On January 21, 1980, an Iran Air Boeing 727-86 was making a domestic flight from Mashad Airport to Tehran-Mehrabad Airport in Iran. At 1911h local time, the aircraft, registered as EP-IRD, collided with the Alborz Mountains, 29 kilometres (18 mi) north of Tehran, during its approach to Tehran-Mehrabad runway 29 in foggy and snowy weather conditions. All 8 crew members and 120 passengers died in the accident, and the plane was destroyed.[3] At the time, Iran Air Flight 291 was the deadliest aircraft disaster in Iranian history.