Air carrier using anti ice has both air conditioning packs shut down. Emergency descent.

Attributes
ACN	238269
Time
Date	199304
Day	Tue
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : shv
State Reference	LA
Altitude	msl bound lower : 10000 msl bound upper : 35000
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zme tracon : jan
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	cruise other descent other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 10000
ASRS Report	238269
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : declared emergency other
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

At FL350 while using engine and air foil anti-ice during the penetration of cirrus clouds with imbedded thunderstorms, both air conditioning packs shut down simultaneously. The cabin rose at approximately 1000 FPM. Lower altitude was requested from ATC. Emergency descent procedures were initiated to FL240. Approaching FL240 further clearance issued to 10000 ft. The right pack cycled on then off during the descent. After clearing the cloud deck anti-ice was secured. Both packs returned to normal operation after leveling at 10000 ft. Flight was continued at 10000 ft to uneventful landing.

Original NASA ASRS Text

Title: ACR USING ANTI ICE HAS BOTH AIR CONDITIONING PACKS SHUT DOWN. EMER DSCNT.

Narrative: AT FL350 WHILE USING ENG AND AIR FOIL ANTI-ICE DURING THE PENETRATION OF CIRRUS CLOUDS WITH IMBEDDED TSTMS, BOTH AIR CONDITIONING PACKS SHUT DOWN SIMULTANEOUSLY. THE CABIN ROSE AT APPROX 1000 FPM. LOWER ALT WAS REQUESTED FROM ATC. EMER DSCNT PROCS WERE INITIATED TO FL240. APCHING FL240 FURTHER CLRNC ISSUED TO 10000 FT. THE R PACK CYCLED ON THEN OFF DURING THE DSCNT. AFTER CLRING THE CLOUD DECK ANTI-ICE WAS SECURED. BOTH PACKS RETURNED TO NORMAL OP AFTER LEVELING AT 10000 FT. FLT WAS CONTINUED AT 10000 FT TO UNEVENTFUL LNDG.

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.