Propeller:
Let's have a look at a propeller: A propeller is nothing different than a wing, turning in a circle...!?

Should we really believe that the thrust is generated by the vacuum arising on the propeller frontside (similar to the top of a wing)? Or is the propulsion not rather generated by the so-called propeller wind, i.e. the air "captured" by the propeller wing and accelerated backwards mass of air, which creates an equal counterforce to the front (thrust). Even with a model plane, you can clearly feel the draught and even measure with a spring gage (the so-called static thrust)!