Engine failure and forced landing involving Lycoming engine components

Casualties unknown • Guntersville, AL, US

An aircraft experienced an engine power loss during cruise flight, leading to a forced landing attempt that resulted in a collision with a tree and subsequent fire.

What happened

During the cruise phase of flight, the aircraft experienced a loss of engine power. In response, the pilot declared an emergency and initiated maneuvers to perform a forced landing in a nearby field. During the approach to the intended landing area, the aircraft struck a tree, causing it to fall to the ground and burst into flames.

The investigation

An examination of the engine revealed that no measurable quantity of oil remained in the sump, with only dark black residual oil present. Investigators discovered that the crankcase had been breached, noting large holes located above the #2 and #6 cylinders.

Further inspection of the internal valve train components showed widespread spalling of the tappet bodies. The camshaft also exhibited severe wear, specifically affecting four of the nine cam lobes. Additionally, the crankshaft main bearings contained dirt and metal particles that had contaminated the oil supply.

Probable cause

The engine failure was caused by metal particle contamination in the oil supply, resulting from severe wear and spalling of the camshaft lobes and tappet bodies.

Frequently asked questions

What happened in the 2004-10-21 Piper PA-32RT-300T accident near Guntersville, AL?

An aircraft experienced an engine power loss during cruise flight, leading to a forced landing attempt that resulted in a collision with a tree and subsequent fire.

What aircraft was involved and where did it happen?

The accident on 2004-10-21 involved a Piper PA-32RT-300T, registration N19TL, operated by Robert Thomas Webb, at Guntersville, AL.

What was the probable cause of the accident?

The engine failure was caused by metal particle contamination in the oil supply, resulting from severe wear and spalling of the camshaft lobes and tappet bodies.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20041101X01729. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.

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