Incident Overview
A cargo flight operating between Beirut and Tehran was attacked by an unknown fighter aircraft during night cruise at an altitude between 13,000 and 15,000 feet. The four-engine aircraft sustained a hit to engine number one, which ignited a fire that spread to the nacelle and wing. Shortly thereafter, engine number four was shut down and its propeller feathered due to fuel exhaustion; the corresponding fuel tank was apparently empty.
Emergency Response
In response to the dual engine emergencies, the crew reduced altitude and initiated an emergency landing near Rasht. The aircraft came to rest in a field and was destroyed in the accident. All three crew members evacuated without injury.
Navigation Error
It is presumed that the crew made a navigation error during the flight, causing the aircraft to deviate into Soviet Union airspace without authorization. This navigational mistake is considered a contributing factor to the encounter with the fighter.
Official Findings
The probable cause of the accident was determined to be a shutdown by an unknown fighter in flight. The accident was attributed to faulty navigation.