On January 21st, 1968, an uncontained fire aboard an American B-52G Stratofortress bomber
sent the aircraft crashing onto the sea ice off the northwest coast of Greenland.
Any search and rescue operation would have already been difficult enough thanks to the
harsh environment, but this bomber was carrying a highly classified payload that would make
the recovery even more urgent.
The doomed flight had been part of a top-secret operation conducted by the United States with
only veiled consent from the Danish governing authorities.
Few were supposed to know that the B-52G had been loaded with four 1.1 megaton nuclear
weapons, one of which is still unaccounted for today...
Operation Chrome Dome
The 1968 accident at Thule Air Base spelled the end for a U.S. Air Force mission known
as Operation Chrome Dome, which had begun in 1960 and was run through the Strategic
Air Command.
This Cold War alert program was responsible for sending B-25 Stratofortress aircraft with
thermonuclear bombs on continuous flights along the USSR border.
The plan was masterminded by General Thomas S. Power, who scheduled missions in a way
that kept twelve bombers airborne at all times.
The main goal was to give Strategic Air Command offensive capability if the Soviet Union struck
with nukes.
It also served as a deterrent to keep the Soviets from launching a first strike.
In 1961 the mission was upgraded with a top-secret addition called Hard Head or Thule Monitor
Missions during which one of the armed bombers would fly over Thule Air Base.
Thule is America’s northernmost Airbase, just 947 miles from the North Pole on the
northwestern coast of Greenland.
This extension of Operation Chrome Dome let the U.S. surveil the base’s Ballistic Missile
Early Warning System.
The system could warn of an attack 15 to 25 minutes before it hit.
The aircraft patrolling the area was also nuclear-armed, and the crew could decide whether
to engage if communication between Aerospace Defense Command and the base ever failed due
to an attack.
Proposed cuts to the Chrome Dome Operation in 1966 saw a mixed response from experts.
The Ballistic Missile Early Warning System was fully operational by then, making some
weary of the continuing flights.
It was calculated that grounding the bombers could have saved the United States 123 million
dollars, which would equate to 969 million dollars today.
The leadership at Strategic Air Command, and the Joint Chiefs of Staff, largely opposed
cutting the program.
Instead, the program was reduced so that only four bombers would fly daily.
Despite the risk involved, the Thule Monitor Missions also continued, but without Congressional
approval.
Strategic Air Command decided that Congress did not need to know the specific operational
targets...
The Accident
On January 21st, 1968, a B-52G Stratofortress bomber carrying four nuclear weapons while
on a Hard Head mission crashed into the ice of the Wolstenholme Fjord, one of the coldest
spots on the planet during winter.
The aircraft, with the callsign HOBO 28, had been on its supervising flight over Biffin
Bay and Thule base with five crew members.
The flight went as planned until their mid-air refueling.
They had to conduct the process manually because the autopilot on the bomber failed.
About an hour later, the crew was reportedly uncomfortably cold despite the heater being
on.
A crewmember opened a bleed valve on an engine to pull some of its hot air to the heating
unit.
Yet, problems with the heater meant that the air entered the cabin without cooling at all,
so for half an hour, the crew suffered through sweltering heat.
A fire eventually broke out, which they could smell but not find.
The navigator onboard searched twice before locating the ignited stow cushions behind
a metal box.
Two fire extinguishers later, the fire was growing.
The pilots asked for permission to land at Thule Air Base, but five minutes later, they
realized such a thing would not be possible.
All fire extinguishers were used, the power went out, and the cockpit had so much smoke
the instruments had become unreadable.
Six of the crew members ejected successfully while flying over the base.
Pilotless, the aircraft continued to fly north and crashed into the ice at North Star Bay
at the shallow angle of 29 degrees.
The conventional explosive elements of the four 1.1 megaton B28FI thermonuclear bombs
exploded upon the crash.
Radioactive material spread over the area as if a dirty bomb had detonated.
Yet, nuclear explosions were not triggered.
The heat generated by the burning fuel lasted about five hours, melted the ice sheet, and
caused the wreck to sink.
Broken Arrow
Every available man was included in the search and rescue efforts for the crew members.
Even off duty staff were called to work.
The search took place in Arctic absolute darkness, with extremely challenging weather conditions.
With low temperatures and dark skies, the base contacted Jens Zinglersen, the representative
for the Royal Greenland Trade Department, for help.
It was decided that dog sled teams would conduct the operation.
Rescue commander Major General Hunziker noted that, [QUOTE] “one of man’s most technically
complex endeavors had gone astray and that recovery from its effects must depend upon
the most primitive of methods.”
Three crew members were rescued two hours after the crash because they landed only a
mile and a half from the base.
Captain Criss fell 6 miles away and stayed by himself for 21 hours since he was the first
to eject.
Exposed to negative 23 degrees Fahrenheit, he suffered from hypothermia… to survive,
he wrapped himself in his parachute.
The dog sled crews rescued him.
For his service and quick action during the search and rescue, Jens Zinglersen was granted
the Air Force Exceptional Civilian Service Medal by U.S. Ambassador K.E.
White on February 26th, 1968.
Aerial photographs of the crash site revealed six engines, a tire, and other small debris
were stuck on the blackened ice.
The accident was labeled a Broken Arrow, a nuclear bomb accident with no risk of igniting
an armed conflict.
Project Crested Ice
Right after the rescue, the next priority became cleaning up the site of the accident.
The explosion had distributed debris and components over a 3 mile by 1-mile area.
Components from the bomb bay were found to the north of the crash site, which suggested
that the aircraft had begun falling apart before impact.
At ground zero, a 160-foot-wide hole of seawater formed on the ice.
A 400-foot black patch of burnt aircraft fuel and radioactive elements formed to the south
of the site.
Radioactive materials included uranium, americium, tritium, and plutonium.
Authorities from both nations commenced Project Crested Ice, also known as Dr. Freezelove,
to clean-up the debris and limit the damage to the environment.
It was essential to complete the clean-up project before the sea ice melter for spring,
or else the contaminants would leak into the sea and therefore go up to the shore.
The American Air Force collaborated with Danish nuclear scientists to explore options for
the clean-up.
For the Danish quick and thorough removal was crucial, and they didn’t want any radioactive
material to stay in Denmark.
General Hunziker had to arrange the removal of the contaminated ice and materials for
transportation to America.
To conduct the clean-up, the U.S. Air Force erected Camp Hunziker.
The temporary facilities included igloos, a heliport, generators, communications facilities,
an ice road from Thule to the site, a prefabricated building, ski-mounted buildings, huts, a latrine,
and a decontamination trailer.
The conditions for the clean-up crew were less than ideal.
Aside from the continuing Arctic darkness, the average temperature was negative, forty
degrees celsius.
Strong winds in the area could reach 89 miles per hour.
These conditions were only mildly mitigated halfway through February with the first rays
of sunlight.
“ Thulegate”
The accident brought on several controversies in Denmark.
The country had taken up a nuclear-free zone policy in 1957 before the Paris NATO summit.
The media and the population accused the government of violating that policy immediately after
reports of the accident came out.
Since Hard Head or Thule Monitor Missions were highly classified, both of the involved
governments claimed that the bomber had crashed after being diverted to Greenland due to an
emergency.
The public had no way of knowing it had happened during a routine operation until an American
declassification of documents in 1995 contradicted the official version.
The Danish press considered this a major scandal that they identified as Thulgate.
The parliament of the Kingdom of Denmark ordered a report from the Danish Institute of International
Affairs to establish the history of American nuclear overflights of Greenland and to determine
the extent to which Thule Air Base was used for the missions.
A two-volume review was published in 1997, revealing to the Danish public that the U.S.
had flown nuclear weapons in good faith over Greenland recurrently.
Prime Minister H.C.
Hansen was signaled out for allowing ambiguity in the nuclear policy between Denmark and
the U.S. regarding the Air Base.
He had tacitly given permission for the U.S. to store nukes at Thule Air Base, against
Danish policy.
After the clean-up, Danish workers complained of long-term health effects from their exposure
to radiation.
They hadn’t worked at Camp Hunziker, but rather at the Tank Farm where the contaminated
ice was sent to.
It has been stated that their absorbed radiation could have come from atmospheric contamination
rather than the ice itself.
Around 200 of the Danish workers unsuccessfully took legal action against America in 1987.
However, the trial forced hundreds of classified documents into the light.
The public learned that the Air Force personnel’s health had not been monitored after the accident.
The Danish employees did receive compensation from Denmark.
1,700 workers each received 50,000 kroner in 1995.
A Secret Under the Ice
Reports from the Danish news publications started surfacing in 1987, claiming that one
of the four nuclear weapons had not been recovered.
Strategic Air Command released a statement saying that all four bombs had been destroyed
during the accident.
However, that wasn’t the end of it.
In 2008 the BBC uncovered its assessment of partly declassified documents and other reliable
sources that traced how only three of the nukes were being accounted for.
While they did find that nuclear primary or secondary had burned and melted the ice under
the surface, they could not find any definitive information on the whereabouts of all the
bombs.
The revelation is most soundly proclaimed in a July of 1968 report that reads: [QUOTE]
“An analysis by the AEC of the recovered secondary components indicates recovery of
85 percent of the uranium and 94 percent, by weight, of three secondaries.
No parts of the fourth secondary have been identified.”