What was found
DURING APPROACH INTO ABY, THE NOSE GEAR FAILED TO EXTEND. THE CAPTAIN ABORTED THE INITIAL APPROACH. WHILE IN A HOLDING PATTERN, APPROXIMATELY 5 MINUTES AFTER BEING SELECTED DOWN, THE GEAR EXTENDED ON ITS OWN. EVEN WITH THE GEAR SAFE INDICATIONS, A VIBRATIONS WAS STILL FELT COMING FROM THE NOSE AREA. AN EMERGENCY WAS DECLARED AND AN UNEVENTFUL LANDING WAS MADE IN ABY. MAINTENANCE REMOVED AND REPLACED THE NOSE LANDING GEAR NR 2 DOWNLOCK PROXIMITY SENSOR. THE AIRCRAFT WAS JACKED, AND THE GEAR WAS SWUNG SEVERAL TIMES. SYSTEM OPERATIONAL CHECKS GOOD. NO DEFECTS WERE NOTED. AIRCRAFT RETURNED TO SERVICE. (M)