[7] This was also stated by an Armenian aviation official, saying that the plane had gone through technical controls in Mineralnye Vody Airport in southern Russia in June.

[10] The aircraft crashed at 11:33 Iran Daylight Time (07:03 UTC), 16 minutes after takeoff from Tehran Imam Khomeini International Airport.

It seemed the pilot was trying to land, and moments later the plane hit the ground, and broke into pieces that were scattered far and wide.

[17] Armenian President Serzh Sargsyan announced on 15 July that a governmental commission had been set up to investigate the crash.

It was claimed that the main reason of the accident was an engine failure and destruction due to a bird strike, which resulted in a fire which led to a loss of control and crash of the airplane.

[8] On 23 December 2014 a chronology of events was published: During the climb to the altitude of 9,700 metres (31,800 ft) the crew sent a message about a fire in the number one engine.

The airplane, three minutes before the crash, made a turn of 270 degrees then started to descend rapidly with a high vertical speed of about 70 metres (230 ft) per second.

16 minutes after takeoff, the Tu-154M, at high speed, collided with the ground in a field near the village of Jannatabad, approximately 120 kilometres (75 mi; 65 nmi) from the Khomeini airport.

The Commission found that it was the destruction of the low pressure compressor in the number one engine that scattered debris and damaged the fuselage and fuel lines causing the rapid spread of fire.

[15] The report found that the accident had been caused by fatigue failure of the first stage rotor of the low pressure compressor in engine No.

[15] Prior to the accident the aircraft manufacturer, Tupolev, had released a service bulletin requiring more stringent testing of low pressure compressor components.