A B727 in climb lost cabin pressure due to the left pack failure and the cargo compartment outflow v...

Attributes
ACN	381526
Time
Date	199709
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : tje
State Reference	FO
Altitude	msl bound lower : 25000 msl bound upper : 25000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : rjff tower : hrl
Operator	common carrier : air carrier
Make Model Name	B727 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : commercial pilot : atp pilot : cfi pilot : flight engineer
Experience	flight time last 90 days : 210 flight time total : 17000 flight time type : 13000
ASRS Report	381526
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : critical non adherence : published procedure other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course flight crew : overcame equipment problem
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

During climb to FL330 the air-conditioning system did not pressurize and we had a warning horn at 10000 ft cabin altitude. We attempted to use 'system knowledge' from memory to determine the problem and the fix. While unsuccessfully trying to stop the cabin rate of climb the passenger oxygen masks (the rubber jungle) deployed. We then turned to the checklist and found that we had not yet closed the cargo heat outflow valve. As soon as the outflow valve was closed, the cabin climb ceased and we were able to control the pressurization. We lowered the cabin altitude below 10000 ft and proceeded to our destination without further problem. The failure was later determined to be the left pack not operating normally. But the next error on the part of the crew was failure to immediately turn to the abnormal checklist. Had we done that in a timely manner, the cabin would have been controllable before the oxygen masks deployed, and cabin altitude would have been kept lower. There is no excuse -- use the checklist as the first response to any abnormal.

Original NASA ASRS Text

Title: A B727 IN CLB LOST CABIN PRESSURE DUE TO THE L PACK FAILURE AND THE CARGO COMPARTMENT OUTFLOW VALVE LEFT OPEN.

Narrative: DURING CLB TO FL330 THE AIR-CONDITIONING SYS DID NOT PRESSURIZE AND WE HAD A WARNING HORN AT 10000 FT CABIN ALT. WE ATTEMPTED TO USE 'SYS KNOWLEDGE' FROM MEMORY TO DETERMINE THE PROB AND THE FIX. WHILE UNSUCCESSFULLY TRYING TO STOP THE CABIN RATE OF CLB THE PAX OXYGEN MASKS (THE RUBBER JUNGLE) DEPLOYED. WE THEN TURNED TO THE CHKLIST AND FOUND THAT WE HAD NOT YET CLOSED THE CARGO HEAT OUTFLOW VALVE. AS SOON AS THE OUTFLOW VALVE WAS CLOSED, THE CABIN CLB CEASED AND WE WERE ABLE TO CTL THE PRESSURIZATION. WE LOWERED THE CABIN ALT BELOW 10000 FT AND PROCEEDED TO OUR DEST WITHOUT FURTHER PROB. THE FAILURE WAS LATER DETERMINED TO BE THE L PACK NOT OPERATING NORMALLY. BUT THE NEXT ERROR ON THE PART OF THE CREW WAS FAILURE TO IMMEDIATELY TURN TO THE ABNORMAL CHKLIST. HAD WE DONE THAT IN A TIMELY MANNER, THE CABIN WOULD HAVE BEEN CONTROLLABLE BEFORE THE OXYGEN MASKS DEPLOYED, AND CABIN ALT WOULD HAVE BEEN KEPT LOWER. THERE IS NO EXCUSE -- USE THE CHKLIST AS THE FIRST RESPONSE TO ANY ABNORMAL.

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.

A B727 in climb lost cabin pressure due to the left pack failure and the cargo compartment outflow valve left open.