What was found
(CAN) DURING CLIMB-OUT, SPARKS BEGAN TO ISSUE FROM EXHAUST PIPES AND HEAVY VIBRATIONS WERE FELT FROM THE NR 1 ENGINE. THE ENGINE WAS SHUTDOWN AND THE AIRCRAFT RETURNED TO ITS POINT OF DEPARTURE. POST-FLIGHT INSPECTION FOUND THE INLET SCREEN PUNCTURED FROM INSIDE OUT AND PIECES OF METAL IN THE COWLING. THE ENGINE WAS REMOVED AND SENT TO THE MANUFACTURER FOR INVESTIGATION.