Investigation Summary
The flight was the second segment of a scheduled six-segment route. During the first segment, a passenger noted the pilot was flying lower than usual and through clouds. After departing Port Heiden for Perryville with a load of mail, the pilot encountered a peninsula of mountainous terrain obscured by clouds and rain showers. Satellite imagery and weather cameras indicated overcast conditions and flat light, which likely hindered the pilot's ability to perceive terrain features and closure rates. The wreckage was found at 2,993 feet MSL on a featureless mountain face, with impact signatures suggesting the aircraft was in a left turn. The NTSB concluded the pilot likely performed this turn to return to visual meteorological conditions (VMC) but failed to recognize his proximity to the mountain due to the flat light conditions. Although the aircraft was equipped with a Terrain Awareness and Warning System (TAWS), it could not be determined if the pilot received or heeded alerts. The NTSB highlighted systemic issues at Grant Aviation, noting that the company's risk assessment for the route was based on hours-old observations from untrained village agents and failed to account for known hazardous terrain and AIRMETs for mountain obscuration.
Final Conclusions
The NTSB determined the probable cause was the pilot's continued VFR flight into mountainous terrain and IMC, resulting in CFIT. Contributing factors included the company's failure to ensure the pilot received recurrent CFIT-avoidance simulator training (his last session was 15 months prior, exceeding the 12-month company requirement) and inadequate risk assessment processes that did not mitigate known hazards on the accident route.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Crew Experience
Captain
Held ATP and Flight Instructor certificates.
Systems & Failure Modes
TAWS (Terrain Awareness and Warning System)
A Garmin GNS 530 with Class B TAWS was installed. Post-accident testing showed the inhibit switch was off and the system was functional, though it is unknown if alerts were generated or heeded.
ELT (Emergency Locator Transmitter)
A C126 ELT was installed and activated upon impact, allowing the US Coast Guard to locate the wreckage within hours.
Interesting Facts
- 01The pilot had flown the accident route on 9 of the previous 10 days.
- 02The aircraft was certified for flight into icing conditions and equipped with a Garmin GNS 530 TAWS.
- 03The company's risk assessment for the flight used weather data that was nearly two hours old.
- 04The pilot's last CFIT-avoidance simulator training was 15 months prior to the accident, despite a company requirement for annual training.
- 05Post-accident examination of the engine and propeller showed signatures consistent with engine power at the time of impact.
- 06Flat light conditions at the site likely hindered the pilot's perception of terrain closure rates.
Safety Actions & Advisories
CFIT-Avoidance Training Compliance
Source ↗The NTSB investigation identified that the pilot's last CFIT-avoidance simulator training was 15 months prior to the accident, exceeding the operator's 12-month requirement. The report emphasized the need for operators to ensure strict adherence to recurrent training schedules to help pilots recognize and respond to reduced visibility and flat light conditions.
Flight Risk Assessment Improvements
Source ↗The investigation highlighted that the operator's risk assessment process failed to account for en route weather hazards, area forecasts, or AIRMETs. The NTSB noted that the company had not performed a formal risk assessment of the specific route since acquiring it, despite pilots considering it hazardous due to terrain and lack of weather infrastructure.
Location
NO VERIFIED COORDINATES · This position predates coordinate provenance tracking. Treat it as an approximate marker for the area, not the accident site. No map is shown, because a marker here would imply a precision the record does not have.
Reported location: 8 miles south of Chignik Lake, Alaska, United States