Incident Overview
A pilot and passenger were concluding a cross-country state-government flight when the engine began running rough during a straight-in approach. The pilot had applied carburetor heat approximately 600 feet above the ground. About 300 feet above the ground, the pilot increased throttle, at which point the engine lost power. The pilot executed an emergency landing to the left side of the runway.
Weather Conditions
The weather at the time was clear, with a temperature of -2 degrees Fahrenheit and a dew point of -8 degrees Fahrenheit. The pilot reported observing visible ice crystals in the air, consistent with conditions conducive to carburetor icing.
Engine Examination
After the airplane was recovered, an examination of the engine did not reveal any mechanical malfunction. The engine was able to run at idle RPM with the carburetor heat control in both the 'Hot' and 'Cold' positions, indicating no pre-existing mechanical issue was found.
Conclusion
The source does not specify a probable cause for the power loss. However, the combination of visible ice crystals, cold temperatures, and the engine's response to carburetor heat settings suggests that carburetor icing may have played a role, though this is not stated explicitly in the investigation report.