Eclipse Aviation Corp EA500 N508JA accident near Sacramento, California

Probable cause

A manufacturing defect that resulted in fatigue failure of the left main landing gear trunnion.

NTSB analysis

According to the airline transport pilot and the commercial pilot, the airplane was taxiing to the runway when they heard a loud bang and the airplane veered to the left. The pilots contacted the tower controller, who informed them that the airplane was leaking a large amount of fuel onto the tarmac. The pilots shut down the airplane and evacuated the passengers. Further examination of the airplane revealed that the left main landing gear trunnion had punctured the left wing.

Postaccident examination revealed that the left main landing gear assembly had fractured due to a fatigue crack that emanated from a sharp corner of a machined feature on the inner surface of the trunnion. The deep machining gouge mark was likely the result of an error in cleaning operation during manufacture; the cleaning tool could have extended deeper into the tapered inner surface than intended and created the deep machine gouge mark. The fatigue crack initiated on the inside of the tube and grew to a crucial size without reaching the outer wall of the tube. As a result, the crack would not have been visible during a visual inspection.

The manufacturer reported that, following the accident, they identified a systemic manufacturing defect that potentially affected the entire fleet. A mandatory service bulletin was issued to address the problem, as well as the initiation of a fleet-wide inspection and landing gear trunnion repair/replacement program.

Text from the NTSB. Open the NTSB docket for WPR15LA184 for the full record.