Aichi Aircraft Eitoku Plant

The Aichi Aircraft Eitoku Plant (愛知航空機永徳工場) was the principal airframe assembly facility of Aichi Kokuki K.K. (愛知航空機株式会社), one of Imperial Japan's most important naval aircraft manufacturers. Located in what is now Noseki 5-chome, Minato-ku, Nagoya, on the banks of the Shonai River estuary facing Ise Bay, the plant was strategically sited to allow direct water access for seaplane testing and delivery.

Origins and Establishment

Aichi Kokuki traces its roots to Aichi Tokei Denki K.K. (愛知時計電機, Aichi Clock & Electric), a precision instruments maker founded in 1898 that began aircraft production for the Imperial Japanese Navy in 1920. The company's original Funakata Plant (船方工場) in Atsuta-ku handled early aircraft manufacturing, but as wartime production demands surged, expansion became imperative.

The site for the Eitoku Plant in southwestern Nagoya was acquired on February 18, 1940, and the first buildings were completed in May 1941. The plant went into limited production in April 1942 when aircraft assembly functions were transferred from the cramped Funakata Plant. By 1943, the aircraft division was formally separated from the parent Aichi Tokei Denki and incorporated as the independent Aichi Kokuki K.K., with the Eitoku Plant serving as its headquarters and primary airframe factory.

Scale of Operations

By 1944, the Eitoku Plant had grown to approximately 95 buildings (excluding dormitories and school buildings), providing 22,170 square meters of floor space across roughly 197 acres. The workforce peaked at over 26,000 employees in September 1944, comprising a complex mix of regular workers, mobilized students (学徒動員), conscripted laborers, and naval personnel.

The Aichi Aircraft Company operated multiple facilities:

• Eitoku Plant (永徳工場): Main airframe assembly, Minato-ku — the largest facility
• Funakata Plant (船方工場): Original airframe factory, Atsuta-ku
• 11-gochi Plant (11号地工場): Airframe sub-assembly, Minato-ku
• Chitose Plant (千年工場): Atsuta engine manufacturing
• 4-gochi Plant (4号地工場): Engine production at former seaplane hangar site
• Iho Plant (伊保工場): Dispersal airframe factory, Toyota City

Aircraft Produced

The Eitoku Plant's principal product was the Yokosuka D4Y Suisei (彗星, "Comet", Allied code name "Judy") — a fast carrier-borne dive bomber designed by Yokosuka Naval Air Technical Arsenal but mass-produced by Aichi. Models 11, 12, 33, and 43 rolled off the Eitoku assembly lines, with Aichi producing about 1,820 of the roughly 2,250 built (a total that includes the Type 2 carrier reconnaissance version; the remainder came from the 11th Naval Air Arsenal). The Suisei was notable as the IJN's fastest dive bomber, capable of 550 km/h, and saw extensive service from the Battle of the Philippine Sea through the final kamikaze campaigns.

The plant also produced:

• Aichi E16A Zuiun (瑞雲, "Auspicious Cloud", "Paul"): A reconnaissance seaplane/dive bomber, approximately 256 built
• Aichi B7A Ryusei (流星, "Shooting Star", "Grace"): An advanced torpedo/dive bomber intended to replace both the D4Y and B6N
• Aichi E13A (零式水上偵察機, "Jake"): Zero-type reconnaissance floatplane, 133 built by Aichi
• H9A: Type 2 training flying boat
• Nakajima B5N (九七式艦上攻撃機, "Kate"): Type 97 torpedo bomber, assembled under license

Most significantly, the Eitoku Plant was where the top-secret Aichi M6A Seiran (晴嵐, "Clear Sky Storm") was developed and assembled. This revolutionary submarine-launched attack floatplane was designed to be carried inside the massive I-400 class submarines for strategic strikes against targets like the Panama Canal. The Seiran was built in a detached experimental-aircraft assembly building on a corner of the Eitoku plant by the river's edge — a secluded facility comparable to Lockheed's celebrated Skunk Works. Only 28 Seiran were completed between November 1943 and July 1945, none seeing combat before Japan's surrender.

The Seaplane Slipway

A defining feature of the Eitoku Plant was its seaplane slipway (スリップ) — a reinforced concrete ramp approximately 35 meters wide descending into the Shonai River. Since seaplanes used floats instead of wheeled landing gear, this inclined surface allowed aircraft to slide from the assembly area directly into the water for testing and delivery flights. The slipway faced the Fujimae tidal flats (藤前干潟), now a Ramsar Convention wetland.

Wartime Destruction

The Tonankai Earthquake (東南海地震) of December 7, 1944 (M7.9) caused significant damage to the Eitoku Plant, misaligning manufacturing jigs and disrupting production — though this natural disaster was suppressed from public knowledge under wartime censorship.

The devastating blow came from American strategic bombing. On June 9, 1945, B-29 Superfortresses attacked the Funakata Plant in Atsuta-ku in what became known as the Atsuta Air Raid (熱田空襲). In approximately 10 minutes of concentrated bombing, the Funakata factory was obliterated. Combined with the adjacent Aichi Tokei Denki facility, the raid killed approximately 2,068 people — workers, mobilized students, and nearby residents — making it one of the deadliest single-factory bombings of the Pacific War.

On June 26, 1945, B-29s attacked several factories in the Nagoya area, including the Eitoku Plant itself, where about 50 bombers caused only light damage. A second raid by 66 B-29s on July 24, 1945 inflicted the heaviest damage the plant sustained during the war.

In the final months, the company attempted to disperse production to underground and satellite facilities, but these efforts came too late to restore meaningful output. By war's end, Aichi Aircraft had produced a total of approximately 5,352 aircraft across all types and facilities.

Postwar Legacy

Following Japan's surrender, the aircraft company was dissolved. The Eitoku Plant site was converted to civilian industrial use and became Aichi Kikai Kogyo K.K. (愛知機械工業, Aichi Machine Industry), a Nissan Motor subsidiary manufacturing automobile components — a transformation that mirrored the broader conversion of Japan's wartime aviation industry.

The seaplane slipway survived demolition and industrial redevelopment. Located near Noseki Station on the Aonami Line (approximately 10 minutes walk), the concrete ramp extends into the Fujimae tidal flats at coordinates 35°04'43"N, 136°50'56"E. Though weathered by eight decades of tidal exposure, the slip's structure remains clearly visible, with discernible concrete slopes and remnant stone steps. A small explanatory marker identifies the site.

The adjacent Fujimae tidal flats were designated a Ramsar Convention wetland in 2002, inadvertently helping to preserve this industrial war relic in its waterfront setting. The slip stands as a rare physical reminder of the massive naval aircraft production complex that once occupied this stretch of the Nagoya waterfront — and of the thousands of workers, including mobilized students, who labored and died here during the final desperate year of the Pacific War.