Accident Details
On February 17, 2010, at 1657 Alaska standard time, a Cessna 208B, registration N207DR, operated by Grant Aviation under Part 135, sustained substantial damage during impact with terrain after takeoff from Kwigillingok Airport (GGV), Kwigillingok, Alaska. The airline transport pilot and seven passengers were not injured. Visual meteorological conditions prevailed, and a company flight plan was filed for the intended destination of Kipnuk, Alaska.
Pilot Report
The pilot reported a normal takeoff, but at 200 feet above ground level during a turn, he observed a reduction in power. He moved the emergency fuel control lever forward, and power was restored. Before the sink rate could be reversed, the airplane impacted the surface of a frozen lake. The outboard right wing was bent up approximately 5 feet, though the aileron was not damaged. The pilot continued straight ahead for 8 miles to Kongiganak, Alaska, where the flight landed without further difficulty.
Passenger Statements
The pilot informed an FAA inspector that cloud conditions at the time were 500 feet overcast with 2.5 miles visibility in light snow, and a light wind from the north at 3 to 5 knots. When asked about ice on the aircraft, the pilot stated there was a "trace" of ice on the wings. Passengers provided the following statements: "There was freezing rain"; "The plane was iced up and when it took off it stalled"; and "The weather was icing rain…There was some ice on the wings before they took off from Kwigillingok."
Weather Information
No weather reporting facility existed at Kwigillingok. The closest station, at Kipnuk, Alaska (26 nautical miles west), reported at 1656: wind 050 degrees at 7 knots, visibility 10 statute miles, broken clouds at 400 feet and overcast at 3,300 feet, temperature and dew point both 23 degrees Fahrenheit, and altimeter 29.67 inches of Mercury. The pilot told the NTSB investigator that the cloud condition was an indefinite ceiling at 500 to 600 feet with light snow and temperature 30 degrees Fahrenheit. An NTSB meteorologist determined the area was subject to light snow showers, freezing fog and mist, with ground temperatures below freezing.
Aircraft Inspection
Maintenance personnel from the operator inspected the engine and airframe, determining that the right wing required a major repair to restore airworthiness. After a field repair, the FAA granted a ferry permit for a single flight from Kongiganak to Anchorage. No discrepancies were found with the engine, which operated normally during the ferry flight.
The Cessna 208B flight manual supplement for known icing equipment states: "Takeoff is prohibited with any frost, ice, snow, or slush adhering to the wings, horizontal stabilizer, vertical stabilizer, control surfaces, proper blades, or engine inlets." It also includes a warning that even small amounts of such contaminants may adversely change lift and drag, degrading airplane performance and potentially preventing a safe takeoff and climbout.