Broken pneumatic duct in air carrier widebody transport leads to a return to landing at lax.

Attributes
ACN	140316
Time
Date	199003
Day	Fri
Place
Locale Reference	airport : lax
State Reference	CA
Altitude	msl bound lower : 8000 msl bound upper : 8000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zla
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 3 Turbojet Eng
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : instrument pilot : flight engineer pilot : commercial pilot : atp
Experience	flight time last 90 days : 210 flight time total : 21000 flight time type : 5000
ASRS Report	140316
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	other other : unspecified
Resolutory Action	flight crew : declared emergency other
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

We were climbing through 8000' when the in-flight service coordinator (senior F/a) called and informed us that all the aft smoke detectors were going off. I sent the F/east aft to assess the situation. He returned promptly and informed me that we had smoke in the aft cabin, and that it smelled like electrical smoke. I advised the first officer to declare an emergency and advise ZLA that we were returning to lax immediately. (The F/east was advised to run the electrical problem checklist.) we also advised ZLA we were dumping fuel, needed the longest runway, and to have the emergency equipment standing by. They advised us that runway 7L was available. We dumped about 18000# of fuel over the ocean. We landed straight in and had no problems. Immediately after clearing the runway I sent the F/east aft to check the situation. He advised all was improving and was ok to continue to the gate. The firemen boarded the aircraft through the loading gate. The passenger deplaned. The problem was a blown pneumatic duct in the aft cabin sidewall, allowing unregulated 'hot' air into cabin. Center, tower and ground control, plus the firemen, did a commendable job. Thanks.

Original NASA ASRS Text

Title: BROKEN PNEUMATIC DUCT IN ACR WDB LEADS TO A RETURN TO LNDG AT LAX.

Narrative: WE WERE CLBING THROUGH 8000' WHEN THE INFLT SVC COORDINATOR (SENIOR F/A) CALLED AND INFORMED US THAT ALL THE AFT SMOKE DETECTORS WERE GOING OFF. I SENT THE F/E AFT TO ASSESS THE SITUATION. HE RETURNED PROMPTLY AND INFORMED ME THAT WE HAD SMOKE IN THE AFT CABIN, AND THAT IT SMELLED LIKE ELECTRICAL SMOKE. I ADVISED THE F/O TO DECLARE AN EMER AND ADVISE ZLA THAT WE WERE RETURNING TO LAX IMMEDIATELY. (THE F/E WAS ADVISED TO RUN THE ELECTRICAL PROB CHKLIST.) WE ALSO ADVISED ZLA WE WERE DUMPING FUEL, NEEDED THE LONGEST RWY, AND TO HAVE THE EMER EQUIP STANDING BY. THEY ADVISED US THAT RWY 7L WAS AVAILABLE. WE DUMPED ABOUT 18000# OF FUEL OVER THE OCEAN. WE LANDED STRAIGHT IN AND HAD NO PROBS. IMMEDIATELY AFTER CLRING THE RWY I SENT THE F/E AFT TO CHK THE SITUATION. HE ADVISED ALL WAS IMPROVING AND WAS OK TO CONTINUE TO THE GATE. THE FIREMEN BOARDED THE ACFT THROUGH THE LOADING GATE. THE PAX DEPLANED. THE PROB WAS A BLOWN PNEUMATIC DUCT IN THE AFT CABIN SIDEWALL, ALLOWING UNREGULATED 'HOT' AIR INTO CABIN. CENTER, TWR AND GND CTL, PLUS THE FIREMEN, DID A COMMENDABLE JOB. THANKS.

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.