A B757-200 FLT CREW ON CLB OUT DECLARED AN EMER AND DIVERTED DUE TO R WING LEADING EDGE INBOARD SLAT #6 VIBRATING AND SHEDDING FRAGMENTS.

Narrative

DURING CLB-OUT; PURSER ADVISED PIECES ON R WING WERE VIBRATING AND SHREDDING OFF. I DIRECTED THE FO AS THE PF TO ENGAGE THE AUTOPLT AND GO BACK TO THE CABIN TO PERSONALLY OBSERVE THE RPTED DAMAGE. HE OBSERVED DAMAGE TO THE LEADING EDGE SLAT ON THE R WING; INBOARD OF THE ENG. THE AFT PORTION WAS VIBRATING STRONGLY. DECLARED EMER; RETURNED TO ZZZ; AND CONFERRED WITH DISPATCH AND MX; WHO ADVISED A NORMAL FLAP LNDG. DUE TO OUR OVERWT CONDITION; IE; 210K LBS; WE LANDED WITH FLAPS 25 DUE TO GUSTING WINDS. LNDG UNEVENTFUL WITH AUTOBRAKES 2. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE #6 SLAT IS LOCATED ON THE R WING INBOARD OF THE ENG AND THE LEADING EDGE AND UPPER SURFACE IS CONSTRUCTED OF KEVLAR OR CARBON FIBER COMPOSITES. THE RPTR SAID THE LEADING EDGE MUST HAVE DEVELOPED A CRACK AND STARTED TO DELAMINATE AND TEAR OFF THE UPPER SURFACE OF THE LEADING G EDGE. THE RPTR STATED ON THE GND A PIECE OF COMPOSITE FOUR FT LONG RUNNING ALONG THE UPPER LEADING EDGE OF THE SLAT AND FROM THREE INCHES AFT OF THE LEADING EDGE WAS FOUND MISSING. THE RPTR SAID WHILE THE COMPOSITE WAS OBSERVED VIBRATING STRONGLY NO VIBRATIONS WERE FELT IN THE COCKPIT.