The British Aerospace Jetstream 32, N912FJ, operating as Aerocaribe Flight 7831, was destroyed upon impact with a steep mountain side while maneuvering around severe weather near Chul£m de Ju rez, Mexico. Instrument meteorological conditions prevailed near the accident site at the time of the accident. An instrument flight rules (IFR) flight plan was filed and an IFR clearance was received for the 80-nautical mile flight from the Tuxla-Gutierrez Airport (TGZ) to Villahermosa Airport (VSA). When establishing contact with the Villahermosa Approach controller, the crew reported that they were 50 miles from their destination at FL160. The crew further indicated that they were off course from the V-3 airway by about 15 miles to the right due to bad weather en route and that they were commencing the descent. The controller requested the flight to report at 25 DME. The last radio contact was when the flight reported at 42 DME at 6200 feet on the 150 radial of the Villahermosa VOR. Immediately after this last call, the aircraft impacted a mountain. Probable cause: “Combining instrument flight (IFR), with visual flight (VFR), the crew lost situational awareness, deviating 29.8 miles to the right of the Victor 3 airway due to bad weather, when the weather conditions imposed the application of the instrument flight rules (IFR), causing collision of the aircraft with the mountain at 6200 feet of elevation without loss of control (CFIT).” Contributing factors: – severe weather conditions en route. – persistence of the pilot in command, to continue the instrument flight (IFR) on visual flight (VFR) – inconsistency in cockpit resource management (CRM) – loss of situational awareness of the flight crew and the controllers, due to numerous deviations from the route, due to severe weather conditions and poor communication between the parties. – inadequate preparation of the flight plan, since in view of the very probable need to circumnavigate severe meteorological conditions, the flight altitudes that would continue outside of the controlled airspace (outside the v-3 airway) were not verified.