Meet the XB-70: During the Cold War, the B-52 Stratofortress remained the workhorse of the United States Air Force, but even by the late 1950s, there were considerations for developing a bomber that could fly higher and even faster. This led to the development of the North American XB-70 Valkyrie, which was conceived by the Strategic Air Command (SAC) as a high-altitude bomber that would be able to fly three times the speed of sound.
As envisioned, the six-engined XB-70 Valkyrie was capable of cruising for thousands of miles at Mach 3+ while flying at 70,000 feet (21,000 m) – which was meant to make it practically immune to interceptor aircraft.
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As initially planned, the XB-70A – which was powered by six General Electric YJ93s of 30,000 lbs. thrust each with afterburner – was to have a maximum speed of Mach 3.1 (2,056 miles per hour, or 3,309 kilometers per hour).
Flying at 35,000 feet (10,668 meters), it could reach Mach 1.90 (1,254 miles per hour, or 2,018 kilometers per hour), while at its service ceiling of 75,550 feet (23,012 meters), it had a maximum speed of Mach 3.00 (1,982 miles per hour, or 3,190 kilometers per hour).
The planned combat range of the XB-70 was to be 3,419 miles (5,502 kilometers) with a maximum range of 4,290 miles (6,904 kilometers).
Yet, by the early 1960s, the development of improved surface-to-air missiles (SAMs) presented a new threat. Even as the bomber was still being developed, less costly, nuclear-armed ICBMs (Intercontinental Ballistic Missiles) were also beginning to enter service. As a result, the B-70 bomber program was canceled before a single Valkyrie had been completed or flown.
That should have been the end of the story.
High-Speed Test Platform
Though it proved not to be the bomber that the United States Air Force needed, the service still saw some potential in the platform – in this case to test aerodynamics, propulsion, and other characteristics of large supersonic aircraft. The XB-70 Valkyrie design actually proved to be a perfect testbed for SST research, which was being conducted jointly by NASA and the Air Force. It was the same size as the projected SST designs and used similar structural materials, such as brazed stainless steel honeycomb and titanium.
Yet, due to funding limitations, only two prototypes were subsequently built as research aircraft – and only one survives today.
The second of the two Valkyrie prototypes was destroyed in June 1966, just a year after it was produced, following an accidental mid-air collision, which resulted in the death of the co-pilot Maj. Carl Cross. A planned third Valkyrie was subsequently canceled.
However, the first XB-70A proved to be far more successful. It completed its maiden flight in from Air Force Plant 42, Palmdale, California, to Edwards Air Force Base in September 1964, with Chief Test Pilot Alvin S. White and Colonel Joseph F. Cotton, U.S. Air Force, at the controls.
The aircraft achieved Mach 3 flight in October 1965, and the prototype continued to fly and generate valuable test data in the research program until it was retired after conducting its final research flight on Feb. 4, 1969. What makes that flight especially impressive is that the futuristic-looking XB-70 “Valkyrie” took to the skies just a mere six decades after the Wright Brothers made their first flight.
That original prototype, Valkyrie AV-1 (AF Ser. No. 62-0001) is now on display in the Research & Development Gallery at the National Museum of the United States Air Force at Wright-Patterson Air Force Base (AFB), Dayton, Ohio.
It is among the largest of the aircraft currently in the museum’s collection and a testament to the Air Force’s efforts to push the boundaries of aviation.
Author Experience and Expertise:
A Senior Editor for 19FortyFive, Peter Suciu is a Michigan-based writer. He has contributed to more than four dozen magazines, newspapers, and websites with over 3,200 published pieces over a twenty-year career in journalism. He regularly writes about military hardware, firearms history, cybersecurity, politics, and international affairs. Peter is also a Contributing Writer for Forbes and Clearance Jobs. You can follow him on Twitter: @PeterSuciu.