This November 2007 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.
Aircraft: Cessna 210. Location: Santa Barbara, Calif. Injuries: None. Aircraft damage: Substantial.
What reportedly happened: Prior to landing the pilot confirmed that the landing gear was down and locked. During the landing roll the airplane began to veer left, followed by the left main landing gear collapsing. The airplane came to rest upright on the left side of the runway with its left elevator resting on the runway surface.
A post-accident examination revealed that the left main landing gear down limit switch plunger was bent and stuck in the closed position, falsely indicating that the left main landing gear was down and locked. The examination further revealed that the two hydraulic hoses to the downlock actuator were making contact with the airplane’s skin, binding the downlock from fully opening. The two hoses were subsequently repositioned to eliminate the binding, which resulted in the landing gear operating normally. It was not determined how the switch had become bent. The pilot reported no anomalies with the airplane prior to the flight.
Probable cause: The left main landing gear’s down limit switch plunger being bent and stuck in the closed position, which resulted in the collapse of the landing gear during the landing roll.
For more information: NTSB.gov