A friend of mine replaced an aileron on a late model 172 after a hangar incident with an off the shelf swap for a newly reskinned part.

One wing is now heavy requiring constant control pressure for straight and level flight.

Would a refurbished part within design tolerance typically require re-rerigging or would there be concern whether the part is made correctly?

The installing IA hasn’t weighed in yet but some insight would be helpful before he starts making rigging adjustments.

Start with the basics and make sure the ailerons are properly centered when the yoke is. Then have him evaluate the rigging overall.

I think it’s more likely that the old aileron was installed with some fudge factor to compensate for a different rigging problem than that the replacement part was made wrong.

Eric beat me to the punch to suggest checking the rigging.

Beyond that check if the airframe is tweaked. Maybe the incident that wrecked the wing did other damage?

Your A&P can stretch a line from the outside corner of the flap to the elevator, and again measure the other side from the same spots and see if the string measures the same length. Just a quick check to see in the sides are plumb.

Not a conclusive test, but a test if dissimilar lengths would show an issues exists.

Thanks for the suggestions! We’ll start here and see what we find.

The 100 series ailerons are built flat (no twist), and the outboard 16 inches of the trailing edge sweeps upward. That upward sweep has a spec, and if it's more or less than spec, it has the same effect as adjusting/bending a fixed trim tab.

Thanks Del!

We’ll look at that!

Thanks for all the help here. I thought I would post an update since the problem was resolved.

The original damaged aileron and the replacement aileron were both carried to the repair facility.

They first checked the replacement aileron (the one that made it fly with a heavy wing) and found it met their specs.

They then checked the damaged aileron. This was the factory original part on a 2000 model 172. They put it on their jig and said that it was built out of spec!

They somehow adjusted the jig to match this aileron and reskinned the part that was damaged.

It was put back on the airplane and it flew perfectly!