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  #51  
Old 12-07-2015, 06:55 PM
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acam37 acam37 is offline
 
Join Date: Aug 2012
Location: Lufkin Tx
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Default Damage

Mike Im not sure he mentioned it to them. The tail was completely replaced. Every inch of the fuse was examined for any hidden damage. The wings were not damaged in the hangar collapse. You can go back to my spar repair thread to see exacly what we did. Only the bottom skin was removed and it went back on perfectly. The wings are straight and not warped. But at this point anything is possible. Maybe if we all brainstorm long enough a cause and solution will be discovered. Im glad people show an interest in helping us out and not just talking trash.
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RV-8 (N269CP) Sold
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  #52  
Old 12-08-2015, 03:34 AM
Jstov Jstov is offline
 
Join Date: Dec 2014
Location: Melbourne beach, fl
Posts: 190
Default Lightening holes

Arlie I went back and looked at your lightening holes and they are indeed big. Do they go all the way forward to the spar attach point for the an3? If so that could be the weak point. It is also be possible that the increase in speed is actually creating drag inside the aileron. Maybe it is ballooning instead of warping like was suggested. I believe that if wind speed is doubled then the force it creates on an object goes up seven fold. That is why cat 4-5 hurricanes although they are not much greater in wind speed compared to the cat 1-3 are much more devastating!
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  #53  
Old 12-08-2015, 08:24 AM
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az_gila az_gila is offline
 
Join Date: Jan 2005
Location: 57AZ - NW Tucson area
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Default

Quote:
Originally Posted by Jstov View Post
Arlie I went back and looked at your lightening holes and they are indeed big. Do they go all the way forward to the spar attach point for the an3? If so that could be the weak point. It is also be possible that the increase in speed is actually creating drag inside the aileron. Maybe it is ballooning instead of warping like was suggested. I believe that if wind speed is doubled then the force it creates on an object goes up seven fold. That is why cat 4-5 hurricanes although they are not much greater in wind speed compared to the cat 1-3 are much more devastating!
Since the ailerons are "hollow" and have no internal ribs the only parts preventing twist are the end ribs.

Removing the inner portion of the spar attach flange with an oversize access hole would certainly make the ailerons much more flexible and act in a unique way from all other RV-4s. Your test pilot's description of warped ailerons makes sense.

It probable wouldn't be too difficult to just replace the end ribs, but new ailerons would be better.
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  #54  
Old 12-08-2015, 09:10 AM
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KatieB KatieB is offline
 
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Location: Stilwell, KS
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Default

Quote:
Originally Posted by acam37 View Post
Im glad people show an interest in helping us out and not just talking trash.
This is why so many of us are on VAF and don't bother with other aviation forums. (try the AOPA Red Board. It's fun if you like Jerry Springer.)

I'm sorry you're having this problem, but it is a very interesting discussion that I'm sure lots of us will learn from. I now have more things to think about when I reassemble my rebuilt airplane.
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  #55  
Old 12-11-2015, 03:34 AM
Jstov Jstov is offline
 
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Location: Melbourne beach, fl
Posts: 190
Default Ailerons

Arlie I did get my aileron in from vans and was pleasantly surprised to find they are pre drilled so if you go that route it will be an easy assembly! You could also order the QB ailerons and they come assembled.
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  #56  
Old 12-11-2015, 07:28 AM
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acam37 acam37 is offline
 
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Default

Thanks for the info. I'm not going to mess with the plane until after the holidays. I'm exhausted and need a break.
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RV-4 (N124TT) Sold
RV-8 (N269CP) Sold
RV-4 (N684ML) completed 3-17-19
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  #57  
Old 12-11-2015, 05:04 PM
sblack sblack is offline
 
Join Date: Dec 2009
Location: Montreal
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Default

A temp plate on the end ribs would plug holes and stiffen the aileron. Could be done with blind rivets. If you are considering new end ribs or new ailerons anyway then you have nothing to lose. Say 0.032". That's what I would do. You would confirm if that is the problem or not.

I would say certainly it is a hinge moment issue i.e. the trailing edge shape of the aileron, either the shape it currently has is bad or it is deforming in flight. If all of the mechanical bits check out that's all it can be, that or the aileron gap seal and I don't think you snagged that.

I helped a guy fix his hummel bird. The elevator TE was rounded off and the airplane was horrible to fly. He just figured all hummels were like that. Maybe they are! But with a few mods it was a different airplane. We increased the tail area and the elevator hinge moment to give him higher forces. Sounds like you need lower forces.
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Last edited by sblack : 12-11-2015 at 05:09 PM.
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  #58  
Old 12-14-2015, 05:41 PM
Jstov Jstov is offline
 
Join Date: Dec 2014
Location: Melbourne beach, fl
Posts: 190
Default Aileron part numbers

Here are the part numbers for the ailerons if you decide to go that route. The slow build does come pre-drilled so it should be easy. The quick build parts actually come assembled so that is your quickest option. The only parts that I can see that are missing are the aileron hinges but you can use your old ones. It is the same part numbers as the -8 as they share the same ailerons.

QP8-8A aileron right or left: Parts only pre-drilled
Q8-8A aileron right or left: quick build option comes assembled

If my memory serves me correctly the quick build is just over $400 and the parts only is just under $200.
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  #59  
Old 12-15-2015, 05:19 PM
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acam37 acam37 is offline
 
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Location: Lufkin Tx
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Default

Today I was sitting in my hangar looking at my ailerons, asking the question "what would cause the aileron to balloon and flex in flight?" And then it dawned on me, The Stiffeners. So I went and took a closer look. What did I find? The stiffeners terminate approx. 3" from the trailing edge, so this could explain a lot. I went ahead and squeezed the trailing edge radius from 3/16" down to 1/8" which tightened the skin a little and straightened it up a bunch. Justin took it up and voila. He said that made a 100% difference in the stick forces. I am still going to build a new set of ailerons, but at least I think I finally solved this mystery.
[IMG][/IMG]
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RV-4 (N124TT) Sold
RV-8 (N269CP) Sold
RV-4 (N684ML) completed 3-17-19
KOCH Nacogdoches
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  #60  
Old 12-16-2015, 05:30 AM
fixnflyguy fixnflyguy is offline
 
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Location: Winston-Salem, N.C.
Posts: 1,213
Default Another thought

Alternatively, you could drill your current skins off, remove and replace just the stiffeners, which can be easily made from bent sheet stock, and put it all back together. The little stiffeners require correct tapering and orientation, as they actually overlap at the trailing edge. Some people add a little proseal to the last inch to help prevent cracking of the skin, and keeping the AFT most rivet away from the radius are which is tricky to buck.
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