Primary finding
Probable cause
The pilot's failure to correctly use carburetor heat, resulting in a loss of engine power and collision with terrain.
Investigator assessment
Analysis narrative
The pilot stated that he was flying down a glacier for an extended period of time at a low power setting without the carburetor heat on. Near the toe of the glacier, he attempted to add power to level the airplane, but the engine did not respond. He stated that their altitude was low and he landed on the glacier moraine, and the airplane nosed over, sustaining substantial damage to the wings and fuselage. The pilot stated that there were no preaccident mechanical anomalies with the airplane that would have precluded normal operation. Based on the temperature and dew point at the time of the accident, the conditions were favorable for serious carburetor icing at descent power.
Source record
Factual narrative
The pilot stated that he was flying down a glacier for an extended period of time at a low power setting without the carburetor heat on. Near the toe of the glacier, he attempted to add power to level the airplane, but the engine did not respond. He stated that their altitude was low and he landed on the glacier moraine, and the airplane nosed over, sustaining substantial damage to the wings and fuselage. The pilot stated that there were no preaccident mechanical anomalies with the airplane that would have precluded normal operation. Based on the temperature and dew point at the time of the accident, the conditions were favorable for serious carburetor icing at descent power. The pilot did not complete and submit NTSB Form 6120.1.