Broken Arrow: “By the Slightest Margin of Chance, a Nuclear Explosion Was Averted”

In 1963,  during a joint meeting of the U.S. Department of Defense and the State Department, Secretary of Defense Robert McNamara was talking about several Broken Arrow incidents and stated,  “By the slightest margin of chance, literally the failure of two wires to cross, a nuclear explosion was averted.”

Rumors of a nuclear bomb from Broken Arrow still in swamp

Airmen stationed at Seymour Johnson AFB (SJAFB) in North Carolina have often heard a rumor that a B-52 carrying a nuclear bomb once crashed in a swamp near the base and that the weapon was buried so deep that officials had to leave it there.

While the rumor was not completely accurate, the Broken Arrow event really did happen, and there is more truth to the story than wrong details.

On 4 January 1961, a B-52G from SJAFB was flying about 12 miles north of the base near the small town of Faro, North Carolina, when it developed a fuel leak in its starboard wing.

The pilot, Major Walter Scott Tulloch, contacted the base, which instructed them to remain in a holding pattern off the coast until the aircraft burned enough fuel. Shortly, however, Tulloch radioed that the bomber had lost 37000 pounds of fuel and was told to return to the base. 

The bomber then lost the entire wing, and Tulloch ordered his crew to eject. Three of the eight crew members lost their lives while attempting to bail out of the aircraft.

The massive bomber broke apart as it descended and struck the field at approximately 700 miles per hour, erupting into flames that cast a bright glare on nearby farmhouses. 

Emergency crews arrived on the scene, and once they put out the fires, they began a critical salvage operation. The airmen on the scene began searching for the two 3-4 megaton MK-39 thermonuclear bombs the B-52 was carrying.

Recovery Focused on Finding Two Nuclear Bombs 

The B-52 had been flying on alert status, and during those days of the Cold War, it was a standard practice for them to fly with live bombs. The process of detonating these weapons included multiple steps to ensure they were as safe as possible until the moment of detonation.

Unfortunately, the crash damaged the safety mechanisms during this incident, and both weapons began the fusing or arming sequence.

Weapon Began Arming Sequence

Crews found the first thermonuclear weapon several hundred yards from the main crash site. Its parachute deployed when it left the aircraft and got tangled in a tree before hitting the ground.

The nose of the nuclear bomb embedded itself about 18 inches in the ground. According to a document titled “New Details on the 1961 Goldsboro Nuclear Accident,” in a security archive called the Nuclear Vault at George Washington University, “The two-stage Mark 39, which contained highly-enriched uranium in its primary, came dangerously close to denotation.” 

More specifically, the crash pulled out lanyards that released saving pins from the weapon. This feature allowed the arming process to continue until the final step, which requires a human to operate the T-249 Arm/Safe switch. Still, “the incident deeply worried Secretary of Defense McNamara.”

Author Joel Dobson wrote about the incident in his book, The Goldsboro Broken Arrow. Referring to the first weapon, he stated, “If the right wire had short-circuited in the airplane as it was disintegrating in midair and sent a very small electrical current to that bomb, 28 volts, there would have been a detonation.”

Second Nuclear Bomb from Broken Arrow Buried Deep in the Ground

The second nuclear weapon presented the recovery crews with different problems.

It broke apart at the moment of impact about 500 yards from where the main part of the fuselage struck. The weapon created a crater about six feet deep and eight in diameter. It partially armed but did not complete the sequence.

The soil in the field was very wet, and components of the weapon penetrated deep into the ground. Its tail went about 22 feet down. Crews began trying to dig up the bomb, but a combination of freezing temperatures, rising water in the crater, and the possibility of unexploded High-Explosive (HE) materials slowed their efforts.

The crews dug eight feet down on 24 January and 12 feet the next day. They reached 15 feet on 26 January, where they found the parachute, part of the nose, and pieces of the device called the “primary.” They recovered more by 28 January, including the arm/safe switches, which they discovered in the “armed” position. 

Crews Abandon Search for Weapon

The work continued, and by 7 February, the excavation crews had enlarged the crater to 42 feet deep, 50 feet wide, and 70 feet long. Digging continued for several months until it finally stopped on 25 May.

During that time, the crater continued to fill with water, and 14 pumps were deployed around its perimeter, removing 60,000 gallons per hour, which could not control the flooding. 

At that point, they still had not found one of the bomb components, called the “secondary,” and officials calculated that it might have been as deep as 180 feet and that it would cost at least $500,000 to reach it. This most serious thing about this is that the part contained plutonium.

Evidence of Nuclear Bomb Still in Field

The Air Force did not release any details about the plutonium or hazards from the Broken Arrow accident, but it did take several actions that strongly hint at the seriousness of the situation. After the accident, the Air Force purchased an easement for $1000 from C. T. Davis, the owner of the field where the weapon was buried.

The easement covered an area in the field 400 feet in diameter and prevented Davis and his heirs from digging or drilling more than five feet deep, although they were allowed to use it for crops, timber, or as a pasture.

Additional evidence of the potential danger is that the North Carolina Division of Radiation Protection tests groundwater near the crash site annually. While they have found no radiation levels beyond what naturally occurs, the Air Force does not intend to stop checking the soil. 

Other Broken Arrow Incidents Involving Lost Nuclear Bomb Components

Unfortunately, the Goldsboro crash was not an isolated incident. Similar accidents involving B-52s carrying thermonuclear weapons have occurred, one near Palomares, Spain, and another near Thule, Greenland.  The Thule incident, which occurred in 1968, was especially serious. 

A B-52 crashed onto sea ice near Thule, and a radioactive cylinder separated from the weapon. It contained uranium and may have dropped through the ice. Salvage crews never found it. However, scientists from Denmark tested the water there for years and found low contamination levels.

Following these accidents, the Sandia National Laboratories studied their causes and began working on new designs to reduce the possibility of radioactive contamination occurring in the future. 

Despite this, an earlier report from the Sandia Corporation, “A Survey of Nuclear Weapon Safety Problems and the Possibilities for Increasing Safety in Bomb and Warhead Design,” from 1959, mentions what may be the stark truth about this topic.

In the report, Carl Carlson stated that he “believed that military readiness requirements meant that absolute safety was impossible and that it was necessary to ‘play the percentages’ as ‘uncomfortable’ as that was.”