During the landing roll the left landing gear leg fractured, which caused the wheel assembly to detach from the leg. Examination of the failure revealed that the lower area of the composite leg had weakened over a period of time, due to the brake calliper abrading the paint and outer layer of the glass fabric reinforced composite material. This caused cracks to develop and propagate in the cotton flock filled composite material in the area of the metal flange plate, as a result of lateral flexing of the leg. This abrading and cracking of the composite material allowed contaminants into the plywood core and, over time, caused the plywood to swell. This swelling caused further cracking of the composite material, weakening the lower leg in the area of the wheel attachment, which resulted in a lateral failure.
Published 10 December 2014