Production

464-49 to B-52AIn May 1948 AMC asked Boeing to incorporate the previously discarded, but now more fuel-efficient, jet engine into the design. This resulted in Boeing developing yet another revision — in July 1948, Model 464-40 substituted Westinghouse J40 turbojets for the turboprops.[15] Nevertheless, on 21 October 1948, Boeing was told to create an entirely new aircraft using Pratt & Whitney J57 turbojets.


XB-52 Prototype on flight line (X-4 in foreground).On 25 October, Boeing engineers produced a proposal and a hand-carved model of 464-49.[16] The new design built upon the basic layout of the B-47 Stratojet with 35° swept wings, eight engines paired in four underwing pods, and bicycle landing gear with wingtip outrigger wheels. A notable feature of the landing gear was the ability to pivot the main landing gear up to 20° from the aircraft centerline to increase safety during crosswind landings.[17] The aircraft was projected to exceed all design specifications.[3] Although the full-size mock-up inspection in April 1949 was generally favorable, range again became a concern since the J40s and the early model J57s had excessive fuel consumption.


Side view of YB-52 bomberDespite talk of another revision of specifications or even a full design competition among aircraft manufacturers, General LeMay, now in charge of Strategic Air Command, insisted that performance should not be compromised due to delays in engine development.[18] In a final attempt to increase the range, Boeing created the larger 464-67, stating that once in production, the range could be further increased in subsequent modifications.[19] Following several direct interventions by LeMay,[20] on 14 February 1951 Boeing was awarded a production contract for 13 B-52As and 17 detachable reconnaissance pods.[21] The last major design change, also at the insistence of General LeMay, was a switch from the B-47 style tandem seating to a more conventional side-by-side cockpit which increased the effectiveness of the copilot and reduced crew fatigue.[22] Both XB-52 prototypes featured the original tandem seating arrangement with a framed bubble-type canopy.[23]


The YB-52 prototype with the bubble canopy is similar to that of the B-47The YB-52 (actually, the second XB-52 with more operational equipment) first flew on 15 April 1952,[24] a 2 hour 21 minute flight from Renton Field in Renton, Washington to Larson AFB with Boeing test pilot Alvin M. Johnston and Air Force Lieutenant Colonel Guy M. Townsend.[25][26] The XB-52 followed on 2 October 1952. The thorough development,[27] including 670 days in the wind tunnel and 130 days of aerodynamic and aeroelastic testing, paid off with smooth flight testing. Encouraged, the Air Force increased its order to 282 B-52s.[28]

Only three of the 13 B-52As ordered were built. All were returned to Boeing, and used in their test program.[29] On 9 June 1952 the February 1951 contract was updated to order the aircraft under new specifications. The final ten—the first aircraft to enter active service—were completed as B-52Bs.[29] At the roll out ceremony on 18 March 1954, Air Force Chief of Staff, General Twining said:

“ The long rifle was the great weapon of its day. ...Today this B-52 is the long rifle of the air age.[30] ”