One of the most exotic aircraft ever built. Originally conceived as a high-altitude, Mach 3–capable bomber to replace the B-52, budget cuts reduced the number of aircraft to two and the program to a research effort aimed at studying aerodynamics, propulsion, and materials used on large supersonic aircraft. The original contract was let in 1955. The XB-70 was built largely of stainless-steel honeycomb sandwich panels and titanium and had heat-resistant paint. On one flight above Mach 3, the recorded skin temperature on the aircraft reached 620•. At Mach 3, it took the aircraft an arc of 287 miles and 13 minutes to make a 180• turn. The aircraft utilized the phenomenon of compression lift, where the aircraft actually rode its own shock wave. It was able to do this in part because of the wingtips that could droop in flight. The first Mach 3 flight came on October 14, 1965, with Al White and Col. Joe Cotton at the controls. That duo was also at the controls on the type's fastest flight, Mach 3.08 on April 12, 1966. On June 8, 1966, test pilot Joe Walker was killed when his F-104 made contact with the number two XB-70, got caught in vortices coming off the Valkyrie's wingtips, and rolled through the XB-70's tails. XB- 70 copilot Maj. Carl Cross was also killed, and the XB-70 was destroyed. The two aircraft were flown 129 times for 252 hours, 28 minutes by seven contractor, Air Force, and NASA pilots. The two aircraft were flown at twice the speed of sound or better for nearly 52 hours. The surviving aircraft was flown to the US Air Force Museum at Wright-Patterson AFB, Ohio, on February 4, 1969, where it is now on display. Even on that flight, test data was collected.
| Contractors: |
North American Aviation, Inc. |
| Locations Built: |
Air Force Plant 42, Palmdale, Calif. |
| Number Built: (USAF) |
Two (two) |
| First Flight: |
September 21, 1964 |
| First Flight Model: |
XB-70A |
| First Flight Location: |
Air Force Plant 42, Palmdale, Calif. |
| First Flight Pilot: |
Alvin S. White (pilot). USAF Col. Joseph F. Cotton (copilot) |
| Models/Variants: |
XB-70A |
| Powerplant: |
Six YJ93-GE-3 afterburning turbojets of 30,000 lb thrust each |
| Wingspan: |
105 ft 0 in. |
| Length: |
189 ft 0 in. |
| Height: |
30 ft 0 in. |
| Weight: |
534,700 lb gross |
| Armament: |
None |
| Accommodation: |
Two (pilot and copilot, side by side) |
| Cost: |
Total program cost was approx $2 billion |
| Max. Speed: |
Mach 3.08 (more than 2,000 mph) |
| Range: |
6,000 mi. |
| Ceiling: |
74,000 ft. |
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