Unlike 262, Kikka was not a lucky aircraft; certainly only jet aircraft which flew in Japan during WWII, but it flew only 2 test flights, and second ended with aborted takeoff. Engines were of Japanese design but derived from BMW 003. Engines in prototype were 2 Ne- 12, 750 lb thrust but were subsequently replaced by Ne-20s of 1050 lb thrust. First prototype flight successful; second and last took place 4 days later. Mistake in installation of 2 auxiliary rockets, which should have assisted on take-off, caused abort; project halted awaiting second prototype's completion. 15 August, all activity stopped. By that date, not only was second prototype ready, but also many of the 18 pre-series aircraft were nearing completion.