XB-70A Valkyrie – The Deep-Penetration Supersonic Strategic Bomber: Originally conceived in the 1950s as a high-altitude, nuclear strike bomber that could fly at Mach 3 – three times the speed of sound – the XB-70A Valkyrie would have been like no other combat aircraft in the skies. The planned B-70 was to be a nuclear-armed, deep penetration supersonic strategic bomber for the Strategic Air Command to strike the then Soviet Union.
Its speed would have meant that no enemy would have been unable to defend against it, and yet by the early 1960s, the development of improved surface-to-air missiles (SAMs) presented a new threat.
At the same time, less costly, nuclear-armed ICBMs (Intercontinental Ballistic Missiles) were beginning to enter service. The B-70 bomber program was canceled before a single Valkyrie had been completed or flown. It could have been a footnote in history, but the United States Air Force still saw a potential – not as a bomber, but as a platform to test aerodynamics, propulsion, and other characteristics of large supersonic aircraft.
Notable XB-70A Facts:
Similar in Design the Concorde
With its delta-wing profile, it isn’t hard to see the similarities in the overall design of the experimental XB-70 and the British-French turbojet-powered Concorde supersonic passenger airline that was operated from 1976 until 2003. However, the XB-70 had actually been conceived well before any consideration was likely given to the high-speed passenger airliner.
A Need for Speed
As planned, the XB-70A was to have a maximum speed of Mach 3.1 (2,056 miles per hour, or 3,309 kilometers per hour). 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 B-70 was to be 3,419 miles (5,502 kilometers) with a maximum range of 4,290 miles (6,904 kilometers).
High Flying Like Icarus
It wasn’t just speed, but altitude that was meant to be the XB-70A’s best defense. As conceived, the bomber could fly so high and fast that any enemy, notably the Soviet Union, couldn’t have easily defended against it – but just as the aircraft was being developed, missile technology was improved. Yet, by the early 1960s, the latest surface-to-air missiles (SAMs) proved to be serious a threat, even to such high-flying bombers – countering the speed and altitude that had promised to protect it.
XB-70A: A Costly Warbird
The other issue that nixed the development of the Valkyrie as a bomber was the price tag. It was estimated that each would cost an estimated $24.5 million ($237 million in today’s money), which proved simply far too expensive for such an aircraft – especially as less costly ICBMs were entering service.
Test Bed Instead
Though the program was actually canceled before any of the prototypes were completed, the Air Force opted to move forward with two aircraft prototypes, which were subsequently used in a research program to test aerodynamics, propulsion and other characteristics of such a large supersonic aircraft. The first of those two prototypes that were eventually built flew for the first time on Sept. 21, 1965 with Chief Test Pilot Alvin S. White and Colonel Joseph F. Cotton, U.S. Air Force, at the controls. That first flight was from Air Force Plant 42, Palmdale, California, to Edwards Air Force Base. A second took flight on July 17, 1965 – however, after the initial flight, it was limited to Mach 2.5 due to structural concerns.
Both of the prototypes were used in a number of research flights that were conducted as a joint agreement between the Air Force and NASA. The second of the two aircraft was destroyed following an accidental mid-air collision that resulted in the death of the co-pilot Maj. Carl Cross.
One XB-70A is Preserved in a Museum
The 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.

XB-70. Image Credit: Creative Commons.

XB-70A. Image Credit: Creative Commons.

XB-70A. Image Credit: Creative Commons.

XB-70. Image Credit: Creative Commons.

XB-70A. Image Credit: Creative Commons.

XB-70 Valkyrie. Picture Details: Viewed from the front the #1 XB-70A (62-0001) is shown climbing out during take-off. Most flights were scheduled during the morning hours to take advantage of the cooler ambient air temperatures for improved propulsion efficiencies. The wing tips are extended straight out to provide a maximum lifting wing surface. The XB-70A, capable of flying three times the speed of sound, was the world’s largest experimental aircraft in the 1960s. Two XB-70A aircraft were built. Ship #1 was flown by NASA in a high speed flight research program.

The futuristic XB-70A was originally conceived in the 1950s as a high-altitude, nuclear strike bomber that could fly at Mach 3 (three times the speed of sound) — any potential enemy would have been unable to defend against such a bomber.
Expert Biography: A Senior Editor for 1945, Peter Suciu is a Michigan-based writer who has contributed to more than four dozen magazines, newspapers, and websites with over 3,000 published pieces over a twenty-year career in journalism. He regularly writes about military hardware, firearms history, cybersecurity, and international affairs. Peter is also a Contributing Writer for Forbes. You can follow him on Twitter: @PeterSuciu.
