We realize this probably doesn't help in your example, but we want to mention that we don't presently think it is possible to have the GAP 26 mounted too far forward.
The AOA probe works really well in clean air and seems to just keep working better the farther forward it is mounted away from the effects of the wing.
We have seen some problems, notably with a number of certified aircraft, mounting the probe too far aft on the wing.
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