How wings work

The latest Scientific American, explaining how wings work:

[...] because the wing top is curved, air streaming over it must travel further and thus faster than air passing underneath the flat bottom. According to Bernoulli's Principle, the slower air below exerts more force on the wing than the faster air above, thereby lifting the plane.

Scientific American, April 2006, P76

Everyone knows that that's how wings work. Unfortunately, it's bollocks.

While I'll let such inaccuracies pass in the non-technical press, I expect better of a magazine that regularly prints articles attempting to explain cutting edge of quantum mechanics, cosmology, immunology, and lots of other -ologies. Even if it's just a throwaway line in an item explaining something different.

The problems with that explanation can be demonstrated with a few fairly straightforward examples:

Firstly, in the course of aerobatics, it is quite common for aircraft to fly upside down (by which, I mean really fly upside down, in sustained level flight, not just a quick loop-the-loop or roll). For that to work, their wings must still be generating lift, despite the fact that the longest side is now on the bottom.

Secondly, not all wings are longer on top than underneath - there are many wing cross-sections that are symmetric, or have the same length on both top and bottom. Yet they still generate lift. For example: sails. Yep, a sail is a wing, turned on end. It's a bit of cloth. To all intents and purposes, both sides of it are the same length (let's not quibble over the tiny difference caused by the thickness of the fabric - trust me, it's irrelevant)

Finally: Two blobs of air approach a wing. One goes over the wing, the other under it. How does the air passing over the top know that it's got to go faster to keep up with the air passing underneath? They're not telepathic, psychokinetic entities. They're inert blobs of air. There's a big lump of metal between them. They cannot directly influence each other. While we're at it, who says that the air passing over the wing has to meet up exactly with the air passing under the wing?

( How wings really work. Warning: contains gratuitous anthropomorphism )