Incident Overview
A retractable landing gear airplane was involved in an accident during landing at a destination airport. The pilot reported that while five nautical miles from the airport under dusk conditions, he extended the landing gear. Upon touchdown, the airplane began to shake. The pilot allowed the airplane to slow and then applied the brakes. Subsequently, the left main landing gear folded back into the fuselage, causing the airplane to skid down the runway, veer left, and collide with a runway exit sign.
The airplane sustained substantial damage to the empennage.
Post-Accident Examination
A mechanic who assisted in recovering the airplane provided a statement to the National Transportation Safety Board. After the accident, the airplane was lifted off the runway surface. The left main landing gear was placed in the down position, and the up-lock hook—which secures the gear in the down and locked position—"went into position with no problem." The mechanic then placed the airplane on jacks and cycled the landing gear through several cycles; during each cycle, the gear locked into position without issue.
Mechanical Findings
In the section of the NTSB Pilot/Operator Accident/Incident Report form titled "Mechanical Malfunction/Failure," the pilot reported that during post-accident repair, a broken gear tooth was found on the selector-main gear actuator (part No. 12810044).
According to the manufacturer, the landing gear could have been extended despite the broken gear actuator tooth. However, once the gear was extended, locked, and weight was applied, the only way for the gear to unseat from the landing gear pocket was through a positive action by the pilot.