Incident
During landing, the right main landing gear shock strut cylinder and piston failed. This failure caused the axle, wheels, and tires to separate from the aircraft.
Investigation
Metallurgical examination of the failed components showed that the fracture surfaces had been damaged after separation. On the cylinder fracture face, two areas were present that were not at an angle suggestive of overstress separation. Ratchet marks were also observed on the cylinder fracture face, which typically indicate initiation sites on offset fracture planes. The piston fracture surfaces exhibited features characteristic of overstress separation.
Previous Maintenance
The right main landing gear torque links had failed during a landing 312 flight hours before this accident. At that time, the torque links, shimmy damper, and piston were replaced. The cylinder was not replaced.