Source: 2005 Q3 Beartracks
As more Bearhawks get into the air we should all be prepared for widely varying comments on the way the airplane handles. Some will love it, and some will dislike it. The difference can most likely be found in how the ailerons are rigged. The BH has no twist in the wings, and, although twist is usually included in an airplane’s design to control tip stall, it also helps to mitigate adverse yaw. With no twist and very little differential action to the ailerons (the amount one goes up is more than the other goes down), if the BH’s ailerons are rigged so they line up with the wing tip and flaps in flight, the airplane is going to have a huge amount of adverse yaw. Although proper rudder usage eliminates the problem, by rigging both the ailerons up, the amount of rudder used diminishes significantly and it feels like a “normal” airplane, only better.
The adverse yaw of the BH can be extremely high because the very thing that makes it such a good flying airplane, — highly effective ailerons — means, as one is deflected down, it generates a lot of lift immediately, which means it also generates a lot of drag on that wing (outside wing). Without a lot of aileron on the other (inside) wing going up to create drag to balance off the down aileron on the other wing, the nose really wants to move to the outside of the turn.
To anyone who learned to fly in a Champ or something similar, this doesn’t sound unusual and you know the cure is to simply get the rudder in a little early or a little faster to catch the adverse yaw before it happens. However, to a pilot used to flying Cessnas with his feet flat on the floor, the tendency of the airplane to initially turn opposite to the way the stick is moved is very disconcerting. With no reflex the nose will slide sideways with the slightest pressure on the stick unless the rudder is right there with the aileron. However, this can all be fixed with aileron rigging.
If both ailerons are rigged to be a little high in flight and a turn is made, the aileron that’s on the outside of the turn that wants to lift the wing, has to travel some distance before it hits neutral and then starts making lift and drag. The other aileron is already part way up so it has a jump on the other aileron, when it comes to creating drag.
The amount you want to reflex them is really matter of taste and the mission of your airplane. However, the more reflex you use, the less you need to lead with the rudder in turns. At the same time, you’ll be giving up a very small (immeasurable, actually) amount of super slow speed performance: it may stall a mile or two faster than with the ailerons neutral.
An average reflex seems to be 5/8”-1” up at the trailing edge. Where they sit on the ground makes little difference because the cable tension is different airplane-to-airplane. Just look down your wings in flight and see how much of the trailing edge of the wing tip you can see. Also, if you want less adverse yaw, use more reflex. A theoretical side benefit to this is that it “might” make the airplane a little faster when being flown lightly loaded.