Van's Air Force
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Is this a problem?
- Thread starter Jstov
- Start date
Uuuuuuuhhhhhh...that's definitely one for Van's to answer. If you do ask them please let us know the response.
JonJay
Well Known Member
The deeper gouges might be from trial fitting into an equally poorly finished spar pass through. The lighter sort of mangled looking lines around the hole are mill marks. These spars where made from raw bar stock. I spent days sanding and polishing out these mill marks before I primed and assembled them. Honestly, not sure if it makes that big of a difference but....
acam37
Well Known Member
Hole
[/URL][/IMG] I encountered the same problem on my -4. I emailed Vans and included the photos. Their response was replace the rear carry through spar and the attach point on the wing. This is unacceptable. I believe they told me you needed 5/16" clearance around the hole. It's an easy fix. The downside is you have to redo the wing sweep and incidence.
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Mike S
Senior Curmudgeon
Edge distance might bite you.
David Paule
Well Known Member
Save the effort - no way can you weld this and retain enough strength to be safe. Not a chance.
Dave
Dave
Andrew M
Well Known Member
Referance
There is an AC43.13 reference that advises not to heat aircraft grade aluminum past 212 degrees to prevent adverse effects on the temper.
There is an AC43.13 reference that advises not to heat aircraft grade aluminum past 212 degrees to prevent adverse effects on the temper.
You can weld castings and thin sheet used for fairings and non structural parts but not on something like this, where the strength comes from the heat treatment.
Christopher Murphy
Well Known Member
scary
REPLACE IT thats a smoking hole in the ground waiting to happen!
I cant believe someone said weld it. OMG.
CM
REPLACE IT thats a smoking hole in the ground waiting to happen!
I cant believe someone said weld it. OMG.
CM
Thanks guys. I will contact Van's just to get there two cents, but I think they will agree with you guys. The only way I see to fix it without replacing the whole piece is to updrill it. I will have to check on the edge distance on that. Does anyone know what is allowable?
Christopher Murphy
Well Known Member
He is a lucky guy i would say....I wouldnt knowingly fly it for 5 minutes with that notch in the rear spar attach hole. Cant tell for sure but it looks like they just riveted a small section on where the hole is vs the complete doubler?
I would look at the bolt holes attaching the empenage too. If the qualty of that hole didnt matter to the builder I would be concerned about other critical points. Did he build the spar?
Cm
fixnflyguy
Well Known Member
See what VAN says
The rear spar is loaded entirely different than the main spar. It carries drag and twisting loads, and carries near zero bending loads (that's why there is only a single hole). There is a plate doubler at the inboard end of the spar that could be replaced if absolutely needed. It does not run the full length of the spar. The little "snowman" hole can likely be plugged. I deal with these scenareos often at my day job on big jets, and you would be surprised at the answers we come up with in engineering.
The rear spar is loaded entirely different than the main spar. It carries drag and twisting loads, and carries near zero bending loads (that's why there is only a single hole). There is a plate doubler at the inboard end of the spar that could be replaced if absolutely needed. It does not run the full length of the spar. The little "snowman" hole can likely be plugged. I deal with these scenareos often at my day job on big jets, and you would be surprised at the answers we come up with in engineering.
LettersFromFlyoverCountry
Well Known Member
Boy, if there's one topic where the opinions of VAF are really worth what you pay for it, this is it.
There's really only one evaluation that matters.
There's really only one evaluation that matters.
brad walton
Well Known Member
The RV8 has a very specific edge distance requirement on the aft spar attach point. 5/16 absolute minimum IIRC. Vans plans instructions identify this as a critical dimension. I expect them to tell you the same about this and require a replace or repair to meet the design strength. I believe they have now developed a repair procedure that allows something short of replacement. But this aircraft must be repaired per Vans procedure to be airworthy in my opinion
JonJay
Well Known Member
I am not surprised. In fact, I would suggest this could have flown this way for it's entire useful life, through the full g load range, day in and day out. Edge distance is still there, there is no sign of a crack developing, and the main hole looks as if it has not been wearing.
However, it is absolutely not acceptable in my mind, not because it may fail, but because it simply isn't right and I would not accept it. Van's would be crazy to accept it as well just from a liability stand point. As mentioned, you are not the first and this can be easily, although a bit time consuming, fixed.
Keep up the good work on your inspection and investigation.
rvator51
Well Known Member
Make sure incidence angles on both wings match after repair.
When you repair it and have to reset the wing incidence angle, be sure to check the wing incidence angle on the other wing. I would think you would want to match the incidence angle on the other wing even if it isnt the same as called out for in the plans or you will be using a big trim tab to make up for it.
When you repair it and have to reset the wing incidence angle, be sure to check the wing incidence angle on the other wing. I would think you would want to match the incidence angle on the other wing even if it isnt the same as called out for in the plans or you will be using a big trim tab to make up for it.
AZSteve053
Member
The opposite side ???
Are you going to pull the other wing to see if the builder was equally lax to quality control?
Are you going to pull the other wing to see if the builder was equally lax to quality control?
longranger
Well Known Member
I don't know about the -4, but in the -7 this part is 2024 aluminum, an alloy not generally considered weldable. Also, as alluded to earlier, even if you could weld it, you couldn't heat treat it back to -T3 condition.
I couldn't agree more.......
When contemplating a repair plan on an important structural member, it is usually valuable to have some understanding of the load path.
It would probably surprise most builders to know that the highest load on the rear spar joint is a tension load resulting from the wing trying to sweep fwd.
This occurs at high G, high alpha (critical angle of attack)
It is what is evaluated when testing in condition "D" for compliance with FAR 23.
It is also why vertical edge distance on this part is so important.
In the photo posted by the OP it looks like the edge distance on the clevis portion of the joint (on the fuselage) may not meet minimum edge distance (based on the paint/primer line visible). The extra hole in the rear spar, though not compromising edge distance, would be an undesirable stress riser, and is reducing the baring area for the bolt in the vertical direction ( the next highest load path).
JonJay
Well Known Member
So, judging from that shadow, he might be faced with changing out the rear wing spar and the fuselage pass through......
Edge distance on the AN5 bolt can be checked without removing the wing.
Extra holes, as seen in some of the photos in this thread, might not be visible if they don't exist in all three of the effected parts.
I talked to the guys at Van's today and they said definately replace it. The comment went something like this, "When we saw your picture it was kind of like having a black cat cross your path.". They also added that it won't be big deal to replace. In the grand schemes of things really is a day's work and a few dollars worth risking your life?
On another note. I have only been a member of the Van's community for two weeks and I can't believe the support I have received from the community and the company. It is great to know that the company monitors sites like this and when they see something wrong they reach out to you and give you advice. I have been involved with other kit companies and the advice you get from them falls along the lines of, "It's your plane and I can not advise you on that." When I posted my first post I got a response from someone saying welcome to the good ship Van's it should he should also include community in the post!
On another note. I have only been a member of the Van's community for two weeks and I can't believe the support I have received from the community and the company. It is great to know that the company monitors sites like this and when they see something wrong they reach out to you and give you advice. I have been involved with other kit companies and the advice you get from them falls along the lines of, "It's your plane and I can not advise you on that." When I posted my first post I got a response from someone saying welcome to the good ship Van's it should he should also include community in the post!
jjconstant
Well Known Member
Between the airplane design, the kits, the company support and this site, the decision to get involved in the building and flying of an RV was one of the best decisions of my life. What a great community, side to side, front to back and top to bottom!
bret
Well Known Member
I too am amazed by the support of this community, if you really want to know who the fine folks we have the privilege of communicating with, search the post (what is your day job) peeps way smarter than me
