The private pilot was landing his Cessna 310 at the airport in Kennesaw, Georgia, 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 one 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.
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 Identification: ERA16LA073
This December 2015 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.
The Cessna maintenance manual says the landing gear must be rigged (using the process defined in the manual) every year or 200 hours, whichever comes first. It’s a 6 to 8 hour process start-to-finish so many shops resist doing it and just swing the gear. It is the owners responsibility to make sure the rigging is accomplished. Every 310 owner should be aware of this. It is common knowledge in the owners community. If a 310 owner is unaware of this, he/she has not done their homework.