The Bolivian cylinder crash (6 May 1978)
On 6 May 1978 thousands of people in southern Bolivia, near the Argentine border, saw a cylinder fall into a mountainside with a sonic boom. An Army corporal saw it pass overhead trailing white smoke, and the military and police described a dull metal cylinder about 12 ft long with a few dents and said they were waiting for technical commissions. According to UAP Gerb, two US Air Force officers arrived, a State Department cable said the 'appropriate agencies' had been told, and Project Moon Dust received a film of the object. What was recovered is not on the record.
How plausible · High
A mass sighting, a military inspection of a physical object and a US cable tasking the Air Force's recovery program fit together; what happened next is not on the record, as secrecy would predict.
- ●●Access The Bolivian military inspected the object; a corporal saw it overhead.
- ●●No gain sought Local witnesses and a military statement; nothing sold.
- ●●Independent convergence Thousands of witnesses, the military, the press and a US cable.
- ●●Fits the documented skeleton Fits Moon Dust's documented remit to recover fallen foreign vehicles.
- ●○Consistent over time Press and cables agree on the date and a metal cylinder.
- ●○Restraint The military described only a dented 12 ft cylinder.
Plausibility weighs how well an account fits where secrecy hides the documents by design, so missing records never count against it. Strength measures what is documented. Assessed 2026-10-24.
On the record
- Contemporary press reports quoting Bolivian military and police on a dented 12 ft metal cylinder.
- A State Department cable under Secretary Vance, released under FOIA, as shown by Gerb.