What happened
Following the landing of a Mitsubishi MU-2, the aircraft experienced a collapse of the nose landing gear. According to statements provided by the pilot, the structural failure occurred immediately after the aircraft had touched down on the runway.
Findings
An investigation into the nose landing gear trunnion revealed that the nose strut assembly was improperly configured. Specifically, the component installed on the right side of the trunnion was actually a left-sided strut. Because the design of these struts utilizes a shared base part number, they are only distinguished by a specific numerical suffix indicating the side for which they are intended. For a correct installation, these identifying numbers must be oriented toward the outboard side.
Maintenance records indicated that the nose gear had undergone recent service involving the strut prior to the accident. The investigation determined that the incorrect installation of the left-sided strut on the right side allowed the bearing to pull away from the trunnion pin, leading to the gear collapse. It was noted that the original manufacturer maintenance manual lacked instructions regarding the proper orientation of the part. While Service Bulletin No. 200B was later issued to clarify how to identify the correct side via the part number orientation, the error persisted during the recent maintenance activity.