Swissair 111 |
 |
Two Transportation Safety Board
investigators working at CFB Shearwater in
September 1998 look over a section of the
fuselage recovered off the waters near
Peggy's Cove, N.S. |
|
Transport Canada is resisting demands for the wholesale
inspection of planes for the same problem that resulted in
the deaths of 229 people in a Swissair crash off Peggy's
Cove, N.S., seven years ago.
In 2003, Canada's Transportation Safety Board issued a
public report attributing the 1998 Swissair Flight 111 crash
to worn or faulty entertainment system wiring surrounded by
flammable thermal-acoustical insulation blankets. The
blankets are hidden from passengers' view, but are used to
keep the cabins warm in flight and to minimize noise from
aircraft engines.
A year later, in June 2004, the board privately slapped
Transport Canada with an "unsatisfactory" rating for its
response to a board recommendation that other types of
blankets that might cause a similar crash be checked and
fixed if necessary, according to federal
access-to-information documents obtained by The Vancouver
Sun.
(The insulation material that contributed to the fire
aboard the Swissair passenger jet was pulled from aircraft
effective June 2005.)
The access-to-information documents provide insight into
the tension between the two federal agencies -- the safety
board, which investigates crashes and makes recommendations,
and Transport Canada, which deals with the reality of
implementing them.
A seven-page document titled "Reassessment of Risk,"
dated June 16, 2004, reveals the safety board wants to know
what other types of blankets still being used in planes fail
the Radiant Panel Test (RPT), a flammability standard
adopted by the Federal Aviation Administration in the U.S.
"Although these materials exist in many aircraft, as of
the final report publication date, no mitigation strategy
has been undertaken to address the known associated risks,"
states the document.
Transport Canada argued in response that those materials
that failed the test are not necessarily unsafe because
some
"did pass a range of other flammability tests and have
performed satisfactorily in-service."
The documents also show that Transport Canada has
developed proposed regulations to implement the RPT on new
transport category aircraft designs and future production of
existing aircraft designs.
Transport Canada said it would also raise the issue of
further testing of insulation blankets with the FAA's
International Aircraft Materials Fire Test Working Group.
Transport Canada does say that despite improvements to
aviation safety taking effect this month, there is still the
risk of another disastrous crash under similar
circumstances.
"Yes, there's clearly a level of risk there," Martin Eley,
director of aircraft certification for Transport Canada,
said in an interview. "To some extent it's not easy to
quantify, and that's been part of the challenge."
The access-to-information documents show the safety board
was clearly dissatisfied with Transport Canada's response,
which did not fully address the issue of untested thermal
blankets on aircraft already in use.
The board states: "TC will not specifically target
materials that have failed the RPT. TC has not provided
information that it would identify the materials that failed
the RPT. Nor has TC indicated an intent to determine the
extent to which such materials are used in
Canadian-registered aircraft. Consequently, TC's response .
. . continues to be assessed as being unsatisfactory."
Since the safety board issued its unsatisfactory
rating, there has been action on the issue:
- The insulation material that contributed to the
fire aboard the Swissair passenger jet, metallized polyethylene terephthalate, has been
pulled from aircraft effective June 2005.
- The FAA has served notice it plans to ban a
second type of insulation blanket constructed of polyethyleneteraphthalate film -- AN-26 -- on
Boeing aircraft after tests showed it can
contribute to the spread of fire as a result of
electrical arcing or sparking.
- Effective this month, the FAA requires the
airline industry to install only RPT-approved
insulation blankets on new aircraft and when
replacing blankets on existing aircraft. Canada
is the process of adopting matching regulations.
That still leaves a big question regarding
the flammability risk posed by numerous other
types of insulation blankets already in use on
aircraft where there are no immediate plans for
their replacement.
In an airworthiness bulletin issued April 4
this year, the FAA noted that "even though we
did extensive testing on a variety of materials,
we could not identify and test every material
produced, as the permutations of material
combinations were too extensive."
Vic Gerden, the safety board's lead
investigator on the Swissair crash, said he is
glad to see progress being made as a result of
the safety board's exhaustive investigation into
Canada's second worst airline crash.
"In good measure, they are the result of our
work," he said, noting work is also under way to
improve detection of fires on aircraft and to
improve crew response. "I'm gratified. There has
been improvement made."
But Gerden cannot say whether other blankets
are still out there posing a threat similar to
that in the Swissair crash.
"Yes, that's true, that's a fact," he said,
noting there are potentially dozens of types of
insulation blankets manufactured over the years.
"I'm not in a position to make that assessment."
Any change in the unsatisfactory rating
issued by Transport Canada will have to await a
further review, Gerden said.
Eley said the unsatisfactory rating is "not
that common," even though the two agencies may
disagree on approaches to solutions.
"Obviously, we don't like to be in that
position," he said of the current rating. "On
the other hand, if anyone wants to know our
position, we can explain why there is a
disagreement."
In this case, Transport Canada, which works
closely with the FAA, felt the board's
recommendation to eliminate potentially
flammable insulation blankets "was a very open
question, and we were reluctant to commit to
it," Eley said. "We've been responding to what
we believe is the concern, but we didn't
necessarily agree with the wording of the
recommendation. We felt there were better ways
to deal with it."
Eley noted that economics play a major part
in any decision related to the further
removal of thermal blankets.
Removal and
replacement of AN-26 blankets on 1,613
aircraft would cost the airline industry
more than US$330 million, the FAA
estimates.
Given the high cost, government and the
aviation industry are looking at cheaper,
yet effective, alternatives, such as
spraying the existing insulation with a
coating that would help to protect it
against fire.
Eley said the two types of insulation
blankets acted upon to date are the ones
that have emerged as problems.
"The risk is out there," Eley said. "We
can't treat it lightly. But experience has
shown it's not a common problem, even though
there is a problem there and we are working
to address it."
The Swissair crash was the second most
serious aviation disaster in Canadian
history. The biggest was the crash of an
Arrow Air DC-8, which went down after
refuelling in Gander, Nfld., killing 256
passengers and crew, mostly U.S. soldiers,
in 1985.
lpynn@png.canwest.com
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© The Vancouver Sun 2005