TWICE AS FAR

 

SWISSAIR 111

CRASH INVESTIGATION

 

 

 

- EXTRACT FROM FILE NOTES -

 

 

FOR

- 2000 JUl 11-

 

00-07-11          0700    Morning routine.        

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            Gus SIDLA approached me this afternoon to advise that his TSB management want to eliminate the Sky Scan examination of the wire beads.  Gus said that a previous decision had been made to do the testing, and money had been set aside.  But they are now looking at the time and cost of doing Sky Scan versus what they might get from it.  Gus stated that they feel there is no certainty that the method will provide results, particularly with regards to providing a cause of the fire.  Gus is quite disappointed over the decision and stated that he now has to supply justification for continuing with the project, or it will definitely be dropped.  I pointed out that if the Sky Scan examination fails, at least we still have the intact beads.  If the sectioning of the beads fails, there is nothing left.  Gus agrees that sectioning is a destructive method after which nothing will be left suitable for further examination. 

            I also suggested to him that Boeing/Swissair are very likely to oppose the sectioning process, perhaps going as far as to get a court order.  Gus was very surprised over this, saying that they had jurisdiction and could do as they wished.  It was pointed out to him that should Boeing obtain a Canadian Federal Court order to not do the work, they would have to adhere to the order or risk being in contempt of court.  This really made Gus think, as they obviously have never considered this.  I told him that we also have a problem with cutting the beads that contain the magnesium, and until such time as the source of the magnesium has been determined, we also do not want to see them destroyed.  To this, he stated that Vic GERDEN is flying in this evening, and he will pass it over to him for his consideration and decision. 

            It was also pointed out to him that Vic GERDEN had stated in a meeting on 00-05-16 (see my notes as minutes of that meeting for that date) that he did not want to see any destruction of the beads until all avenues of examination had been exhausted.  It was also agreed that there would be further meetings to discuss the matter and that notice would be given before anything was undertaken that would destroy any of the beads.  In short, we have been assured that these tests would be undertaken, or nothing destructive would occur.  Both GARSTANG and SIDLA agree that sectioning is a destructive process.  FOOT even agreed in the meeting that some of the beads would be destroyed in the process.

            The FIB/TEM process was mentioned, and he stated that Dr. BROWN is selecting two wires today for the process, as a test of the procedure and to make a comparison of the results with other test wires.  Nothing further was mentioned regarding it. 

            I then spoke with Insp. LATHEM about this and let him read these notes.  He indicated that he would speak with Vic GERDEN in the am, and that I should have some bulleted points as to why the process should be completed.  He also felt that Boeing would have a tough time in getting such a court order.  I question that.  I also wonder what our approach would be if TSB decided not to do Sky Scan & FIB/TEM but went directly to sectioning.  The feeling I had was that we would do nothing, that there isnít any desire from our management to continue with any form of the investigation.  This is contrary to my interpretation of the comments made during the meeting with DUNCAN and ATKINS.

            The following are points in favour of Sky Scan:

- The Sky Scan process has the ability to x-ray the wires and to provide a series of 3D photos of each that is viewable as a virtual reality interactive format on the computer. 

- It will provide a layered view of the internal makeup of the bead, showing any voids, or inclusions, etc.

- It will allow a determination as to whether or not the bead is a total melt or a partial melt, exactly what areas are melted, how many arced areas are present, if it was a total arcing process involving the whole wire or just a light touch involving only part of the wire, etc.  This could lead to later interpretations as to how the wire came to be arced in that particular manner.

- It will allow a determination as to whether or not the wires are fused as a wire bundle instead of being melted together as one mass unit.  Is what we see a real melt due to arcing, or merely fusing of the wires internally with some exterior melting?

- It is a totally non-destructive method, an industrial cat scan similar to that used in the medical field.  It is an equally high-tech process as the AES but is a newer process.  But unlike AES or FIB, it provides a hands-on ability to view the whole internal area of the wire.

- The cost of the Sky Scan is less than $300 Canadian per bead (2 hours at $100 US per hour), or about $6000 Canadian for twenty beads (not all beads need to be examined).  But for that price, why not do all thirty-three?

- Examination by sectioning is a totally destructive method (these are the words of TSB members).  To examine, for example, the largest wire by sectioning will require cutting it along it longitudinal axis (it has to be done this way to determine if it is a weld or a melt).  This can only be done by encasing the bead totally then cutting and grinding it to a smooth finish to expose the centre half only.  This then only provides a view of one layer of the bead.  To view more layers, more of the bead will have to be removed by grinding.  The smaller beads will be just as hard to handle as many of them will have to be cut at odd angles, or more than one angle.  Sky Scan provides a look at the whole bead area, not just at one or two central planes and can answer this question about the large bead without cutting or destroying it.

- Once the bead is encased in epoxy, it will be impossible to remove should the need arise at a later date.  The epoxy is a liquid that will totally surround each wire filament and surface imperfection, including all rough edges.  Once it hardens, it is permanent.  Any attempt to remove it will destroy the wire and itís integrity, leaving behind epoxy residue. 

- Sky Scan and FIB/TEM will likely eliminate the necessity to section the wires, providing a greater range of answers than that supplied by sectioning alone.  Sky Scan and FIB/TEM will certainly do no harm to the wires.  But to miss the opportunity and go to sectioning will eliminate the chance to undertake these processes.  Once sectioned, we cannot reverse the process, as it is destructive.

- We were assured by Vic GERDEN on 00-05-16 that every attempt would be made to examine the beads thoroughly by non-destructive methods before any consideration would be given to sectioning (meeting at ĎAí hangar on 00-05-16).

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