Question About Aileron Pinching

SuperDave · #1 10-09-2013, 04:42 PM

Recently bought an RV-8 that is out of rig. It has a heavy right wing and the builder has pinched the right aileron the full length to the point that there appears to be no way to increase the radius per Van's (block of wood and hammer). It is my understanding that you pinch the LIGHT side aileron. For some reason it appears that this former owner went too far.
Would it now be acceptable to pinch the left aileron to achieve the proper balance?

GeneL · #2 10-09-2013, 05:06 PM

Probably could, but it would be heavy in roll. Try to un-pinch.

eddieseve · #3 10-09-2013, 10:34 PM

If its not painted, buy a new skin and stiffeners from VANs and re-skin the rear of the offending aileron, it does not take long to remove the old skin and fabricate the new parts to get you back to square one.

The parts are cheap.

The outboard ribs can be re-used if your careful when removing the rivets.

I ended up doing the same thing when I did not spread the load far enough over area I was squeezing and ended up leaving some pinch marks in the training edge.

Mine was painted too, but the whole refurbishment process only took about 6 hours over a couple of days including repainting.

Cheers

N208ET · #4 10-10-2013, 06:45 AM

can you balance it out with fuel load? does it get worse or less depending on speed? If it isn't too bad and your just trying to get things perfect I would pinch the left aileron if it was mine.

Randy
8A

SuperDave · #5 10-11-2013, 05:10 AM

We've already tried to "unpinch" the right aileron but when it was pinched it was done aggressively enough that the trailing edge is beyond help. Haven't tried it but full left tank and empty right tank might even it out. So far I have only had 10 gallons of imbalance and it helped some.
In my tiny little brain it just seemed like pinching the other side a little bit would be the easiest thing to do as long as there weren't any aerodynamic repercussions.
I'd like to hear from someone that has been in this situation, and how they handled it, but hopefully nobody has been in this situation!

N208ET · #6 10-11-2013, 06:43 AM

I chased a heavy wing for a long time. I tried slotting my aileron brackets and moving my aileron up and down to correct it. Ended up pinching the aileron trailing edges along with moving the aileron vertically. The controls get heavier the tighter the radius the trailing edge is. You could try pinching your left aileron and see if you can get close enough that way, the controls will become heavier than they are now, not a big deal really. After pinching my controls were much heavier than before, at first I was a little bummed, but now it doesn't bother me, its what you get used to. Vans has some info published for this, its basically what I followed. http://www.vansaircraft.com/pdf/Wing_Heavy.pdf

Randy
8A

rvator10 · #7 10-11-2013, 12:55 PM

I had the same problem with my -8 and flew it for 25 hours, finally I was sick of the way it was flying and started trying to find why.
I took a straight edge to the aileron and found that I had over bent the TE during the fold process.
It was bent like a banana?ok quarter inch in the mid section over the length.
I was able to un-rivet, and very gently unbend the TE, allowing me to reestablish a uniform TE.
WOW it made all the difference in the way she flew, very glad I found and fixed the heavy wing.

SuperDave · #8 10-12-2013, 10:09 AM

I'm going to take a test flight in the morning with a full left tank since there is just 5 in the right tank. This way I'll be able to quantify the heaviness.

I really appreciate everyone's ideas and opinions, keep'em comin'!

I've taken measurements and the wings/flaps/ailerons are all off a little bit, so short of starting over I figure the best thing to do is go with the best Band-Aid. I've already invested too much time getting this bird back in the air.

SuperDave · #9 10-14-2013, 04:11 AM

Quote:

Originally Posted by SuperDave

I'm going to take a test flight in the morning with a full left tank since there is just 5 in the right tank. This way I'll be able to quantify the heaviness.

I really appreciate everyone's ideas and opinions, keep'em comin'!

I've taken measurements and the wings/flaps/ailerons are all off a little bit, so short of starting over I figure the best thing to do is go with the best Band-Aid. I've already invested too much time getting this bird back in the air.

Flew the plane this morning and it appears that a 13 gallon fuel imbalance keeps it straight and level.

cfiidon · #10 10-14-2013, 04:39 AM

Quote:

Originally Posted by SuperDave

Flew the plane this morning and it appears that a 13 gallon fuel imbalance keeps it straight and level.

That sounds significant to me. My original imbalance was about 7 gallons of fuel. After l pinched a bit, I discovered that the trailing edge of my flap was 1/4 inch low. Corrected that and all is well.

I might suggest you check all alignment and get it as close as you can before any further pinching happens. Is your aileron trim disconnected?

Don