In 1951, the USAF asked Convair to build a prototype of an all-jet variant of the B-36.
Convair complied by replacing the wings on a B-36F with swept wings, from which were suspended eight Pratt & Whitney XJ57-P-3 jet engines.
The result was the B-36G, later renamed the Convair YB-60.
The YB-60 was deemed inferior to Boeing's YB-52, and the project was terminated.
Just as the C-97 was the transport variant of the B-50, the B-36 was the basis for the Convair XC-99, a double-decked military cargo plane that was the largest piston-engined, land-based aircraft ever built, and the longest practical aircraft (185 ft/56 m) of its era.
The sole example built was extensively employed for nearly 10 years, especially for cross-country cargo flights during the Korean War.
In 2005, this XC-99 was dismantled in anticipation of its being moved from the former Kelly Air Force Base, now the Kelly Field Annex of Lackland AFB in San Antonio, Texas, where it had been retired since 1957.
The XC-99 was subsequently relocated to the National Museum of the United States Air Force at Wright-Patterson AFB near Dayton, Ohio for restoration, with C-5 Galaxy transports carrying pieces of the XC-99 to Wright-Patterson as space and schedule permitted.

A commercial airliner derived from the XC-99, the Convair Model 37, never left the drawing board.
It would have been the first "jumbo" airliner.
In 1951, the USAF asked Convair to build a prototype of an all-jet variant of the B-36. Convair complied by replacing the wings on a B-36F with swept wings, from which were suspended eight Pratt & Whitney XJ57-P-3 jet engines. The result was the B-36G, later renamed the Convair YB-60. The YB-60 was deemed inferior to Boeing's YB-52, and the project was terminated. Just as the C-97 was the transport variant of the B-50, the B-36 was the basis for the Convair XC-99, a double-decked military cargo plane that was the largest piston-engined, land-based aircraft ever built, and the longest practical aircraft (185 ft/56 m) of its era. The sole example built was extensively employed for nearly 10 years, especially for cross-country cargo flights during the Korean War. In 2005, this XC-99 was dismantled in anticipation of its being moved from the former Kelly Air Force Base, now the Kelly Field Annex of Lackland AFB in San Antonio, Texas, where it had been retired since 1957. The XC-99 was subsequently relocated to the National Museum of the United States Air Force at Wright-Patterson AFB near Dayton, Ohio for restoration, with C-5 Galaxy transports carrying pieces of the XC-99 to Wright-Patterson as space and schedule permitted.
A commercial airliner derived from the XC-99, the Convair Model 37, never left the drawing board. It would have been the first "jumbo" airliner.
Convair B-36 Peacemaker