Now this seems to be the question of the ages, and various questions on this site regards it.
The often told description of lift is that it is due to air traveling faster over the wing than under it, creating pressure differences according to the Bernoulli equation.
This however, makes little sense to me and as I've read it is entirely false. Particularly interesting is this article where the author writes that
Those with this view must also believe that one can pinch with one finger and clap with one hand.
I had settled with the description that lift is caused by the downwash of air which imparts an equal but opposite force on the wing itself. As noted in the linked article, the downwash is attributed to the impact of air on the lower side of the wing constituting some, albeit little of the lift, and the air on top of the wing being curved downwards following the coanda effect.
Now, my confusion was re-initiated as I am currently reading "Aircraft Design: A Conceptual Approach" 6th edition, by Daniel P. Raymer - a highly regarded aerospace engineer.
In the 4th chapter on airfoil and wings, he writes:
An airfoil generates lift by changing the velocity of the air passing over and under itself. The airfoil angle of attack and/or camber causes the air over the top of the wing to travel faster than the air beneath the wing. Bernoulli's equation shows that the higher velocities produce lower pressures, so that the upper surface of the airfoil tends to be pulled upward by the lower-than-ambient-pressures while the lower surface of the airfoil tends to be pushed upward by the higher-than-ambient pressures.
Now I cannot imagine Raymer to have any misunderstanding on what causes lift, which makes me very curious about this statement.
The pressure difference found in calculations by using the Bernoulli equation and an equal transit time is much insufficient to lift an aircraft and windtunnel experiments show that the air on the top of the wing reaches the trailing edge much sooner than the air traveling below the wing.
Is it a simplification to avoid becoming too technical and into the "physics" for the average reader - or is something else going on? It is very difficult to become confident in what actually causes lift with a seemingly endless number of descriptions.
As a side note: on the bottom of the page in the book, this common dispute is mentioned and told that this view of lift is completely correct as is the Newtonian downwash description.