What was found
ON APPROACH TO KTEB, FLAPS SELECTED FROM 0* TO 15*, FLAPS FAILED TO EXTEND. CREW FOLLOWED CHECKLIST. EMERGENCY WAS DECLARED, DIVERTED TO SWF AND 0* FLAP LANDING PERFORMED. LANDING WAS UNEVENTFUL. MAINTENANCE CLEANED THE FLAP CONTROL HANDLE OPTICAL SENSORS. GROUND OPERATIONAL CHECKS PERFORMED WITH NO DEFECTS NOTED. A SUCCESSFUL OPERATIONAL CHECK FLIGHT WAS PERFORMED. AIRCRAFT WAS RETURNED TO SERVICE.