What was found
DURING CRUISE AT FL330, THE AIRCRAFT LOST CABIN AUTO PRESSURIZATION AND CREW COULD NOT MAINTAIN IT IN MANUAL EITHER. FLIGHT PERFORMED AN EMERGENCY DESCENT TO 10,000 FEET AND DIVERTED TO A NORMAL SAFE LANDING AT ATL. CABIN ALTITUDE MADE IT TO 12,000 FT DURING DESCENT. MAINTENANCE DISCOVERED A LOOSE COUPLING AT THE AFT END OF THE LEFT WATER SEPARATOR. THE COUPLING WAS RESECURED, THE VESSEL WAS LEAK CHECKED, AND NO PROBLEMS WERE FOUND. THE AIRCRAFT HAS RETURNED TO SERVICE.