What happened
On the evening of the accident, an aircraft departed from Tehran-Mehrabad Airport following a delay of over two hours caused by adverse weather at the destination. During the night descent toward Orūmīyeh Airport, the flight crew encountered heavy snowfall and significantly reduced visibility of approximately 800 meters, with multiple cloud layers present between 1,500 and 6,000 feet.
After failing to intercept the Instrument Landing System (ILS) signal, the crew initiated a go-around procedure. During this maneuver, the aircraft approached its stall speed, triggering the stick shaker. The aircraft likely encountered icing conditions during this phase. While maintaining a left bank angle estimated between 26 and 40 degrees, the number 1 and number 3 engines failed. At an altitude of 600 feet and a speed of 96 knots, the retraction of the flaps led to a stall. The aircraft subsequently struck the ground and broke into three sections, though no fire was reported. The accident resulted in 70 fatalities and 27 injuries, with some passengers and crew sustaining serious harm.
Findings
- The flight encountered severe weather including snow and low visibility.
- The retraction of flaps during the go-around maneuver contributed to the loss of airspeed and subsequent stall.
- The aircraft likely experienced icing conditions, as evidenced by the activation of the stick shaker near stall speed.
- The failure of both the number 1 and number 3 engines occurred during a banked turn.