MD-11
Flight Crew Air Transport Pilot (ATP)
Confusion
Aircraft Equipment Problem Less Severe
Aircraft Aircraft Damaged; General Maintenance Action
Aircraft
After shutdown checklist and all debriefs complete; and getting ready to disembark aircraft; RFO mentioned that the aircraft had some damage. I was flabbergasted because I was unaware of any errors or actions we would have done to cause any damage!  As soon as I stepped over to the door and the top of the stairs; it was obvious that part of the right inboard slat had been damaged. It appeared that the outer edge (which is a shiny metallic verses dull aluminum) had been torn back and was missing rivets. Maintenance notified us of the damage after we blocked in; and we have no idea how it occurred. Obviously there was a problem when the slats were retracted; something caught and caused the metal to be bent up and away from the wing; tearing the rivets out. As a crew; we were unaware of any damage during the flight until after we had blocked in. I asked maintenance if they wanted me to write it up; but they said they would do it since it was damage noted on the post flight inspection. Upon arriving at the hotel I called the Dispatch to inform them about aircraft damage per FOM. I verified they did write it up by checking the aircraft maintenance history.I was unaware of any damage to the aircraft until we blocked in. It could have occurred on slats retract on departure or possibly on the after landing checklist. There were no alerts in the aircraft; nor did there seem to be any adverse performance affects over the 9+ hour flight.
Upon further inspection; it appears the moveable slat edge cover had bound up on the fixed slat cover and partially tore the fixed slat cover plate off the wing during the retraction process. No flight issues were noted that would have caused this damage. This damage was not done prior to departure. No odd flight characteristics were recognized by the flight crew.
After gate arrival; Maintenance notified the crew that the left wing inboard slat movable edge cover bound on the fixed slat cover and partially tore the fixed slat cover plate off.