The pilot was flying a Cessna 175B near Wellsville, Utah, when during a climb to cruise flight, the engine rpm suddenly reduced. He applied carburetor heat, which momentarily increased engine rpm, then it decreased again.
He began troubleshooting the engine and performed the emergency landing checklist. He turned the ignition switch off and back on and the engine backfired once; however, the engine rpm remained at 1,000. He made a forced landing to an open, snow-covered field. During the landing roll, the plane nosed over.
During the post-accident examination the carburetor was disassembled and examined. The carburetor float bowl contained water.
Investigators determined that at the time of the accident the temperature was 25° Fahrenheit with a dew point at 19°. The reported weather conditions were conducive to carburetor icing at glide and cruise power.
Given the sudden loss of engine rpm before and the rise in engine rpm following the application of carburetor heat, investigators determined it was likely that carburetor ice was the reason for the loss of engine power and subsequent off-airport landing.
NTSB Identification: WPR13LA108
This February 2013 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.