Flight and Weather Encounter
While flying over mountainous terrain, the pilot encountered what he described as "horizontal snow squalls." He reported flying through the snow squall for approximately 25 miles while maintaining visual contact with the ground. Approaching a cloud layer, he was able to climb above it at 16,500 feet mean sea level.
Engine Issues
As the flight continued, the engine began to run roughly. The outside air temperature was -15 degrees Fahrenheit, which placed the carburetor air temperature gauge needle below the yellow arc. Concerned about using carburetor heat under these conditions, the pilot initially refrained from applying it. He switched fuel tanks and checked magnetos, but these actions did not improve engine operation. Eventually, he applied full carburetor heat, but the engine continued to run roughly and ultimately stopped.
Emergency Descent and Crash
With the engine failed, the pilot entered the clouds. The vacuum system was not providing suction, requiring him to rely on the needle, ball, and airspeed indicator for attitude control. He turned into the wind to reduce ground speed. At approximately 10,000 feet, the aircraft struck trees and came to rest. The emergency locator transmitter (ELT) activated, but its antenna was broken.
Rescue
The pilot constructed a shelter and remained at the crash site overnight. He was rescued the following afternoon. Subsequent examination of the engine did not reveal any mechanical problems, but the plastic foam induction air filter was found to contain water when checked.