Accident Overview
On August 24, 2009, at about 1720 Alaska daylight time, a wheel-equipped Cessna 180 (registration N4601A) sustained substantial damage during a forced landing approximately five miles northeast of Birchwood Airport in Chugiak, Alaska. The aircraft was operated as a visual flight rules (VFR) personal flight under Title 14 Code of Federal Regulations Part 91. The airline transport pilot and three passengers all sustained minor injuries. The flight originated from Birchwood Airport at about 1600.
Flight Details
The pilot stated that the purpose of the flight was to show passengers Alaskan scenery. While in level cruise flight at 1,200 feet above ground level, the engine began to run rough and lose power. The carburetor air temperature gauge indicated a temperature just above the red-marked carburetor ice zone. The pilot applied full carburetor heat, which was followed by a complete loss of engine power. After executing emergency procedures, the pilot was unable to restart the engine and selected a marshy, tree-covered area for a forced landing. During the landing, the airplane collided with trees, resulting in substantial damage to the fuselage and wings.
The aircraft was equipped with a naturally aspirated Teledyne Continental Motors O-470-K engine.
Meteorological Conditions
The closest official weather observation station, at Birchwood Airport, reported at 1753: wind from 300 degrees true at 4 knots; visibility 10 statute miles; clear skies; temperature 57 degrees Fahrenheit; dew point 45 degrees Fahrenheit; altimeter 29.58 inches of mercury. Birchwood Airport is situated adjacent to the waters of Cook Inlet. The temperature and dew point values, when entered into a carburetor icing probability chart, coincided with the "serious icing—cruise power" category.
Post-Accident Examination
On September 15, 2009, a Federal Aviation Administration airworthiness inspector from the Anchorage Flight Standards District Office examined the airplane after it was recovered to Big Lake Airport in Big Lake, Alaska. The inspector reported that he was unable to find any preaccident mechanical problems with the airplane.