The Economic Times

Boeing spent $67,000,000 of its own money on the YF-118G Bird of Prey stealth aircraft with borrowed landing gear and ejection seat. It flew just 38 times

The YF-118G Bird of Prey, an aircraft secretly designed by Boeing, was pivotal in testing stealth technology. This innovative project delved into new designs and manufacturing techniques for better low visibility. By reusing existing parts, it minimized both costs and development time, completing 38 test flights at Area 51 during 1996-1999. Boeing disclosed the program in 2002 once its technologies were applied to other projects.