Incident Overview
The pilot reported that before landing, all landing gear indicators showed the gear were down and locked. However, during the landing roll-out, as the nosewheel was lowered to the runway, the left main gear collapsed. This resulted in damage to the left wing, left propeller, and left elevator.
Post-Incident Examination
Following the incident, the landing gear extension and retraction mechanism was tested and found to operate normally. However, examination of the left landing gear side brace link revealed it was improperly adjusted. According to the aircraft maintenance manual, the side brace link should require 50 pounds of force to move it out of the locked position. In this case, the link could be moved with light finger pressure, estimated to be less than 5 pounds.
Conclusion
The malfunction of the left main gear was attributed to the improper adjustment of the side brace link, which failed to maintain the gear in the locked position during landing.