Air carrier medium large transport could not maintain cabin pressure and made an emergency descent f...

Attributes
ACN	112150
Time
Date	198905
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : irw
State Reference	OK
Altitude	msl bound lower : 10000 msl bound upper : 24000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zkc
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : intermediate altitude 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 : 248 flight time total : 11000 flight time type : 460
ASRS Report	112150
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa
Resolutory Action	flight crew : declared emergency none taken : unable
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

During climb to FL350 cabin pressure problems were noted due to trip off of left pack. Aircraft was leveled off at FL240 to correct problem. Left pack would not remain reset. Right pack airflow was insufficient along with cabin air leaks to maintain cabin pressure. Cabin pressure loss was so large that an emergency descent was initiated. ATC was informed of emergency and descent to 10,000' was performed without further incident. Better maintenance and inspection of aircraft would have prevented this incident.

Original NASA ASRS Text

Title: ACR MLG COULD NOT MAINTAIN CABIN PRESSURE AND MADE AN EMERGENCY DESCENT FROM FL240 TO 10,000'.

Narrative: DURING CLIMB TO FL350 CABIN PRESSURE PROBLEMS WERE NOTED DUE TO TRIP OFF OF LEFT PACK. ACFT WAS LEVELED OFF AT FL240 TO CORRECT PROBLEM. LEFT PACK WOULD NOT REMAIN RESET. RIGHT PACK AIRFLOW WAS INSUFFICIENT ALONG WITH CABIN AIR LEAKS TO MAINTAIN CABIN PRESSURE. CABIN PRESSURE LOSS WAS SO LARGE THAT AN EMER DESCENT WAS INITIATED. ATC WAS INFORMED OF EMER AND DESCENT TO 10,000' WAS PERFORMED WITHOUT FURTHER INCIDENT. BETTER MAINT AND INSPECTION OF ACFT WOULD HAVE PREVENTED THIS INCIDENT.

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

Air carrier medium large transport could not maintain cabin pressure and made an emergency descent from FL240 to 10,000'.