What happened
While performing taxi operations in preparation for takeoff, the right main landing gear of the aircraft collapsed.
The investigation
An examination of the landing gear assembly identified that the barrel lugs, which are used to attach the swinging lever to the main landing gear barrel, had failed. Specifically, the fracture of the outboard lower lug showed a fatigue crack that originated from corrosion pits located within the bore of the lug.
Further inspection revealed that the bushings for the lower lugs, which had been replaced during a previous overhaul, lacked the proper interference fit. Additionally, it was determined that during the overhaul process, the required application of corrosion preventatives to the bushing surfaces—as mandated by the manufacturer's procedures—was not performed correctly.
As part of the broader investigation, nine different landing gears with varying numbers of total cycles since their manufacture or most recent overhaul were inspected. These inspections identified several recurring issues, including:
- Corrosion present on the lug faces
- Corrosion within the lug bores
- Torn or missing rubber sealant on the bushing flanges