Sorry to those who've already read this on uk.rec.models.radio-control.air but I've drawn a blank there so far.
I'm flying a Hangar 9 Arresti at the moment and notice there is quite a lot of negative roll coupling. That is full left (say) rudder causes a right bank, which the slight dihedral translates into a right yaw. This tends to cancel out the intended direction change.
On my other planes with positive dihedral, left rudder usually results in left roll as well as the expected left yaw. On this model it results in a roll in the opposite direction. Could it perhaps be due to insufficient dihedral? No actual dihedral angle is given in the assembly instructions, but is based on one wingtip raised by 1.5" with the other wing placed flat.
Anybody have any ideas as to the cause or is it just a feature of this model?