Event Description
During the landing rollout, the right main landing gear of an aircraft collapsed. The pilot had reported three green lights on approach, indicating that the landing gear was down and locked. However, after touchdown, the right main gear failed, causing the aircraft to slide off the runway into the grass.
Examination
A post-incident examination of the right main landing gear revealed that the bellcrank assembly had failed due to binding. The binding was caused by a lack of lubrication of the down lock brace.
Maintenance History
The pilot had previously taken the aircraft to maintenance for corrective action when the right landing gear light did not function on the previous flight. The aircraft was checked and found to be OK, after which it was released for flight.