Return land account unable to pressurize aircraft.

Attributes
ACN	92738
Time
Date	198808
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : bur
State Reference	CA
Altitude	msl bound lower : 775 msl bound upper : 7000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : bur tower : bur
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : atp pilot : commercial pilot : flight engineer
Experience	flight time last 90 days : 75 flight time total : 10000 flight time type : 125
ASRS Report	92738
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : flight engineer pilot : instrument
Experience	flight time last 90 days : 100 flight time total : 3300 flight time type : 75
ASRS Report	92736
Events
Anomaly	aircraft equipment problem : less severe
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	none taken : unable other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

On climb out from bur en route to oak we were unable to pressurize the aircraft and returned to bur. Flight duration was about 10 mins and maximum altitude was 7000'. Maintenance personnel met the aircraft and found the forward cargo door not completely closed. On the master warning panel there is a yellow caution light: 'lower door not closed' that should have been illuminated. Upon further inspection we found that both peanut bulbs for that caution light were burned out. At 1 hour prior to our departure time the first officer and I started an originating preflight on this aircraft. This preflight is extensive and requires checks of all systems on the aircraft, including the lights on the master warning panel. During this preflight we found all the lights on the master warning panel to be functioning properly. The cargo pit door is normally closed by ground service personnel just mins prior to departure, once the final bags are loaded. It appeared that they had tried to close the cargo pit door, however one of the locking pins in the door mechanism had not properly seated itself.

Original NASA ASRS Text

Title: RETURN LAND ACCOUNT UNABLE TO PRESSURIZE ACFT.

Narrative: ON CLBOUT FROM BUR ENRTE TO OAK WE WERE UNABLE TO PRESSURIZE THE ACFT AND RETURNED TO BUR. FLT DURATION WAS ABOUT 10 MINS AND MAX ALT WAS 7000'. MAINT PERSONNEL MET THE ACFT AND FOUND THE FORWARD CARGO DOOR NOT COMPLETELY CLOSED. ON THE MASTER WARNING PANEL THERE IS A YELLOW CAUTION LIGHT: 'LOWER DOOR NOT CLOSED' THAT SHOULD HAVE BEEN ILLUMINATED. UPON FURTHER INSPECTION WE FOUND THAT BOTH PEANUT BULBS FOR THAT CAUTION LIGHT WERE BURNED OUT. AT 1 HR PRIOR TO OUR DEP TIME THE F/O AND I STARTED AN ORIGINATING PREFLT ON THIS ACFT. THIS PREFLT IS EXTENSIVE AND REQUIRES CHKS OF ALL SYSTEMS ON THE ACFT, INCLUDING THE LIGHTS ON THE MASTER WARNING PANEL. DURING THIS PREFLT WE FOUND ALL THE LIGHTS ON THE MASTER WARNING PANEL TO BE FUNCTIONING PROPERLY. THE CARGO PIT DOOR IS NORMALLY CLOSED BY GND SVC PERSONNEL JUST MINS PRIOR TO DEP, ONCE THE FINAL BAGS ARE LOADED. IT APPEARED THAT THEY HAD TRIED TO CLOSE THE CARGO PIT DOOR, HOWEVER ONE OF THE LOCKING PINS IN THE DOOR MECHANISM HAD NOT PROPERLY SEATED ITSELF.

Data retrieved from NASA's ASRS site as of August 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.