The Tupolev Tu-104A took off from Novosibirsk Airport at 17:19 hrs local time and climbed to the cruising altitude of 8400 m. The en route part of the flight was uneventful. After receiving descent and course instructions from the air traffic controller, the flight crew began the approach to Alma-Ata Airport. At a distance of 12.5 km to the runway, a slow drop in power of the no.1 engine occurred as the flaps were selected down to 35ø. The crew detected the abnormal operation of the engine and started raising the flaps up to 20ø. At the distance of 8 km to the runway, the crew reported: “Come in on one engine, left engine failed.” They subsequently shut down the engine and increased power on the remaining engine. The aircraft then deviated to the left of the planned approach course. The crew then radioed two incomprehensible words. This was the last contact. The crew did not answer the following calls. At distance of 3.5 km from the runway, the aircraft abruptly climbed from 195 m to 285 m, at a critical angle of attack. The aircraft then sank and impacted a flat, snow-covered field 3280 m from the end of runway 23 and 480 m to the left of its extended centreline. It broke up and burst into flames. An investigation concluded that a fire had broken out in the area of the left engine some 10-15 minutes before the accident. There flight crew was not aware of this fire. The cause of the accident was the fire that occurred on the aircraft in the air in the area of the left engine due to a fuel leak due to the destruction of a fuel line. The fuel line failed because it was subjected to hot air from a pipeline that was not properly fastened. The consequence of the fire was a disturbance in the controllability of the aircraft, carbon monoxide poisoning of the crew and creation of rear centre of gravity as a result of possible movement of passengers as a result of panic. The source of carbon monoxide emissions was the thermal insulation materials of the aircraft fuselage when exposed to high temperatures.