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6a tanks

Mike6A

Well Known Member
Friend is looking at a 6a that has the tank riveted on. The first row of screws are riveted on and not screwed on. The second row is screwed on. These tanks need to come off because of slosh. Pic to follow. Cannot attach photo.
 
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on a normal build, e.g. acc plans, the rear flange and end ribs (amongst others) are riveted to the tank skins. The outer line has dimpled holes for the retaining screws.
Loosening them all, and removing the fuse/tank bracket attach bolt (and associated qty measurement etc. elec wiring) should set the relevant tank free for removal.
 
Well, now, that is a major screw up if I might say. As most know there are two rows of screws at the rear of the tanks, one countersunk and the other dimpled, both top and bottom. They are structural to boot. Single row of screws on both ends.
Looks like somebody has some work ahead of them .
No the big gotcha is if this is screwed up how much other stuff is also????
Costly or time consuming to say the least.
I bought an RV-6A where the builder drilled 5/16" holes and used Tinnerman washers instead of dimpling or countersinking. STUPID to say the least. The tanks leaked and I knew I was going to build new tanks, But, the purchase price took that into consideration.
Art
 
Tanks

I have built two 6 and a 10. Never saw this. The tank cannot come off. The plane has 1800 tt
 

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If as described by the OP, this aircraft is not airworthy. The shear strength of 2117 versus versus steel is a small fraction. Doesn't matter how many "successful trouble free" hours the airframe has to date. Hard to believe there isn't more to this. Hopefully more facts immerge.

Edit = Has to be more to this. IIRC those screws are all blind installs. No conceivable way I can imagine to rivet those.

Edit 2 = Didn't see the attached pic. Probably added when I was typing. Blind rivets make it "do-able" but no less unacceptable. Looks like possible filiform near screw heads; something more common with stainless/aluminum versus cad plated steel. Check those as well. Smells more and more. be careful.
 
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The truth

Actually those tanks have to come off. As said this thing is not an airworthy airplane as I see it.
They can be taken off, drill them out and rip the tanks off. Not really as hard as some might say. Maybe, you'll get lucky and be able to fix it properly without rebuilding the tanks.
The rest of the paint in the picture looks pretty bad. Probably need a repaint and that adds more weight.
Better have a good prebuy on this one for sure.
Problems lurk around this type of construction when a builder can't pay attention to the simple instructions.
Gives everybody a bad rap in the end.
Art
 
Tanks

I Agree the airplane is not airworthy. My worry is the rear holes are to close to the spar web to install nut plates. I am doing my best to get him to walk but the price is to attractive to him.
 
Talk to vans

Mike

As always I think your first stop should be to consult vans.

Certainly not per plans however it might not be a total loss. But very difficult to tell until you remove the tank if it can be corrected. However to remove the tank you’ll have to remove the cherry max rivets very carefully. It will depend upon spar edge distance if the holes can be enlarged safely and plate nuts fitted.


Regards

Peter
 
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an excerpt from the plans, left wing tank section…
 

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I agree with Mike, Check with Vans and see what they say. They may allow using blind rivets with a tighter spacing.

That said, I wouldn't buy it..... I just wonder what other issues / build errors are in the airframe.
 
Please have him pull the tanks before anything else. If the spar web is butchered due to bad countersinking or messed up screw holes then the wings are toast. How do I know? I got burned on a RV-4 kit.
 

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If the price is right, may be worthwhile to pursue. I wouldn't walk away from it but do a thorough inspection so you know condition.
 
That paint is so bad it looks like it was sloshed on the outside of the tank as well as the inside. And none of that sheet metal looks flat. Scary indeed.
 
This looks really bad. Some filiform corrosion too underneath some of the screw heads as well.

I don't know if this is easily*fixable. My guess is that they left the rear row of nutplates off during construction. Once that top skin is on the wing, I think these nutplate locations might be inaccessible; hence the rivets.

I don't think this is structurally sound either. Vans should be consulted.

Vic
 
Throw in the towel

Just the picture of this wing reminds me of a job I was asked to do.
Having been a home builder for 43 years I have seen a lot of screw ups
25 years ago I was asked to evaluate an unfinished home (not mine) for a prospective buyer
It was sheet rocked and partially finished.
The list and cost of repairs needed to even bring this home up to code specs was so long it was scary. The possible repair bill was more than 60% of the asking sales price. But what was hidden?????? $$$$
About 5 months later the building department called and asked for my advise. I sent them my list of defects, obvious and hidden. They condemned the house and it was actually torn down to the foundation.
The house isn't a flying machine, An RV is.
Funny how life's lessons are?
Art
 
The last rivet on the right and forth from the left look like there may be an edge distance problem. Wonder what the spar looks like? Corrosion on the rt side skin too. Skins are all wavy. Bad paint. Slosh in tanks will cost $2k to ship and pay to be removed. Impossible to remove it all w/o removing rear baffle. Run from this one
 
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Friend is looking at a 6a that has the tank riveted on. The first row of screws are riveted on and not screwed on. The second row is screwed on. These tanks need to come off because of slosh. Pic to follow. Cannot attach photo.

I would have your friend run not walk from that plane. If one cannot follow instructions, it is likely that there are MANY unpleasant surprises lurking below the surface.

Larry
 
I saw the exact same thing on a Rocket build 25+ years ago. The builder somehow got things backwards in his mind and swapped the line of screws and the line of rivets. He built both wings that way. I don't know what ever happened to that project.
 
Zooming in on the photo, it looks like some filiform corrosion around the screws and at some spots on the skin. Might check that out.

The rivets definitely make one wonder what else is done incorrectly.
 
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