Aircraft equipment problem. Air carrier lost pressurization on climb out and returns to land.

Attributes
ACN	305120
Time
Date	199505
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : lga
State Reference	NY
Altitude	msl bound lower : 18000 msl bound upper : 18000
Aircraft 1
Controlling Facilities	artcc : zny
Operator	common carrier : air carrier
Make Model Name	MD-80 Super 80
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	climbout : intermediate altitude other other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	305120
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	aircraft equipment problem : critical conflict : airborne less severe non adherence : required legal separation other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other controllera other flight crewa
Resolutory Action	controller : issued new clearance flight crew : declared emergency flight crew : exited adverse environment other
Consequence	Other
Miss Distance	horizontal : 12000 vertical : 0
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

On departure from lga after cleanup checks and 10000 ft checks, approaching 18000 ft, cabin altitude warning came on with the associated aural. Cabin altitude was observed at 11000 ft and climbing rapidly. An emergency descent was initiated and an emergency declared. An immediate clearance to 10000 ft was requested and received. In the descent the pressurization controller seemed to catch and the cabin started to repressurize. Manual control was not initiated because of this. Upon talking with the aft flight attendant, she complained about very loud noise coming from the aft galley door. I became concerned then that we had an open door, although there were no door warning annunciators on. We stayed with the declared emergency and returned to lga. On descent through 12000 ft, the ATC controller asked to level at 12000 ft. Since we had the apparent lack of structural integrity and since the pressurization controller was releasing cabin pressure again, I insisted on continuing the descent to 10000 ft. We continued to 10000 ft with the concurrence of ATC and came approximately within 2 mi of another aircraft at 11000 ft. No conflict was reported by ATC or the involved aircraft. Landing was uneventful at lga and the crash equipment was released after we cleared the runway. Landing was accomplished at 129700 pounds gross weight. The controller was replaced by maintenance and we were re- released by dispatch for the flight to dfw.

Original NASA ASRS Text

Title: ACFT EQUIP PROB. ACR LOST PRESSURIZATION ON CLBOUT AND RETURNS TO LAND.

Narrative: ON DEP FROM LGA AFTER CLEANUP CHKS AND 10000 FT CHKS, APCHING 18000 FT, CABIN ALT WARNING CAME ON WITH THE ASSOCIATED AURAL. CABIN ALT WAS OBSERVED AT 11000 FT AND CLBING RAPIDLY. AN EMER DSCNT WAS INITIATED AND AN EMER DECLARED. AN IMMEDIATE CLRNC TO 10000 FT WAS REQUESTED AND RECEIVED. IN THE DSCNT THE PRESSURIZATION CTLR SEEMED TO CATCH AND THE CABIN STARTED TO REPRESSURIZE. MANUAL CTL WAS NOT INITIATED BECAUSE OF THIS. UPON TALKING WITH THE AFT FLT ATTENDANT, SHE COMPLAINED ABOUT VERY LOUD NOISE COMING FROM THE AFT GALLEY DOOR. I BECAME CONCERNED THEN THAT WE HAD AN OPEN DOOR, ALTHOUGH THERE WERE NO DOOR WARNING ANNUNCIATORS ON. WE STAYED WITH THE DECLARED EMER AND RETURNED TO LGA. ON DSCNT THROUGH 12000 FT, THE ATC CTLR ASKED TO LEVEL AT 12000 FT. SINCE WE HAD THE APPARENT LACK OF STRUCTURAL INTEGRITY AND SINCE THE PRESSURIZATION CTLR WAS RELEASING CABIN PRESSURE AGAIN, I INSISTED ON CONTINUING THE DSCNT TO 10000 FT. WE CONTINUED TO 10000 FT WITH THE CONCURRENCE OF ATC AND CAME APPROX WITHIN 2 MI OF ANOTHER ACFT AT 11000 FT. NO CONFLICT WAS RPTED BY ATC OR THE INVOLVED ACFT. LNDG WAS UNEVENTFUL AT LGA AND THE CRASH EQUIP WAS RELEASED AFTER WE CLRED THE RWY. LNDG WAS ACCOMPLISHED AT 129700 LBS GROSS WT. THE CTLR WAS REPLACED BY MAINT AND WE WERE RE- RELEASED BY DISPATCH FOR THE FLT TO DFW.

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.