Tag Archives: B-70

21 September 1964

North American Aviation XB70A-1-NA 62-001 takes off for the first time, 21 September 1964. (U.S. Air Force)
North American Aviation XB70A-1-NA 62-0001 takes off for the first time, 21 September 1964. (U.S. Air Force)

21 September 1964: The first prototype North American Aviation XB-70A-1-NA Valkyrie, serial number 62-0001, flown by Chief Test Pilot Alvin S. White and Colonel Joseph F. Cotton, U.S. Air Force, made its first flight from Air Force Plant 42, Palmdale, California, to Edwards Air Force Base.

Originally a prototype Mach 3 strategic bomber, 62-0001 (also known as AV-1) and it’s sister ship, XB-70A-2-NA, 62-0207, (AV-2), were built and used by the Air Force and NASA as high-speed research aircraft. The third Valkyrie, XB-70B-NA 62-0208 (AV-3), was never completed.

Major Joseph F. Cotton, USAF, and Alvin S. White, North American Aviation, with the XB-70A Valkyrie. (Autographed photograph courtesy of Neil Corbett, TEST & RESEARCH PILOTS, FLIGHT TEST ENGINEERS)
Colonel Joseph F. Cotton, USAF, and Alvin S. White, North American Aviation, with an XB-70A Valkyrie. (Autographed photograph courtesy of Neil Corbett, TEST & RESEARCH PILOTS, FLIGHT TEST ENGINEERS)

The B-70 was designed as a high-altitude Mach 3 strategic bomber armed with thermonuclear bombs. The XB-70A is 196 feet, 6 inches (59.893 meters) long with a wingspan of 105 feet (32.004 meters) and an overall height of 30 feet, 8 inches (9.347 meters) . It weighs 231,215 pounds (104,877 kilograms) empty and has a maximum takeoff weight of 534,792 pounds (242,578 kilograms).

The XB-70A was powered by six General Electric YJ93-GE-3 single-spool, axial-flow turbojet engines, which used an 11-stage compressor and two-stage turbine. The engine required a special heat-resistant JP-6 fuel, and was rated at 22,000 pounds of thrust (97.86 kilonewtons), or 31,000 pounds (137.90 kilonewtons) with afterburner. The YJ93-GE-3 was 19 feet, 7.0 inches (5.969 meters) long, 4 feet, 7.0 inches (1.397 meters) in diameter, and weighed 5,200 pounds 2,359 kilograms).

A Boeing B-52 Stratofortress flies formation with North American Aviation XB-70A Valkyrie 62-0001, approaching the runway at Edwards Air Force Base, California. (U.S. Air Force)

The XB-70A had 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), and 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 for the production  bomber was 3,419 miles (5,502 kilometers) with a maximum range of 4,290 miles (6,904 kilometers).

North American Aviation XB-70A Valkyrie 62-0001 made 83 flights with a total of 160 hours, 16 minutes flight time. 62-0001 is on display at the National Museum of the United States Air Force, Wright-Patterson Air Force Base, Ohio.

North American Aviation XB-70A Valkyrie 62-0001 lands at Edwards Air Force Base at the end of its first flight, 21 September 1964. (U.S. Air Force)
North American Aviation XB-70A-1-NA Valkyrie 62-0001 just before landing at Runway 4 Right, Edwards Air Force Base, ending of its first flight, 21 September 1964. A Piasecki HH-21B rescue helicopter hovers over the adjacent taxiway. (U.S. Air Force)

© 2017, Bryan R. Swopes

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17 July 1965

North American Aviation XB-70A-2-NA 62-0207 takes off for the first time at AF Plant 42, 17 July 1965. (U.S. Air Force)

17 July 1965: At Air Force Plant 42, Palmdale, California, the second North American Aviation B-70 Valkyrie prototype, XB-70A-2-NA 62-0207, took off on its maiden flight enroute Edwards Air Force Base where it would continue the flight test program with its sister ship.

The Valkyrie was designed as a Mach 3+ strategic bomber, capable of flight above 70,000 feet (21,336 meters), with intercontinental range. It’s altitude allowed it to avoid interceptors of the time, but improvements in radar-guided surface-to-air missiles increased its vulnerability. Ultimately, though, political decisions ended the B-70 program.

62-0207 was flown just 46 times, for a total of 92 hours, 22 minutes of flight. Changes to the aircraft corrected the deficiencies discovered in testing the Number 1 XB-70A, 62,-201. The most visible change was 5° dihedral added to the wings for improved stability. On 16 April 1966, 62-0207 reached its maximum design speed, Mach 3.08, which it sustained for 20 minutes.

Less than one year after its first flight, 8 June 1966, the Valkyrie was involved in a mid-air collision with a Lockheed F-104N and crashed just north of Barstow, California. North American’s B-70 test pilot, Al White, was seriously injured and co-pilot, Major Carl Cross, USAF, was killed. NASA test pilot Joe Walker, flying the F-104, was also killed.

© 2015, Bryan R. Swopes

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