Air carrier widebody transport unable to pressurize, return and land mandated.

Attributes
ACN	281111
Time
Date	199408
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : pdx
State Reference	OR
Altitude	agl bound lower : 0 agl bound upper : 6000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : pdx
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	climbout : intermediate altitude climbout : takeoff ground : preflight
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	other personnel other
Qualification	other other : other
ASRS Report	281111
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : critical non adherence other other anomaly other
Independent Detector	other flight crewa
Resolutory Action	other
Consequence	Other
Supplementary
Air Traffic Incident	other

Narrative:

Aircraft was dispatched with lwr. Center avionics compartment door open. Door was in lwr. Area of track and looked if it were closed. (Gap approximately 1 inch when door lowered on track). Crew did not report of any door warning lights when dispatched. After they were airborne, crew called back and advised maintenance they could not pressurize aircraft. It was necessary to dump fuel due to aircraft weight for landing would be exceeded. Crew advised maintenance that r-hand fuel dump valve would not open. Necessary to define r-hand and l-hand fuel dump valves. Some of the reasons for this incident happening was a lot of activity (maintenance wise) prior to departure of trip. Aircraft was taxied to gate from remote parking area. The taxi crew entered aircraft through this door to get into aircraft. When taxied to gate maintenance taxi crew shift ended at 0700 (midnight crew). Day shift took over and maintenance was advised of several items during crew preflight (trim warning and oil service, ovens, full gallery, etc). No maintenance was accomplished in center avionics compartment. Door was not noted to be open on so's walk around or by maintenance dispatch mechanic.

Original NASA ASRS Text

Title: ACR WDB UNABLE TO PRESSURIZE, RETURN AND LAND MANDATED.

Narrative: ACFT WAS DISPATCHED WITH LWR. CTR AVIONICS COMPARTMENT DOOR OPEN. DOOR WAS IN LWR. AREA OF TRACK AND LOOKED IF IT WERE CLOSED. (GAP APPROX 1 INCH WHEN DOOR LOWERED ON TRACK). CREW DID NOT RPT OF ANY DOOR WARNING LIGHTS WHEN DISPATCHED. AFTER THEY WERE AIRBORNE, CREW CALLED BACK AND ADVISED MAINT THEY COULD NOT PRESSURIZE ACFT. IT WAS NECESSARY TO DUMP FUEL DUE TO ACFT WT FOR LNDG WOULD BE EXCEEDED. CREW ADVISED MAINT THAT R-HAND FUEL DUMP VALVE WOULD NOT OPEN. NECESSARY TO DEFINE R-HAND AND L-HAND FUEL DUMP VALVES. SOME OF THE REASONS FOR THIS INCIDENT HAPPENING WAS A LOT OF ACTIVITY (MAINT WISE) PRIOR TO DEP OF TRIP. ACFT WAS TAXIED TO GATE FROM REMOTE PARKING AREA. THE TAXI CREW ENTERED ACFT THROUGH THIS DOOR TO GET INTO ACFT. WHEN TAXIED TO GATE MAINT TAXI CREW SHIFT ENDED AT 0700 (MIDNIGHT CREW). DAY SHIFT TOOK OVER AND MAINT WAS ADVISED OF SEVERAL ITEMS DURING CREW PREFLT (TRIM WARNING AND OIL SVC, OVENS, FULL GALLERY, ETC). NO MAINT WAS ACCOMPLISHED IN CTR AVIONICS COMPARTMENT. DOOR WAS NOT NOTED TO BE OPEN ON SO'S WALK AROUND OR BY MAINT DISPATCH MECH.

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.