What happened
Following the deployment of parachutists from the aircraft, the pilot returned to the airfield and observed that the left main landing gear lacked a green down-and-locked indication. In response to this indication, the pilot performed emergency protocols and conducted two fly-bys of the runway to assess the situation. While ground staff noted that the landing gear appeared to be properly extended and locked, the aircraft experienced a lateral slide during the landing roll. During this sliding motion, the right main landing gear collapsed and eventually detached from the airframe. The left main gear subsequently collapsed as the aircraft slid to a halt.
Findings
An inspection of the wreckage revealed that the upper torque knee on the left main landing gear had sustained a break. The specific mechanism or mode that led to the failure of this upper torque knee remained undetermined.