RV-4 ailerons/elevator

I recently purchased an rv4 and it is unpainted yet with around 500hrs on it and the left aileron has a small crease in it so I'd like to replace the aileron or just possibly reskin it. My question is I read someone mention that you can buy prebuilt rv8 ailerons which are the same as the rv4's, is this true?
If not am I better off saving everything other then the skin or should I build an entirely new aileron. Also I'd like to put electric trim on it if that makes any difference.
Also while I'm at it durning my inspection I found one very small crack around a rivet (as many people find on rv4s with .016 skins) on the top of the left elevator. Being that I want to paint it I'm thinking I better replace or rebuild the elevator or else that crack will just ruin the paint, am I right? The right elevator seems to be perfect so do I replace both with .020 or just the left with another .016. (Engine is 0360 with 2 blade c/s if that makes a difference). Seems crazy to replace the whole thing just cause that one tiny tiny little crack but think I have no choice before paint.

Let me know your guys feelings and insights on these two topics..
Also if anyone has an aileron or elevator that they wanna sell let me know!

Thanks

I can not answer on the 8 vs 4 aileron question but I have my doubts.
The general consensus on control surface reskinning is that it is easier and faster to build another one unless you are highly skilled and experienced.
How many hours and where is the crack? If the crack is in the common locations, trailing edge of stiffeners or emanating from the spar, it is probably just a matter of time before more appear. However, I had one crack develop on my .016 rudder very early on. I stop drilled it and put a small patch glued on with proseal and 650 hours later, no other cracks in any of my .016 surfaces.
So, it might be a one time anomaly.
I would not have one .016 and another .020. Not sure it matters that much but it would not fly with me.
If it where me, I would stop drill and patch, paint, and wait and see. You can always build new and keep flying while your doing it if more cracks appear.

The airplane has 470 hrs on it and the elevator crack is around a rivet just forward of the trim tab I will try to get some pics

I bought a pair of pre built RV-8 aelerons from VAN's for my wife's RV-4.
They confirmed these are dimensionally the same, however the RV-8 units have thicker skin.
At the time, they were about $400 each.
I have not put them on yet, it's a few items down 'the list'.

aileron and elevator

JonJay said:

I can not answer on the 8 vs 4 aileron question but I have my doubts.
The general consensus on control surface reskinning is that it is easier and faster to build another one unless you are highly skilled and experienced.
How many hours and where is the crack? If the crack is in the common locations, trailing edge of stiffeners or emanating from the spar, it is probably just a matter of time before more appear. However, I had one crack develop on my .016 rudder very early on. I stop drilled it and put a small patch glued on with proseal and 650 hours later, no other cracks in any of my .016 surfaces.
So, it might be a one time anomaly.
I would not have one .016 and another .020. Not sure it matters that much but it would not fly with me.
If it where me, I would stop drill and patch, paint, and wait and see. You can always build new and keep flying while your doing it if more cracks appear.

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The RV-4s are pretty much custom built. I would be surprised if any other aileron fit properly if at all. The guy who painted my airplane dropped the left airleron and its about as easy to build a completely new one as it is to replace the skin. The advantage of replacing the skin only is that the spar and hinge points will already match your airplane.

Chris M

I replaced my right elevator of .016 skin with one I made with the .020 and balanced it and it flys just fine with the left one that is .016.

Christopher Murphy said:

I replaced my right elevator of .016 skin with one I made with the .020 and balanced it and it flys just fine with the left one that is .016.

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My concern would not be how it flys, but how it might affect the potential for flutter, operating at the extremes. Probably not a legitimate concern as they are bolted together and balanced anyway. I just don't know enough to say. So, for me, I would have to keep the same skins on both. That's just me, so please don't take any offense....

Thanks for the info guys

tested

I tested the new elevator up to the Vne and it was fine.

Maybe some of the aero engineer guys can address any issues with one elevator of .016 and one of .020. I know on my airplane there hasn't been any issues with it and I fly alot of acro and I fly it fast at altitude.

cm

Christopher Murphy said:

I tested the new elevator up to the Vne and it was fine.

Maybe some of the aero engineer guys can address any issues with one elevator of .016 and one of .020. I know on my airplane there hasn't been any issues with it and I fly alot of acro and I fly it fast at altitude.

cm

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Can't argue that.

Anybody happen to have an aileron or elevator sitting around (rv4)??