What happened
The aircraft was engaged in a night cross-country flight under clear but extremely cold weather conditions. While cruising at 7500 feet mean sea level, the pilot experienced a total loss of engine power. Air traffic control provided the location of the nearest airport, but the pilot initially elected to continue toward his intended destination, which was located five miles further away.
After realizing that the aircraft could not reach the planned airport, the pilot accepted vectors from approach control to the closest field. However, he determined that this airport was also unreachable and decided to attempt a landing on a nearby highway. During the maneuvering for a short final approach toward the highway, the aircraft struck a light pole.
The investigation
A thorough inspection of the engine revealed no mechanical defects. When tested in a test cell, the engine operated normally and produced full power. The pilot reported that the maximum oil temperature recorded was 80 degrees Fahrenheit. Notably, he stated that he was not utilizing the winterization kit during this flight.
Findings
The pilot noted that the engine only reached 2200 RPM at full throttle both on the ground and during cruise. According to the engine manufacturer, operation in severe cold temperatures can allow minute ice particles to accumulate on the carburetor inlet screen. This accumulation can restrict or completely block fuel flow, leading to a total loss of power.
Safety message
Pilots operating in very cold weather should be aware that carburetor icing can occur even without visible moisture. Utilizing winterization kits or other anti-icing measures is critical when temperatures are low enough to allow ice formation on the carburetor inlet screen.