Engine parts for a secret Imperial Japanese Army jet aircraft under development in the closing days of World War II have been found at a Tokyo university by a student and a high school teacher.
The parts were discovered collecting dust on the campus of International Christian University (ICU) in Mitaka, western Tokyo, by Hideaki Furukawa in June 2015, who is now a 21-year-old fourth-year liberal art student of the university.
The research lab of the Nakajima Aircraft Co., predecessor of Subaru Corp., which was developing the jet fighter Karyu at the end of the war, formerly stood on the site of ICU. Japan surrendered in August 1945 before the company finished making the first prototype.
The parts are not only historically significant, but also could be an important resource to gauge the technological level of Japan at the time and the progress of its aeronautic development, according to experts.
Furukawa first found out about the old aircraft parts when he interviewed the president of a company that manages the campus for a classroom assignment. The president told him that the former president of the company found parts of the Fugaku on the campus grounds. The Fugaku was a heavy bomber whose development was also abandoned unfinished, and was a brainchild of Chikuhei Nakajima, the founder of Nakajima Aircraft.
The former company president kept the parts at his home for decades, before the current president placed them in storage on the ICU campus.
Nakajima was an Imperial Japanese Navy veteran turned entrepreneur, and after founding the aircraft company, he became a politician. He lived in his residence that was on the premises of the university from the closing days of the war until his death in 1949.
The university was founded in 1953 on the premises where the company’s Mitaka research lab once was located. The old research rebuilding is now used as the University Hall building.
Even today, Subaru’s Tokyo Regional Office stands by the campus.
After hearing the story, Furukawa contacted Masahisa Takayanagi, 51, a Japanese history teacher at ICU High School, who once taught the student. The teacher and his former student located two exhaust nozzles and one nozzle covering in storage.
The nozzles are made of stainless steel, and the outer diameter of the wider opening is about 75 centimeters wide, measures 73 cm in length, and weighs around 71 kilograms.
Seeing their shape, Takayanagi quickly surmised that they did not belong to the Fugaku. He contacted experts who replied only that "they are possibly parts of jet engines," and nothing more.
Then, Takayanagi deduced that they "could be parts of the jet engine Ne-230 for the Karyu, which is known to have been developed in the Mitaka research lab."
He found design plans for the Ne-130 and Ne-330, other jet engine test models that were produced during a similar time frame as the Ne-230, among documentation in the collection of the Defense Ministry.
As the designs were remarkably similar to the engine parts found in the ICU, Takayanagi asked the Japan Aeronautic Association to investigate further.
Association members examined the parts in detail along with the Tokyo National Institute for Cultural Properties, and the two bodies concluded the parts are "highly likely of the Ne-230" in an interim report in October.
According to Takayanagi, Japan obtained specifications on jet engines from its ally Germany. Based on these, Nakajima Aircraft developed the Ne-230 model in collaboration with Hitachi Ltd., and some parts of the model were produced in the Mitaka lab.
The prototype of the Karyu, which was to have a maximum speed of 852 kph and a flying range of 980 kilometers, was scheduled to be finished in December 1945.
Many engineers who worked on the Ne-230 later made contributions as engineers for major Japanese automakers.
"(The discovery) is a graphic reference to one aspect of wartime Japanese society that teaches us where we are at in the course of history," Takayanagi said.