The Nakajima Kikka, also known as “Orange Blossom,” stands as a testament to Japan’s late-war efforts to develop jet-powered aircraft during World War II. This twin-engine jet, inspired by Germany’s Messerschmitt Me 262, was the only Japanese jet aircraft of the era capable of taking off under its power.
In September 1944, following glowing reports on the Me 262 flight trials in Germany by the Japanese air attaché, the Imperial Japanese Navy issued a contract to Nakajima Aircraft Company for the design of a jet attack aircraft. Under the design team led by Kazuo Ohno and Kenichi Matsumura, the design for this aircraft was somewhat similar to that of the Me 262, though much smaller, without any swept-wing design as found in the German version. The Kikka was largely an all-metal machine with fabric-covered control surfaces. Its engines mounted in pods beneath each wing are considered a major feature of the design for flexibility in testing several different jet engines.
Development of turbojet technology in Japan began as early as the winter of 1941-42. In 1943, a technical mission to Germany resulted in the decision to manufacture the BMW 003 axial-flow turbojet. Although a cargo of engines and engineering plans was lost en route to Japan, one engineer returned with personal notes and photographs, which proved invaluable in the Naval Technical Arsenal’s development of a Ne-20 turbojet at Kugisho. The Ne-20, partially derived from the BMW 003, went from initial design to operational ground testing in only six months.
The Kikka’s first flight was made on 7 August 1945 by Lt. Cmdr. Susumu Takaoka. On the 11th, a second test flight ended in a crash when takeoff-assist rockets mounted on the belly of the aircraft were fitted incorrectly and broke free during takeoff. This misfortune, combined with Japan formally surrendering just a few days later, ended the development of the Kikka. At the time, a second prototype was well along, and American forces located about 25 other Kikkas in various stages of assembly at a Nakajima factory.
Several Kikka prototypes were taken to the United States in the post-war period for evaluation. One of these airframes is preserved and now is located at the Steven F. Udvar-Hazy Center, Chantilly, Virginia, in the Smithsonian National Air and Space Museum. Communication in 2001 with Japanese powerplant specialist Kazuhiko Ishizawa elicited that the NASM Kikka airframe was built up for static, not flight testing, which explained why the engine nacelles on this airframe are too small for fitting Ne-20 engines.
The Kikka’s specifications were: wingspan of 10 meters, length of 8.1 meters, height of 3 meters, empty weight of 2,300 kg, gross weight of 4,080 kg. Powered by two Ne-20 axial-flow turbojets, of which each gave 475 kg static thrust, the maximum speed possible was 696 kph; the range with a 500 kg bomb load was 205 km.
Despite a very short and fitful history, the Nakajima Kikka fills an important chapter in the annals of military aviation that shows Japan’s late-war ingenuity and will.