[dleary]

I think it's far from useless... Because it helps to focus on what could possibly be happening. It's not "true enough for an 8 year old's purposes", it is the actual truth.

The air is being accelerated downwards by the airplane. Newton's third law. To stay aloft, the airplane has to manufacture a counteracting force to gravity. And the only way to do that is by accelerating something downwards.

So, we can discuss whether or not the curvature of the airfoil matters, or the angle of attack matters, but the simple fact is that a lot of air has to be accelerated downwards somehow for the plane to stay up.

And the more magical descriptions of lift, including the broken Bernoulli airfoil model that was accepted for so long, are easy to discount once you focus on this important fact.

[jvanderbot]

The wing is curved to force air downward without the clumsy ruddering effect described in top level comment. That downward force is the newtons law lift. If you go too fast you lose the smooth flow over the wing and you lose lift. Too slow and you don't force enough down to generate enough lift.

[danielschreber]

What about stalls?