In article ,
Carl Ellis wrote:

The wing root ventilation tubes on a 172 can cause a very strange noise if
they are pulled most of the way out. I aborted a take off one time because
of it. They noise was low frequency and oscillating, following the
throttle and acceleration of the airplane.


A real hard pushover will cause the vent tubes to "scream".

--
Dale L. Falk

There is nothing - absolutely nothing - half so much worth doing
as simply messing around with airplanes.

http://home.gci.net/~sncdfalk/flying.html