Aircraft: Mooney M20J. Injuries: None. Location: Romeoville, Illinois. Aircraft damage: Substantial.
What reportedly happened: The airplane was touching down when the left main landing gear collapsed. It subsequently veered to the left and hit a runway edge identifier light.
A post-accident examination confirmed that the left main landing gear had partially collapsed into its wheel well. The nose and right main landing gear remained fully extended.
Damage sustained to the push-pull tubes that extend and retract the main landing gear precluded the determination of why the left landing gear collapsed. However, the observed damage to the push-pull tubes was likely attributable to the collapse of the left landing gear during the accident.
With the exception of the damaged push-pull tubes, there were no additional mechanical or rigging anomalies found with the landing gear extension/retraction system. Additionally, the landing gear position warning horn, instrument panel indicator lights, and floor-mounted visual/mechanical indicator functioned as designed, providing proper indication that the landing gear was in the fully extended position before landing.
Probable cause: The collapse of the left main landing gear during the landing roll for undetermined reasons.
This February 2011 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
