Okay, not really noticed this before as I usually go around in my P-47, but after loading up a 'Vanilla' IL2 4.09 I went and loaded up a P-51D 20NA (it also appears on the B and C Models too) and took it for a flight.
Looking out at the wings I saw this:
Now this is a default skin, so not a custom made error, but I don't know what it is that causes it.
I loaded a Custom skin too and got the same result.
If this is part of the model, then I'm embarrassing myself, apologies, but if it isn't, what is causing it?
Cheers, MP