Accident Sequence
During the landing rollout, the left main landing gear collapsed, and the aircraft skidded to a stop.
Examination of Failed Components
Examination of the landing gear revealed that the barrel lugs, which attach the swinging lever to the main landing gear barrel, had failed. The fracture of the outboard lower lug exhibited clam shell marks typical of a fatigue crack. The fatigue crack originated from a corrosion pit in the bore of the lug.
Maintenance Findings
Further investigation identified that the four bushings for the lower lugs of the barrel, which were replaced during overhaul, did not have the proper interference fit. Additionally, the bushings lacked the proper application of corrosion preventative on their surfaces. Primer paint had not been applied during overhaul; instead, Mastinox was used in place of the wet primer specified by the manufacturer's procedures.
Inspection of Other Landing Gears
During the investigation, nine landing gears with various numbers of total cycles since overhaul or manufacture were inspected. The inspections revealed torn or missing rubber sealant on bushing flanges, corrosion in the lug bores, and corrosion on the lug faces.