The crash of the XB70

North American XB-70A Valkyrie just after collision. Note the F-104 is at the forward edge of the fireball and most of both XB-70A vertical stabilizers are gone. (U.S. Air Force photo)

North American XB-70A Valkyrie just after collision. Note the F-104 is at the forward edge of the fireball and most of both XB-70A vertical stabilizers are gone. (U.S. Air Force photo)

This is an interesting article on the crash of the supersonic bomber prototype.

The two test pilots were in the cockpit of a T-38 trainer flying off the left wing of the new XB-70 Valkyrie bomber, aircraft number 62-0207. They just saw the civilian registered NASA F-104N Starfighter of pilot Joe Walker slide upside down across the top of the huge white bomber, shear off both it’s twin tails and skid sideways, then break in two, killing Walker instantly. Behind the XB-70 Walker’s F-104N tumbled end over end, a pinwheel of bright orange flame nearly six hundred feet long tracing its convulsive death spiral.

The flight was a photo shoot for GE which made the jet engines of all the aircraft being photographed.

The fatal error was including an F 104 star fighter which had unreliable handling characteristics in low speed flight.

The poor safety record of the Starfighter brought the aircraft into the public eye, especially in German Air Force service. Fighter ace Erich Hartmann famously was retired from the Luftwaffe because of his protests against having to deploy the unsafe F-104s. The F-104 was also at the center of the Lockheed bribery scandals, in which Lockheed had given bribes to a considerable number of political and military figures in various nations in order to influence their judgment and secure several purchase contracts; this caused considerable political controversy in Europe and Japan.

It was considered a “widowmaker” at low speed especially takeoff and landing.

The F-104 series all had a very high wing loading (made even higher when carrying external stores). The high angle of attack area of flight was protected by a stick shaker system to warn the pilot of an approaching stall, and if this was ignored, a stick pusher system would pitch the aircraft’s nose down to a safer angle of attack; this was often overridden by the pilot despite flight manual warnings against this practice. At extremely high angles of attack the F-104 was known to “pitch-up” and enter a spin, which in most cases was impossible to recover from. Unlike the twin-engined McDonnell Douglas F-4 Phantom II for example, the F-104 with its single engine lacked the safety margin in the case of an engine failure, and had a poor glide ratio without thrust.


The safety record of the F-104 Starfighter became high-profile news, especially in Germany, in the mid-1960s. In West Germany it came to be nicknamed Witwenmacher (“The Widowmaker”). Some operators lost a large proportion of their aircraft through accidents, although the accident rate varied widely depending on the user and operating conditions; the German Air Force lost about 30% of aircraft in accidents over its operating career, and Canada lost 46% of its F-104s (110 of 235). The Spanish Air Force, however, lost none.

The B 70 was an amazing aircraft. My father-in-law walked up the air intake to one engine which he could do without bending over. It was designed to evade interceptors and to carry nuclear weapons at Mach 3 speeds. It first flew in 1964, and the introduction of Soviet anti-aircraft missiles put its mission in doubt.

the B-70 program was canceled in 1961. Development was then turned over to a research program to study the effects of long-duration high-speed flight. As such, two prototype aircraft were built, and designated XB-70A; these aircraft were used for supersonic test-flights during 1964–69. In 1966, one prototype crashed after colliding in mid-air with a smaller jet aircraft; the remaining Valkyrie bomber is in the National Museum of the United States Air Force near Dayton, Ohio.

The crash of the XB 70 was a public relations mishap and cost some people their jobs and two pilots their lives.

Joe Walker has arguably the toughest position in the formation. The little needle-nosed F-104 has stubby wings and a kite tail. It is built for high-speed intercepts, not low speed demonstration formation flight. There are reasons the Thunderbirds never flew the F-104. Some reports suggest Joe Walker questioned the reason for the photo flight, suggesting the formation flight yielded no useable data to contribute to the operational test program.

Walker’s job in the formation is a tough one, even for an outstanding test pilot. He has to keep the flying missile F-104 tightly positioned off the right wingtip of the XB-70 and spaced at a visually pleasing interval between the XB-70 and the F-5A to his right. He will not be able to see the wingtip of the XB-70 behind him unless he cranes his neck uncomfortably to his left rear in his flight helmet and oxygen mask. The high tail design of the F-104 and the drooping right wingtip of the XB-70, lowered into this position to facilitate greater lift for low speed flight, make for another bad combination.

This may have been a time before the vortices from wingtips of large aircraft were understood. That was fatal.

As the aircraft prepare to separate Walker’s controls suddenly feel vague and mushy, as though the plane’s control surfaces have been taken over by some greater force. He is trapped in the swirling vortices tumbling at cyclonic speed off the lowered wingtips of the XB-70.

The needle nose F-104 bucks upward, there is a thud, another buck, and the plane’s nose rears violently upward like a bronco hurling its rider. Walker likely slams his stick forward and right, but it is too late. Physics have taken over.

The photo at the top shows the result as the F 104 disintegrates and takes off both vertical stabilizers of the XB 70. Two pilots are killed and one survives.

Trapped in the whirlpool hurricane of the wingtip vortices from the XB-70, the F-104 rolls inverted to the left, executing a snap roll with the XB-70 wingtip as its axis. Yaw control is lost, and in an instant Walker is turnstiled sideways to the flight path. His body is slammed forward and right into the harness holding him in the ejection seat of the F-104N.

It is over in seconds and is all on film.


The XB 70 crashes in the desert below.


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