What happened
The scheduled flight from Moscow to Prague departed at 06:50 GMT. During the transit through Soviet, Romanian, and Polish airspace, the crew followed all altitude instructions, adjusting levels between 10,650 m and 8,850 m as directed by various air traffic control sectors. Upon approaching the Czechoslovak border, the aircraft descended to 6,700 m.
As the flight neared Prague, the crew transitioned through several frequencies and navigation aids, including the Rodnice VOR. At approximately 09:02 GMT, the aircraft was operating on radar frequency and was cleared for an ILS approach to Runway 25. While descending toward 350 m, controllers noted a slight deviation from the course line, though they later confirmed the aircraft had regained alignment. The crew contacted the tower frequency at 09:05 GMT and acknowledged updated wind information and runway braking coefficients.
The final communication with the aircraft occurred at 09:06:30 GMT. During the approach, the Ilyushin Il-18 maintained the correct headings and altitudes without reporting any mechanical issues or difficulties. However, as the aircraft approached the "L" marker, it abruptly deviated below the glide path, descending at an average angle of 4.62°. The aircraft struck the ground with its nosewheel approximately 467 m before the threshold of Runway 25. The impact caused the airframe to disintegrate and a subsequent fire destroyed the wreckage. The accident resulted in 66 fatalities (comprising 62 passengers and four flight attendants) and 18 serious injuries, while 16 occupants escaped without injury.
Findings
Due to the extreme destruction of the airframe and the intensity of the post-crash fire, investigators were unable to determine a definitive cause for the sudden descent below the glide path. Investigators noted that unexpected atmospheric turbulence during the final approach phase could not be excluded as a contributing factor.