38 HANDLING UPDATE
GROUND HANDLING INTERNATIONAL APRIL 2013
a subject about which much has been written in the safety pages over the years. And, as to whether these tools are in general use, that’s another matter entirely. From the above investigation it seems that not every station is equipped with a scanning device; and indeed, Menzies’ spokesman suggested that in these early days of Dreamliner operation, it could well be that on existing (thus familiar) routes, it was not deemed a priority. However, that situation would surely change as the Dreamliner began operations to more remote destinations.
Back to Boeing for clarification: the airframe manufacturer subsequently confirmed that the Olympus device and another, the GE Bond Tracer, were referenced in its repair manuals for initial investigation purposes. As for the (bigger) C scan apparatus, it lists other models aside from the Toshiba example. And were these actually endorsed by Boeing? That specific question remained unanswered.
I was able to learn from LOT, which also operates a B787, that it keeps scanning equipment in its maintenance division at Warsaw airport and that this is a Boeing endorsed product. The carrier’s spokesperson revealed that it has plans to add transportable scanners at a future date.
Is beauty skin deep?
So, after beginning this feature by posing a question, it seems that there is a perfectly viable answer for the handler concerned about working with this new aircraft. There is, surely, some
degree of comfort to be derived from the knowledge that in the unlikely (and let’s hope that word is the correct one) event of a ground impact, at least the Dreamliner’s integrity can be assessed. Or can it?
Earlier on we mentioned composite panel testing. Hyonny Kim* is Professor in the Department of Structural Engineering, at the University College of San Diego, and he is less than confident about what’s available for checking over this new generation of aircraft, be they Boeing or Airbus since he has carried out research with some gradates and undergraduates on the sensitivity of the composite panel. He was aided in this by Cytec, San Diego Composites and Boeing and there was participation by Airbus, Bombardier, UAL, Delta and JC Halpin. There was also collaboration with Sandia Labs and the earlier-mentioned Peter Bishop. Here is the nub of his correspondence.
“I think a strict policy should be that if contact to the aircraft has occurred by GSE, then the location should be tagged and a qualified inspector should come to assess.
“This type of instrument (the 35RDC) will only find delamination damage within the skin, or separation between the stringer flange and the skin. It will not see damage to shear ties or cracking of the frame(s). In our tests, we produced shear tie damage and frame cracking without any skin or skin-stringer delamination. Even with the more complicated UT A-scan system we use (this is a Pocket UT model manufactured by Physical
Acoustics), we are not able to detect the shear tie and frame damage if we are sensing just from the outside skin.” Another materials expert consulted says that the above-mentioned device… “is simply an inspection tool which is substantiated in the context of the damage it can detect relative to the damage levels requiring consideration in AMC 20-29, along with the other inspection methods, damage levels, and inspection intervals. Anything considered to be outside this, CAT 5, in accordance with training guidance, should drive thorough internal and external inspection.”
All well and good – but how does one determine what is CAT 5? Especially if it may not be visible? “Cat 5 damage is that considered to be outside Certification; in other words, it is a known event or is obviously evident (visible) damage driving more extensive inspection. The manufacturer training emphasises this point. If in doubt – inspect.”
In conclusion
Thus, in the absence of any firm comment from the airframe manufacturers and given the complexity of the new aircraft material, we are left with something of a conundrum. Sooner or later, whether we like it or not, the composite aircraft is going to become a much more common sight at airports around the world.
On that supposition, when you sign up to handle a B787 or an A350, you might want to re-read this feature…
*Footnote: For readers desiring to see the results of simulated GSE impact on a composite panel, the following links provide footage of some of the testing carried out by Professor Hyonny Kim at San Diego University:
https://www.youtube.com/watch?v=TJofm5MuLoc https://www.youtube.com/watch?v=bBXhcQNbcI8
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