So we all know how planes fly, right? The top of the wing is rounded and the bottom of the wing is more straight. Air takes longer to travel over the top of the wing than the bottom, which results in more pressure on the bottom, hence the lift. Right? As it turns out, no.

This is what I was taught, and it’s what I’ve always believed (it’s even in most lower-level text books), but it’s simply not true. The concept is called the Bernoulli Principle, and it accounts for very little of the lift that makes flight possible. The main reason planes fly is far simpler: wings force air downward, which in turn pushes the wings upward.

The primary actor here is the the Coanda Effect, with the Bernoulli Principle taking a supporting role. It all starts with the air wrapping downward along the back of the wing (Coanda).