Loss of cabin pressurization. Emergency descent.

Attributes
ACN	139011
Time
Date	199003
Day	Sat
Place
Locale Reference	atc facility : jhw
State Reference	NY
Altitude	msl bound lower : 10000 msl bound upper : 37000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zob tracon : abe
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 3 Turbojet Eng
Navigation In Use	Other
Flight Phase	cruise other descent other other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : flight engineer
ASRS Report	139011
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	other flight crewa
Resolutory Action	controller : issued new clearance flight crew : declared emergency none taken : unable other
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

In cruise at FL370 approximately 45 mins out from destination (jfk) cabin rate of climb went from 0 to pegged out a 6000 FPM up. Standby and manual backups had no effect on arresting cabin rate of climb. Completed the rapid depressurization and explosive depressurization checklists and initiated emergency descent. ATC cleared us initially to FL240 and then to 10000'. Did not declare an emergency or squawk since ATC immediately cleared us for a descent. Of note was that our PA's could not be heard due to a weak PA and the air noise. Also one passenger with his son on the floor west/O a mask and a lady in the next row having trouble with her mask continued to film the event with his video camera. When asked why he didn't help his son replied his son would just pass out and not be hurt. Overall there was no panic from the people just concern. Callback conversation with reporter revealed following information. Reporter states that the pressurization failure was immediate and complete. Since the press fail lights were on it was assumed that the aircraft structural integrity was intact and a high speed descent procedure was used allowing the aircraft to descend from FL370 to 10000' in less than four mins. Maintenance experienced some difficulty locating the actual failure and ended up changing most of the components of the pressurization system.

Original NASA ASRS Text

Title: LOSS OF CABIN PRESSURIZATION. EMERGENCY DESCENT.

Narrative: IN CRUISE AT FL370 APPROX 45 MINS OUT FROM DEST (JFK) CABIN RATE OF CLB WENT FROM 0 TO PEGGED OUT A 6000 FPM UP. STANDBY AND MANUAL BACKUPS HAD NO EFFECT ON ARRESTING CABIN RATE OF CLB. COMPLETED THE RAPID DEPRESSURIZATION AND EXPLOSIVE DEPRESSURIZATION CHKLISTS AND INITIATED EMER DSCNT. ATC CLRED US INITIALLY TO FL240 AND THEN TO 10000'. DID NOT DECLARE AN EMER OR SQUAWK SINCE ATC IMMEDIATELY CLRED US FOR A DSCNT. OF NOTE WAS THAT OUR PA'S COULD NOT BE HEARD DUE TO A WEAK PA AND THE AIR NOISE. ALSO ONE PAX WITH HIS SON ON THE FLOOR W/O A MASK AND A LADY IN THE NEXT ROW HAVING TROUBLE WITH HER MASK CONTINUED TO FILM THE EVENT WITH HIS VIDEO CAMERA. WHEN ASKED WHY HE DIDN'T HELP HIS SON REPLIED HIS SON WOULD JUST PASS OUT AND NOT BE HURT. OVERALL THERE WAS NO PANIC FROM THE PEOPLE JUST CONCERN. CALLBACK CONVERSATION WITH RPTR REVEALED FOLLOWING INFO. RPTR STATES THAT THE PRESSURIZATION FAILURE WAS IMMEDIATE AND COMPLETE. SINCE THE PRESS FAIL LIGHTS WERE ON IT WAS ASSUMED THAT THE ACFT STRUCTURAL INTEGRITY WAS INTACT AND A HIGH SPD DSCNT PROC WAS USED ALLOWING THE ACFT TO DSND FROM FL370 TO 10000' IN LESS THAN FOUR MINS. MAINT EXPERIENCED SOME DIFFICULTY LOCATING THE ACTUAL FAILURE AND ENDED UP CHANGING MOST OF THE COMPONENTS OF THE PRESSURIZATION SYS.

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.