"Bill Silvey" wrote in message
. ..

snip

Moreover, he thinks they produce two pressures and produce airspeed as
well.

All that is required is a manometer to subtract dynamic pressure from static
pressure to have IAS; both pressures being a product of a pitot tube. WWI
rplanes did not even have IAS, until some French person put a pitot tube on
his airplane. It is very simple and even a simpleton like Bill should get
it.