Incident Overview
A pilot performed a precautionary landing at Indianapolis after experiencing a rough running engine. Following the landing, a mechanic attempted to diagnose and resolve the issue. The mechanic cleaned the spark plugs and added hydraulic fluid to the airplane. Subsequent engine run-ups could not reproduce the roughness.
Maintenance Attempt
Despite the mechanic's efforts, the engine's initial roughness could not be duplicated during ground testing. The airplane was deemed airworthy and cleared for departure. Shortly after takeoff, however, the engine again began to run rough, and the airplane was unable to maintain altitude.
Final Approach and Landing
The pilot elected to return to Indianapolis. During the landing attempt, the airplane contacted powerlines, trees, and a fence, ultimately touching down short of the runway.
Post-Accident Findings
Examination of the engine after the accident revealed two significant contamination issues: the fuel metering valve screen was almost completely blocked by foreign material, and the fuel distributor valve was nearly full of water.