Ahh… Anyone Seen Our Nuclear Bomb?
February 5, 1958: Hydrogen Bomb Lost
On this day in 1958 the US Air Force lost a 7,600 pound Mark 15 nuclear bomb in the waters off Tybee Island, near Savannah Georgia. It was during a practice exercise that the B-57 bomber carrying the bomb collided in midair with and F-86 fighter plane.
Bombs are intended to be jettisoned in the event of a crash to protect the crew which is what happened to this Mark 15 nuclear bomb. The B-47 managed to remain airborne although it was badly damaged. The F-86 crashed after the pilot ejected from the plane.
The crew requested permission to jettison the bomb in order to reduce weight and prevent the bomb from exploding during an emergency landing. Permission was granted, and the bomb was jettisoned at 7,200 feet. The crew did not see an explosion when the bomb struck the sea, and managed to land the B-47 safely at Hunter Air Force Base (the nearest base). The pilot, Colonel Howard Richardson, was awarded the Distinguished Flying Cross after this incident.
Whom to believe
Sources describe the bomb as a functional nuclear weapon… other sources describe it as disabled. If the bomb had a plutonium nuclear core installed, it was a fully functional weapon. If the bomb had a dummy core installed, it was incapable of producing a nuclear explosion but could still produce a conventional explosion.
As noted in the Atomic Energy Commission “Form AL-569 Temporary Custodian Receipt (for maneuvers)”, signed by the aircraft commander, the bomb contained a simulated 150-pound cap made of lead. But according to 1966 Congressional testimony by then Assistant Secretary of Defense W.J. Howard, the Tybee Island bomb was a “complete weapon, a bomb with a nuclear capsule,” and one of two weapons lost by that time that contained a plutonium trigger.
Nevertheless, a study of the Strategic Air Command documents indicates that in February 1958, Alert Force test flights (with the older Mark 15 payloads) were not authorized to fly with nuclear capsules on board. Such approval was pending deployment of safer “sealed-pit nuclear capsule” weapons that did not begin deployment until June 1958.
Starting on February 6, 1958, the Air Force 2700th Explosive Ordnance Disposal Squadron and 100 Navy personnel equipped with hand held sonar and galvanic drag and cable sweeps mounted a search. On April 16, the military announced the search had been unsuccessful.
To date, no undue levels of unnatural radioactive contamination have been detected in the regional Upper Floridian aquifer by the Georgia Department of Natural Resources (over and above the already high levels thought to be due to monazite, a locally occurring sand naturally high in radiation).
This event, as well as the 1956 B-47 disappearance, were the basis for NCIS Episode “Broken Arrow,” which aired in 2010.