What was found
LEFT PACK COMPARTMENT DOOR DEPARTED AIRCRAFT IN FLIGHT. AIRCRAFT RETURNED TO IAD. *S/D* LEFTHAND PACK DOOR WAS FOUND MISSING. IT APPEARED THAT AS PORTIONS OF THE DOOR BROKE LOOSE, THEY HIT THE PARTS INSIDE LEFTHAND PACK BAY LEAVING PUNCTURES AND DENTS ON SEVERAL COMPONENTS (CONDENSER/REHEATER, FAN AIR DIFFUSER HOUSING, AND OTHER DUCTING). PARTS REPLACED INCLUDE: ALL DAMAGED PARTS IN LT PACK BAY, LT PACK BAY DOOR (P/N 149W2300-1), AND FITTINGS (P/N 145W2401-3 & 145W2403-3). INCIDENT IS UNDER INVESTIGATION.