Hi Dave,

I understand now why you want to decrease the area of thetail fin.
I've read somewhere that the damping worsens with the Mach number and the altitude.

I found a MIT document about lateral stability. It says on page 9to damp the Dutch roll mode with a largetail fin.
It is an interesting documentbecause itexplains in a clear waythe origin of the lateral stability derivativesLp Lr Np Nr.

But the document does'nt analyse the respective influences of the airspeedand thealtitude on the static and dynamic lateral stabilities.

-Paul