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01-09-26
0700 Morning routine.
…..
At 1200 hrs, the conference call was held
between the TSB and the FAA. Gus
SIDLA, Don ENNS, and John GARSTANG for the
TSB, Larry FOGG for Boeing, Pat CAHILL, Dr.
Rick LYON, Tim MARKER for the FAA, and
myself. It went for an hour and forty
minutes, so there was a lot of discussion
about the upcoming test. The following
is a rough outline of the meeting:
LYON was asked about the results of the Cone
Calorimeter and Micro Calorimeter tests, and
he advised that the results were good.
Rick WALTERS is still conducting the Micro
Calorimeter tests, and Rick had a concern
that the materials supplied did not include
samples of the materials burnt in the Cone
Calorimeter tests. He requires samples
and will obtain some from material left for
other tests. He also advised that as
far as the heat release parameters are
concerned, the numbers for each material
indicates that they are relatively uniform
for all, with no “bad actors” among them.
The conversation then got onto the upcoming
tests. The question was raised as to
how to ignite the foam duct. It was
commented upon that the usual manner for the
FAA is to take foam material soaked in
heptane and to light a match to it.
The idea of a radiant heat panel was
discussed. The unit Pat CAHILL had
access to supplied a temperature setting of
1200oF, however there was no way to be sure
that would be enough to cause a fire.
Pat CAHILL had calculated some time ago that
it would provide a heat flux effect of about
1.5 BTU per square foot per sec. It
was not known if that would be sufficient.
Rick LYON went over the requirement to
preheat the surface as if a fire was already
ongoing. He suggested to burn a chunk
of polyurethane to get the material going,
but Gus wanted the duct heated up
sufficiently first. Larry FOGG
reminded everyone of the fact that
conditioned air has to flow through the
duct. John GARSTANG felt that there
was a need to preheat the whole space, to
correspond to the hot gasses likely overhead
during the fire. Larry FOGG reminded
that there would be an effect created from
the overhead Mylar at the ceiling. To
further explain the required effect, John
explained that the wires below the duct were
relatively intact, but the ducts are burnt
along with the overhead skin and station
pieces. So, it was agreed that there
was a need to install further insulation and
Metallized Mylar material. There was a
discussion mainly between Larry and Pat
about what material should be used, and it
was then agreed that one layer of Metallized
Mylar would be used to represent the muff
around the three ducts adjacent to the foam
duct. Larry then pointed out that
there was a need to correspond to the
heating effect on the upper surface caused
by the overhead blankets. John also
mentioned about the type 3 tape, that it is
a problem to locate a similar type at this
time, but that tape had to have played a
part in the fire as there was a fair amount
applied to the ducts and insulation
blankets. Larry FOGG commented that
much of the tape may have been after the
fact repair tape. John went on to
describe the amount of tape at the forward
end of the foam duct, that there were
several wraps around the end to fasten the
connecting ducts. There was a
discussion over the tape to be used.
It was felt that the difference in the
adhesives is the actual problem, that one
will burn more readily than another.
After much discussion over tape types and
the amount to be used, it was agreed that
Metallized Mylar tape, type 4, class 2 would
be used. It would be wrapped twice at
both ends of the foam duct. It was
also agreed that one layer of Metallized
Mylar would be placed around metal ducts
under the foam duct. Larry FOGG agreed
to supply Pat CAHILL the specs on the
fibreglass insulation after the meeting.
It was then agreed that this part of the
test is Phase 1. The Metallized Mylar
will be match lighted to start the fire,
that a clearance between the ceiling and
duct, and duct and lower ducts is important,
as well as the positioning in relation to
the lower ducts.
Should the duct survive Phase 1, then it
will be used in Phase 2. Gus reminded
everyone of the fact that the cone
calorimeter tests indicate that a
25-heat-flux with a spark will cause the
duct to burn. LYON commented that this
is because of the epoxy skin. Larry
FOGG commented that it had fully passed the
vertical flame spread test without any
burning. LYON finally agreed that
without the radiant heat panel, the duct may
not burn. There was a question raised
about a mild airflow in all phases.
Don ENNS then commented that should the duct
pass Phase 2, it will be placed in a raging
fire as Phase 3.
There was a discussion over blocking off the
ends to keep the heat in, and the question
of air accessibility was raised. The
idea of an open bottom with a closed of top
was raised, and generally it was agreed to,
so that it would trap the heated air while
still allowing fresh air. LYON then
suggested that the TSB should supply a
schematic of what the test should look like,
with the proper placement of ducts, sizing,
etc. It was suggested that a rough
sketch had already been supplied, but it was
agreed that further sketches will be
forthcoming ASAP. It was also agreed
that the test would be run in the full-scale
facility, on the floor using the 747
section, which is about 10 feet long by 10
feet wide. Pat calculated that she had
sufficient Metallized Mylar to cover the
insulation and the ducts. A question
was raised about fastening the materials.
LYON pointed out that the micro calorimeter
tests have shown the nylon fasteners to be
very flammable, but that he would be able to
find something of a similar nature to fasten
the material. The question of the door
track was raised, as it tends to support the
overhead blankets in place. It was
agreed that something would be set up to
restrict the fall of the blankets.
The question of igniting Phase 2 was raised,
would it be heptane or a kerosene burner?
John wanted something that produced hot air
without consuming the O2. John
expressed a concern over an air flow, as it
was felt that any airflow may affect the
burning of the Metallized Mylar, that it may
indeed blow out a small fire. LYON
suggested a steel plate over a pan of
burning fuel. However, Larry quickly
commented that this would cause the bottom
of the duct to receive the radiant heat,
exactly opposite to what is believed to have
happened. It was agreed that more
thought would have to go into the matter.
Then the timing of the test was questioned.
Don questioned the ability to have
everything in place by the week of Tuesday,
the 9th Oct. Monday is a US holiday
(as well as being Thanksgiving Day up here).
Larry FOGG suggested that one trip be used
to set up the test, and that the test be
completed on a second trip. The FAA
people advised that they have a conference
the week of 22-25 OCT, and that they need a
day before this test to prepare for that.
Gus and John both reiterated the fact that
there was a push on by TSB management to get
things completed ASAP, or it may get
cancelled. So, there was a definite
need to conduct the tests during the week of
the 9th. It was suggested that should
the duct burn up on Phase 1, there would be
no further Phases. So, it was pretty
much agreed that Phase 1 would go beginning
the 9th, with that as a set up date.
Things would be prepared and ready for a
burn on the 10th or the 11th.
The question of video was raised by John.
He requested that they photograph and
videotape everything, including infrared
video of the burn. LYON advised that
they didn’t use 35 mm but asked if digital
photos were sufficient. It was also
agreed that LYON would conduct cone
calorimeter tests on the AN-34 Metallized
Tedlar before the burn test. Don has
yet to get the Metallized Tedlar from
Swissair. They are conducting a ‘D’
check in South Africa and are to send up the
material from that aircraft. Dr. LYON
will also pre-test the Metallized Mylar tape
on the cone calorimeter to determine if
there is any or how much of a difference.
I raised the question of the connecting
ducts for the foam duct, and it was
generally thought that they were not
necessary, even if one of the correct
diameter can be found in the debris.
So in conclusion, it was agreed that we
would all meet at the FAA test centre at
0800 hrs on 01-10-09, with the burn test on
Thursday.
The conference call was completed.