What happened
While cruising at 7,500 feet MSL, the pilot reported a gradual loss of engine power. The pilot established radio and radar contact with Florence Approach Control to advise the controller of the engine problem. Following the report, the pilot was provided radar vectors toward Darlington County Airport, which was identified as the nearest suitable airport.
A second aircraft flying in the same flight suggested several remedies for the power loss. One suggestion was for the pilot to check the magnetos. The pilot reported that the engine operated smoothly on one magneto but nearly failed when switched to the other. Shortly thereafter, the pilot reported a complete loss of engine power.
The aircraft subsequently disappeared from radar and crashed 3 miles short of Darlington County Airport. The impact forces and a post-crash fire resulted in the destruction of the airplane. The second aircraft in the flight landed at the airport without incident, though the pilot noted a layer of fog present at the field.
Findings
The investigation into the engine performance revealed that while the engine functioned on one magneto, it failed to maintain power when the pilot switched to the alternative magneto.