The Air Force's newest superbomber, the XB-36, compared with veteran B-29. The Air Force's huge six-engine bomber, the Convair XB-36, parked alongside a battle tested Boeing B-29, has a wingspan of 230 feet and the B-29, a wingspan of 141 feet. The length of the XB-36 is 163 feet; the B-29, 99 feet. The range of the XB-36 with a bomb load is 10,000 miles; the B-29 with a bomb load, approximately 4,100 miles. Though the Boeing B-29 Superfortress was the latest of the very heavy bombers, the improvements and the new developments incorporated in the Convair XB-36 show the remarkable technological advancement of the AF in the brief time that has elapsed since the end of the war. The XB-36 flew for the first time on 8 August 1946.