Since it became operational in 1955, the B-52 has been the main long-range heavy bomber of the Strategic Air Command. It first flew on Apr. 15, 1952. Nearly 750 B-52s were built when production ended in Oct. 1963, of which 170 were -Ds. The -Ds were modified to carry conventional bombs and Quail decoy missiles. The B-52 has set many records in its 25-plus years of service.

On Jan. 18, 1957, three B-52Bs completed the world's first non-stop round-the-world flight by jet aircraft, lasting 45 hours and 19 minutes with only three aerial refueling en route. It was also a B-52 that made the first airborne hydrogen bomb drop over Bikini Atoll on May 21, 1956. In June 1965, B-52s entered combat when they began flying missions in Southeast Asia (SEA). By Aug. 1973, they had flown 126,615 combat sorties with 17 B-52s lost to enemy action.