Freighter large transport lost cabin prssure clt at FL310, had to descend to FL180.

Attributes
ACN	153254
Time
Date	199008
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : bwg
State Reference	KY
Altitude	msl bound lower : 18000 msl bound upper : 31000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	cruise other
Route In Use	enroute airway : zid
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : commercial pilot : flight engineer pilot : instrument
Experience	flight time last 90 days : 150 flight time total : 9500 flight time type : 4100
ASRS Report	153254
Person 2
Affiliation	company : air carrier
Function	flight crew : second officer
Qualification	pilot : private pilot : instrument pilot : flight engineer pilot : commercial pilot : atp
Experience	flight time last 90 days : 200 flight time total : 8000 flight time type : 5000
ASRS Report	153499
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa
Resolutory Action	flight crew : overcame equipment problem flight crew : declared emergency
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

Cruise at FL310 cabin started climbing at 1000 FPM, the F/east could not control cabin with both packs on, large heat outflow closed and full rate on automatic press control. Full closed on manual press had no control, requested and descended to FL280. At FL280, cabin still climbing at 400 FPM crew went on oxy as cabin climbed through 9000'. Descended to FL250 cabin stopped climbing, descended to FL230, cabin descended at 100 FPM. Descended to FL180, where cabin started descending at 400 FPM. Crew and 2 jumpseaters (1 a FAA inspector) came off oxy when cabin started descending through 8700'. Flight had started out with FAA maintenance inspector pointing out that #2 engine was leaking a small amount of oil. The automatic press controller had been replaced in alb because of our write-up that morning.

Original NASA ASRS Text

Title: FREIGHTER LGT LOST CABIN PRSSURE CLT AT FL310, HAD TO DESCEND TO FL180.

Narrative: CRUISE AT FL310 CABIN STARTED CLBING AT 1000 FPM, THE F/E COULD NOT CTL CABIN WITH BOTH PACKS ON, LARGE HEAT OUTFLOW CLOSED AND FULL RATE ON AUTO PRESS CTL. FULL CLOSED ON MANUAL PRESS HAD NO CTL, REQUESTED AND DSNDED TO FL280. AT FL280, CABIN STILL CLBING AT 400 FPM CREW WENT ON OXY AS CABIN CLBED THROUGH 9000'. DSNDED TO FL250 CABIN STOPPED CLBING, DSNDED TO FL230, CABIN DSNDED AT 100 FPM. DSNDED TO FL180, WHERE CABIN STARTED DSNDING AT 400 FPM. CREW AND 2 JUMPSEATERS (1 A FAA INSPECTOR) CAME OFF OXY WHEN CABIN STARTED DSNDING THROUGH 8700'. FLT HAD STARTED OUT WITH FAA MAINT INSPECTOR POINTING OUT THAT #2 ENG WAS LEAKING A SMALL AMOUNT OF OIL. THE AUTO PRESS CTLR HAD BEEN REPLACED IN ALB BECAUSE OF OUR WRITE-UP THAT MORNING.

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.