What was found
BROKEN WIRE IN NLG DOWNLOCK SWITCH AT SPLICE WHERE NG SWITCH IS SPLICED IN (IN ENG COMP) CAUSED PUMP TO STOP TOO SOON; NOSE GEAR WOULD NOT LOCK DOWN, AIRCRAFT LANDED WITH NG NOT LOCKED, COLLAPSED. SUBMITTER RECOMMENDS VINYL TUBING AROUND SPLICES BE CHANGED PERIODICALLY SO IT DOES NOT GET STIFF. ALSO, SPLICES CAN BE CHECKED FOR CONDITION.