NTSB Factual Report

On June 19, 2015 about 1340 mountain daylight time, a Cessna 180A, N9699B, was substantially damaged during a forced landing near Polson, Montana. The commercial pilot and two passengers were not injured. The airplane was registered to and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed for the cross-country flight, and no flight plan was filed. The flight originated from Cavanaugh Bay Airport (66S), Coolin, Idaho at 1140 with a planned destination of Polson Airport (8S1), Polson, Montana.

In a written statement, the pilot stated that during approach, about 3 miles from the airport, the engine lost all power. The pilot continued his descent while maintaining the best glide airspeed. He performed the engine restart procedures where he applied carburetor heat. Despite his efforts the engine would not restart and he initiated a forced landing to a small field. During the landing, the right main gear collapsed, subsequently resulting in substantial damage to the right wing and fuselage. The pilot further stated that he had 26 gallons of fuel on board prior to departing 66S.

An onsite examination of the wreckage was conducted by a Federal Aviation Administration (FAA) inspector on June 19, 2015. The inspector was present during the transportation process of the wreckage. Seven gallons of fuel was collected from each main tank with some fuel remaining in each. The main fuel line to the carburetor was disconnected and fuel was present.

A postaccident examination of the wreckage was conducted on July 6, 2015. The carburetor drain plug was removed and fuel flowed freely from the drain. The gascolator was filled with fuel and free of contaminates. The gascolator was inspected with a flashlight and its screen was free of debris and contaminates. The crankshaft was rotated by hand and engine gear continuity was attained from the propeller assembly to the accessory case. Confirmed compression from all six cylinders and spark from both magnetos were attained. Additionally, on July 20, 2015, the wing tank vent lines and left and right fuel tank caps were examined and revealed no anomalies. The postaccident examination revealed no evidence of mechanical malfunction or failures that would have precluded normal operation.

The Glacier Park International Airport, Kalispell (GPI), Montana, located 37 nautical miles north of the accident site, at 1255 the automated weather observation, included winds from 230 degrees at 16 knots, gusting to 23 knots, visibility 10 miles, clear skies, temperature 25 degrees C, dew point 3 degrees C, and an altimeter setting of 29.89 inches of mercury.

The GPI 1355 automated weather observation, included winds from 240 degrees at 17 knots, gusting to 22 knots, visibility 10 miles, clear skies, temperature 26 degrees C, dew point 3 degrees C, and an altimeter setting of 29.87 inches of mercury. In the remarks section of the observation, peak winds were recorded from 220 degrees at 27 knots.

Temperature and dew point values for the approximate time of the accident indicated that the relative humidity was approximately 24 percent. When the intersection of the two temperature values was located on a chart that depicted carburetor ice envelopes, the point was in the region of the chart denoted as "Icing at Glide and Cruise Power."

NTSB Probable Cause

A total loss of engine power during approach for reasons that could not be determined because postaccident examination revealed no anomalies that would have precluded normal operation.