Narrative:

Level FL330 started losing left pack. After checklists started; slow descent to low 20's; then lost right pack. Declared emergency and started emergency descent procedure. Due to WX; diverted. Outcome very successful. Cabin never was above 10300 ft.callback conversation with reporter revealed the following information: reporter stated that he later reviewed that aircraft's maintenance log but detailed repair descriptions were not included. Reporter stated that the event began with a flight attendant calling the flight station to report extremely high aft cabin temperature but normal forward cabin. The pilots completed the QRH pack reset procedure. After selecting cooler on the right pack the pilots noted a lower rt pack pressure followed shortly thereafter by a low flow. A descent was then begun and at about FL270 the left pack failed. The flight had been at cruise altitude for approximately 2.5 - 3 hours and had had wing anti-ice on and were cycling through the tail de-ice. After the second pack failure the crew did an emergency descent; attempting to prevent the cabin oxygen masks from dropping. The reporter suspects either a dual bleed valve problem or a major duct leak had developed.

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Original NASA ASRS Text

Title: A PACK FAILED ON AN MD80 AT FL330. DURING DESCENT THROUGH FL200 A SECOND PACK FAILED. AN EMERGENCY WAS DECLARED WITH A DIVERSION TO A NEARBY ARPT.

Narrative: LEVEL FL330 STARTED LOSING LEFT PACK. AFTER CHKLISTS STARTED; SLOW DESCENT TO LOW 20'S; THEN LOST RIGHT PACK. DECLARED EMER AND STARTED EMER DESCENT PROC. DUE TO WX; DIVERTED. OUTCOME VERY SUCCESSFUL. CABIN NEVER WAS ABOVE 10300 FT.CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: REPORTER STATED THAT HE LATER REVIEWED THAT ACFT'S MAINT LOG BUT DETAILED REPAIR DESCRIPTIONS WERE NOT INCLUDED. REPORTER STATED THAT THE EVENT BEGAN WITH A FLT ATTENDANT CALLING THE FLT STATION TO REPORT EXTREMELY HIGH AFT CABIN TEMPERATURE BUT NORMAL FORWARD CABIN. THE PILOTS COMPLETED THE QRH PACK RESET PROCEDURE. AFTER SELECTING COOLER ON THE RIGHT PACK THE PILOTS NOTED A LOWER RT PACK PRESSURE FOLLOWED SHORTLY THEREAFTER BY A LOW FLOW. A DESCENT WAS THEN BEGUN AND AT ABOUT FL270 THE L PACK FAILED. THE FLT HAD BEEN AT CRUISE ALT FOR APPROXIMATELY 2.5 - 3 HOURS AND HAD HAD WING ANTI-ICE ON AND WERE CYCLING THROUGH THE TAIL DE-ICE. AFTER THE SECOND PACK FAILURE THE CREW DID AN EMERGENCY DESCENT; ATTEMPTING TO PREVENT THE CABIN OXYGEN MASKS FROM DROPPING. THE REPORTER SUSPECTS EITHER A DUAL BLEED VALVE PROBLEM OR A MAJOR DUCT LEAK HAD DEVELOPED.

Data retrieved from NASA's ASRS site as of January 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.