On 28 Okt, 05:39, Dave wrote:
If you will be satisfied with empirical evidence, stick your hand out
the window of the car while going 50-60 MPH. Experiment with different
angles of attack. You will no doubt experienceliftwhen your hand has
a positive angle of attack. Poor man's wind tunnel - but illustrates
that just about anything relatively flat will fly
given enough speed and a positive angle of attack.

David Johnson

The problem is probably, that Bertie does have a car, so the simple
experiment is not possible for him.

He might find a bus, where he can open the window and try.

The risk is that he does not understand the physical effects on his
hand.

Since he does not understand how to see the vertical airflow from the
wings at AOA in this picture, he has a big problem:

http://www.efluids.com/efluids/galle...s/Morris_4.jsp