What happened
During a night flight under instrument meteorological conditions, the aircraft was executing a GPS instrument approach. While positioned between the intermediate approach fix and the final approach fix, the aircraft was operating at an altitude roughly 200 feet beneath the established sector minimum. Radar tracking indicated that the aircraft's final position was approximately 3/4 nautical miles past the final approach fix, situated about 1,000 feet to the left of the course centerline.
Prior to the final impact, the aircraft made contact with trees approximately 1 nautical mile before reaching the missed approach point. This initial strike occurred about 700 feet left of the centerline at an elevation nearly 480 feet below the required minimum descent altitude. Eyewitnesses observed the aircraft flying at a notably low altitude immediately before it struck the hilly terrain. Observers also noted that the engines produced a continuous, loud roaring sound during the approach.
Findings
Investigation into the circumstances revealed that the aircraft was flying significantly below the prescribed minimum descent altitude during the approach phase. There was no evidence of any mechanical failure or malfunction contributing to the event. The flight was occurring in darkness under conditions that required instrument flight rules.