Kawasaki Aircraft Gifu Plant

The Kawasaki Aircraft Gifu Plant (川崎航空機工業岐阜工場) was the primary airframe production facility for Kawasaki's military aircraft during World War II, located in Kakamigahara City, Gifu Prefecture, directly adjacent to the Kakamigahara Airfield (now JASDF Gifu Air Base). The factory and airfield together formed an integrated complex for aircraft manufacture, test flight, and delivery that was central to Japan's wartime aviation industry.

The facility traces its origins to 1922, when Kawasaki Dockyard Company (川崎造船所) established its Kakamigahara Branch Works (各務原分工場) to enter the aircraft manufacturing business. The company had secured a license to build the French Salmson 2A2 reconnaissance aircraft, and the airplane assembly factory was completed in 1923, strategically sited adjacent to the Army's Kakamigahara Airfield for immediate flight testing. Approximately 300 Salmson 2A2s were manufactured here as the plant's first major production run.

In 1937, the Kakamigahara Branch Works was upgraded to full Works status, and Kawasaki Aircraft Co., Ltd. (川崎航空機工業株式会社) was spun off as an independent company, with about 1,200 staff transferred from the parent company's Kobe operations. On February 7, 1939, the factory was officially renamed from Kakamigahara Works to Gifu Works (岐阜工場), reflecting its growing scale and importance.

Throughout the 1920s and 1930s, the plant produced a succession of significant military aircraft. The Type 87 heavy bomber, completed in 1926, was Japan's first large all-metal aircraft. The Type 88 reconnaissance/light bomber series followed, then the Type 92 fighter and the Type 95 fighter (Ki-10), of which approximately 580 were built. The Type 99 twin-engine light bomber (Ki-48) and the Type 1 cargo transport (Ki-56) were also mass-produced here, totaling 1,977 units.

The Gifu Works' most significant wartime product was the Ki-61 Hien (飛燕, 'Flying Swallow'), designed by chief engineer Takeo Doi (土井武夫) and his deputy Shin Owada (大和田信). The Ki-61 was unique among Japanese fighters as the only mass-produced type to use a liquid-cooled inverted-V engine — the Kawasaki Ha-40, a licensed derivative of the German Daimler-Benz DB 601A. The first prototype made its maiden flight at the adjacent Kakamigahara Airfield on December 6, 1941 — just one day before the attack on Pearl Harbor.

Adopted as the Type 3 Fighter (三式戦闘機) in 1943, the Ki-61 entered mass production at the Gifu Works while its Ha-40 engines were manufactured at Kawasaki's Akashi Works (明石工場) in Hyogo Prefecture. The factory achieved remarkable production rates, peaking at approximately 200 airframes per month. Allied intelligence designated the Ki-61 'Tony,' initially mistaking its inline-engine silhouette for an Italian or German design. Total production of the Ki-61 reached approximately 3,159 aircraft across all variants (Ki-61-I, Ki-61-I KAI, and Ki-61-II).

A catastrophic blow to Ki-61 production came on January 19, 1945, when a B-29 raid destroyed the Kawasaki Akashi engine plant, halting production of the Ha-140 engine needed for the improved Ki-61-II. With 275 engineless Ki-61-II KAI airframes sitting at the Gifu Works, chief engineer Doi improvised a brilliant solution: fitting the readily available Mitsubishi Ha-112-II 14-cylinder radial engine to the Ki-61 airframe. The resulting Ki-100, first flown on February 1, 1945, proved to be one of the best Japanese fighters of the war, with excellent performance against B-29s and American escort fighters.

The Gifu Works itself became a direct target of American strategic bombing on June 22, 1945. That morning at approximately 9:00 AM, 44 B-29 Superfortresses approached from the west and conducted a medium-altitude daylight precision attack lasting about 20 minutes. The bombers dropped 2,000-pound (1-ton) general purpose bombs and 4,000-pound (2-ton) semi-armor-piercing bombs. A one-ton bomb scored a direct hit on the Kawasaki Aircraft main building, and the factory complex was nearly completely destroyed, along with adjacent Mitsubishi Heavy Industries hangars and the Army Aviation Arsenal (陸軍航空廠).

The death toll was 169 persons. Of these, 63 were Kawasaki Aircraft employees and mobilized student workers (動員学徒). The high casualty count among Kawasaki personnel resulted from a tragic circumstance: workers had evacuated to air-raid shelters in nearby Kawasaki-yama and Akaboshi-yama hills, but American bombers specifically targeted these hills believing they contained aircraft revetments and fuel storage facilities, dropping one-ton bombs directly onto the shelters where evacuees had sought refuge.

Additional air raids struck the Kakamigahara area on June 29 and July 12, 1945, further devastating the already crippled industrial complex. By war's end, the Gifu Works' production capacity had been effectively eliminated.

After Japan's surrender, all aircraft production was prohibited by the Allied Occupation authorities. The ban was lifted in 1952, and Kawasaki resumed aerospace manufacturing at the Gifu site. In 1969, three Kawasaki companies merged to form the consolidated Kawasaki Heavy Industries, Ltd. The factory celebrated its 100th anniversary in 2022 and continues today as the Gifu Works of Kawasaki Heavy Industries' Aerospace Systems Company, manufacturing the P-1 maritime patrol aircraft, C-2 transport aircraft, T-4 intermediate trainer, and components for the Boeing 787 Dreamliner. The address remains 1 Kawasaki-cho, Kakamigahara City — the 'Kawasaki-cho' (川崎町) place name itself a testament to the factory's century-long presence in the community.

The sole surviving Ki-61 airframe, a Ki-61-II KAI (serial number 6117), was returned to the Kawasaki Gifu Works in September 2015 for restoration after decades at the Chiran Peace Museum. Kawasaki Heavy Industries meticulously restored the aircraft over one year, and since March 2018 it has been displayed at the adjacent Gifu-Kakamigahara Air and Space Museum (岐阜かかみがはら航空宇宙博物館) — returning to its birthplace. It is recognized as a Significant Aviation Heritage (重要航空遺産) of Japan.