Los Angeles: One of two hydrogen bombs that a doomed B-52 accidentally dropped on North Carolina in 1961 came perilously close to exploding, according to a recently declassified report. The 4-megaton Mark 39 bombs -- each packing 260 times more powerful than the device that devastated Hiroshima -- broke loose over Goldsboro, North Carolina, as the bomber went into a tailspin and crashed.
All four safety mechanisms designed to prevent accidental detonation worked properly on one bomb, which landed in a meadow, but three failed on the other, and only a low-voltage switch kept it from exploding upon impact in a field in Faro, North Carolina said the 1969 report.
There has been persistent speculation about how serious the incident was and the U.S. government has repeatedly denied its nuclear arsenal put Americans' lives at risk through safety flaws, the newspaper said. One of the two bombs behaved exactly in the manner of a nuclear weapon in wartime, with its parachute opening and its trigger mechanisms engaged. Only one low-voltage switch prevented a cataclysm.
Had the warhead exploded, radioactive fallout could have spread over the Eastern Seaboard, hitting Washington, Baltimore, Philadelphia and New York. The accident happened just three days after President John F Kennedy was inaugurated in January 1961. Five of the eight crew members survived the crash.
In the document, Parker Jones, a senior engineer in the Sandia National Laboratories responsible for the mechanical safety of nuclear weapons, concluded that "one simple, dynamo-technology, low-voltage switch stood between the United States and a major catastrophe." Jones' report, titled "Goldsboro Revisited or: How I Learned to Mistrust the H-Bomb," was written eight years after the accident in which one hydrogen bomb fell into a field near Faro, North Carolina, and the other into a meadow.
He found that three of four safety mechanisms designed to prevent unintended detonation failed to operate properly in the Faro bomb. When the bomb hit the ground, a firing signal was sent to the nuclear core of the device and it was only the final, highly vulnerable switch that averted a disaster. "The MK 39 Mod 2 bomb did not possess adequate safety for the airborne alert role in the B-52," Jones concluded.
