B757-200 FLT CREW WAS ADVISED THAT COMPOSITE MATERIAL ON INBOARD WING SLAT WAS DELAMINATING. DELAMINATED AREA SEPARATED FROM ACFT JUST PRIOR TO LNDG AT DIVERSION STATION.

Narrative

AT TOP OF CLB; THE PURSER CALLED TO SAY THAT THEY HAD HEARD AN UNUSUAL NOISE AND BUZZING COMING FROM THE OVERWING EXIT. I HAD NOT HEARD ANYTHING AND HAD NO UNUSUAL INDICATIONS; SO ASKED HER TO KEEP ME INFORMED. APPROX 20 MINS LATER WE RECEIVED A CALL FROM THE BACK SAYING THAT A FLT ATTENDANT RIDING IN THE EXIT ROW WANTED TO SEND US A NOTE. THE NOTE SAID; 'THERE IS A PIECE OF WING PEELING OFF. IT'S ABOUT 1 1/2 FT LONG AND 1 INCH THICK. MORE SKIN IS LOOSE (ANOTHER 1 FT LONG).' WE ASKED HER TO COME TO THE COCKPIT WHERE SHE GAVE US A MORE DETAILED DESCRIPTION OF WHAT SHE OBSERVED. I THEN ASKED THE FO TO GO TAKE A LOOK. HE CAME BACK WITH THE SAME DESCRIPTION. WE DISCUSSED IT AND THE PRUDENT DECISION WOULD BE TO DIVERT TO THE NEAREST ARPT. WE NOTIFIED DISPATCH AND DIVERTED TO ATL. ON THE APCH INTO ATL; THE PURSER CALLED AND SAID THAT A PIECE HAD FALLEN OFF. THE APCH AND LNDG WERE UNEVENTFUL. WE FLEW THIS ACFT INTO RSW FROM ORD THE NIGHT BEFORE AND THERE WAS NOTHING UNUSUAL NOTED WITH THE AIRPLANE. THE FO SAID THAT THE PREFLT WALKAROUND WAS NORMAL. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR ADVISED THE MATERIAL WAS DELAMINATING FROM AN INBOARD SLAT.