What happened
While performing a stabilized approach and touchdown, the aircraft experienced a failure of the right main landing gear. Despite the mechanical failure, the crew maintained control of the aircraft, which eventually came to a halt on the runway. The aircraft ended the sequence resting on its right wing.
Emergency responders from the DFW Fire Department reached the scene within 35 seconds. After the Captain communicated with the Incident Commander, the decision was made that an emergency evacuation of the passengers and crew was not required. A review of the aircraft's maintenance history showed no previous irregularities or issues.
Findings
Investigation into the wreckage determined that the outer cylinder of the right main landing gear had fractured. This breakage caused the lower part of the gear, including the wheel assembly, to detach from the airframe.
Technical analysis of the cylinder identified that a forging fold had been created during the initial manual stage of the component's manufacturing process. This defect acted as a starting point for a fatigue crack. While the growth of this crack was initially slowed by crack blunting, the stresses from subsequent landings caused the crack to expand. The landing gear ultimately failed once the fatigue crack reached a critical length.