As an example of how flight is explained in the literature let us quote form the standard text Aircraft Flight by RH Barnard and DR Philpott:
- Most of the world’s aircraft are flown by people who have a false idea of what keeps them in the air.
- Our objective is to give an accurate description of the principles of flight in simple physical terms. In the process of doing so, we will need to demolish some well-established myths.
- On popular and misleading explanation refers to a typical cambered wing section profile. It is argued, that the air that takes the longer upper-surface-route has to travel faster than that which takes the shorter under-surface-route, in order to keep up.
- We find that the production of lift depends, rather surprisingly, on the viscosity or stickiness of air.
- The feature of the flows meeting at the trailing edge is known as the Kutta condition…the viscosity is thus ultimately responsible for the production of lift.
- A major breakthrough came when it was realized that a wing thus behaves rather like rotating vortex placed in an air stream. This apparent odd conceptual jump was important, because it was relatively easy to mathematically analyze the effect of a simple vortex placed in a uniform flow of air.
- It is the viscosity working through the mecahsim of boundary layer separation and starting vortex formation, that is ultimately responsible for the generation of lift.
We see that the authors seek to sell Kutta-Zhukovsky’s circulation theory, while admitting that they find it “odd”, but then try to cover up by hinting at boundary layer effects of small viscosity. This is representative of what is considered as the scientific explanation flight presented in the literature.
The New Theory shows that lift does neither come from circulation nor from boundary layers and thus that the authors, together with all other authors explaining flight, belong to the large group of people who have a false idea of what keeps airplanes in the air.
The Secret of Flight 