Can someone please write an expression for the frictional force on a smooth
aircraft as a function of airspeed.
I think it is something like f=kv^n where n=n(v), but it might be a series
of terms.
Thus the frictional drag on the plane increases with airspeed.
BUT
I am told by my pilot son that the frictional drag due to the extension of
the airplane's ailerons or flaps _decreases_ with increasing airspeed -- at
least at the normal extensions during landing.