What happened
During an instrument flight approach, the aircraft was cleared for an ILS approach to its destination airport. While the crew was maneuvering to intercept the final approach course, the flight encountered significant convective activity, specifically thunderstorms, in the area. Air traffic control contacted the pilot to verify the aircraft's position relative to the approach course. Radar data from the tower indicated that the aircraft was positioned between one-quarter and one-half mile east of the localizer. Despite the pilot's assertion that the aircraft remained on the localizer, the plane eventually struck trees approximately one and one-half miles northeast of the airport and one-half mile east of the intended approach path.
All four occupants of the aircraft were killed in the accident. At the time of the collision, the pilot had been receiving updated weather information from controllers and was aware of the level four thunderstorm activity occurring near the destination airport.
Findings
An investigation into the incident included a functional check of the ILS equipment by airways facilities, which determined that the approach system was operating correctly. Furthermore, an examination of the wreckage revealed no evidence of mechanical failure or malfunctions within the aircraft. The primary contributing factor was the encounter with thunderstorm activity while the aircraft was off the established approach course.