Narrative:

Approximately 2 mins after top of climb, a strong acrid smell was noted in cockpit. Suspected electrical smoke/fire. Smell was strongest along centerline of cockpit and at upper level near P7 and P12 panels (overhead circuit breaker panels). Effort was made to localize the source area by smell and touch, but unsuccessfully. 1 a/C pack was shut down, but crew was mostly convinced that the source of smell was electrical wiring in the cockpit. Crew donned O2 masks and operated remainder of flight on O2. An emergency was declared due to the potential severity of consequences, although the strength of the smell had levelled off and later dissipated somewhat. The electrical smoke and fire emergency checklist was performed--systems isolated and non-essential equipment was turned off. The fuel dump checklist was performed and approximately 24000# was jettisoned over international waters and at 17000' MSL. Aircraft gross weight was lowered to 590000 pounds and remainder of flight was uneventful. Landing was made at 585000 pounds (the normal maximum gross landing weight for the aircraft). Fire and rescue equipment at ont was standing by, but aircraft was taxied to ramp under own power due to the smell have dissipated considerably. Lax was not used for landing due to the forecast for marginal WX for the time frame (xz ft lax clear ocnl -X 70 2F). San not used due to it being a 'special airport qualification,' and no pictorial means material available. Due to the relatively superfluous additional flying time to ont and crew's great familiarity with the airport, decision was made to land there. Ont ATIS for landing: 'west' 150-0 200-overcast 10 81/59 2409 981. An additional problem that resulted through the use of O2 masks was the unique communication constraints placed on the crew during high workload times. Juggling audio panel selectors between interphone, ATC and company communications while performing emergency and normal checklists is a significant factor to be reckoned with. Although cockpit discipline was maintained during the performance of assigned duties in checklists and procedures, it was difficult and the workload was increased due to the use of O2 masks. Whereas it is normal to have 2 types of hearing available--cockpit communications via the 'open mouth and ear' and ATC communications via headset in the other ear compared with all communications (sometimes covering each other) via the headset alone--makes the situation much more difficult. I have recommended that our training department emphasize this scenario in future simulator training to prepare us for a similar situation.

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Original NASA ASRS Text

Title: EMERGENCY DECLARED WHEN SMELL OF ELECTRICAL SMOKE WAS DETECTED IN COCKPIT.

Narrative: APPROX 2 MINS AFTER TOP OF CLB, A STRONG ACRID SMELL WAS NOTED IN COCKPIT. SUSPECTED ELECTRICAL SMOKE/FIRE. SMELL WAS STRONGEST ALONG CENTERLINE OF COCKPIT AND AT UPPER LEVEL NEAR P7 AND P12 PANELS (OVERHEAD CB PANELS). EFFORT WAS MADE TO LOCALIZE THE SOURCE AREA BY SMELL AND TOUCH, BUT UNSUCCESSFULLY. 1 A/C PACK WAS SHUT DOWN, BUT CREW WAS MOSTLY CONVINCED THAT THE SOURCE OF SMELL WAS ELECTRICAL WIRING IN THE COCKPIT. CREW DONNED O2 MASKS AND OPERATED REMAINDER OF FLT ON O2. AN EMER WAS DECLARED DUE TO THE POTENTIAL SEVERITY OF CONSEQUENCES, ALTHOUGH THE STRENGTH OF THE SMELL HAD LEVELLED OFF AND LATER DISSIPATED SOMEWHAT. THE ELECTRICAL SMOKE AND FIRE EMER CHKLIST WAS PERFORMED--SYSTEMS ISOLATED AND NON-ESSENTIAL EQUIP WAS TURNED OFF. THE FUEL DUMP CHKLIST WAS PERFORMED AND APPROX 24000# WAS JETTISONED OVER INTL WATERS AND AT 17000' MSL. ACFT GROSS WT WAS LOWERED TO 590000 LBS AND REMAINDER OF FLT WAS UNEVENTFUL. LNDG WAS MADE AT 585000 LBS (THE NORMAL MAX GROSS LNDG WT FOR THE ACFT). FIRE AND RESCUE EQUIP AT ONT WAS STANDING BY, BUT ACFT WAS TAXIED TO RAMP UNDER OWN PWR DUE TO THE SMELL HAVE DISSIPATED CONSIDERABLY. LAX WAS NOT USED FOR LNDG DUE TO THE FORECAST FOR MARGINAL WX FOR THE TIME FRAME (XZ FT LAX CLR OCNL -X 70 2F). SAN NOT USED DUE TO IT BEING A 'SPECIAL ARPT QUALIFICATION,' AND NO PICTORIAL MEANS MATERIAL AVAILABLE. DUE TO THE RELATIVELY SUPERFLUOUS ADDITIONAL FLYING TIME TO ONT AND CREW'S GREAT FAMILIARITY WITH THE ARPT, DECISION WAS MADE TO LAND THERE. ONT ATIS FOR LNDG: 'W' 150-0 200-OVCST 10 81/59 2409 981. AN ADDITIONAL PROB THAT RESULTED THROUGH THE USE OF O2 MASKS WAS THE UNIQUE COM CONSTRAINTS PLACED ON THE CREW DURING HIGH WORKLOAD TIMES. JUGGLING AUDIO PANEL SELECTORS BTWN INTERPHONE, ATC AND COMPANY COMS WHILE PERFORMING EMER AND NORMAL CHKLISTS IS A SIGNIFICANT FACTOR TO BE RECKONED WITH. ALTHOUGH COCKPIT DISCIPLINE WAS MAINTAINED DURING THE PERFORMANCE OF ASSIGNED DUTIES IN CHKLISTS AND PROCS, IT WAS DIFFICULT AND THE WORKLOAD WAS INCREASED DUE TO THE USE OF O2 MASKS. WHEREAS IT IS NORMAL TO HAVE 2 TYPES OF HEARING AVAILABLE--COCKPIT COMS VIA THE 'OPEN MOUTH AND EAR' AND ATC COMS VIA HEADSET IN THE OTHER EAR COMPARED WITH ALL COMS (SOMETIMES COVERING EACH OTHER) VIA THE HEADSET ALONE--MAKES THE SITUATION MUCH MORE DIFFICULT. I HAVE RECOMMENDED THAT OUR TRNING DEPT EMPHASIZE THIS SCENARIO IN FUTURE SIMULATOR TRNING TO PREPARE US FOR A SIMILAR SITUATION.

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.