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Heavy Wing

When I was test flying my Bearhawk I noticed that in level flight the right aileron was reflexed slightly more than the left. It flew very stable, wings level, even hands off. There are two possible causes for this.

  1. The result of a heavy wing, probably the 2 lbs of magnetometer and landing light in the left wing which showed up as a 12 lb higher weight on the left wheel at the W&B (a head scratcher).

  2. If the aileron hinges are not perfectly aligned when match-drilled to the aft spar, the aileron may be slightly higher or lower that the main wing. This was very common.

Steady heading side slip

The resulting condition inflight is referred to as a steady heading side slip. With wings level and ball centered, the aircraft would continually change heading by a barely perceptible amount. With wings level and a constant heading the ball would be slightly out of center. This is a steady heading side slip.

The other frustration was that during early Phase One fuel would continually transfer (or draw unevenly) when in the BOTH position, in the direction of the ball.


The symptoms in my case were:

  1. at the initial weight and balance one wheel weight was 12 lbs heavier than the other (heavy wing).

  2. slight roll input required to maintain wings level (increased aileron drag).

  3. one aileron reflexed higher than the other in wings level flight.

  4. with wings level, ball centered, the heading would very slowly change.

  5. with wings level, fixed heading, the ball would be slightly off center indicating a steady heading side-slip​​.

  6. when refueling it often took more fuel to fill one tank than the other. Fuel seemed to be either transferring between tanks, or burning more from one tank.


I installed washers under the top hinge bolts of the "light" wing. Alternatively you can install washers under the lower bolts of the heavy wing. Bearhawk owner and engineer Kevin Deuscher mentions HERE that using washers changes the hinge line and the camber of the wing.

Next, we adjusted the flap push-rods (acting as ailerons in the retracted position) to counter the slight tendency to roll left and managed to balance it out.

It took a while to resolve the issue, and the aircraft was then capable of flying with the ball centered, wings level.


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