What happened
During an approach to Tehran-Mehrabad Airport, the flight encountered significant visibility restrictions caused by dense fog. Following instructions from Air Traffic Control to divert the flight to Isfahan Airport, the pilot-in-command altered the flight path. During this period, the crew communicated to controllers that the remaining fuel on board was inadequate to complete the diversion to the alternate destination.
Shortly after these communications, the crew declared an emergency due to critical fuel levels and attempted an unplanned landing. The aircraft subsequently crashed in a field situated approximately 7 km from Tehran-Mehrabad Airport. Emergency responders reached the wreckage roughly two hours after the impact. While two passengers were rescued from the site with serious injuries, the remaining 27 occupants of the aircraft perished in the accident.
Findings
Investigations into the crash determined that the primary reason for the accident was fuel exhaustion. The investigation also identified several contributing elements, including the heavy fog which reduced visibility during the descent, and a failure by the crew to accurately calculate the fuel required to reach the designated alternate airport.