What was found
IND-CLT - FLT 1163 - DURING CRUISE, AT 37,000 FT, THE PRESSURIZATION FLOW LIGHT ILLUMINATED, AND THE CABIN ALTITUDE WAS RISING. INCREASING ENGINE POWER DID NOT HELP CONDITION. DESCENDED TO 25,000 FT BUT THE CABIN CONTINUED TO CLIMB AND COULD NOT BE CONTROLLED IN AUTO OR MANUAL. AN EMERGENCY WAS DECLARED AND THE AIRCRAFT MADE AN EMERGENCY DESCENT TO 10,000 FT. MAINTENANCE REINSTALLED CABIN SUPPLY AIR DUCT AT THE RIGHT ACM. (M)