.jpg) | |
| Accident | |
|---|---|
| Date | 13-14 February 1950 |
| Summary | Engine failure |
| Site | Mount Kologet,British Columbia, Canada 56°1′27.61″N128°37′11.91″W / 56.0243361°N 128.6199750°W /56.0243361; -128.6199750 |
 | |
| Aircraft | |
| Aircraft type | Convair B-36B |
| Operator | United States Air Force |
| Registration | 44-92075 |
| Flight origin | Eielson Air Force Base nearFairbanks, Alaska, United States |
| Destination | Carswell Air Force Base inFort Worth, Texas |
| Occupants | 17 |
| Passengers | 1 |
| Crew | 16 |
| Fatalities | 5 |
| Survivors | 12 |
Sometime after midnight on 14 February 1950, aConvair B-36B, United States Air Force Serial Number44-92075 assigned to the US7th Bombardment Wing, Heavy atCarswell Air Force Base in Texas, crashed in northwesternBritish Columbia onMount Kologet after jettisoning aMark 4 nuclear bomb.[1] This was the first suchnuclear weapon loss in history.[2] The B-36B had been en route fromEielson Air Force Base nearFairbanks, Alaska, to Carswell AFB, more than 3,000 miles southeast, on a mission that included a simulated nuclear attack onSan Francisco.[2]
Convair B-36B44-92075 was flying on a simulated nuclear strike combat mission by theSoviet Union.[3][4] The B-36 took off on 13 February 1950 from Eielson AFB with a regular crew of 15 plus a Weaponeer and a Bomb Commander. The plan for the 24-hour flight was to fly over the North Pacific, due west of theAlaska panhandle andBritish Columbia, then head inland overWashington state andMontana. Here the B-36 would climb to 40,000 feet (12,000 m) for a simulated bomb run to southern California and then San Francisco, and it would continue its non-stop flight to Fort Worth, Texas. The flight plan did not include any penetration of Canadianairspace. The aircraft carried aMark 4 atomic bomb, containing a substantial quantity ofnatural uranium and 5,000 pounds (2,300 kg) of conventionalexplosives.[5][failed verification] The bomb did not contain theplutonium core necessary for a nuclear detonation. Until 1951, the US military had no nuclear cores in its possession, as they were still entirely in the custody of theU.S. Atomic Energy Commission. The flight did contain a "dummy capsule," a simulated container for a nuclear core (filled withlead), which was recovered much later.[2]
Cold weather (−40 °F/−40 °C on the ground at Eielson AFB) adversely affected the aircraft involved in this exercise, and some minor difficulties with44-92075 were noted before takeoff. Seven hours into the flight, three of the six piston engines began shooting flames and were shut down, and the other three piston engines proved incapable of delivering full power. The subsequent investigation blamedice buildup in the carburetor air intakes.[2]
The crew decided to abandon the aircraft because it could not stay aloft with three engines out of commission while carrying a heavy payload. The atomic bomb was jettisoned and detonated in mid-air, resulting in a large conventional explosion over theInside Passage. The USAF later stated that the fake practice core on board the aircraft was inserted into the weapon before it was dropped.[2]
The aircraft was in regular radio contact withStrategic Air Command headquarters atOffutt AFB,Nebraska. The crew bailed out, using parachutes.
Within minutes of the bailout theRoyal Canadian Air Force launched Operation Brix to find the missing men. Poor weather hampered search efforts; nevertheless 12 of the 17 men were eventually found alive. One of the five deceased, the weaponeer, was rumored to have been recovered four years later (1954) at the crash site. The remaining four airmen were believed to have bailed out of the aircraft earlier than the surviving crew members, and it was assumed that they landed in the ocean and died of hypothermia. Canadian authorities were never told that the aircraft was carrying a nuclear weapon.[2]
To search for the B-36, aircraft were pulled off the search fora Douglas C-54 that had disappeared three weeks earlier. A more exhaustive search was not launched for the B-36, as it was believed to be at the bottom of the Pacific. Three years later, an RCAF flight searching for the missingde Havilland Dove aircraft of Texas millionaire oilman Ellis A. Hall spotted the B-36's wreckage.[6] It was found on the side of Mount Kologet, about 50 miles (80 km) east of the Alaskan border, roughly due east of the towns ofStewart, British Columbia, andHyder, Alaska, on the east side of the isolatedNass Basin northwest ofHazelton, British Columbia.[2]
The USAF immediately began an investigation. A team was sent in September 1953, as the effort was given a high priority, but they failed to reach the site after 19 days of trudging through the wilderness. The effort was resumed the following year with better equipment, and in August 1954 a new team of USAF personnel accompanied by a local guide reached the wreckage. They recovered important components and then used explosives to destroy what was visible above the snow.[7]
In 1956, two civilian surveyors chanced on the wreck and noted its exact location, which otherwise remained unknown for the next 40 years.[8] In 1997 one of the surveyors provided the coordinates[8] to two distinct expeditions, one American and one led by the CanadianDepartment of National Defence, seeking to conduct an environmental analysis of the site. Both expeditions reached the wreck around the same time, and members were apparently the first humans to set foot in the area since 1956. The Canadian-led mission found no unusualradiation levels.[9] In late 1998, the Canadian government declared the site protected.[10] A portion of one of the gun turrets is on display at The Bulkley Valley Museum inSmithers, British Columbia.[11]
In late October 2016 a diver reported he had discovered something looking like a segment of the partially disarmed Mark IV nuclear bomb which the co-pilot said had been dumped before the crash. The location nearPitt Island in theInside Passage was mistakenly reported as offHaida Gwaii. The Royal Canadian Navy later confirmed that the item was not the Mark IV bomb.[12][13][14]