And now for something completely different...

One of my interests has always been airplanes. I've been drawing them since before grade school, read lots of books about them, and built lots of plastic models of them.

At a relatively young age, I was introduced to the textbook explanation for how a wing develops lift, which is called the 'Bernoulli principle', named after the scientist who discovered it. A simplistic summary of it is that air must flow faster over the curved top surface of a wing than under the flat bottom surface of a wing, and the faster air on top creates lower pressure, which creates lift.

As I read more about airplanes, there were pictures of many airfoils (wing cross sections) that, according to the 'Bernoulli principle', should not create lift. Flattened and/or symmetrical airfoils do not have those characteristics, but there are many examples of actual aircraft that use them. Dad, who worked in an aircraft factory for several years, explained to me that the 'angle of attack' of the wing is much more important than the 'Bernoulli principle' in the creation of lift on a wing. More advanced books explain this, and how it ties in to Newton's laws of action and reaction, but the primary explanation continues to be Bernoulli's in most books.

Just a couple of years ago, I saw a display in an aviation museum of a very small wind tunnel. Less than a foot square, and maybe four feet long, it had a small fan which pulled air over a small balsa model wing section allowed to move up and down on metal posts. There were two inlets for the air - one on the opposite end from the fan, and a smaller one on the bottom of the box just in front of the wing. The intended use of the diplay was to just press the button to turn on the fan and watch the demonstration of the 'Bernoulli principle' in action. However, it was easy to demonstrate that that force does not provide enough lift to raise the wing. Simply covering the bottom air inlet reduced the wing's effective 'angle of attack' with the oncoming air, causing the wing to drop.

This is probably the most innocuous bit of disinformation I've seen in a museum, but what possible purpose could be served by perpetuating this myth?

Nasa has a page about this issue, and here is another page, or you can just google bernoulli lift fraud and get quite a few others.