NTSB Identification: CHI97IA031.
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Incident occurred Wednesday, November 20, 1996 in COVINGTON, KY
Probable Cause Approval Date: 12/15/1997
Aircraft: ATR 42, registration: N47AE
Injuries: 44 Uninjured.

NTSB investigators used data provided by various sources and may not have traveled in support of this investigation to prepare this aircraft incident report.

While taxiing for takeoff, the right main landing gear collapsed. Examination of the landing gear revealed that the barrel lugs (used to attach the swinging lever to the main landing gear barrel) had failed. The fracture of the outboard lower lug exhibited a fatigue crack emanating from corrosion pits in the bore of the lug. The bushings for the lower lugs (replaced during overhaul) did not have the proper interference fit. During overhaul, the bushings did not have the proper applications of corrosion preventatives applied to the surface of the bushings as specified by the manufacturer's procedures. During the course of 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 used on bushing flanges, corrosion in the lug bores, and corrosion on the lug faces.

The National Transportation Safety Board determines the probable cause(s) of this incident to be:

improper use of procedures by maintenance personnel at an overhaul facility during overhaul of the landing gear, allowing corrosion to occur on the barrel lugs of the landing gear, which subsequently led to fatigue cracking of the lugs and eventual collapse of the gear.

Full narrative available

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