The project was to use a Convair B-36 bomber as a testbed aircraft, and though one NB-36H was modified during the early stages of the project, the program was canceled before the actual X-6 and its nuclear reactor engines were completed.
Proyek ini menggunakan bomber Convair B-36 sebagai pesawat testbed, dan meskipun salah satu NB-36h dimodifikasi selama tahap awal proyek, program tersebut dibatalkan sebelum sebenarnya X-6 dan mesin reaktor nuklirnya diselesaikan.