Swissair Flight 111
McDonnell-Douglas MD-11
September 2, 1998
Peggy's Cove, Nova Scotia



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© Peter Frei



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Following takeoff from New York, while passing through Canadian airspace, an inflight fire began in the flight deck ceiling area


Loss or malfunction of numerous airplane systems and instruments

As the fire progressed, nav equipment and radios quit working

Lost all means to navigate, or communicate

Airplane crashed into the ocean off Peggy's cove, Nova Scotia, 1 hour and 13 minutes after takeoff

Accident investigation conducted by Canadian Transport Safety Board (TSB)



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Airplane equipped with Inflight Entertainment Network (IFEN) installed post-production via Supplemental Type Certificate (STC)


No means for flight crew to immediately remove power from system.

Inadequate instructions in installation drawings regarding wire crimping, wire bundle bend radii, terminal torque requirements, wire bundle routing and wire separation.

Non-conformities between installation drawings and actual installations.



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Highlighted area shows

general location of fire


View of wreckage

reconstruction looking

forward into flight deck



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Cross-sectional

View of fire area



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Damage patterns observed in recovered and reconstructed wreckage revealed that the fire occurred in the areas above the cockpit ceiling liner and above the forward cabin drop-ceiling.



Most of the heat damage in the cockpit was concentrated above the level of the bottom of the upper avionics circuit breaker (CB) panel approximately 72 inches above the cockpit floor, and in the area of the forward cabin drop-ceiling.

Significant heat damage on portions of the airframe structure and air conditioning system ducts in the cockpit area.

Electrical components in area of fire revealed no evidence of internal failures.






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Damage Patterns (Cont'd)



Areas of arc damage were found on 20 wire segments.

Eight of these segments were wires associated with the in-flight entertainment network (IFEN) installed as a post-delivery modification.

One of these segments had been located in the area where the fire was believed to have originated.

Most likely ignition source was electrical arcing in the area above the cockpit ceiling.



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Metallized polyethylene terephthalate (MPET) covered insulation blankets were identified as the most likely source of fuel for the fire -



MPET insulation blankets would be the first materials to be ignited by an arc caused by an electrical fault in the cockpit attic area

During certification testing, MPET met flammability requirements required by FAR 25.853

Following the accident, TSB and FAA conducted various tests (specimen, and mockup) to determine ability of MPET to sustain a fire

Test results showed that in "real world" conditions, MPET would easily sustain a fire

FAA flammability requirements may not be adequate







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Certification testing of MPET insulation -


Sample of material must be subjected to vertical burn test specified in FAR 25.853, per procedure in Appendix F, Part 1.

Test specifies that 3 samples must be exposed to 1550 degree F at flame for 12 seconds.

Burning must self-extinguish in no longer than 15 seconds from time flame is removed.

Drippings must extinguish in 5 seconds.

Average burn length must not exceed 8 inches.



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Photograph of Test Specimen Installed in Specimen Holder (view of end of specimen to which flame will be applied)



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Certification burn

test apparatus (vertical

and horizontal tests)



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Location of MPET


The following slides indicate the location and extent of MPET in the area of the fire, and how it contributed to the continuation of the fire.



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Wire bundle routing showing IFEN runs

– note close proximity of MPET



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Wire runs in aft cockpit

"ceiling" – note MPET

above wire bundles



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Reconstruction showing

Cockpit crown area where

Fire was most intense



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Video -


Tests run by TSB to investigate flammability of MPET

Attempted to duplicate configuration of material when installed

MPET readily ignited, and fire propagation rapid

Illustrative of "real world" conditions, and inadequacy of certification tests




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View this movie at:
http://av-info.faa.gov/dst/Seminar2004/searec/alaska and swissair/Videoclip 1-burntest_hollowtube.mpeg



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Video -


Test run at FAA Technical Center to investigate propagation of fire

Mock-up of DC-10 flight deck crown area

Included MPET enclosed ducts

Fire propagation rapid even without convective airflow that would have been induced in real installation

Certification tests not reflective of "real world" conditions



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View this movie at:
http://av-info.faa.gov/dst/Seminar2004/searec/alaska and swissair/videoclip 2-mpetblanketburntest.mpeg



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Unsafe Conditions:


Fire hazard caused by the ability of thermal acoustic insulating materials to burn.

Improperly installed electrical wiring which served as a source of ignition for flammable materials.

Flight crews were not provided with a readily accessible means of removing electrical power from non-essential systems in the event of smoke and/or fire of undetermined origin.



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Lessons Learned:


A readily accessible means for the removal of electrical power from the equipment and wiring of non-essential systems must be provided to flight crews.

Current flammability tests for interior materials may not be adequate to prevent propagation of fire.




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Lessons Learned: (Cont'd)


The installation of electrical wiring and related equipment must be designed and certified in a manner that is consistent with a system whose function is required for continued safe operation of the airplane.

The level of supervision and oversight of FAA delegated organizations needs to be increased.



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Questions?

This was a seminar held in '04 where the Alaska Air and swissair 111 tragedies were discussed.

http://www.google.com/search?q=swissair+ifen&hl=en&lr=&ie=UTF-8&start=20&sa=N

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This message has been edited. Last edited by: BF,