Monogram 5712 1:72 B-36 Peacemaker Plastic Model Kit NIB. History of the Plane: The Convair B-36 "Peacemaker" was a strategic bomber built by Convair and operated by the United States Air Force (USAF) from 1949 to 1959. The B-36 is the largest mass-produced piston-engined aircraft ever built, with the longest wingspan of any combat aircraft at 230 ft (70 m). Model is new in box, and still on all sprues ready to build.