What was found
ON CLIMBOUT, CABIN PRESSURE CLIMBED AT 1000 FT/MIN AT 26,000 FT: CABIN AT 8000 FT AND CLIMBING AT 600 FT/MIN. ACCOMPLISHED EMERGENCY DESCENT TO 10,000 FT. MAXIMUM CABIN PRESSURE REACHED WAS 12,000 FT. THERE WAS A LOUD AIR LEAK SOUND IN CABIN. OXYGEN MASKS DID NOT DEPLOY. FOUND OUTBOARD BELLOWS DUCT FOR RIGHT PACK TORN AND CLAMP MISSING. REPLACED DAMAGED DUCT AND PRESSURIZED AIRCRAFT TO 7.9 PSI DIFFERENTIAL WITH EACH PACK INDIVIDUALLY. SYSTEM TESTED NORMAL. AIRCRAFT RETURNED TO SERVICE.