As the advent of jet aircraft began to emerge in the late 1940s and early 1950s, Convair started design on a swept-winged version of the B-36 with all-jet propulsion.
About the B-36: Design, Production, Deployment & Scrapping
B-36 - National Museum of the U.S. Force
B-36 - Pima Air & Space Museum
B-36 - Strategic Air Command & Aerospace Museum
Carswell AFB and Its Role in the B-36 Program
It also designed and built a prototype large-scale transport plane, the Convair XC-99.
In March 1951, the US Air Force authorized Convair to convert two B-36Fs to B-36Gs.
Since the jet aircraft was so different from production B-36 models, the designation was later changed to YB-60.
The eight-engine YB-60 shared 72% of its parts with the B-36. The fuselages of the two aircraft were nearly identical, although the YB-60 had a longer, pointed nose with a needle-like instrument probe, instead of the B-36's rounded nose.
The wingspan of the plane was 206 feet, the length 171 feet.
One YB-60-1-CF prototype was completed, S/N 49-2676, and used in test flights, with its maiden flight on April 18, 1952, piloted by Chief Test Pilot Beryl A. Erickson, and Arthur S. Witchell.
The YB-60 was subsequently flown to the Edwards Air Force Base Flight Test Center for further testing by Convair and Air Force teams.
The second prototype, S/N 49-2684, although 95% assembled and only missing its engines (delayed by the USAF), never flew.
The YB-60's competitor was the Boeing B-52 Stratofortress, which the Air Force selected as its next generation of heavy bomber. The B-52 could fly about 100 mph faster than the B-60.
YB-60 assembly at the Convair Fort Worth Plant
The YB-60 program was cancelled on January 20, 1953 by the Air Force, which formally accepted the two aircraft on July 1, 1954.
Workmen began the scrapping process with axes and blowtorches, salvaging parts still of use to the B-36F program. Sadly, from an aviation historian's perspective, the two prototypes were completely salvaged by the end of July, 1954.
Convair YB-60 Heavy Bomber (Wings Friend or Foe)
Armament: Designed for two 20mm cannons in the tail and up to 72,000 lbs. of bombs
Engines: Eight Pratt & Whitney XJ57-P-3 turbojets of 8,700 lbs. thrust each, paired in four under-wing pods
Maximum speed: Approx. 510 mph
Cruising speed: 435 mph
Range: 10,000 miles maximum ferry range
Service ceiling: 52,000 ft.
Span: 206 ft. 0 in.
Length: 171 ft. 0 in.
Height: 50 ft. 0 in.
Weight: 300,000 lbs. maximum
Crew: Five (pilot, copilot, navigator, bombardier, tail gunner)
Convair YB-60 S/N 49-2676 with a young admirer, Bill Whiteside, at the Edwards AFB Test Flight Center. His father - Walter W. "Whitey" Whiteside - was the chief of bomber maintenance at Edwards in the early 1950s when this photo was taken
Convair YB-60 and B-36 shown side by side at Edwards AFB in California
Convair YB-60 on apron showing its huge swept-wing area
Convair YB-60 at the Convair Fort Worth plant with B-36 aircraft in the background
Convair YB-60 in Flight