The YB-49 was a jet powered development of the propeller driven XB-35 and YB-35 Flying Wing designs. Its first flight took place on October 22, 1947. There were three aircraft built in total.
During testing the airplane it set an unofficial endurance record for remaining above 40,000 feet altitude for 6.5 hours. The airplane also showed a small radar cross section.
Knowledge and experience gained from the XB-35, YB-35 and YB-49 Flying Wing programs proved valuable decades later when the B-2 was designed and developed.
It was a time of tremendous innovation, experimentation and progress in aviation. It was a time when we felt that anything was possible; the sky was the limit.