Engines: Eight Pratt & Whitney J57s Top Speed: 638 mph. Range: 8,338 miles Celling: 49,400 ft. Span: 185 ft. 0 in. Length: 156 ft 6 in. Height: 48 ft. 4 in. The B-52 has been the main long-range heavy bomber with SAC since becoming operational in 1957, three B-52s completed the world's first non-stop round-the-world flight by jet aircraft. This B-52 at the USAF Museum. W-P AFB Ohio, saw extensive service on Southeast Asia and was severely damaged by an enemy surface air missile in 1972.