Narrative:

This aircraft has been in service with a pack 2 problem since early june according to maintenance history. On our flight; the cabin temperature on the ground in ZZZZ was over 90 degrees F and the cockpit was 99 degrees F. The aircraft could not be cooled to normal temperature for about 3 hours in-flight; not including ground time. These temperatures present a danger of hyperthermia to elderly passenger and those with other health concerns; of which we had many on board. Many passenger were complaining about the intolerable conditions. The item keeps getting cleared with no repair. I am especially concerned about maintenance history items which clearly indicate that cockpit and cabin temperatures over 90 degrees F for 3 hours in-flight; not including ground time of 30 mins; is an acceptable condition. These conditions present a hazard to crew members and passenger alike; and should not be allowed to continue. Callback conversation with reporter revealed the following information: reporter stated he has flown the B777's and B747-400 for a long time. But his carrier's -400's aircraft seem to suffer numerous air conditioning problems in comparison to the B777; which he believes was far more reliable with fewer air conditioning issues. Reporter stated he recently became aware the -400 with the continuing temperature and pack problem was apparently repaired after maintenance replaced a failed pack flow control valve. He is not aware of any further problems with the cabin temperature since.

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Original NASA ASRS Text

Title: PILOT OF A B747-400 REPORTS OF UNCONTROLLABLE HIGH CABIN AND COCKPIT TEMPS OVER 90 DEGREES FOR APPROX THREE HOURS IN FLIGHT. SAME ACFT; SAME CONDITION FOR TWO MONTHS; NUMEROUS WRITE-UPS; SIGNED-OFF BY MAINT.

Narrative: THIS ACFT HAS BEEN IN SVC WITH A PACK 2 PROB SINCE EARLY JUNE ACCORDING TO MAINT HISTORY. ON OUR FLT; THE CABIN TEMP ON THE GND IN ZZZZ WAS OVER 90 DEGS F AND THE COCKPIT WAS 99 DEGS F. THE ACFT COULD NOT BE COOLED TO NORMAL TEMP FOR ABOUT 3 HRS INFLT; NOT INCLUDING GND TIME. THESE TEMPS PRESENT A DANGER OF HYPERTHERMIA TO ELDERLY PAX AND THOSE WITH OTHER HEALTH CONCERNS; OF WHICH WE HAD MANY ON BOARD. MANY PAX WERE COMPLAINING ABOUT THE INTOLERABLE CONDITIONS. THE ITEM KEEPS GETTING CLRED WITH NO REPAIR. I AM ESPECIALLY CONCERNED ABOUT MAINT HISTORY ITEMS WHICH CLRLY INDICATE THAT COCKPIT AND CABIN TEMPS OVER 90 DEGS F FOR 3 HRS INFLT; NOT INCLUDING GND TIME OF 30 MINS; IS AN ACCEPTABLE CONDITION. THESE CONDITIONS PRESENT A HAZARD TO CREW MEMBERS AND PAX ALIKE; AND SHOULD NOT BE ALLOWED TO CONTINUE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: REPORTER STATED HE HAS FLOWN THE B777'S AND B747-400 FOR A LONG TIME. BUT HIS CARRIER'S -400'S ACFT SEEM TO SUFFER NUMEROUS AIR CONDITIONING PROBLEMS IN COMPARISON TO THE B777; WHICH HE BELIEVES WAS FAR MORE RELIABLE WITH FEWER AIR CONDITIONING ISSUES. REPORTER STATED HE RECENTLY BECAME AWARE THE -400 WITH THE CONTINUING TEMP AND PACK PROBLEM WAS APPARENTLY REPAIRED AFTER MAINT REPLACED A FAILED PACK FLOW CONTROL VALVE. HE IS NOT AWARE OF ANY FURTHER PROBLEMS WITH THE CABIN TEMP SINCE.

Data retrieved from NASA's ASRS site as of May 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.