Two delicate paper dragons occupy the cockpit of the Aichi Seiran, a 1940s-era Japanese dive and torpedo bomber recently restored at the National Air and Space Museum’s Garber facility in Suitland, Maryland. The dragons were sent to the Museum specialists who worked on the Seiran by a leading origami instructor who had been an engineer for the Aichi Aircraft Company in Nagoya, Japan, more than 50 years ago. The artist is one of a group of former Aichi workers and military veterans who, during the past few years, have given unprecedented support and assistance to the Museum’s rejuvenation of the Seiran, whose top-secret mission was to take a stealthy submarine ride across the Pacific and bomb targets in North America.
“We have many times more information about the Seiran than when we started the project” in 1989, says NASM restoration specialist Bob McLean (right, standing in front of the Seiran), who was the main contact with the restoration’s collaborators in Japan. “Our Japanese friends have been extremely important to the accuracy of the final product.” Representing the Japanese friends has been Tetsukuni Watanabe (his American friends call him Tet). Watanabe is a recently retired quality assurance specialist with Aichi Machine Industry, Ltd., Aichi’s postwar incarnation, which manufactures parts for automobiles. For the past eight years, Watanabe has been talking shop with former Aichi Aircraft workers (like the origami artist), seeking information and documentation about the company’s unusual wartime product.
“I have liked model planes and warbirds since I was [a child],” the 57-year-old Watanabe explains in a recent e-mail exchange. He began researching the history and engineering of Aichi Aircraft in 1992, an undertaking that led him to contact the Museum. When he started, he says, there were more than 40 former Aichi employees who could supply him with the materials that would later prove so valuable in the Seiran’s restoration. Today, Watanabe puts their number at about 10. “Many Aichi old boys [are] gone,” he laments.
Through the 1990s Watanabe grew close to the Aichi veterans, visiting their homes and helping with odd jobs. He rallied them and some of their family members to support the 10-year-long Seiran restoration taking place halfway around the world. “These fellows over there,” says McLean, his voice full of admiration, “they’re working on their own time and on limited budgets, and have given incredible cooperation to us, relative strangers, to make this restoration a success.”
Watanabe and others gathered information and materials, including planning documents, designers’ drawings, and detailed diagrams of original components. They hosted McLean when he made a visit to Japan in 1999, and they helped him make contact with a Seiran mechanic, a former Seiran squadron commander, and a test pilot. Finally, Watanabe and others helped the restorers at Garber by translating engineering documents and other material, which went immeasurably further than mere photographs toward rebuilding the Seiran. McLean calls the result of the exchange “certainly one of the most successful bones-to-complete restorations of Japanese aircraft anywhere in the world.
“The most perplexing mystery of the airplane, for me, is how things are configured on the interior,” continues McLean. “A lot was missing when we got ahold of the Seiran. We had the choice of restoring the relatively empty aircraft with whatever we had, or creating replicas to make it at least look right. And there are an infinite number of fine points between those two options as well.” Now the Museum has an airplane that is more authentically restored than anyone would have thought possible.
The 7,200-pound Seiran was an ingenious response to a directive issued by Japanese military leaders for a weapon that could attack U.S. cities. To overcome the distance, the Seiran worked in conjunction with the huge Japanese I-400-class submarine. Three of the bombers fit into an 11.5-foot-wide hangar tube inside the sub. The Seiran’s wing spars rotated and allowed the wings to fold and tuck against the fuselage. The supersub was to make the journey across the Pacific and surface within flying range of the target. Then a carefully choreographed crew would open the hangar tube, unpack the first of the amphibious bombers, attach its floats, start the liquid-cooled engine, and catapult the manned Seiran from the sub’s deck—all within a period of seven minutes.
When the floatplanes returned from their mission, a crane would lift them out of the water, allowing crews to remove the floats, fold the wings, and stuff them back into the cargo hold for the trip home. Two Seiran-laden submarines were on their way to Micronesia in August 1945 when the Japanese emperor surrendered. By that time, Aichi had manufactured 28 of the airplanes.
The Museum’s Seiran, the only survivor, sports some wartime doodlings, likely drawn by Aichi factory workers wielding pencils and etching tools on the aircraft’s skin. Aside from some anti-Allied graffiti, there is a carefully etched drawing of a geisha and a few nonsensical English letters and words, perhaps someone practicing his command of the language.
Watanabe’s group has been able to shed some light on the history of the Museum’s artifact. Evidence indicates that it was the last Seiran off the assembly line in Nagoya before the region was occupied by Allied troops at the end of the war. Shortly after, the aircraft was shipped by the U.S. Navy to the Alameda Naval Air Station in California, where it was stored for several years. The Seiran arrived at the Museum’s Garber facility in 1962.