Flight Planning and Departure
An IFR flight plan and slot reservation were filed for a planned flight over mountainous terrain. The flightcrew intended to reposition the aircraft to an airport about 30 miles southeast of the departure airport, pick up passengers, and then complete a revenue flight to another airport. The airplane departed under visual flight rules (VFR), and the flightcrew never activated the filed IFR flight plan.
Accident Site and Wreckage
A debris path consistent with straight and level flight was located near the peak of a mountain at an elevation of 3,475 feet mean sea level. Examination of the wreckage did not reveal any pre-impact mechanical malfunctions. Instrument meteorological conditions (IMC) prevailed near the accident site around the time of the accident.
Operator History and Oversight
Further investigation revealed that the aircraft operator was involved in two prior weather-related accidents, both of which resulted in fatalities. A third accident went unreported, and the weather conditions at the time of that accident were unknown. Over a period of 14 years, the same Federal Aviation Administration (FAA) principal operations inspector was assigned to the operator during all four accidents; however, no actions were ever initiated as a result of any of the accidents.
Probable Cause
The official probable cause was determined to be the pilot-in-command's improper decision to continue VFR flight into IMC conditions, which resulted in controlled flight into terrain. Factors contributing to the accident were the FAA Principal Operations Inspector's inadequate surveillance of the operator and a low ceiling.