Narrative:

During taxi out, informed by flight attendant that cabin was getting warm. I selected full cold in automatic mode on both packs. Both air mix valves showed full cold and duct temperature approximately 80 degrees F. Outside air temperature was 88 degrees F and full (119) passenger. We started left engine to help cool down the cabin. During climb out (approximately 3000 ft MSL) flight attendant informed us the cabin was getting extremely hot. I selected full manual cold on both temperature selectors. Passing 6000 ft noticed warm air exiting gasper fan, and duct temperature showed 120 degrees F with both air mix valves showing full cold. We checked circuit breakers and the flight operations manual. Breakers checked good and flight operations manual had no guidance for this situation. Approximately 20 mi north of mco informed ZJX of our return to mco. ACARS message sent to flight control, mco maintenance notified, flight attendants notified and a PA was made to the passenger. During descent with power in idle, duct temperature showed 75 degrees F and cabin temperature showed 90 degrees F. Both air mix valves still showed full cold. Maintenance found the 35 degree controller and sensor had failed on the right pack and the left pack air cycle machine was seized. This was the reason we could not control the cabin temperature. The captain discussed the situation with maintenance, the dispatcher and the duty pilot. The left pack was placarded inoperative and the right air conditioning system was repaired and thoroughly operations checked. The aircraft was redispatched to rdu with the left air conditioning system inoperative. Gasper fan was left on during entire flight to help cool the cabin. Cruising at FL250 the duct temperature showed 50 degrees F and the cabin temperature indicated 75 degrees F. Passenger and flight attendants reported the cabin was still warm and stuffy. Callback conversation with reporter revealed the following information: the reporter stated that on the return maintenance found the left pack air cycle machine seized and was deferred per the MEL as the pack inoperative. The reporter said the finding on the right pack was a 35 degree deicing valve that failed allowing the right water separator to ice up, blocking cool air flow.

Google
 

Original NASA ASRS Text

Title: A B737-200 ON INITIAL CLB AT 3000 FT TO 11000 FT EXPERIENCED DIFFICULTY COOLING THE PAX AND CTL CABIN. RETURN TO THE FIELD CAUSED BY FAILED L AIR CYCLE MACHINE AND R PACK DEICING VALVE.

Narrative: DURING TAXI OUT, INFORMED BY FLT ATTENDANT THAT CABIN WAS GETTING WARM. I SELECTED FULL COLD IN AUTO MODE ON BOTH PACKS. BOTH AIR MIX VALVES SHOWED FULL COLD AND DUCT TEMP APPROX 80 DEGS F. OUTSIDE AIR TEMP WAS 88 DEGS F AND FULL (119) PAX. WE STARTED L ENG TO HELP COOL DOWN THE CABIN. DURING CLBOUT (APPROX 3000 FT MSL) FLT ATTENDANT INFORMED US THE CABIN WAS GETTING EXTREMELY HOT. I SELECTED FULL MANUAL COLD ON BOTH TEMP SELECTORS. PASSING 6000 FT NOTICED WARM AIR EXITING GASPER FAN, AND DUCT TEMP SHOWED 120 DEGS F WITH BOTH AIR MIX VALVES SHOWING FULL COLD. WE CHKED CIRCUIT BREAKERS AND THE FLT OPS MANUAL. BREAKERS CHKED GOOD AND FLT OPS MANUAL HAD NO GUIDANCE FOR THIS SIT. APPROX 20 MI N OF MCO INFORMED ZJX OF OUR RETURN TO MCO. ACARS MESSAGE SENT TO FLT CTL, MCO MAINT NOTIFIED, FLT ATTENDANTS NOTIFIED AND A PA WAS MADE TO THE PAX. DURING DSCNT WITH PWR IN IDLE, DUCT TEMP SHOWED 75 DEGS F AND CABIN TEMP SHOWED 90 DEGS F. BOTH AIR MIX VALVES STILL SHOWED FULL COLD. MAINT FOUND THE 35 DEG CTLR AND SENSOR HAD FAILED ON THE R PACK AND THE L PACK AIR CYCLE MACHINE WAS SEIZED. THIS WAS THE REASON WE COULD NOT CTL THE CABIN TEMP. THE CAPT DISCUSSED THE SIT WITH MAINT, THE DISPATCHER AND THE DUTY PLT. THE L PACK WAS PLACARDED INOP AND THE R AIR CONDITIONING SYS WAS REPAIRED AND THOROUGHLY OPS CHKED. THE ACFT WAS REDISPATCHED TO RDU WITH THE L AIR CONDITIONING SYS INOP. GASPER FAN WAS LEFT ON DURING ENTIRE FLT TO HELP COOL THE CABIN. CRUISING AT FL250 THE DUCT TEMP SHOWED 50 DEGS F AND THE CABIN TEMP INDICATED 75 DEGS F. PAX AND FLT ATTENDANTS RPTED THE CABIN WAS STILL WARM AND STUFFY. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THAT ON THE RETURN MAINT FOUND THE L PACK AIR CYCLE MACHINE SEIZED AND WAS DEFERRED PER THE MEL AS THE PACK INOP. THE RPTR SAID THE FINDING ON THE R PACK WAS A 35 DEG DEICING VALVE THAT FAILED ALLOWING THE R WATER SEPARATOR TO ICE UP, BLOCKING COOL AIR FLOW.

Data retrieved from NASA's ASRS site as of July 2007 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.