Cessna 310 N7675Q accident near Kennesaw, Georgia

Probable cause

Inadequate inspection and rigging of the landing gear system, which resulted in the subsequent failure and collapse of the left main landing gear during landing.

NTSB analysis

The private pilot was landing the airplane after conducting a local flight. He reported that, during the landing roll, after a normal touchdown on the concrete runway, the left main landing gear (MLG) collapsed. The airplane then veered left off of the runway onto grass. The airplane sustained substantial damage to the left wing, left horizontal stabilizer, and the bottom fuselage near the tail section.

Examination of the airplane revealed that the left MLG down-lock bellcrank was fractured and had separated from its trunnion. The bellcrank bolt was sheared at the bolt head, consistent with overload. The upper end of the bellcrank remained attached to the outboard push-pull tube. The lower end of the bellcrank that attached to the rod end fitting at the lower side link was broken, consistent with a ductile tension failure. The fracture location was consistent with additional stress that would have been placed on the bellcrank if the landing gear had not been properly rigged. However, the damage to the landing gear precluded the ability to functionally check the gear or verify whether the landing gear system was properly rigged.

According to the airplane service manual, during each annual inspection, the landing gear's down-lock tension is to be checked. Review of the airplane's maintenance logbooks revealed that the last annual inspection was completed 1 year before the accident and that the airplane had been operated for 16 hours since that inspection. The maintenance logbook entries did not indicate that the landing gear system was checked during the inspection.

Text from the NTSB. Open the NTSB docket for ERA16LA073 for the full record.