# I read a book saying bernoulli's flight equations didn't have as much impact on lift as most people think [duplicate]

I'm a computer scientist that likes to read about math and physics occasionally. A local author at a nearby aviation center brought bernoulli's flight equations into question.

It was clear enough logic, but I didn't understand all the math involved. He basically said that the lift equations don't account for why a plane can have lift while it's still upside down and took some sample data on his small aircraft to show.

Anyhow, I didn't know what to make of it, my only point of view and my first acquaintance with flight physics.

How much effect does Bernoulli's equations play in flight, especially when an aircraft is upside down?

He suggested that Newton did some early work on lift equations, is this true?

What is a sufficient way to view Bernoulli's lift equations?

• There's obviously no way anyone can comment without seeing the actual content of the book. – user4552 May 2 '13 at 12:33
• airspacemag.com/flight-today/Upside-Down.html: "Most airfoils are cambered, or curved, on top but flat on the bottom. As a result, they fly better upright than inverted. Symmetrical airfoils, which have the same curvature on both surfaces, perform exactly the same upright or inverted, and so are favored by aerobatic pilots. In order to fly at all, however, a symmetrical airfoil must be positioned at a slight positive angle—leading edge high—with respect to the flight path; otherwise the airflow around the upper and lower surfaces would be the same, and no lift would be created." – Wandering Logic May 2 '13 at 12:39
• Can't really address the book without clearer info, but try here for a good accessible discussion of the aerodynamics of flight. Short story: Bernoulli works perfectly well, though the shape of the wing doesn't come into it in the way a lot of people think it does, and a lot of other things people say don't work at all. – Michael Brown May 2 '13 at 12:40
• That does help, and he did mention airfoils in his book. – mathacka May 2 '13 at 12:58
• – user4552 May 2 '13 at 13:13