Boeing B-52 Stratofortress YB-52

YB-52 49-231 began life as the second of the two prototypes the Air Force contracted for under the XB-52 designation. Both traced their shape to the Model 464-49 that George Schairer's team drew up over a weekend in October 1948 in a Dayton hotel room, when Colonel Pete Warden made it clear that the four-engined turboprop bomber Boeing had brought to Wright Field was not what he wanted: a jet with wings swept 35 degrees, eight engines in four underwing pods and bicycle landing gear with outriggers. Boeing then scaled the design up into the 464-67, the standard to which both aircraft were actually built. Why one of the pair was completed as a YB-52, a prefix that denotes a pre-production test aircraft, has never been entirely clear; it may have been a budgetary manoeuvre, and the differences between the two prototypes were minor.

The YB-52 was finished with more operational equipment than its sister, but the two shared everything that mattered: the tandem cockpit under a framed bubble canopy inherited from the B-47, and the eight experimental Pratt & Whitney YJ57-P-3 turbojets of 8,700 pounds-force of static thrust each. Like the XB-52 it was an aircraft for proving the formula rather than dropping bombs; the changes General LeMay demanded, above all a side-by-side cockpit, were left for the B-52A.

Chance decided which prototype would fly first. On 29 November 1951 the XB-52 suffered an explosion of its pneumatic system during a ground test that wrecked the trailing edge of its wing, and while it was being repaired the programme pressed on with 49-231. On 15 April 1952 the YB-52 took off from Renton, Washington, with Boeing test pilot Alvin M. "Tex" Johnston in command and Lieutenant Colonel Guy M. Townsend of the US Air Force as co-pilot, and landed a little over two hours later at Larson Air Force Base in the same state. It was the first flight of any Stratofortress; the XB-52 did not follow until 2 October 1952.

There was an element of a race about that first flight. The B-52's unofficial rival was the Convair YB-60, a swept-wing, all-jet development of the B-36 with the same eight J57s in paired pods, and a far cheaper proposition because it modified an existing design rather than starting from scratch. The YB-60 flew on 18 April 1952, with Beryl Erickson at the controls, only three days after the YB-52. Boeing's advantage went beyond the calendar: the Convair aircraft was roughly 160 km/h slower and had serious handling problems, and its one strong card, a bomb load of 32.6 tonnes against the YB-52's 19.5, did not outweigh the rest in the Air Force's eyes.

The YB-52 spent the following years as a test aircraft; in 1953 it was photographed landing on Rogers Dry Lake in California, the usual setting for trials out of Edwards. The results of that flight programme, free of serious incident, led the Air Force to increase its order to 282 bombers. Once its usefulness was over, 49-231 was scrapped, as was the XB-52, and neither prototype survives.

In April 2022 Boeing marked the seventieth anniversary of the YB-52's flight as the birthday of the BUFF. That take-off from Renton opened a production run of 744 aircraft that ended in 1962 and an operational career that is still running: the configuration proved on 49-231, a flexible swept wing, eight jets slung beneath it, bicycle gear with outrigger wheels, is instantly recognisable in the B-52Hs still flying today.