The very nature of an aeroplane will create ‘pressure effects’ around it – an aerofoil stays in the air because of the high pressure region beneath the wing attempting to migrate towards the low pressure region above the wing - well, that and all the little Bernoullis that hold it up! Try holding the back of a spoon under a running tap – it will get sucked into the stream, which is a simple demonstration of the drop in pressure associated with the water speeding up as it travels over the back of the spoon; the same effect is present when air passes over a wing. If an aircraft passed low enough over a person, they would definitely experience the pressure change. The swirl of wing-tip vortices can often be heard after even a moderately low pass or from an aircraft on approach to land.
Last edited by Captain Kirk; 12th February 2007 at 05:41.