The XB-70 Valkyrie was a prototype strategic bomber for the United States Air Force. It had speed well over Mach 1 and thus was hard to destroy with fighter interceptors. Only two were built for testing at Edwards Air Force Base, California.
The XB-70 had several notable features, among them an escape pod which, should the airplane depressurize, would automatically move up and enclose the 2 man crew. From there, the pilot could decide to shoot the escape pod loose from the airplane or keep it on. If the pod was jettisoned, the pilot had limited control over it.
The Valkyrie used the theory of 'Compression lift', trapping its own shock wave at high speed by drooping the outer 30% of the wing by as much as 65%.
The bomber was intended to operate at high altitudes so as to avoid Soviet missiles. It made its maiden flight on September 21, 1964. On the very first flight, the hydraulic mechanism to raise the landing gear went awry, forcing the prototype to fly landing gear down. It also suffered fuel leaks and the engine construction proved unsuitable for such high speeds. The first aircraft attained a speed of Mach 3.02 at 70,000 feet on October 14, 1965, but the speed badly damaged the engine and ripped two feet of wing off the left side.
On Air Vehicle Number Two, the problems were mostly fixed. The engine was better constructed and the hydraulic gear was repaired. On January 3, 1966, the second prototype achieved Mach 3.05 at 70,000 feet. The tests continued to go well until June 8, 1966. That day, Air Vehicle Number Two was flying on another test flight, with an F-4, an F-104, a T-38, and an F-5 as chase planes. The F-104 rolled over the top of the bomber and collided with the plane's tail. The F-104 pilot, NASA pilot and X-15 test pilot Joe Walker was killed in the collision, as was Carl Cross, the copilot of the XB-70. However, Al White, the pilot of the bomber, ejected safely and was later picked up with minor injuries.
The XB-70 program was cancelled in 1969. The United States Air Force planned a reconnaissance version, the RS-70, but it never went into production.
The surviving XB-70 Air Vehicle Number One is on display at the National Museum of the United States Air Force in Dayton, Ohio.