What was found
(CAN) DURING INSPECTION, A HOLE WAS FOUND ON THE ELBOW PORTION OF THE COMPRESSOR CROSSOVER DUCT. THIS DUCT WAS LOCATED ON THE FORWARD SIDE OF THE AIR CONDITIONING PACK. FOR RECTIFICATION, THE DUCT HAD BEEN REPLACED. IPC REFERENCE 21-51-66, FIGURE 25, ITEM 10, PN 820942-1, ACFT CYCLES: 4196. HRS: 6111:07.