wrote:

wrote:

Is there a simple (or complex) guideline for the relationships between
CG, pivot axis and aerodynamic center for a control surface to prevent
flutter?

Is it as simple as keeping the CG at or ahead of the aerodynamic
center, similar to designing for stability of the aircraft itself?

--

FF



No. This is aviation, dealing with real physics. Nothing is as ever as
simple as it seems.

A big component in flutter is the stiffness of the structure. The
stiffer it is, the closer you get to the idealized world where it is all
about CG and aerodynamic centers.

The biggest problem with flutter is that you have several complex and
unquantified forces creating stresses in complex structures, resulting
in unquantified deflections which create another set of compex and
unquantified forces. The reason it is all unquantified is that the
forces are constantly moving in an almost random manner, and only at
just the wrong time they'll settle into a pattern that'll rip the wings off.

--
This is by far the hardest lesson about freedom. It goes against
instinct, and morality, to just sit back and watch people make
mistakes. We want to help them, which means control them and their
decisions, but in doing so we actually hurt them (and ourselves)."