What happened
During a nighttime approach under instrument meteorological conditions (IMC), an aircraft struck trees in a mountainous region before reaching the intermediate approach fix (IAF). The flight was conducting an ILS approach in weather characterized by fog and light snowfall, which was causing visibility to decrease.
Data from the flight path indicates that the aircraft's altitude at the outer marker was 7,713 feet, which was significantly below the required minimum descent altitude (MDA) of 10,600 feet for that segment of the approach. The wreckage was eventually discovered at an elevation of 7,600 feet, positioned directly beneath the localizer path.
Analysis of the impact site showed damage to the tops of trees along the debris field. This pattern suggests the aircraft maintained a level flight path through the canopy until it made contact with the ground roughly 300 feet into the tree line.
Findings
An investigation into the wreckage revealed no signs of mechanical malfunction or system failure prior to the impact. The primary contributing factor was the aircraft's descent below the prescribed minimum altitude during the approach in deteriorating visibility.