From Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/Convair_B-36

The Convair B-36 “Peacemaker” was a strategic bomber built by Convair and operated solely by the United States Air Force (USAF) from 1949 to 1959. The B-36 was the largest mass-produced piston engine aircraft ever made. It had the longest wingspan of any combat aircraft ever built (230 ft or 70 m), although there have been larger military transports. The B-36 was the first bomber capable of delivering nuclear weapons that fit inside the bomb bay without aircraft modifications. With a range greater than 6,000 mi (9,700 km) and a maximum payload of 72,000 lb (33,000 kg), the B-36 was the first operational bomber with an intercontinental range. This set the standard for subsequent USAF long range bombers, such as the B-47 Stratojet, B-52 Stratofortress, B-1 Lancer, and B-2 Spirit