What was found
ON APPROACH, GEAR EXTENDED, LT MAIN GREEN LIGHT FAILED TO ILLUMINATE: EMERGENCY GEAR EXTENSION USED TO LOCK GEAR. DURING INSPECTION, FOUND INTERIOR OF DOWNLOCK SHELL LEFT SIDE PEELED BACK INTERFERRING WITH MAIN LEG FULL TRAVEL, THEREFORE, PREVENTING OVERCENTER LOCKS FROM BEING ENGAGED. SUSPECT CAUSE IS RUBBER COMPOSITE INSERT BEING OLD AND BRITTLE WHICH CREATED DELAMINATION.