PBS Program Focuses On In-Flight Fire Danger
A new program to air on PBS later this month reports the majority of
America's civil aviation fleet is prone to undetectable and unfightable
in-flight fires. "NOVA Presents: Crash Of Flight 111" further alleges the
FAA and the airline industry have been aware of this problem since 1993
and have, in
the case of most recommendations from the Canadian Transportation Safety
Board, failed to act.
NOVA, renowned for its scientific approach to technically complex stories,
takes an inside look at the Canadian investigation into the watery crash of
Swiss Air Flight 111. On September 2, 1998, the crew aboard that New York to
Geneva flight reported smelling smoke in the cockpit approximately 53
minutes into the flight. The MD-11 was diverted to Halifax, Nova Scotia for
a non-emergency landing. Upon reaching the vicinity of the airport, the crew
decided the aircraft was too high and too heavy for a safe landing --
especially given the possibility of a fire. So they turned back out to sea
to dump fuel and lose altitude.
That's when things started going horribly wrong for Flight 111. The CTSB, in
a report last year, wrote, "About 13 minutes after the
abnormal odor was first detected, the aircraft's flight data recorder began
to record a rapid succession of aircraft systems-related failures. The
flight crew declared an emergency and indicated a need to land immediately.
About one minute later, radio communications and secondary radar contact
with the aircraft were lost, and the flight recorders stopped functioning.
About five and one-half minutes later, at 10:31 p.m. Atlantic daylight
saving time (ADT), the aircraft crashed into the ocean about five nautical
miles southwest of Peggy's Cove, Nova Scotia, Canada. The aircraft was
destroyed and there were no survivors."
That was the beginning of a four-and-a-half year long, $39 million
investigation into why Flight 111, with all 221 people on board,
disintegrated upon impact with the Atlantic Ocean, just six smiles from
Peggy's Cove, Nova Scotia.
Investigators knew there had been a fire on board Flight 111. But they were
unable to figure out where or how it started.
WGBH-TV in Boston (MA), which produces
NOVA, reports the investigation was all but finished without conclusion when
a Canadian investigator, wrapping up his inconclusive report on the
accident, came across evidence that an electrical arc within the aircraft's
in-flight entertainment network (IFEN) may have sparked the fire.
Eventually, the CTSB concluded, "Reconstruction of the wreckage indicated
that a segment of arced electrical cable associated with the in-flight
entertainment network (IFEN) had been located in the area where the fire
most likely originated. The Board concluded that the arc on this electrical
cable was likely associated with the fire initiation event. The Board also
concluded that it is likely that one or more additional wires were involved
in the lead arcing event, and that the additional wire or wires could have
been either IFEN or aircraft wires. Therefore, it could not be concluded
that the known arcing event on the IFEN cable located in the area where the
fire most likely originated was by itself the lead event."
NOVA reports the electrical arc, generating up to 12,000 degrees (F),
ignited the supposedly fireproof mylar insulation surrounding the interior
of the aircraft. The program quotes experts who say, in aircraft where
there's as much as 150 miles of wire on board, there can be up to 1500
cracks in wiring insulation. Couple that with the type of condensation
typical in the upper compartments of an aircraft in flight and NOVA's
experts suggest the possibility for a disastrous in-flight fire event are
Isn't that metalized mylar insulation, variants of which are used in most
commercial aircraft, supposed to be fireproof? It is. But it isn't, reports
NOVA. The program quotes one NTSB official
who acknowledged the flammability of metalized mylar, saying, "I think quite
clearly that there was an oversight, that the testing procedures were not
adequate to reveal the danger from this metalized mylar. And it
took a tragedy such as Swiss Air 111 to highlight that more needed to be
done in this area."
Further, the PBS
program reports silicone end caps used in air circulation ducts --
also certified by the FAA as fireproof --
burned after just four seconds' exposure to an ignition source. The end caps
were flame-tested at the FAA's testing center near Atlantic City (NJ).
"I think it was a surprise to a number of people," said a CTSB official,
"and not just our team. It certainly was a surprise to me. I didn't think it
would burn like that. I never even thought about it. I think that most of
the other pilots in the world would be in the same boat."
With the end caps burned away, fresh air was allowed into the area where the
metalized mylar was already burning, lending fresh fuel to the fire and
forcing the flames toward the overhead wiring compartments above the
NOVA reports the flight crew, which originally believed they had time to
dump fuel and descend at a reasonable rate, actually ran out of time. The
fire burned through the cockpit ceiling, filling the cockpit with fire,
smoke and toxic fumes. Before their power and sensor leads were burned out
by the fire, the flight data recorder indicated a loss of primary
instrumentation, forcing the flight crew to rely on hard-to-read backup
instruments and, finally, trying to fly over water at night, peering through
a smoke-filled windscreen.
"The pilots seat was retracted," said Ken Adams, the ALPA representative to
the Swiss Air 111 investigation. "So we have a pretty good indication he was
not in his seat, which means to me he was actually up fighting the fire. He
was probably using a fire extinguisher. But if he didn't have any protection
from the toxic gasses, then he was probably disabled."
The Legacy Of Swiss Air 111
The most stinging allegation uncovered in
the NOVA story on Swiss Air 111 is that the FAA and airlines knew about the
flammability of metalized mylar as far back as 1993, after an MD-11 burned
on the taxiway at an airport in Denmark. The program reports an MD-87 also
burned on the tarmac in China. In fact, NOVA sources allege there were
several aircraft fires in China during the 1990s -- so many, in fact, that
Chinese officials contacted the FAA and suggested "you guys might have a
flammability problem." But NOVA reports there was no action taken by the FAA
until after the Swiss Air tragedy.
The FAA eventually did order airlines to remove the metalized mylar used by
McDonnell-Douglass in its passenger aircraft by this year. The airlines
quickly appealed and were given until next year to remove and replace the
The CTSB issued 23 recommendations on improving the fire detection and
protection philosophies among aircraft manufacturers and air carriers.
Replacing the metalized mylar was chief among them. But they also included
adding detection capabilities in inaccessible parts of aircraft -- the
wiring compartments in particular.
"The TSB believes that the risk to the flying public can be reduced by
re-examining fire-zone designations in order to identify additional areas of
the aircraft that should be equipped with enhanced smoke/fire detection and
suppression systems. Therefore, the TSB made the following recommendation:
"Appropriate regulatory authorities, together with the aviation community,
review the methodology for establishing designated fire zones within
pressurized portion of the aircraft, with a view to providing improved
detection and suppression capability. A00-17 (issued 4 December 2000)
"Along with initiating the other elements of a comprehensive firefighting
plan, it is essential that flight crews give attention, without delay, to
preparing the aircraft for a possible landing at the nearest suitable
airport. Therefore, the TSB made the following recommendation:
"Appropriate regulatory authorities take action to ensure that industry
standards reflect a philosophy that when odor/smoke from an unknown source
appears in an aircraft, the most appropriate course of action is to prepare
to land the aircraft expeditiously. A00-18 (issued 4 December 2000)
"Aircraft accident data indicate that a self-propagating fire can develop
quickly. Therefore, odor/smoke checklists must be designed to ensure that
the appropriate troubleshooting procedures are completed quickly and
effectively. The TSB is concerned that this is not the case, and made the
"Appropriate regulatory authorities ensure that emergency checklist
procedures for the condition of odor/smoke of unknown origin be designed so
as to be completed in a time frame that will minimize the possibility of an
in-flight fire being ignited or sustained. A00-19 (issued 4 December 2000)"
The problem, according to NOVA, is that
these safety recommendations are not being implemented by the FAA,
considered the world's leader in implementing aviation safety protocols.
"We're presently having new airplanes designed -- they're on the drawing
board," said ALPA's Ken Adams. "Boeing has one. Airbus has what's called the
Airbus 380, a 550 passenger airplane. The regulations haven't changed. They
don't have to provide any more fire detection or fire protection than we had
on Swiss Air 111."
"NOVA Presents: Crash Of Flight 111" airs on PBS stations February 17th at
8:00 p.m. EST.
FMI: Canadian TSB Report On Flight 111,