A B747-400 returned to field after dumping fuel with door #4L false latched.

Attributes
ACN	347492
Time
Date	199608
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : zzz
State Reference	US
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Light	Night
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B747-400
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	other personnel other
Qualification	other other : other
ASRS Report	347492
Person 2
Affiliation	company : air carrier
Function	other personnel other
Qualification	other other : other
Events
Anomaly	non adherence : published procedure other anomaly other
Independent Detector	other flight crewa other other : unspecified cockpit
Resolutory Action	flight crew : overcame equipment problem other
Consequence	Other
Supplementary
Air Traffic Incident	other

Narrative:

On aug/thu/96 flight returned to field with door #4 left open with a false latch. This door was closed by DDDD catering personnel. The aircraft had to dump 100000 pounds of fuel, at a cost of about $75000 for fuel and crew flight time. 4 passenger deplaned on return. We found the top portion of the door was false latched. Recycled and inspected door found ok. Please when we accomplish a circle check that we pay special attention to the top part of the door. This door was about 2 inches inside of being faired which could be seen from the ground. I was the dispatching mechanic responsible for the exterior door-panel check. I completed a predep walk around or 'circle check' and verified that all doors and panels were faired with the fuselage. In addition, I also completed the required B747 main cargo door closing log. Prior to pushing back the aircraft I informed the captain that 'all doors are closed and circuit breakers are pulled view-port alignment marks are visible' and the captain concurred that 'all lights indicated out' (closed). I pushed back and dispatched the aircraft. After takeoff and climb out crew stated that door warning for door #4L appeared. Suspect aircraft pressurization popped the falsely latched door ajar, the crew dumped fuel and returned to ZZZ. Inspection revealed that the door was latched at the bottom but not at the top corner. Flight attendants made mention that the food catering personnel had difficulty with the door but neither party had reported it to maintenance.

Original NASA ASRS Text

Title: A B747-400 RETURNED TO FIELD AFTER DUMPING FUEL WITH DOOR #4L FALSE LATCHED.

Narrative: ON AUG/THU/96 FLT RETURNED TO FIELD WITH DOOR #4 LEFT OPEN WITH A FALSE LATCH. THIS DOOR WAS CLOSED BY DDDD CATERING PERSONNEL. THE ACFT HAD TO DUMP 100000 LBS OF FUEL, AT A COST OF ABOUT $75000 FOR FUEL AND CREW FLT TIME. 4 PAX DEPLANED ON RETURN. WE FOUND THE TOP PORTION OF THE DOOR WAS FALSE LATCHED. RECYCLED AND INSPECTED DOOR FOUND OK. PLEASE WHEN WE ACCOMPLISH A CIRCLE CHK THAT WE PAY SPECIAL ATTN TO THE TOP PART OF THE DOOR. THIS DOOR WAS ABOUT 2 INCHES INSIDE OF BEING FAIRED WHICH COULD BE SEEN FROM THE GND. I WAS THE DISPATCHING MECH RESPONSIBLE FOR THE EXTERIOR DOOR-PANEL CHK. I COMPLETED A PREDEP WALK AROUND OR 'CIRCLE CHK' AND VERIFIED THAT ALL DOORS AND PANELS WERE FAIRED WITH THE FUSELAGE. IN ADDITION, I ALSO COMPLETED THE REQUIRED B747 MAIN CARGO DOOR CLOSING LOG. PRIOR TO PUSHING BACK THE ACFT I INFORMED THE CAPT THAT 'ALL DOORS ARE CLOSED AND CIRCUIT BREAKERS ARE PULLED VIEW-PORT ALIGNMENT MARKS ARE VISIBLE' AND THE CAPT CONCURRED THAT 'ALL LIGHTS INDICATED OUT' (CLOSED). I PUSHED BACK AND DISPATCHED THE ACFT. AFTER TKOF AND CLBOUT CREW STATED THAT DOOR WARNING FOR DOOR #4L APPEARED. SUSPECT ACFT PRESSURIZATION POPPED THE FALSELY LATCHED DOOR AJAR, THE CREW DUMPED FUEL AND RETURNED TO ZZZ. INSPECTION REVEALED THAT THE DOOR WAS LATCHED AT THE BOTTOM BUT NOT AT THE TOP CORNER. FLT ATTENDANTS MADE MENTION THAT THE FOOD CATERING PERSONNEL HAD DIFFICULTY WITH THE DOOR BUT NEITHER PARTY HAD RPTED IT TO MAINT.

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.