Amateur-built GLASAIR (SH2F) N67WH accident near Maynardville, Tennessee

Probable cause

The in-flight failure of the No. 3 cylinder connecting rod for reasons that could not be determined during postaccident examination.

NTSB analysis

While the airplane was climbing to 7,500 ft mean sea level, the private pilot noted that the engine oil temperature was getting high, so he leveled off for a few minutes to cool down the engine before resuming the climb. When the airplane was passing through 6,000 ft, the engine shuddered and lost all power; smoke started filling the cockpit. The pilot declared an emergency, shut down the engine, and selected an uncongested two-lane highway for landing. During his final approach, after maneuvering to avoid power lines, he pulled back to flare the airplane, but the airplane "pancaked" onto the road, which resulted in substantial damage to the fuselage. Postaccident examination of the engine revealed that the No. 3 cylinder connecting rod had separated from the piston near the wrist pin. The investigation could not determine the reason for the separation.

Text from the NTSB. Open the NTSB docket for ERA16LA272 for the full record.