take out or lower the diehedral
extend the rudder

the avistar dose not have a flat bottom air foil.
it'll snap and spin easy without modifications
i had a hard time trying to get it to go flat. wiegth to the tail might had help...
recovering from a spin was a bit freakie...leave plenty of altitude

here sum'in i found out too late..
don't snap roll on a high speed dive or a dive on a high wing plane.
especially an arf
controling a missle was cool thou.

if you have an arf..you might consider adding fiberglass to the wing joint.
my avistar wing joint piece broke away from the spar an rip thur the sheeting,
i put over 50 flights snaping and spining...stressing the crap out of the wing.
being a noobie at the time...of course the throttle was stuck on high all the time.
a .46 and a high speed prop was another rookie mistake, but it pulled it to the moon !