That is a very good video which I have now saved. Below is a quote from the attached explanatory text.
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“What actually causes lift is introducing a shape into the airflow, which curves the streamlines and introduces pressure changes – lower pressure on the upper surface and higher pressure on the lower surface,” clarified Babinsky, from the Department of Engineering. “This is why a flat surface like a sail is able to cause lift – here the distance on each side is the same but it is slightly curved when it is rigged and so it acts as an aerofoil. In other words, it’s the curvature that creates lift, not the distance.” - See more at:
How wings really work | University of Cambridge
Unquote
It doesn't say
why there is lower pressure on the top and higher pressure on the bottom. Of course the "correct" answer as to the why is quite complicated so this is why I believe the faster air on the top = lower pressure has been used by PPL instructors. They are looking for a fast and easy explanation. '
I used to do the same thing but I was uncomfortable because I knew it was wrong. Now I just avoid the issue entirely.
I tell PPL students they have to know 4 things about wings
1) As the wing moves through the air the airflow splits with some going around the top of the wing and some below it
2) The air above the wings will have a lower pressure than the air below the wing
3) The angle the airflow meets the wing at is important and is called AOA
4) The air is bent downwards as it flows off the back of the wing.
All of these facts have direct practical application for the pilot. Any higher level of more detailed knowledge has little practical application and detracts from all of the many other practical knowledge items that a pilot must know.