On November 30, 2000, a Mooney M20C (registration N942TB) was involved in an aviation accident near Hazard, KY. Investigators recorded the probable cause as: The incorrect routing of the cabin air scat tubing by an unknown person, which resulted in a carbon monoxide leak into the cabin, and subsequent pilot incapacitation. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A pilot became incapacitated during cruise due to carbon monoxide. A passenger flew the aircraft and woke the pilot, who landed safely. Investigation found a hole in cabin air scat tubing caused by misrouting near an exhaust joint.
Incident Overview
During cruise flight, the pilot became incapacitated. A pilot-rated passenger took control of the airplane and flew toward an airport, where they successfully woke the pilot. The pilot landed the aircraft without further incident.
Medical Findings
After landing, the pilot was found to have toxic levels of carbon monoxide in their system.
Aircraft Examination
A post-flight examination of the airplane revealed a hole in the cabin air scat tubing. The hole was located near the joint connecting the number one cylinder to the exhaust manifold, where a visible gap was observed. Further inspection determined that at some point in the airplane's history, the scat tubing had been misrouted.
Conclusion
The investigation identified the hole in the scat tubing and the misrouting as relevant findings. No further details were provided.