KB-29s were in service with SAC until being replaced by the KC-97 Stratofreighter (which was itself based on the B-29) by 1955. After the Korean War and the phaseout of the B-29/KB-29 from SAC, KB-29s were acquired by Tactical Air Command to serve as dedicated aerial refueling tankers for Tactical Fighter aircraft to give TAC a worldwide deployment capability separate from SAC. However, it was found that the KB-29 was totally unsuitable for the refuelling of jet fighters because they were too slow. The KB-29s were replaced beginning in 1956 with faster KB-50s. During the Cold War, the Military Air Transport Service the controlling command for Air Commando units which performed special operations during the 1950s, including during the Korean War. As part of the equipment used by the Air Resupply And Communications Service (ARCS) were B-29s modified for special operations missions. Air Weather Service (part of Military Air Transport Service) received their first B-29s in various versions (B-29, RB-29, TB-29, WB-29) in 1946 AWS initially used B-29s in support of the 1946 Operation Crossroads atomic bomb tests at Bikini Atoll. Weather reconnaissance duties required special variant of the B-29. Armament and related equipment was removed and in place of upper forward turret astrodome was installed. Additional radio and specialized meteorological equipment was installed and such refitted aircraft was redesignated WB-29. While the B-29's "public" mission was that of weather reconnaissance, the "covert" mission, that of atmospheric sampling for radiation debris, was perhaps the more critical task. WB-29s soldiered on through the mid-1950s, providing critical data on tropical storms, nuclear tests, and many other routine but important reconnaissance tasks. But the airplanes were weary, and by 1956 were replaced by a modification of seventy-eight B-50Ds to WB-50 configuration. NOTE: *Under operational control of Far East Air Forces flying combat weather reconnaissance missions over North Korea during the Korean War   B-29-96-BW serial number 45-21800 was used as the "mother" aircraft for launches of the Bell X-1 rocket-powered research aircraft at Edwards AFB. On October 14, 1947, Capt Charles E. "Chuck" Yeager was dropped in his X-1 from the B-29 and was credited as the first human to pilot an aircraft faster than the speed of sound.