One needs to keep in mind that ASI fluctuations may not be a good indicator of what the air is actually doing. The ASI is only a pressure diff gauge and is very very subject to static pressure fluctuations and internal plumbing problems. Thus, if the ASI is swinging wildly, this may have little to do with the variations in actual airspeed and lots to do with fluctuations in local static source pressure as eventually sensed by the instrument.
One ought to be a little circumspect in interpreting ASI readings in other than steady or slowly varying situations.
[ 17 October 2001: Message edited by: john_tullamarine ]