What happened
During the landing phase of the flight, the aircraft experienced a significant impact upon touchdown. The descent rate was not properly managed by the first officer, which resulted in a heavy landing. As the aircraft continued its rollout on the runway, the left main landing gear assembly separated from the airframe.
During the incident, the pilot-in-command noted that he anticipated a poor landing would occur. While the pilot-in-command did instruct the first officer to increase engine power at the start of the maneuver, no further corrective actions were taken to mitigate the impact of the descent.
Findings
An inspection of the left main landing gear assembly following the separation revealed that a crack was already present in the outer cylinder housing. This preexisting crack in the structural component was identified during the examination of the failed assembly.