Incident Overview
The commuter flight was en route to its home airport over mountainous terrain when it encountered low ceilings and rain showers. The aircraft was not certificated for instrument flight rules (IFR) commuter operations. Instead of diverting to an alternate airport, the pilot attempted to maintain visual conditions and requested and received a visual clearance into the Terminal Control Area (TCA). During the clearance read back, the pilot's radio transmission became garbled. Shortly thereafter, air traffic control observed the aircraft's radar target turn left from its westerly track and disappear from the scope. No further communications were received from the pilot.
Flight Details
The pilot reported his altitude as 5,100 feet mean sea level (MSL) during the transmission. When the aircraft failed to arrive at its destination, an ALNOT (Alert Notice) was issued. The following morning, the wreckage was found, having impacted a mountain at an elevation of 4,100 feet MSL. The accident site was approximately 10 miles south of the planned flight course.
Investigation Findings
Investigators determined that the pilot had previously and successfully flown the accident aircraft in IFR conditions. The probable cause was attributed to the pilot's decision to continue the flight under visual flight rules into instrument meteorological conditions rather than proceeding to an alternate airport.
Probable Cause
The pilot-in-command's poor inflight decision by not electing to proceed to an alternate airport and to continue to the flight under visual flight rules into instrument meteorological conditions. The low ceilings and visibilities across the flight route and the mountainous terrain were factors in the accident.