ANCHORAGE (AP) -- Fifteen months after a plane crash that killed 10 people in Dillingham, The National Transportation Safety Board has concluded the crash was probably caused by ice on the wings of the Cessna 208.
Contributing to the accident, the agency said, was the fact that pilots aren't required to closely examine the upper wing surfaces of a Cessna 208 for ice as part of their preflight inspection.
The crash was the deadliest commercial aircraft accident in Alaska in 14 years. The plane was flying from Dillingham to King Salmon when it went down shortly after takeoff on Oct. 10, 2001, plunging to the tundra about a half mile from the airport.
The pilot and eight of the passengers were killed instantly. The lone survivor died the following day.
Seven of those killed were board members or employees of Bristol Bay Native Association, the social service agency serving the region. The board members were returning to their home villages on the Alaska Peninsula after attending a board meeting.
The NTSB's final report, released late last week, says the plane, operated by PenAir, had been parked outside the night before the accident and was exposed to rain, snow and temperatures that dipped below freezing.
Other pilots whose planes were also parked outside told investigators they had about 1/4 to 1/2 inch of snow or frost covering a layer of ice on their planes.
The plane was deiced by a PenAir ramp supervisor with a heated mixture of glycol and water before takeoff on October 10, 2001. The supervisor said he believed the upper surface of the wing was clear of ice, but that he did not actually touch the wing to check for ice.
Investigators were unable to determine if the pilot, Gordon Mills, checked the wing and tail surfaces after deicing.
''The big issue with this airplane is the configuration of the wing. It's a high-wing configuration, so the wing is well over the pilot's head,'' said Joe Sedor, the investigator in charge of the NTSB's major investigations division in Washington, D.C.
The pilot would have to stand 10 to 20 feet behind the wing to see the top of the wing, Sedor said. But being that far from the wing would make it difficult to see any residual clear ice on the wing surface. Even a small amount of ice can cause disruption of the air flow over a wing, he said.
The safety board could recommend changing preflight inspection requirements for the Cessna 208 to include a close-range inspection for ice on the wings, Sedor said.
PenAir spokesman Dick Harding said he could not comment on the report because of pending litigation, but said he stands behind his crew.
''I believe the actions of our crew and staff were reasonable and appropriate on the conduct of that flight,'' Harding said.
Relatives of two people killed in the crash filed a lawsuit last year against PenAir, Cessna Aircraft and the estate of the dead pilot.
The lawsuit, filed on behalf of Michael E. Grunert and his son, Samuel, says the Cessna Caravan has design flaws that make it dangerous in icy weather. The lawsuit also says PenAir did not properly deice the plane.
The nine passengers killed included Carla Grunert, the wife and mother of the plaintiffs, and her 15-year-old son, Michael R. Grunert. The family is from Chignik Lagoon.
The lawsuit also blames pilot Gordon Mills for the crash. It says he was unsuited by temperament to be a commercial pilot and didn't have enough experience flying a Caravan to carry passengers.
Peninsula Clarion ©2015. All Rights Reserved.