Accident Summary
An aircraft impacted powerlines and then collided with three automobiles. Federal Aviation Administration personnel arriving at the scene observed that the carburetor heat control was in the cold position.
Pilot Statement
The pilot reported that he "has never had to routinely use the carb heat on this aircraft." He also stated that he had descended from 4,500 feet at reduced power.
Engine Test
Later, the engine was operated on a test stand and started on the first attempt. For safety reasons due to an unsecured test stand, power output was limited to 1,800 RPM.
Meteorological Conditions
At the time of the accident, the air temperature was 58 degrees Fahrenheit and the dewpoint was 45 degrees Fahrenheit. According to carburetor icing charts, the probability of icing was high under those conditions.
Carburetor Heat Setting
The carburetor heat was found in the cold position, and the pilot indicated he did not routinely use carburetor heat on this aircraft.