The Boeing B-54 Ultrafortress was a strategic bomber designed by Boeing for use by the United States Air Force. Derived from the YB-50C Superfortress, construction of the prototype was cancelled before completion, and the aircraft was never flown.
An early B-50A was set aside to serve as a prototype for the YB-50C. The mockup of the B-50C was completed by November of 1948.
In late 1948, the Air Force concluded that the B-50C was sufficiently different from the B-50A and B which preceded it that a new bomber model number of B-54 was assigned.
In the B-54, the Pratt & Whitney R-4360 engines of the B-50 bomber were replaced with R-4360-51 Variable Discharge Turbine (VDT) engines, the fuselage was lengthened by over 10 feet and the wingspan was extended by 20 feet. Large fuel tanks under the outboard wing section were required to carry the additional 3,000 US gallons of fuel needed to achieve the intended range of 9,300 miles.
The B-54 was to be have a fuselage lenth of 111 feet, and a wingspan of 161 feet. The wingspan was so wide that outrigger gears were needed under the outermost engine nacelles.
The addition of the outrigger gears wasn't popular with the Air Force as its bases would need to have widened taxiways and runways to accommodate the B-54.
As a comparison, the B-29 weighed 120,000 lbs fully loaded and the B/RB-54 would weighed in at 207,000 lbs at takeoff.
It would be manned by a crew of 10.
In May of 1948 contracts were placed by the U.S. Air Force for 21 B-54A bombers and 52 RB-54A reconnaissance aircraft.
However, the B-54 offered limited growth potential since it squeezed the maximum possible amount out of an already obsolescent design.
General Curtis LeMay vigorously opposed it and argued for the cancellation of the B-54 in favor of more Convair B-36 Peacemakers.
The B-54 project was ultimately canceled in April of 1949. Construction of the prototype B-54A had started by Boeing at Seattle and it was approximately 75% complete when the project was canceled.
Boeing B-54 Ultrafortress drawing ... courtesy of the San Diego Air and Space Museum
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