Hi all, I've got a question about the A340 plastron (the triangular fairing added inboard of the outboard pylons to deal with aerodynamic interference and flutter), I've googled but not found, so here goes:
1. Did every 340-200 and -300 have the plastron, or was a different fix added at some point to get rid of it?
2. Did the 340-500/600 wing, with its additional chord, obviate the need for the plastron by providing more torsional strength?
Any input is appreciated
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Re: History of the A340 plastron
I'm trying to get some info on this for you but not much out there.
Re: History of the A340 plastron
According to my sources, only the original old A340's had the plastron, later models had modified wings.
Re: History of the A340 plastron
Anybody have a picture they's be able to post? I'm really curious to see this device!
Re: History of the A340 plastron
https://www.airliners.net/forum/viewtopic.php?t=773913&start=100
If you look closely between the o/b flap track fwd fixed fairing and the engine pylon you can just see the plastron fitted to the wing lower surface:
If you look closely between the o/b flap track fwd fixed fairing and the engine pylon you can just see the plastron fitted to the wing lower surface:
Re: History of the A340 plastron
Balerit wrote:According to my sources, only the original old A340's had the plastron, later models had modified wings.
Do you know at which l/n they got rid of it? The SAA bird in that picture was l/n 8
Re: History of the A340 plastron
I think it could have been when the -500 and 600 were built, they had completely new wings.
Re: History of the A340 plastron
Balerit wrote:I think it could have been when the -500 and 600 were built, they had completely new wings.
Yeah, I always thought they didn't get them, but a handful of 300s were still produced in parallel. I want to figure out if all the 300s had them, or only some subset.
Re: History of the A340 plastron
Thanks for the photo. What an interesting aerodynamic solution!
Re: History of the A340 plastron
If you follow the link I posted, you'll see that the pylons for 1 & 4 engines end in flap track type fairings as well.
Re: History of the A340 plastron
Thanks for that link. In that thread, we discussed what the outboard thingies were, and concluded that they were most probably part of the pylon structure. Regarding the plastron and whether it was on all 200 and 300 frames, I'm inclined to guess that it was, seeing as the aerodynamic issue didn't magically go away after EIS. It looooks like this picture of l/n 561 has the plastron, but the photo is not the best:
Re: History of the A340 plastron
I found the answer: only the first ones had the plastron, after that they modified the wing twist to get rid of it. I want to say this happened with l/n 74, but I could be wrong. I'm away from my book this week, but I know it's somewhere around there in the lineup.
https://books.google.ca/books?id=V1DuJf ... rt&f=false
https://books.google.ca/books?id=V1DuJf ... rt&f=false
Re: History of the A340 plastron
Ok that's great, now I can stop looking through hundreds of photos 
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