Ron,

The link you poseted does an excellent job explaining what I tried to say. It also disagrees with your statements on lift

Wouter,
Look at the link that Ron posted. It does an excellent job. I will also try to explain it better.

I'm sure you have heard of the hand sticking out of a car window. You have probably done it. This creates a very crude wing. You know if you tip the forward part of your hand up your hand will be lifted into the air. The more you tip it the more you feel your hand being lifted, to a point (about 45 degrees). A tool we use in mechanics, vector diagrams, allows us to break down the direction forces act into components of X, Y, and Z. For the sake of this discussion we will use only two dimentions, horizontal and vertical. Once you understand it in 2 dimensions adding the third is easy.

On a piece of paper draw a line at an angle with the left end fo the line higher on the paper than the right. This is your wing. Now draw a horizontal arrow into the wing's underside. Have the point of the arrow in contact with the wing. This is your initial airflow. Now, just like light reflecting off a mirror, the airflow changes direction. Draw a new arrow starting at the first arrows point. The new arrow will angle downward. This is the new direction of the air.

To break this new direction of airflow down into vertical and horizontal components, draw a rectangle such that the arrow starts in the upper left corner of the rectangle and end in the lower right corner. The vertical sides of the rectangle represent the vertical component of the airflow and the horizontal sides of the rectangle represent the horizontal component of the air flow.

At this time think of these arrows as representing forces. You can see how changing the angle of the wing (angle of attack) will change the vertical and horizontal force components.

I want to say at this time I am keeping this explaination very simple and not using any math, just visualization. Chances are the horizontal component in your diagram is larger than the vertical which would not make sense in the real world. Again, this is just for visualization purposes only.

This vertical component is what keeps airplanes in the air.

I hope this very simple explaination helps. I will try to draw a diagram and post it over the weekend.

One of the reasons why I love sailing is the amount of mechanics involved in making a boat sail and truly understanding what happens when you make any adjustments to the boat.

Again, I hope I was clear enough on this. It is much easier to explain in person with a pen an paper.