Looking for help diagnosing a Heavy Wing

[lr172]

I have a heavy left wing. I suppose that I am good company I have read quite a few posts here about the issue and did some investigation today. I examined the trailing edges and they are both very similar. Both are just slightly over-bent, according to the picture on the Section 5 document, but are pretty much identical. If anything the right is more over-bent than the left. I put a caliper on the ends and they are very close in size.

I also put a straight edge on on the underside of the wing skin / aileron skin. on the right aileron, the wing and aileron sit on the same plane (straight edge laying across the two surfaces showed no gaps). On the left aileron, the outboard hinge left the surfaces, as above, but the inboard side had the aileron up (solid parallel gap between aileron skin and straight edge). I didn't measure, but would say it was between 1/16" and 1/8". I called Van's to ask if this type of alignment could cause the heavy wing, as all of the posters I searched found and adjusted mis-alignment on the light wing. The Tech didn't know and said less than 1/8" was in spec. Can this cause the heavy wing?

I ended up putting a 2" tapered balsa block on the light aileron and this eliminated most of the heaviness, but not all of it. I will do more testing tomorrow.

What do you guys think as a next step. I am hesitant to further pinch the right trailing edge given that it seems very consistent with the left.

I also noticed that both of my flaps are about a 1/4" higher than the ailerons at cruise speed. The gap is the same on both sides. I noticed on the ground that I can pull up each flap at least a 1/4" from it's resting position (slop in actuating system). On initial setup, I aligned each aileron using the tooling holes and then set the flaps to the ailerons.

I appreciate any guidance that you can provide.

Larry

[BobTurner]

On my -10, 1/16" made a big difference. (Aileron high = heavy wing) Mine was at the outboard hinge so a longer moment arm. I slotted the bracket so I could move the aileron down, heavy wing went away. Vans sells brackets with no pre-drilled holes for a permanent solution.

[aturner]

Bob, and other -10 or -9 builders who have dealt with this, how did you determine that the aileron was high? The top of the wing is not flat, not sure what to use as a reference. 1/16 high is difficult to measure.

[BobTurner]

Yes it is hard to measure. But in my case, standing in front of the wing and sighting down the aft part of the Wing and start of aileron, it was obvious that the left aileron was higher than the right. The right was 'smooth', the left had a very small 'step up' at the leading edge of the aileron. Not sure you'd notice if you only had one wing to look at, but it.'s the difference that matters. And it is easy to measure how much you slot the bracket, after the fact.
BTW, make the measurement with the ailerons AND elevator neutral. Full down elevator induces a small droop in the ailerons.

[aturner]

Thanks Bob, I will try that approach. I have the usual heavy left wing.

[lr172]

Originally Posted by BobTurner

On my -10, 1/16" made a big difference. (Aileron high = heavy wing) Mine was at the outboard hinge so a longer moment arm. I slotted the bracket so I could move the aileron down, heavy wing went away. Vans sells brackets with no pre-drilled holes for a permanent solution.

Thanks Bob. This was the data point I was looking for. I will slot it tomorrow and cross my fingers.

[Bugsy]

I had a huge heavy wing. Had to trim way right and even then it wasn't level.

I monkeyed around with adjusting ailerons and just goofed it up worse. I took a big breadth came back to it after a week and then took the wing tips off and reset the ailerons with the adjustment tool. that cut the heaviness in half. Then I pinched the aileron and made it all right. It doesn't take a lot of pinch. If you can see the deflection from your pinch you applied too much.

[catmandu]

My heavy wing was caused by a drooping flap. Just something else to look at.

[lr172]

Originally Posted by catmandu

My heavy wing was caused by a drooping flap. Just something else to look at.

How did you figure that out?

[lr172]

Today I used the top of the left wing as a guide and found the outboard side was sitting a bit high relative to the inboard side and the right aileron. I dropped this 1/16" and they now all match pretty well. It took about half of the heavyness away. I put the 2" trim tab back on and it is almost gone.

Does it make sense to start pinching the light wing trailing edge now to balance them or should I enlarge the trim tab.

Thanks for all of your assistance here.

Larry