Investigation Summary
The flight was part of a Strategic Air Command exercise simulating a nuclear attack on San Francisco. The aircraft departed Eielson Air Force Base in extreme cold, with ground temperatures reaching -40 degrees Celsius. Approximately seven hours into the flight, the aircraft encountered severe icing conditions. Ice buildup in the carburetor air intakes led to catastrophic failures in three of the six R-4360 piston engines, which began trailing flames and were subsequently shut down. The remaining three engines were unable to maintain level flight at the aircraft's heavy mission weight. Facing a steady loss of altitude over rugged terrain, the crew followed emergency procedures to jettison the Mark 4 nuclear weapon. To prevent the weapon from falling into unauthorized hands or causing an uncontrolled ground impact, the crew triggered the conventional explosives in mid-air over the ocean. After the jettison, the crew members bailed out over Princess Royal Island. While 12 survived, four of the first to jump were never found and are presumed to have drowned in the freezing sea. The co-pilot, Capt. Theodore F. Schreier, did not bail out with the others; his body was recovered from the wreckage in 1954. The unmanned aircraft continued to fly on autopilot for approximately 210 miles before impacting Mount Kologet, hundreds of miles from where the crew exited.
Final Conclusions
The investigation concluded that the primary cause was the failure of multiple engines due to carburetor icing, a condition exacerbated by the extreme Arctic weather and the design of the B-36's engine intakes. The crew's decision to abandon the aircraft was deemed necessary as the remaining power plants could not support the airframe's weight. The loss of the weapon was classified as the first 'Broken Arrow' incident, though the absence of a plutonium core prevented any possibility of a nuclear explosion.
Video Analysis
The Convair B-36 that Lost a Nuclear Bomb - America's First Broken Arrow — A detailed look at the 1950 crash of a B-36 bomber off the coast of British Columbia, which resulted in the first recorded loss of a nuclear weapon.
If playback is blocked, the owner has disabled embedding — use the link above.
Airframe & Maintenance
Systems & Failure Modes
Pratt & Whitney R-4360 Wasp Major
The aircraft's six radial piston engines suffered from carburetor icing, which blocked air intakes and caused three engines to catch fire.
Mark 4 Nuclear Bomb
A weapon based on the Fat Man design, jettisoned and detonated conventionally to prevent recovery of the uranium components.
Interesting Facts
- 01This was the first 'Broken Arrow' (loss of a nuclear weapon) in history.
- 02The aircraft was carrying a Mark 4 nuclear bomb containing 5,000 pounds of conventional explosives.
- 03The bomb did not contain a plutonium core, as these were held by the U.S. Atomic Energy Commission at the time.
- 04The wreckage of the aircraft was located during a search for a different missing plane.
- 05The ground temperature at takeoff was -40 degrees Celsius, contributing to the icing issues.
Safety Actions & Advisories
Carburetor Heat Improvements
The incident highlighted the vulnerability of the B-36's pusher-configuration engines to icing, leading to revised cold-weather operating procedures and intake modifications.
Known Controversies & Unanswered Questions
Recovery of Capt. Schreier
Reference ↗While four crew members were officially presumed to have drowned in the Pacific, the body of the co-pilot, Capt. Theodore F. Schreier, was recovered from the wreckage on Mount Kologet in 1954. This discovery led to speculation that he had remained at the controls after the rest of the crew bailed out, as the crash site was over 200 miles from the bailout zone.