The engineers figured out that they needed to bypass the breaker with a jumper.
Co Pilot Joe Cotton (photo above with the plane) saved this 750 million dollar (5.5 bil. in today's money) aircraft from destruction with a paperclip.
April 30th, 1966.
Al White and Joe Cotton prepared to take AV/2 past the final hurdle to having "unlimited" status for Mach 3 flight -- a 30+ minute run at Mach 3 to fully heatsoak all systems. Shortly after takeoff, Cotton retracted the landing gear. The nose gear jammed into its door, and as good as things had been going, they were going bad now. The attempt to lower the gear using the normal hydraulic system failed. Trying the backup electrical system, Cotton heard a "pop" as THAT system went dead. Given the Valkyrie's long, graceful neck, and the intake design, retracting the main gear and landing on her belly wasn't possible -- in fact, it was so impossible that North American had never attemped to simulate it!
White first brought the XB-70 around for a touch-and-go, hoping that a hard impact on the main gear would knock the nose gear loose and let it fall to the extended position. Even after a second try, however, the nose gear remained jammed. At this point, bailing out and losing the aircraft was quickly becoming the only option.
But there was fuel to burn away in any case, so while people on the ground pulled out plans and diagrams, White and Cotton circled around Edwards slowly but surely.
Finally, Cotton was sent to the back of the cockpit to open service panels and check on things for the people below. After more than an hour of this (and 2 hours of flying), the problem with the backup system was traced -- hopefully -- to a circuit breaker.
Now all Cotton had to do was find a way to short circuit the unit by closing two contacts. Of course, the Valkyrie had no on-board toolkit -- that would have made things too simple. But Cotton HAD brought along his briefcase with his various notes and plans, and opening it, he found a good, thick paperclip (actually, it was part of a legal-style paperclip, not a conventional one) .
Straightening out the paperclip, then grasping the middle of it with a leather glove, Cotton carefully reached in and ZAP! short circuited the breaker. As Al White hit the switch to extend the gear, and was rewarded with the sound of a working backup system, Cotton gratefully dropped into his seat. As several newspapers exclaimed the following day, a "39 cent paperclip saves $750 million aircraft!"
trivia,
the maximum takeoff weight was more than half a million pounds
the pilot was 65 feet in front of the nose gear.
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