Command and Control: Nuclear Weapons, the Damascus Accident, and the Illusion of Safety

The B-52 was carrying two Mark 39 hydrogen bombs, each with a yield of 4 megatons. As the aircraft spun downward, centrifugal forces pulled a lanyard in the cockpit. The lanyard was attached to the bomb release mechanism. When the lanyard was pulled, the locking pins were removed from one of the bombs. The Mark 39 fell from the plane. The arming wires were yanked out, and the bomb responded as though it had been deliberately released by the crew above a target. The pulse generator activated the low-voltage thermal batteries. The drogue parachute opened, and then the main chute. The barometric switches closed. The timer ran out, activating the high-voltage thermal batteries. The bomb hit the ground, and the piezoelectric crystals inside the nose crushed. They sent a firing signal. But the weapon didn’t detonate.

Every safety mechanism had failed, except one: the ready/safe switch in the cockpit. The switch was in the SAFE position when the bomb dropped. Had the switch been set to GROUND or AIR, the X-unit would’ve charged, the detonators would’ve triggered, and a thermonuclear weapon would have exploded in a field near Faro, North Carolina. When Air Force personnel found the Mark 39 later that morning, the bomb was harmlessly stuck in the ground, nose first, its parachute draped in the branches of a tree.

The other Mark 39 plummeted straight down and landed in a meadow just off Big Daddy’s Road, near the Nahunta Swamp. Its parachutes had failed to open. The high explosives did not detonate, and the primary was largely undamaged. But the dense uranium secondary of the bomb penetrated more than seventy feet into the soggy ground. A recovery team never found it, despite weeks of digging.

The Air Force assured the public that the two weapons had been unarmed and that there was never any risk of a nuclear explosion. Those statements were misleading. The T-249 control box and ready/safe switch, installed in every one of SAC’s bombers, had already raised concerns at Sandia. The switch required a low-voltage signal of brief duration to operate — and that kind of signal could easily be provided by a stray wire or a short circuit, as a B-52 full of electronic equipment disintegrated midair.

A year after the North Carolina accident, a SAC ground crew removed four Mark 28 bombs from a B-47 bomber and noticed that all of the weapons were armed. But the seal on the ready/safe switch in the cockpit was intact, and the knob hadn’t been turned to GROUND or AIR. The bombs had not been armed by the crew. A seven-month investigation by Sandia found that a tiny metal nut had come off a screw inside the plane and lodged against an unused radar-heating circuit. The nut had created a new electrical pathway, allowing current to reach an arming line — and bypass the ready/safe switch. A similar glitch on the B-52 that crashed near Goldsboro would have caused a 4-megaton thermonuclear explosion. “It would have been bad news — in spades,” Parker F. Jones, a safety engineer at Sandia, wrote in a memo about the accident. “One simple, dynamo-technology, low-voltage switch stood between the United States and a major catastrophe!”

With strong northerly winds, the groundburst of that 4-megaton bomb in Goldsboro would have deposited lethal fallout over Washington, D.C., Baltimore, Philadelphia, and New York City. And the timing would have been unfortunate: the new president of the United States, John F. Kennedy, had delivered his inaugural address only three days earlier, promising renewal and change, vowing to “pay any price, bear any burden, meet any hardship, support any friend, oppose any foe, to assure the survival and the success of liberty.” The spirit of youthful optimism sweeping the United States would have been dimmed by the detonation of a hydrogen bomb in North Carolina and an evacuation of the nation’s capital.

The Goldsboro accident, far from being an isolated or improbable event, was a portent of the nuclear threats that the Kennedy administration would have to confront. Robert S. McNamara, the new secretary of defense, learned about the accident during his third day on the job. The story scared the hell out of him. McNamara knew remarkably little about nuclear weapons. The previous month, when Kennedy had asked him to head the Department of Defense, McNamara was the president of the Ford Motor Company. He was a young, supremely self-confident businessman devoted to systems analysis and efficiency. At the Harvard Business School, he’d taught accounting. Aside from a three-year stint in the Army Air Forces — where he’d served in the Office of Statistical Control and helped General LeMay calculate optimal fuel use for the bombing of Japan — McNamara had no military experience. And he’d spent little time thinking about military strategy or procurement. Determined to shake things up at the Pentagon, McNamara found himself, instead, feeling profoundly shaken during his first week on the job.