On January 21, 1961 a B-52 bomber went into a tailspin, breaking apart mid-flight over Goldsboro, N.C. The plane was carrying two nuclear bombs, both of which were pushed into free-fall. The parachute for one of the bombs was safely deployed, but the other continued to plummet.
It had been previously believed that, though nerve-racking, the incident was not nearly as dangerous as it sounded as neither bomb was armed. But documents released Thursday by the National Security Archive reveal that the bomb that was in free-fall was in fact armed, and only failed to detonate due to a technical malfunction.
"The report implied that because Weapon 2 landed in a free-fall, without the parachute operating, the timer did not initiate the bomb's high voltage battery ("trajectory arming"), a step in the arming sequence," recorded Bill Burr of the National Security Archives.
"For Weapon 2, the Arm/Safe switch was in the "safe" position, yet it was virtually armed because the impact shock had rotated the indicator drum to the "armed" position. But the shock also damaged the switch contacts, which had to be intact for the weapon to detonate."
"Weapon 2" was an armed 3.8 megaton nuclear bomb. By comparison, the bombs dropped on Hiroshima and Nagasaki that devastated Japan for over a generation weighed .03 megatons combined. If "Weapon 2" had detonated, the fallout would have been 190 times worse than the explosions that ended the World War II.
"Perhaps this is what Secretary of Defense Robert McNamara had in mind, a few years later, when he observed that, 'by the slightest margin of chance, literally the failure of two wires to cross, a nuclear explosion was averted,"