The DC-3 departed Cali for a return flight to Condoto at 08:27. At 09:50 the flight left Condoto again for Cali. After 8 minutes the crew contacted Cali about there departure and radioed that they had a load of 975 kg including 11 passengers and that they were proceeding to Cali via Buenaventura. This was the last contact with the flight. It was found out that the aircraft had crashed against hill in the Trujillo Hills at 7800 feet. PROBABLE CAUSE: “Instrument flight at inadequate altitude. Contributing causes: 1) The Buenaventura route was not followed; 2) Instrument flight which precluded visual means of checking the aircraft’s position; 3) The pilot did not consider it necessary to check his position by means of El Paso radio beacon.; 4) Over-confidence on the part of the pilot regarding his knowledge of the route; 5) Flight outside the established route or airway; 6) Unfavourable weather conditions. As the aircraft crashed on the direct route Condoto-Cali and the said route had not been authorized by the Civil Aeronautical Department, it can be logically assumed that the pilot is solely responsible for this accident wince he flew, on instruments, a route which had not been authorized, even for visual flights.”