That is absolutely the most bizarre thing I think I've seen all day. I saw those things extended on that 727 that sits at CLT, and I just thought the wing was broken or something. I feel really stupid now, I should probably know that, but I've never heard of them before.

So the rest of the wing has regular slats right? That's how it looked to me. If that's the case, do you have any idea why regular slats just wouldn't work for the entire wing?

And forgive me, but I don't quite understand what you mean about the reason behind blocking flaps 40 and 30. But that's A LOT of flap settings. By comparison, how many do, oh say... B757/767 have?