What was found
(CAN) IN DESCENT TO LGW, FLIGHT CREW REPORTED, L/G NOSE WHEEL UNSAFE INDICATION. PERFORMED L/G GRAVITY EXTENT ION. NLG UPLOCK ASSY WAS REPLACED AND OPERATIONAL CHECK WAS CARRIED OUT SERVICEABLE. AS SAFETY PRECAUTION, BOTH NOSE LANDING GEAR DOOR SEQUENCE VALVE WERE REPLACED.