Aero Commander 112 N1181J accident near Granbury, Texas

Probable cause

The loss of engine power due to metal contamination within the cylinder following poor maintenance.

NTSB analysis

The pilot stated that he performed a new engine run-up on the day of the accident. He stated that after he conducted a preflight inspection of the airplane, he taxied and performed multiple engine run-ups. He then shut down the engine and added fuel. The pilot started the engine and performed multiple engine run-ups both before and after taxiing to the runway with no engine anomalies noted. After takeoff, the engine sustained a loss of power while climbing through about 100 ft above ground level. The pilot performed a forced landing to a road, during which the airplane sustained substantial damage to the fuselage.

Postaccident examination of the airplane revealed one of the airbox’s three aluminum spacers was missing. Pieces of the spacer were found in cylinder Nos. 1 and 2 with additional material within the No 1 spark plug lead. The cylinders exhibited pitting damage from the spacer. It is likely that the metallic pieces within the engine cylinder shorted the engine ignition, thus reducing and/or ceasing engine power production on those cylinders. An examination of the remaining engine and systems revealed no anomalies that would have precluded normal operations.

The accident occurred on the first flight following an annual inspection and engine installation following a propeller strike inspection. Investigators were not able to determine how the spacer was introduced to the cylinder.

Text from the NTSB. Open the NTSB docket for CEN22LA322 for the full record.