What was found
EXPERIENCED RAPID DECOMPRESSION AT FL310, COMMENCED EMERGENCY DESCENT, WERE UNABLE TO REGAIN CONTROL OF PRESSURIZATION IN MANUAL MODE, DROPPED ALL PASSENGER OXYGEN MASKS. DEPLETED OXYGEN SUPPLY, CABIN ALTITUDE RWP. REMOVED AND REPLACED OUTFLOW VALVE. SHOP FINDINGS, FAULT NOT CONFIRMED BUT FAILED VISUAL, REJECTED FOR OVERSPRAY, CONTAMINATED DIAPHRAGM. REPLACED RETAINER, VALVE ASSEMBLY, DIAPHRAGM ASSY, FILTER AND GASKET. (M)