THE BASICS OF FLIGHT

You can test the Bernoulli effect and the lifting force of an airstream over a wing with a sheet of typing paper. Hold it by two corners so that it hangs down at the back and below hard so that your breath hits the top of the front edge. You will see the paper rise in the airflow because of the reduction in air pressure on its upper surface. The reverse effect takes place on the underside of an aerofoil: the air slows down and pressure increases. You can think of the lift coming from the reduced pressure over the upper surface of the aerofoil 'sucking it upward' and the increased pressure underneath 'pushing it upwards.'