- 2001 SEP 26 -


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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.



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