# Stupid (?) question: How do planes really fly? **URL:** \ **Category:** Factual Questions\ **Created:** [May 7, 2026, 2:37pm UTC](https://boards.straightdope.com/t/stupid-question-how-do-planes-really-fly/1029890 "2026-05-07T14:37:34Z")\ **Posts on this page:** 1\ **Showing post:** 9
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [May 7, 2026, 3:41pm UTC](https://boards.straightdope.com/t/stupid-question-how-do-planes-really-fly/1029890/9 "2026-05-07T15:41:04Z")
For reference, here’s a previous discussion about the Bernoulli effect and its relative irrelevance: > [@Stop abusing Bernoulli when describing lift](https://boards.straightdope.com/t/stop-abusing-bernoulli-when-describing-lift/647933): > > Many references and encyclopedias, even some published by the FAA, give incorrect explanations of lift. Cecil repeats one of the more common theories in his explanation of why golf balls have dimples. He says, “The Bernoulli principle tells us that slow moving air has higher pressure than fast moving air. The difference in pressure forces the golf ball up.” This is untrue. Lift is a force, created by turning the flow of air. If Bernoulli were the governing principle of flight, golf balls would n… Also here, nominally about jet engines, but where I was educated about the fact that even the “barn door effect”, or a flap at the edge of a wing, is technically an airfoil – it doesn’t have to be the pedagogical Bernoulli-touting wing cross-section: > [@Compressor stalls on jets: why flame out the back?](https://boards.straightdope.com/t/compressor-stalls-on-jets-why-flame-out-the-back/752298/7): > > Sure they do. The upward force on a wing is exactly counterbalanced by the acceleration of air downwards. How that acceleration happens is by a variety of (partially overlapping) mechanisms, but regardless, airfoils absolutely “shove air downwards” as their primary purpose in life. > [@LSLGuy](#): > > The vast majority of lift is the “barn door effect”. Hold the wing at an angle to the incoming air such that the incoming air “bounces off” the bottom side and is deflected downwards. > > A secondary effect at lower speeds is Coanda effect. Air will tend to follow a convex curvature. With the result that a curved upper surface will impart a downward vector to the air departing the trailing edge Indeed, it seems to me that early airplanes, with their thin flimsy fabric wings, exploited both of those effects, and not at all the Bernoulli effect because they didn’t have the cross-section profiles of modern wings. --- _[View the full topic](https://boards.straightdope.com/t/stupid-question-how-do-planes-really-fly/1029890)._