What was found
AIRCRAFT RETURNED OF FLIGHT AS A CONSEQUENCE OF STRONG VIBRATION ON NOSE LANDING GEAR. DURING CHECK, IT WAS DETECTED THAT THE NOSE LANDING GEAR RIGHT DOOR WAS OPEN. DOOR MECHANISM WAS LUBRICATED AND BRAKES WERE COOLED. OPERATIONAL CHECK WAS PERFORMED TO DOOR MECHANISM BEING CORRECT IN ACCORDANCE WITH MM 32-20-00. DURING TRANSIT CHECK AT MEX, NOSE LANDING GEAR DOORS WERE CHECKED DETECTING THAT THE FASTENER DID NOT OPERATE CORRECTLY, IT WAS REPLACED AND ACTUATOR WAS ADJUSTED IN ACCORDANCE WITH MM 32-22-01, TESTS CORRECT.