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)

62-0001 was the first of three prototype Mach 3+ strategic bombers. (The third prototype, XB-70B 62-0208, was not completed.) The Valkyrie utilized the most advanced technology available. Materials and manufacturing techniques had to be developed specifically to build this airplane. It is a large delta wing airplane with a forward canard and two vertical fins. The outer 20 feet (6.096 meters) of each wing could be lowered to a 25° or 65° angle for high speed flight. Although this did provide additional directional stability, it actually helped increase the compression lift, which supported up to 35% of the airplane’s weight in flight.

The XB-70A is 185 feet, 10 inches (56.642 meters) long with a wingspan of 105 feet (32.004 meters) and overall height of 30 feet, 9 inches (9.373 meters). The delta wing had 0° angle of incidence and 0° dihedral. (The second XB-70A had 5° dihedral.) The wing has 3.0° negative twist. At 25% chord, the wing has 58.0° sweepback. Total wing area is 6,297 square feet (585 square meters). The Valkyrie has a empty weight of 231,215 pounds (104,877 kilograms), and maximum takeoff weight (MTOW) of 521,056 pounds (2236,347 kilograms).

It is powered by six General Electric YJ93-GE-3 turbojet engines. The J93 is an afterburning single-shaft axial-flow turbojet with an 11-stage compressor section and two-stage turbine. It has a Normal Power rating of 17,700 pounds of thrust (78.73 kilonewtons), 19,900 pounds (88.52 kilonewtons), Military, and 28,000 pounds (124.55 kilonewtons) Maximum. (All ratings are continuous, at 6,825 r.p.m.) The YJ93-GE-3 is 236.3 inches (6.002 meters) long, 54.15 inches (1.375 meters) in diameter, and weighs 5,220 pounds (2,368 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 maximum speed achieved was Mach 3.1 (1,787 knots/2,056 miles per hour, or 3,309 kilometers per hour) at 73,000 feet (22,250 meters). Its mission maximum speed is 1,721 knots (1,980 miles per hour/3,187 kilometers per hour) at 79,050 feet (29,094 meters). The XB-70A has a rate of climb of 33,000 feet per minute (168 meters per second). The service ceiling is 79,000 feet (24,079 meters).

The Valkyrie has a maximum fuel capacity of 43,646 gallons (165,218 liters) JP-5 or JP-6, carried in 11 tanks throughout the fuselage and wings. It also carries 42.4 gallons (161 liters) of engine oil. The maximum range is 2,969 nautical miles (3,417 statute miles/5,499 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)

© 2024, Bryan R. Swopes

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, 62-0001. 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