Captain of an MD80 declared an emergency descent after losing aircraft pressurization resulting in d...

Attributes
ACN	430891
Time
Date	199903
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : mco.airport
State Reference	FL
Altitude	msl bound lower : 10000 msl bound upper : 31500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zjx.artcc
Operator	common carrier : air carrier
Make Model Name	MD-80 Series (DC-9-80) 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 : atp
Experience	flight time last 90 days : 240 flight time total : 20000 flight time type : 12000
ASRS Report	430891
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : multi engine
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : declared emergency flight crew : diverted to another airport
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

After intermediate leveloff, given climb to FL330. After passing FL310 sound of pressurization change. Saw flow light on pressurization panel, causing climbing at +1500 FPM, cabin altitude above 8000 ft. Could not regain control of cabin by use of standby pressurization or manual pressurization. Informed ATC of need for immediate descent. Declared emergency and informed ATC we were descending to 10000 ft MSL. Informed ATC we would divert to mco. Received vectors to final approach course, made uneventful landing in VMC at mco. Upon landing, discovered pressure relief valve had opened and failed to close upon recycling. Apparent overpressurization.

Original NASA ASRS Text

Title: CAPT OF AN MD80 DECLARED AN EMER DSCNT AFTER LOSING ACFT PRESSURIZATION RESULTING IN DIVERTING TO LAND.

Narrative: AFTER INTERMEDIATE LEVELOFF, GIVEN CLB TO FL330. AFTER PASSING FL310 SOUND OF PRESSURIZATION CHANGE. SAW FLOW LIGHT ON PRESSURIZATION PANEL, CAUSING CLBING AT +1500 FPM, CABIN ALT ABOVE 8000 FT. COULD NOT REGAIN CTL OF CABIN BY USE OF STANDBY PRESSURIZATION OR MANUAL PRESSURIZATION. INFORMED ATC OF NEED FOR IMMEDIATE DSCNT. DECLARED EMER AND INFORMED ATC WE WERE DSNDING TO 10000 FT MSL. INFORMED ATC WE WOULD DIVERT TO MCO. RECEIVED VECTORS TO FINAL APCH COURSE, MADE UNEVENTFUL LNDG IN VMC AT MCO. UPON LNDG, DISCOVERED PRESSURE RELIEF VALVE HAD OPENED AND FAILED TO CLOSE UPON RECYCLING. APPARENT OVERPRESSURIZATION.

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.

Captain of an MD80 declared an emergency descent after losing aircraft pressurization resulting in diverting to land.