What was found
IAH - FLIGHT 555, THE CREW REPORTED A LANDING GEAR AIR GROUND FAIL MESSAGE. THE AIRCRAFT RETURNED TO IAH WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED THE AIRCRAFT, REMOVED AND REPLACED THE NOSE LANDING GEAR WOW PROXIMITY SWITCH. OPERATIONALLY TESTED WITH NO DEFECTS, AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE. (A)