What was found
DURING CRUISE,UNABLE TO MAINTAIN CABIN ALTITUDE AT FLIGHT LEVEL 310, DIVERTED TO MSP. LANDED AIRCRAFT AT 169000 LBS, LANDING WAS UNEVENTFUL. FOUND BLOWN DUCT ON RIGHT PACK FROM FORWARD HEAT EXCHANGER TO COMPRESSOR DISCHARGE PORT OF ACM. REMOVED AND REPLACED RIGHT 35 DEGREE VALVE AND RIGHT COALESCER BAG PRECAUTIONARY. REMOVED AND REPLACED DUCT ASSEMBLY OP CHECKS AND LEAK CHECKS GOOD. ACCOMPLISHED OVERWEIGHT LANDING INSPECTION, NO DAMAGE FOUND. AIRCRAFT WAS RETURNED TO SERVICE. (M)