The Tybee Island mid-air collision was an incident on February 5, 1958, in which the

United States Air Force The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Si ...

lost a Mark 15 nuclear bomb in the waters off Tybee Island near

Savannah A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to ...

Georgia Georgia most commonly refers to: * Georgia (country), a country in the Caucasus region of Eurasia * Georgia (U.S. state), a state in the Southeast United States Georgia may also refer to: Places Historical states and entities * Related to the ...

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

. During a practice exercise, an

F-86 The North American F-86 Sabre, sometimes called the Sabrejet, is a transonic jet fighter aircraft. Produced by North American Aviation, the Sabre is best known as the United States' first swept-wing fighter that could counter the swept-wing Sov ...

fighter plane collided with the

B-47 The Boeing B-47 Stratojet (Boeing company designation Model 450) is a retired American long-range, six-engined, turbojet-powered strategic bomber designed to fly at high subsonic speed and at high altitude to avoid enemy interceptor aircraft. ...

bomber carrying the bomb. To protect the aircrew from a possible detonation in the event of a crash, the bomb was jettisoned. Following several unsuccessful searches, the bomb was presumed lost somewhere in

Wassaw Sound Wassaw Sound is a bay of the Atlantic Ocean on the coast of Georgia, United States near Savannah at the mouth of the Wilmington River. American Civil War naval battle It was the location of an American Civil War naval battle between the CSS At ...

off the shores of Tybee Island.

Midair collision

The

bomber was on a simulated combat mission from

Homestead Air Force Base Homestead Air Reserve Base (Homestead ARB), previously known as Homestead Air Force Base (Homestead AFB) is located in Miami–Dade County, Florida to the northeast of the city of Homestead. It is home to the 482nd Fighter Wing (482 FW) of th ...

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and ...

. It was carrying a single bomb. At about 2:00 a.m., an

fighter collided with the B-47. The F-86 crashed after the pilot ejected from the plane. The damaged B-47 remained airborne, plummeting from when the pilot, Colonel Howard Richardson, regained flight control.BBC News
Missing for 50 years – US nuclear bomb (June 22, 2009) 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 while the bomber was traveling at about . The crew did not see an explosion when the bomb struck the sea. They managed to land the B-47 safely at the nearest base,

Hunter Air Force Base Hunting is the human practice of seeking, pursuing, capturing, or killing wildlife or feral animals. The most common reasons for humans to hunt are to harvest food (i.e. meat) and useful animal products (fur/ hide, bone/tusks, horn/antler, ...

. Colonel Richardson was awarded the Distinguished Flying Cross after this incident.

The bomb

Some sources describe the bomb as a functional nuclear weapon, but others describe it as disabled. If it had a

plutonium Plutonium is a radioactive chemical element with the symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exh ...

nuclear core installed, it was a fully functional weapon. If it had a dummy core installed, it was incapable of producing a nuclear explosion but could still produce a conventional explosion. The 12-foot (4 m) long Mark 15 bomb weighs and bears the serial number 47782. It contains of conventional high explosives and highly enriched

uranium Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weak ...

. The Air Force maintains that its " nuclear capsule" (

physics package Nuclear weapon designs are physical, chemical, and engineering arrangements that cause the physics package of a nuclear weapon to detonate. There are three existing basic design types: * pure fission weapons, the simplest and least technically ...

), used to initiate the nuclear reaction, was removed before its flight aboard the B-47. 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 cap made of lead. However, according to 1966 Congressional testimony by 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 that contained a plutonium trigger. Nevertheless, a study of the

Strategic Air Command Strategic Air Command (SAC) was both a United States Department of Defense Specified Command and a United States Air Force (USAF) Major Command responsible for command and control of the strategic bomber and intercontinental ballistic missile ...

documents indicates that Alert Force test flights in February 1958 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, which did not begin deployment until June 1958.

Recovery efforts

Starting on February 6, 1958, the Air Force 2700th Explosive Ordnance Disposal Squadron and 100 Navy personnel equipped with hand-held

sonar Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances (ranging), communicate with or detect objects on o ...

and galvanic drag and cable sweeps mounted a search. On April 16, the military announced the search had been unsuccessful. Based on a hydrologic survey in 2001, the bomb was thought by the Department of Energy to lie buried under of silt at the bottom of

. In 2004, retired

Air Force An air force – in the broadest sense – is the national military branch that primarily conducts aerial warfare. More specifically, it is the branch of a nation's armed services that is responsible for aerial warfare as distinct from an ...

Lt. Colonel Derek Duke claimed to have narrowed the possible resting spot of the bomb down to a small area approximately the size of a football field. He and his partner located the area by trawling in their boat with a

Geiger counter A Geiger counter (also known as a Geiger–Müller counter) is an electronic instrument used for detecting and measuring ionizing radiation. It is widely used in applications such as radiation dosimetry, radiological protection, experimental p ...

in tow. Secondary radioactive particles four times naturally occurring levels were detected and mapped, and the site of radiation origination triangulated. An Air Force nuclear weapons adviser speculated that the source of the radiation was natural, originating from

monazite Monazite is a primarily reddish-brown phosphate mineral that contains rare-earth elements. Due to variability in composition, monazite is considered a group of minerals. The most common species of the group is monazite-(Ce), that is, the ceriu ...

deposits.

Ongoing concerns

As of 2007, no undue levels of unnatural

radioactive contamination Radioactive contamination, also called radiological pollution, is the deposition of, or presence of radioactive substances on surfaces or within solids, liquids, or gases (including the human body), where their presence is unintended or undesirab ...

have been detected in the regional Upper Floridan aquifer by the

Georgia Department of Natural Resources The Georgia Department of Natural Resources (DNR) is an administrative agency of the U.S. state of Georgia. The agency has statewide responsibilities for managing and conserving Georgia’s natural, cultural, and historical resources, and has fiv ...

(over and above the already high levels thought to be due to

, a locally occurring mineral that is naturally radioactive).

In popular culture

In February 2015, a

fake news Fake news is false or misleading information presented as news. Fake news often has the aim of damaging the reputation of a person or entity, or making money through advertising revenue.Schlesinger, Robert (April 14, 2017)"Fake news in reality ...

web site ran an article stating that the bomb was found by vacationing Canadian divers and that the bomb had since been removed from the bay. The fake story spread widely via social media.

Notes

References

* * * * * * Michael H. Maggelet and James C. Oskins (2008). "Broken Arrow: The Declassified History of U.S. Nuclear Weapons Accidents". Lulu. .

External links

America's Lost H Bomb
Marabella Productions & Discovery's Science Channel documentary about the Tybee Bomb (2007)
NPR
For 50 Years, Nuclear Bomb Lost in Watery Grave (February 3, 2008)
BBC News
Missing for 50 years – US nuclear bomb (June 22, 2009)

Nuclear Bomb Dropped in Georgia; No Nuclear Capsule Inserted, Documents Show (2004)

Chart of nuclear bombs, including the Mark 15

by Col. Derek Duke (as told to Fred Dungan)
Broken Arrow
BBC audio programme on the Tybee Bomb, streaming audio {{DEFAULTSORT:Tybee Island B-47 Crash 1958 in Georgia (U.S. state) 1958 in military history February 1958 events in the United States Chatham County, Georgia Military nuclear accidents and incidents Mid-air collisions Mid-air collisions involving military aircraft History of Georgia (U.S. state) Aviation accidents and incidents in the United States in 1958 Aviation accidents and incidents in Georgia (U.S. state) Accidents and incidents involving United States Air Force aircraft Nuclear accidents and incidents in the United States