Mooney M20C N7887V accident near Reno, Nevada

Probable cause

The in-flight separation of the exhaust tube at a weld joint due to erosion and corrosion, which resulted in a subsequent in-flight fire.

NTSB analysis

The airline transport pilot reported that, while on the downwind leg of the airport traffic pattern, he noticed smoke in the cockpit. The pilot-rated passenger then took control of the airplane and initiated a forced landing. As the pilot and his passenger exited the airplane, they observed flames originating from the lower cowling area near the air intake. Postaccident examination of the wreckage revealed that the tube from the turbocharger wastegate to the exhaust was separated into two pieces along a weld joint at the exhaust side of the tube. Corrosion and erosion were noted throughout the areas of the separated exhaust tubes, which included thinning of the wall thickness. In addition, a heavy amount of oil was observed in the area surrounding the tube. It is likely that when the tube failed at the weld joint, it allowed hot exhaust gases to escape from the exhaust and turbocharger that subsequently ignited an in-flight fire.

Text from the NTSB. Open the NTSB docket for WPR15LA180 for the full record.