9 Aug 2010: DEHAVILLAND DHC-3 (N455A) — General Communication Corporation (GCI) — Aleknagik, AK

5 fatalitiesAleknagik, AK, United States

A turbine-powered amphibious airplane crashed into mountainous terrain in Alaska, resulting in five fatalities.

What happened

On August 9, 2010, at approximately 14:42 Alaska daylight time, a de Havilland DHC-3T impacted tree-covered, mountainous terrain roughly 10 nautical miles northeast of Aleknagik, Alaska. The aircraft, registration N455A, had departed at approximately 14:27 from a private lodge on the shore of Lake Nerka. The flight was operated by GCI Communication Corp. and was traveling toward a remote sport fishing camp located about 52 nautical miles southeast on the Nushagak River.

The accident resulted in 5 fatal injuries, involving the pilot and four passengers, and 4 serious injuries to four additional passengers. The aircraft sustained substantial damage, including a breached and deformed fuselage. No flight plan had been filed for the flight. At the time of the accident, weather conditions at Dillingham Airport, located about 18 nautical miles south of the site, were reported as meeting marginal visual flight rules criteria.

The investigation

The investigation was hindered by the absence of a cockpit recorder system capable of capturing parametric data, audio, or images, which prevented a definitive reconstruction of the flight's final minutes.

Probable cause

The pilot became temporarily unresponsive for reasons that could not be determined from the available information.

Contributing factors

PilotData recorders (flight/maint)Damaged/degradedMeteo equip coverage/availEmergency equipment