In the 1960s, the United States Air Force set out to develop a high-altitude, nuclear strike bomber that could fly at Mach 3 – three times the speed of sound – so that it could outrun any interceptor sent against it. The planned B-70 was to be a nuclear-armed, deep penetration supersonic strategic bomber for the Strategic Air Command.
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 B-70 had actually been conceived well before any consideration was likely given to the high-speed passenger airliner.
B-70: Too Ambitious, But Too Late
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).
As noted, the goal was to have a bomber that 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.
In fact, the bomber was dead even before its arrival, and likely just a huge waste of taxpayer dollars. By the early 1960s, the latest Russuan 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. Additionally, it was expected that each aircraft 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.
The program was actually canceled before any of the prototypes were completed, and that should have rightfully resulted in the flightless Valkyrie. Yet, 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.
You Can See a B-70 Today
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, while today the first prototype, Valkyrie AV-1 (AF Ser. No. 62-0001) is on display at the National Museum of the United States Air Force at Wright-Patterson AFB near Dayton, Ohio.
Peter Suciu is a Michigan-based writer who has contributed to more than four dozen magazines, newspapers and websites. He regularly writes about military small arms, and is the author of several books on military headgear including A Gallery of Military Headdress, which is available on Amazon.com.