The answer is just the once but they did drop four of them…
By the 1960s the world was in the most tense phase of the “Cold War”. The “West” was in a nuclear standoff with the Soviet Union. Both sides had enough nuclear weapons to ensure M.A.D (mutually assured destruction). However contrary to popular belief, for most of the Cold War these nukes were not in missile payloads but in heavy bombers.
It was General Thomas S. Power who initiated a program whereby there would always be B-52 Stratofortresses in the air flying over friendly airspace, but always within an hour’s flight time of targets within the Soviet Union. This constant state of readiness was called Operation Chrome Dome. These B-52s would fly thousands of miles, sometimes circling entire continents, and as such needed air-to-air refuelling to ensure they were always up there and always ready to go.
All those airplanes, all those bombs and all that tension- something bad was bound to happen sooner or later and in January 1966 it did.
The B-52 in question began its flight from Seymour Johnson Air Force Base in North Carolina. Its payload was four state-of-the-art Type B28RI hydrogen bombs. The flight plan took the B-52 from continental America across the Atlantic Ocean and towards the European borders of the Soviet Union before returning home. The lengthy flight required the bomber to have two occasions for mid-air refuelling, once on its flight out and the other on its return home. Both were to be carried out over Spain.
For those of you who aren’t weapons nerds, there is the question of what and how powerful is a Type B28RI hydrogen bomb. These were bombs that were dropped and not missiles to be fired they could either detonate on impact or at a certain height from sea level. Together these four bombs had roughly 25% more destructive energy than the total energy of all explosives used in World War Two (including the Hiroshima and Nagasaki bombs). Forget cities, this one B-52 could level a small country.
On the morning of January 17th the B-52 rendezvoused with a Stratotanker from the US run Morón Air Base in Spain. It’s worth noting that the name Morón doesn’t mean the same in Spanish as it does in English (and is just one of those quirks of language which the locals do not find amusing in anyway). The Stratotanker has a payload that can carry more than 35,000 Kgs of aviation fuel.
What happened next is best described by the pilot of the B-52 on that fateful day, Major Larry G. Messinger-
“We came in behind the tanker, and we were a little bit fast, and we started to overrun him a little bit. There is a procedure they have in refuelling where if the boom operator feels that you’re getting too close and it’s a dangerous situation, he will call, ‘Break away, break away, break away.’ There was no call for a break away, so we didn’t see anything dangerous about the situation. But all of a sudden, all hell seemed to break loose.”
Major Messinger obviously is a master of understatement as what actually happened was a heavy laden flying fuel tanker collided with a bomber laden with 4 colossal nuclear bombs. The nozzle of the refuelling boom from the Stratotanker tore the top of the B-52 fuselage, and snapped off the left wing. The friction from the collision caused the tanker to explode killing all four men on board. The fireball was so bright, it was witnessed by a second B-52 about a mile away. As the B-52s plummeted to earth surrounded by burning jet fuel and debris four of the seven crew managed to escape the doomed bomber and parachuted to safety.
All this happened high above the sleepy and tiny Spanish fishing of Palomares, the inhabitants largely unaware of the rain of death descending towards them. Fortunately what happened next was three bombs landed near the village. One was later discovered relatively intact the other two detonated their conventional charges on impact but did not create a nuclear chain reaction. This resulted in spreading plutonium particles over an area of 260 hectares resulting in a contamination clear up that would last years. The word “fortunately” was used deliberately because while radioactive contamination is nasty, it’s not as nasty as you, your family and your entire house being burned in an explosion as hot as the surface of the sun. Remarkably there were no casualties on the ground.
As soon as the accident happened the race was on for recovery. It was the Cold War era and highly sensitive and dangerous military material was now spread over the Spanish coastline. The three bombs that didn’t vaporise Palomares were quickly recovered, but where was the fourth?
Days passed and no sign. Had it been captured by terrorists? Soviet spies? Or curious locals? The answer was none of these. A fisherman reported seeing something “splash down” in the Mediterranean and as there was no sign of the bomb on land it was likely it had sunk to the bottom of the sea. The hunt was on to find one bomb in the whole Mediterranean. However using some mathematical modelling and 27 ships/submarines it only took them 80 days to find it. Then as it was slowly brought to the surface, it slipped and was lost to the depths of the sea for another week as it was finally found again and recovered successfully on the second attempt.
The fisherman who had correctly identified that the bomb had landed in the sea technically had salvage right, the US Air Force settled out of court for an undisclosed sum. This whole mess is referred to simply as the “Palomares Incident”.