Someone sometime gave a rough explanation of how that theory fits fairly well with an aerodynamic state which is far removed from level flight? Well, I guess that settles it then.
Regarding the pointlessness of having convex lower surfaces on airfoils, I think there are
people you may want to
call and tell
them about it.
Note how the airflow curves upward around the forward part of the bottom of the wing in the last pic in the last link. Recall what I said about there never being a velocity change in a fluid without a pressure gradient? Something is clearly making the air turn upwards as it passes approximately quarter chord. What does this tell us about the pressure near the wing as compared with the pressure a distance out from the wing?
To get somewhat back on topic, to the ATPL theory... I for one haven't got the foggiest on what they're teaching this week. I just have a fairly good grip on what really makes aircraft fly. I have long since concluded that this may or may not have a bearing on what is actually being taught at flight schools...
The FAA used to be way off, with half-digested theories about half venturis and what not. In the hope of things having improved I went to check what they currently have to say on the subject and found this gem:
Originally Posted by FAA Pilot's Handbook of Aeronautical Knowledge
The pressure difference between the upper and lower surface of a wing alone does not account for the total lift force produced.
I think I'll just continue to ignore them.