What happened
A non-scheduled international cargo flight departed Rancho Boyeros Airport in Havana, Cuba, destined for Mexico City International Airport. During the early morning hours, the aircraft communicated with the Mexico Control Centre to request entry into the controlled airspace. While initial weather updates and clearances were provided, the crew's responses on the primary frequency became difficult to understand, necessitating a switch to an alternative frequency.
As the flight progressed over Nautla and Tulanciago, controllers informed the crew of heavy fog and reduced visibility at the destination. The aircraft was instructed to descend from 18,000 feet to 12,000 feet and transition to the approach frequency. After reporting over the Tepexpan area, the pilot was directed to descend further to 11,000 feet and report passing the VOR to begin a standard descent. The final successful communication occurred at 0500 hours as the aircraft left the VOR at 11,000 feet, with instructions to contact the control tower. The aircraft failed to establish contact on the tower frequency.
The aircraft type crashed approximately 18 km from the runway threshold, positioned 400 meters to the right of the extended centerline. The impact resulted in a post-crash fire that destroyed the airframe. There were 10 fatalities among the occupants.
Findings
Investigation into the crash revealed that the aircraft struck the ground in a nose-down attitude with a significant left bank. While no fire or explosion occurred prior to impact, the breaking of the left wing allowed fuel to ignite upon contact with the engine exhausts. The investigation determined that the aircraft was not in its landing configuration at the time of the accident.
The crew discontinued instrument flight procedures and attempted a visual approach despite unfavorable weather conditions. It was concluded that the pilot failed to follow the established IFR descent procedures for Mexico City International Airport and transitioned to a visual flight pattern outside of protected airspace and below established minimum altitudes.