Kip Powick Posted November 5, 2004 Share Posted November 5, 2004 An excellent document, complete with color photos showing the buckling of the Airbus 340-500 wings (in flight) vs Boeing has been passed to me. I am unable to post it here but if anyone is at all interested I will pass it on. Send request to me at; kidi@sympatico.ca I will respect any anonimity, as always. The document is 789 KBs Link to comment Share on other sites More sharing options...
Guest rattler Posted November 5, 2004 Share Posted November 5, 2004 Kip: are you talking actual buckling (damage) or normal flex??? Link to comment Share on other sites More sharing options...
AME Posted November 5, 2004 Share Posted November 5, 2004 Here is the Airbus response to this doc "Airbus have recently been made aware of the exsistence of photographs on the internet of the A340-500/600 in flight all taken in similar lighting conditions where the wing reflections show an extended image of the winglet on the reflective painted surface of the wing. Some distortions of the reflected image seem to indicate local undulations of the wing skin. The location of these features coincides with the manual refuel hole, the safety line attachment point at rib bay 22 to 23, the stringer 15 joint at rib bay 26 to 27 and the relatively stiff outboard pylon support ribs. The features are a natural consequence of the design, which includes changes in local structural stiffness and hence curvature in that area of the wing under flight loading. Under certain conditions, these features can become visable to the naked eye and appear as undulations. This optical effect can magnify such features between 100 and 1000 times depending upon the curvature and lighting angle. This ia s well known phenomenon and as such is used in surface quality inspection techniques. As is the case on all Airbus aircraft, a comprehensive structural test programme was under taken as part of the certification in order to demonstrate structural robustness. In the case of the A340-600 this involved an outer wing static test, full airframe fatique test and structural load measurement flight tests, which were satisfactorily carried out beyound certification requirements." Link to comment Share on other sites More sharing options...
Kip Powick Posted November 5, 2004 Author Share Posted November 5, 2004 AME..... ObviouslyI don't fly the aircraft but it is interesting. On the other hand re Airbus rebuttal......what else would you expect them to say?? Only time will tell. Link to comment Share on other sites More sharing options...
Vsplat Posted November 6, 2004 Share Posted November 6, 2004 There's an old saying, that which does not bend, breaks. Since metal is not totally elastic, I'm not surpised to see this kind of thing. To me it doesn't signal anything one way or another. Now, if Airbus follows this up with a Service Bulletin regarding cracking in the structure or skin around that area, THAT would get my attention. Just my opinion Vs Link to comment Share on other sites More sharing options...
Mitch Cronin Posted November 6, 2004 Share Posted November 6, 2004 I'm inclined to agree with Vsplat... Having now had the chance to look over the pictures, it is evident that there is some skin deflection happening that, on the long angle appears as wrinkles... but I have no doubt that if it were possible to measure them, - depth over width - the amount of deformation would be well within accepted limits. The only question becomes, will the continued flexing there result in fatigue cracking over many hours... Airbus seems to be addressing that question with their comments about the certification testing. A wild guess (though not without some basis in knowledge) of the actual deformation based on what I see in those photos, would be about an eighth of an inch depth, over a width of about 8 to 10 inches or so... in two areas a couple feet apart... which would be, in the highly technical vernacular of the highly trained aircraft maintenance engineer, "dick all". Link to comment Share on other sites More sharing options...
Mitch Cronin Posted November 6, 2004 Share Posted November 6, 2004 Here's a crop of two of the photo's: Link to comment Share on other sites More sharing options...
Mitch Cronin Posted November 6, 2004 Share Posted November 6, 2004 Perhaps the best of the pictures: Link to comment Share on other sites More sharing options...
Canus Chinookus Posted November 7, 2004 Share Posted November 7, 2004 There's an old saying, that which does not bend, breaks. Since metal is not totally elastic, I'm not surpised to see this kind of thing. To me it doesn't signal anything one way or another. Now, if Airbus follows this up with a Service Bulletin regarding cracking in the structure or skin around that area, THAT would get my attention. Just my opinion Vs which is exactly why i'm not all that excited about the industry's love affair with composite these days... :/ Especially in vertical stabs. Link to comment Share on other sites More sharing options...
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