Narrative:

Enroute; level at FL360 in IMC conditions; engine and airfoil heat on. 'Pressurization flow' light illuminated; right pack 0 flow; supply temperature 150 with right air mix valve full hot. Both left and right pack temperature controllers where being operated in auto. Almost concurrently; descent clearance received from center to FL200. Passing through FL300 control of cabin reestablished. Cabin altitude approximately 8;000 ft and descending. A few minutes later the left pack went to zero flow. Air mix value showed mid-position and supply temperature showed 80. Received clearance to 10;000 ft. Cabin climbing 1;500 ft/min. Notified flight attendants of nature of situation. 'Cabin altitude' light illuminated and cockpit masks donned and QRH procedures followed. Left pack began working again passing through 15;000 ft. Maximum cabin altitude reached was approximately 11;500 ft with left pack operating; control of pressurization was regained. Leveled at 10;000 ft; now in VMC conditions. Right pack began operating again after leveling of the 10;000 ft. Continued in VMC conditions to our destination where normal landing occurred. Debriefed event with maintenance control where it was determined that both packs had history of write ups going back a number of weeks.

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Original NASA ASRS Text

Title: An MD80 crew reported dual pack failures descending through FL300 IMC while both engine and airfoil anti-ice were on. With oxygen masks on and working the QRH the cabin altitude reached 11;500 before the crew was able to restore both packs to normal operation.

Narrative: Enroute; level at FL360 in IMC conditions; engine and airfoil heat on. 'Pressurization Flow' light illuminated; right pack 0 flow; supply temperature 150 with right air mix valve full hot. Both left and right pack temperature controllers where being operated in auto. Almost concurrently; descent clearance received from Center to FL200. Passing through FL300 control of cabin reestablished. Cabin altitude approximately 8;000 FT and descending. A few minutes later the left pack went to zero flow. Air mix value showed mid-position and supply temperature showed 80. Received clearance to 10;000 FT. Cabin climbing 1;500 FT/min. Notified Flight Attendants of nature of situation. 'Cabin Altitude' light illuminated and cockpit masks donned and QRH procedures followed. Left pack began working again passing through 15;000 FT. Maximum cabin altitude reached was approximately 11;500 FT with left pack operating; control of pressurization was regained. Leveled at 10;000 FT; now in VMC conditions. Right pack began operating again after leveling of the 10;000 FT. Continued in VMC conditions to our destination where normal landing occurred. Debriefed event with Maintenance Control where it was determined that both packs had history of write ups going back a number of weeks.

Data retrieved from NASA's ASRS site as of April 2012 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.