What happened
The incident occurred when the left main landing gear assembly collapsed during the landing phase of flight. Prior to this event, the gear had exhibited a wobbling motion while the aircraft was taxiing at Anchorage. During that taxi, both the pilot and a baggage handler visually inspected the landing gear and reported finding no abnormalities or issues with the assembly.
Following the inspection, the pilot contacted company maintenance regarding the observed shimmy. The general manager of the company responded by stating that the organization was already aware of the shimmy problem but believed it to be caused only by worn bushings. Management instructed the pilot to proceed with the flight despite the known deficiency. The pilot accepted the aircraft for operation and did not formally enter the discrepancy into the logbooks until after the incident had occurred.
The investigation
Mechanical examination revealed that although records did not indicate a landing gear change, an incorrect part had been installed in violation of the parts manual specifications. Maintenance personnel stated they had inspected the component but found no problem, despite being aware of the shimmy issue and attributing it to worn bushings. Additionally, the aircraft was released for flight by an uncertificated assistant to the director of maintenance without a qualified mechanic performing the required inspection.
Findings
Contributing factors included the installation of the wrong part as outlined in the parts manual and the release of the airplane by personnel lacking proper certification. The pilot-in-command accepted the aircraft with a known deficiency and failed to document the issue prior to flight. Company management's assessment that the shimmy was only due to worn bushings proved incorrect, leading to the structural failure of the landing gear under load.