Flight
The aircraft departed Zahedan on a flight to Kerman, carrying 257 passengers and a crew of 18. Most on board were members of the Revolutionary Guards, including several high-ranking officers who had participated in a narcotic control program in the province of Zahedan.
Accident
While descending to Kerman Airport by night, the crew encountered poor weather conditions with heavy snow falls and strong winds. On approach, the aircraft struck the slope of Mount Sirach, located 32 km from the airport. The wreckage was found about 100 metres below the summit. First rescuers arrived on the scene the next morning. All 275 occupants were killed.
Probable Cause
The official findings state that the accident was a controlled flight into terrain after the crew continued the descent below the minimum descent altitude in poor visibility due to the night and bad weather conditions. For unknown reasons, the crew started the descent prematurely.