Nakajima Ki-27 Nate
The Nakajima Ki-27, the Army Type 97 Fighter codenamed "Nate" by the Allies, was the Imperial Japanese Army Air Service's first monoplane fighter and still its most numerous fighter when the Pacific War began in December 1941. It won the Army's fighter trials on manoeuvrability rather than speed, and Nakajima built 2,005 of them; a wider accounting that adds Tachikawa and Manchurian production totals 3,368. It gave Japanese pilots their first combat experience over China and against the Soviet Union at Khalkhin Gol in 1939, but it was lightly armed and unprotected, and it ended the war as a trainer and kamikaze aircraft. One Ki-27 survives, at the Tachiarai Peace Memorial Museum in Japan.
Why It Mattered
The Nakajima Ki-27, ordered into production as the Army Type 97 Fighter and codenamed "Nate" by the Allies, was the first monoplane fighter to enter service with the Japanese Army Air Force. Nakajima began with a head start: its private-venture Type P.E. monoplane was already in hand when the Army's fighter contest was run, and in the 1937 trials the Ki-27 won on manoeuvrability although it was slower than its rivals and only second in climb. Four years later the type was obsolescent by world standards, yet in December 1941 it was still numerically the most important fighter in Army service. The combat it saw over China and Manchuria also gave many of the pilots who became Japan's most successful of the Second World War their first real fighting experience.
Design Notes
The Ki-27 was a low-wing cantilever monoplane with a fixed, spatted undercarriage; the prototypes had an open cockpit and production aircraft a closed canopy, though many pilots flew with it open. Power came from Nakajima's Ha-1 radial — 650 hp in the prototypes — which left the fighter somewhat underpowered beside the 1,000 hp fighters then being developed in the West. It carried two 7.7 mm machine guns, the standard fighter armament of the mid-1930s, at a time when much more heavily armed aircraft were under development elsewhere. Manoeuvrability was the design's whole purpose: the second prototype's wing was enlarged to improve it, and the production Ki-27a kept the larger wing. The structure was atypically light, and a remarkably low wing loading underlay the outstanding turning ability the Army prized. What the design left out was protection: there was no armor for the pilot and no self-sealing or fire suppression for the fuel tanks.
Operational History
The Ki-27 entered service with the 59th Sentai at Kagamigahara on 1 July 1938, just as the Army was reorganising its mixed air regiments into specialist sentai. From the late summer of 1938 it fought over northern and central China, where it helped Japan gain air superiority against the Chinese Curtiss Hawk IIIs and still controlled the skies into 1939. In the 1939 border fighting with the Soviet Union at Khalkhin Gol, the Ki-27 proved greatly superior to the Polikarpov I-15bis biplane, though the I-16 monoplane was a more serious threat. The victory claims made for that fighting were wildly exaggerated on both sides: Japan claimed 1,340 Soviet and Mongolian aircraft shot down for 120 of its own lost, while the Soviets claimed 215 victories and said they had deployed only 450 aircraft to the area. The campaign's top-scoring Japanese pilot, Hiromichi Shinohara, was credited with 58 Soviet aircraft, including eleven in a single day, before I-16s shot him down on 27 August 1939. In December 1941, Ki-27s still made up the majority of the Army fighters that overran Malaya, Burma and the Philippines. Over Burma, once Allied pilots learnt to avoid dogfights, the Ki-27 was found very vulnerable to battle damage. After the opening victories the type was phased out of front-line service and replaced by the Nakajima Ki-43. The many surviving aircraft became trainers, then returned to the front late in the war as one of the most widely used kamikaze types.
Afterlife
Just one Ki-27 is known to survive today. It is displayed at the Tachiarai Peace Memorial Museum in rural Fukuoka Prefecture, situated on the site of a wartime airfield once used by suicide pilots. The aircraft had ditched in Hakata Bay in April 1945; wartime diaries later identified it as the machine flown by Lieutenant Toshihiro Watanabe, who was afterwards killed on a kamikaze mission. The wreck was discovered in the bay during construction work in 1996, remarkably well preserved, and was restored and displayed locally. When the Tachiarai Peace Memorial Museum opened in 2009, the recovered Ki-27 became one of its centrepieces. A close relative survives alongside it in the record: the Mansyū Ki-79, a trainer developed directly from the Ki-27 and built in Manchuria, is preserved at the Satria Mandala Armed Forces Museum in Jakarta.