TWICE AS FAR
SWISSAIR 111
CRASH INVESTIGATION
- EXTRACT FROM FILE NOTES -
FOR
- 2000 SEP 17 -
00-09-17
0700 Routine
weekend. Worked on notes, then
turned exhibits.
John GARSTANG advised that he has
received results from Skip PALENIK
about the cockpit carpets.
Wendy NORMAN from Ottawa CDL
Chemistry had cut samples of
suspected burn areas when she was
down here working, early in the
investigation. John finally
heard back on them, and they
definitely are burn areas in the
carpet. It would appear that
the cockpit liner had melted and
dropped to the floor, burning the
carpet surface. These sample
locations can be seen in my overhead
photos as a cut out triangle &
rectangle. It seems that the
areas of short carpet are actual
burn areas where the object that was
on it burning has suddenly been
shifted or torn away, as if on
impact.
Lee and John GARSTANG also confirmed
that the reason for TSB wanting to
shut down the file so soon is
because Ken JOHNSON wants to retire
but wants to present the report to
the board before his retirement.
Lee apparently had a conversation
with Vic GERDEN a week ago Friday
(00-09-08), on returning from their
financial meeting over at RCMP HQ.
Vic confirmed then the rumour for
Lee. At the same time, he
complained that they were working
their people too hard with too many
long hours. John’s comment was
to the effect that how else does he
expect the work to be completed by
their deadline. …..
John GARSTANG came in to the studio
to see me this afternoon to ask
about further filming of more end
cap burn tests. He plans to do
further samples this week. I
then asked him about the oxygen line
tests. He said that they had
conducted several tests last week
with significant results. They
had received only one O2 line from
Boeing, so they worked with what
they had. Paul FIOCCA and
Larry FOGG were present for Boeing,
and they audio taped the test (did
not videotape it as it was in an
enclosed furnace). The first
test involved dialling in a
temperature of 800 deg F with the O2
line in the furnace. It took
nearly half an hour to come to
temperature. The line had 70
lbs of pressure on it, and it did
slow a leak around the threads of
about 10 lbs pressure in ten
minutes. This test was
completed, and John then went on to
the next test, this one having the
furnace at 800 deg F and inserting
the line with it under 70 lbs
pressure. The unit was in the
furnace for about 3.5 minutes when
they heard a definite pop sound.
The line was connected to a
regulator that could only maintain
64 lbs pressure, a reduction of 6
lbs of pressure. So, the leak
did not result in a complete loss of
pressure. The pilot’s system allows
for a loss of up to 8 lbs, or down
to 62 lbs pressure. Therefore,
they would still maintain an oxygen
feed, and the tank should have been
sufficient to last through the
suspected fire duration. John
indicated that he could feel the air
blowing from the popped cap, but
they could not visually see the
difference in the cap. They
had placed witness marks on the cap
and line, and the cap had not
turned. However, it could now
be hand twisted off, even though it
had been torqued into position with
120 inch/pounds of torque. It
is also interesting to note that the
Boeing reps did not want this test
performed as they advised that
because the lines had been
previously baked, they were no
longer pristine lines, and the
anodising had been removed.
This was ignored, because the line
was shown to hold pressure before
being placed in the furnace.
On losing pressure, it was argued
that the loss could be due to a
break in the line rather than the
aluminium cap separating from the
stainless-steel line. So, a
stainless-steel cap was used to
replace the aluminium cap, and there
no longer was a loss of pressure.
The test was then repeated with the
temperature at 1200 deg F., and the
cap popped again at about 3.5
minutes. It may be noted that
Metallized Mylar burns with a flame
of about 1200 deg F.
Because only one length of tubing
was supplied, further tests could
not be run. However, it was
determined that the tubing is a
standard stainless-steel tube, with
a standard stainless steel cap
applied to it by a standard method
for this type of air line tubing.
So CANMET is to create further lines
to the Boeing specs (to be supplied
to them by TSB), and they will
conduct further tests. It is
expected that sufficient tests will
be conducted using the same
standards to create a statistical
record of events, so it cannot be
argued that it was an unusual event
that occurred at CANMET.
The final analysis of the leak will
depend greatly on the fire patterns
being generated on the computer from
the debris and will involve someone
like QUINTIERE. The shut down
of the re-circulation fans
(indicated on the FDR) would cause a
change of the airflow towards the
forward area of the aircraft.
This would likely cause the Velcro
tabs on the smoke curtain to melt or
burn, allowing it to fall down and
provide a routing for the smoke and
flame into the overhead cockpit
area, being sucked in by the airflow
system below the cockpit in the
forward avionics bay. At the
same time, the Metallized Mylar
around the oxygen line would burn,
causing sufficient heat to cause the
line’s cap to leak, providing pure
oxygen to the fire. Even if
only a small leak, it would have an
effect. The FDR indicates a
significant change in events
(numerous items being shut down due
to blown fuses) shortly after the
shutdown of the re-circulation fans.
Since we now have evidence of
burning on the cockpit carpet, it
would appear that there was
sufficient heat to melt the cockpit
liner and cause it to burn.
This is the same environment in
which the co-pilot is trying to fly,
and the captain is trying to follow
his checklist.
Boeing has already put out a recall
notice to all the airlines with
MD-11’s to change the cap to
stainless steel. The FAA has
been asked by the TSB to issue an AD
on the subject, but they have
declined at this time, stating that
they need to allow time for the
airlines to make the change on their
own. I don’t understand this
line of thinking. John’s
concern is that if there is another
similar fire situation, they don’t
need this line as an oxygen source
to keep the fire going.
It is interesting to note Larry
FOGG’s description of the test when
he spoke to me on Friday, 00-09-15
when he said: (my notes for the
subject written on that day) . .
that at high heat (800 deg F), there
was a slight leak around the
threads, but nothing that amounts to
very much, and no weakening of the
cap’s structure.
It is also interesting to note that
Paul FIOCCA mentioned the magnesium
problem to John GARSTANG and
indicated to him that I was very
interested in the matter, as were
they. It is even more
interesting to note that John is of
the opinion that Vic GERDEN is also
very interested in the magnesium
matter, having mentioned it several
times. …..
John GARSTANG also advised that the
IFEN report is presently being
written. They have completed
the latest interviews of people in
Long Beach. The report will be
over 80 pages in length. This
fact has generated some comments
from the TSB management. The
person whom Vic GERDEN reports to
has expressed his opinion that if
the IFEN report is this long, then
they cannot be writing it correctly,
as it should only be a few pages in
length. John also noted that
there are fifteen or so aircraft
flying with the IFEN system still in
tact the way it was on HB-IWF at the
time of the crash. He
expressed concern over this.
I expressed concern to John that the
tests had not been videotaped.
Even if the test is in an enclosed
furnace, the set up, the equipment
going in, the time involved, and the
equipment coming out, plus viewing
the regulator dial is of
significance. This is
something that Boeing is going to
argue heavily, and a jury should be
able to witness for themselves.
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