘Jim’ Army Type 1 Fighter

By the time of its retirements, in 1945 in Japan and 1952 in China, a total of 5,919 Nakajima Ki-43s had been built, with 13 variants.

 

A Japanese Nakajima Ki-43-I Hayabusa at Brisbane, Queensland (Australia) in 1943.

 

A Japanese Nakajima Ki-43-II Hayabusa fighter.

 

Front view, Nakajima Ki-43-IB Oscar at the Flying Heritage Collection.Photo Articseahorse CC BY-SA 4.0

 

Japanese Nakajima Ki-43 Hayabusa (隼 Peregrine Falcon), designated as an Army Type 1 Fighter, and referred to by Allied forces as “Oscar”.

 

Ki-84s, Ki-43s on a JAAF base post-war.

 

Nakajima Ki-43 from “Kato hayabusa sento-tai (Colonel Kato’s Falcon Squadron)”.

 

Nakajima Ki-43 Hayabusa fighter, taken as war booty by the Chinese Nationalists and issued to the 6th Group of the Chinese Nationalist Air Force, runs up before a flight.

 

Nakajima Ki-43-IB Hayabusa taking off at Brisbane, Queensland (Australia) in 1943. After its capture it was rebuilt by the Technical Air Intelligence Unit (TAIU) in Hangar 7 at Eagle Farm, Brisbane.

 

Nakajima Ki-43-IB Oscar at the Flying Heritage Collection.Photo Articseahorse CC BY-SA 4.0

 

Nakajima Ki-43-II Hayabusa in the Great Patriotic War Museum.Photo Mike1979 Russia CC BY-SA 3.0

 

Nakajima, Ki-43, Hayabusa “Peregrine Falcon” Oscar “Jim” Army Type 1 Fighter

 

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.

 

Wreck of a Japanese Army Air Force Nakajima Ki-43 Hayabusa plane (Oscar) in the Southwest Pacific in 1943.