Accident Sequence
The scheduled commuter flight departed 40 minutes late for a two-stop flight. During the first leg of a night visual flight rules (VFR) flight, weather at the first destination airport deteriorated, prompting the pilot to divert to the second destination airport. The pilot requested and received a special VFR clearance from an air route traffic controller into the diversion airport area. Automatic dependent surveillance-broadcast data showed that after clearance, the airplane's track changed and proceeded directly toward the diversion airport.
Postaccident examination of the pilot's radio revealed that his audio panel was selected to the ARTCC frequency rather than the destination airport frequency. Consequently, although the pilot attempted to activate the pilot-controlled lighting at the destination airport—as heard on the ARTCC frequency—the lighting did not activate. Witnesses on the ground at St. Mary's reported that the airport lighting system was not activated when they observed the accident airplane fly over and then proceed away from the airport.
About 1 mile from the runway, the airplane began to descend, followed by a descending right turn and controlled flight into terrain. The pilot appeared to be in control of the airplane up to the point of the descending right turn. Witnesses described the weather at the airport as deteriorating with fog and ice. Given the lack of runway lighting, restricted visibility due to fog, and witness statements, the pilot likely lost situational awareness of the airplane's geographic position, leading to the subsequent controlled flight into terrain.
After the airplane proceeded away from the airport, witnesses attempted to contact the pilot by radio. When the pilot did not respond, they accessed the company's flight tracking software and noted the airplane's last reported position. They searched the area and found the airplane about one hour later.
Weather and Lighting
Weather at the diversion airport was reported by witnesses as deteriorating, with fog and ice present. The pilot-initiated approach occurred at night under visual flight rules, but the airport's pilot-controlled lighting was not activated due to the pilot's radio being tuned to the ARTCC frequency. Postaccident examination of the airframe and engine revealed no mechanical malfunctions that would have precluded normal operation. About 3/4 inch of ice was noted on nonprotected surfaces of the empennage, but ice formation on the de-ice boots was consistent with normal operation, and structural icing was likely not a factor.
Operational Control and Risk Assessment
According to the company's General Operations Manual, operational control was held by the flight coordinator for the accident flight. The flight coordinator and pilot-in-command were jointly responsible for preflight planning, flight delay, and release, including risk assessment. The flight coordinator assigned a risk level of 2 (on a scale of 1 to 4) due to instrument meteorological and night conditions and contaminated runways. A first flight coordinator assigned another coordinator to create the manifest, which listed eight passengers and a risk level of 2. Company procedures required a discussion between the pilot and flight coordinator about risks for a level 2 flight; however, no such discussion occurred. Neither flight coordinator had received training on the risk assessment program. At the time of the accident, no signoff was required on the risk assessment form, and the form was not integrated into company manuals.
Regulatory Oversight
A review of FAA surveillance activities showed that aviation safety inspectors had performed numerous operational control inspections and repeatedly noted deficiencies within the company's training, risk management, and operational control procedures. Enforcement records indicated that FAA inspectors observed multiple incidents of noncompliance and opened investigations, but those investigations were closed after only administrative action. Thus, while FAA inspectors identified discrepancies, the FAA did not hold the operator sufficiently accountable for correcting operational deficiencies evident in this accident, such as failure to comply with operations specifications, training manual, GOM, and federal regulations.