By curiosity I have just found this threat. For a long time I have been looking for reasonable explanation of lift, and guess what I have found one. Not me, but Dr Wolfgang Send. He has a webpage with some good explanations. Www.aniprop.de
The origin of all lift is because more more air is flowing over the top of the wing than underneath. As the separation point of the airflow moves forward and down (that is the interesting fact) from the leading edge at a positive angle of attack, more mass of air is now routed above the wing (might it be a symmetrical wing or whatever). Thus, the air is being accelerated and you get this tube-effect described by Bernoulli resulting in low pressure above the wing and high pressure below. The wing gets sucked up.
