Convair X-6 First Flight: Never built. (Test bed NB-36H) Mission: Test feasibility of aircraft nuclear propulsion. Major Accomplishments: N/A Power Source: (Projected) General Electric P1 (Specifications below are based on NB-36H test bed) Span: 230 ', 0 Length: 162' , 1 . Height: 46', 8 Engines: Six Pratt & Whitney R-4360-53 radials of 3, 800 hp. each (takeoff power) and four General ...