What was found
IAH- DURING FLIGHT 3642, AT CRUISE ALTITUDE THE CREW NOTED A FLAP FAIL MESSAGE AND RETURNED TO IAH AND LANDED WITHOUT INCIDENT. MAINTENANCE REMOVED AND REPLACED THE FLAP ELECTRONIC CONTROL UNIT, PERFORMED A OPERATIONAL CHECK OF THE FLAP SYSTEM AND NO DEFECTS NOTED. PERFORMED A TEST FLIGHT, WHICH WAS SATISFACTORY. THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.