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Should I replace?

I would replace..

From the pic, it doesn't look like you've installed it. A rib is pretty cheap, so I'd replace it... No big deal.
 
I would install the nose rib and keep building. If the scratch really bothers you fab a doubler plate and rivet it on over the damaged area.

I see no need to replace the rib.
 
Not saying that I wouldn't replace it or double it but the opinions of the following posters make an interesting observation.

Where do you draw the line?

For all of those who say "replace it", did you replace EVERY scratched, mis dimpled, oversized hole, smiley faced skin or whatever, in your project? (And if you did, are you done building yet?)

For those who say "no biggie, build on", did you NOT replace any errors on your project?

Personally, I have done both. There are things that you can let go, and there are things that need to be replaced for "peace of mind' reasons.

Everyone has their own "standard". If there is a question, pick up the phone and call Van's, that is why it is called "builders support".

So where do YOU draw the line?
 
A notch with a sharp valley can significantly reduce the fatigue life of a part and reduce the tensile and bending strength. Generally, though a rule of thumb can be applied to parts not critically stressed that says polish out the damage so that the deepest marks are removed, measure the amount of material removed and if the remaining material is 90% of the original, press on.

Leaving any sign of a sharp mark or gouge is much worse than removing the material necessary to completely polish it out due to something call a "notch factor" . The same goes for sharp corners on cutouts in sheets.

If it were me I'd polish it out and measure, if 90% of the original thickness remains press on. If not replace. Hope this lends some objectivity to the decision.

Dan
 
Repair or replace??

Per comments from both rocketman1988 and RVDan and others, I would dress it, measure thickness, and then send pic and info to Vans for input from the manufacturer.

It is interesting to me as well to see the the range of responses from different builders when it comes to gouges, creases, or other deformities that do not show obvious immediate signs of rips, cracks, or tears.

For me I guess I can see going either way with a doubler or replacing it. But I would also want some input from the manufacturer if I was thinking about salvaging it, to give me some of that coveted "peace of mind" folks are talking about.
 
I have 5 or 6 doublers

I will be flying around with 5 or 6 doublers on my plane. One messup has a tripler. twisted metal on a rib ground down and a plate on each side of the oops. riveted together. Use thin metal cause you dont want to effect the flex point of the structure.
 
Per comments from both rocketman1988 and RVDan and others, I would dress it, measure thickness, and then send pic and info to Vans for input from the manufacturer.

It is interesting to me as well to see the the range of responses from different builders when it comes to gouges, creases, or other deformities that do not show obvious immediate signs of rips, cracks, or tears.

For me I guess I can see going either way with a doubler or replacing it. But I would also want some input from the manufacturer if I was thinking about salvaging it, to give me some of that coveted "peace of mind" folks are talking about.

For me as a new builder and with none of the expertise to say what might or might not be a good idea, I rely on the Vans engineering plans as my bible. If I don't understand something or something comes up out of the ordinary outside of those plans, of course it would make sense to seek a higher knowledge.

Having said that, my concern would be the potential failure of that rib at a later time. If there is any chance that a crack could develop in that rib along that line, then I for one would replace it. I guess the real question is how much can you safely buff out of a rib without weakening its structural integrity?
 
Since it goes across a hole, I would replace it. However, I have heard one from Van's say before, 'It's just an airplane'.
 
well the gouge is deep. I am surprised that it did not come out the back side. I would say that the gouge is at least 50 % through the metal in one place. The rest of the gouge is not very deep.

I will probably just replace, since i don't need it right now. It is for the right wing and I am on the left wing.

I guess that I will end up making art work to hang on the wall with all the bad parts.:)

Thanks for the input.

ken
 
Another option for Discussion

Primary loads on nose rib is crushing load due to wing bending, and shear load due to wing twisting. The scratch is mostly a fatigue concern for shear load. If you think you need to remove too much material to smooth out the scratch, here is another option. If the edge margin can be maintained close to the flange cutoff, just treat the scratch as existing crack, and stop drill it at both ends. The doubler method will work too.

Having said that, since the rib is not riveted, I still think replacing it is the best option.
 
Well... now that you're building a new aircraft and posting on the internet about should I fix this, as a tech counselor I would dig deep into your finished product if anyone ever called for a pre-purchase inspection. it is a cheap part... replace it.
 
One of the best things about building an RV is the parts are cheap and available. Go find a nose rib quote for a 30 year old Cessna.
The 90% rule is the guide though. I polish out anything that can catch my nail.
 
I accidentally ran the dremel across one of the nose ribs. As you can see the cut is fairly deep. I have tried some to sand out, but I am concerned that the metal will be very thin at the deepest point if I continue to try to sand out the cut. Should I just order a new one?

http://i1335.photobucket.com/albums/w663/Kenneth_Stockman/photo1-5_zpsdb9f68b6.jpg

Ken, the various replies to your question are an indication of the varying attitudes that builders have to quality issues. In the Experimental category the quality of aircraft being built covers a very wide spectrum indeed...everything from the sublime to the abortionate.

I would hesitate a guess that the posters who advised you to replace the rib are building better quality aircraft than those who said repair it. And those who advised you to repair it are building better quality aircraft than those who said move on.

My opinion is that defect, if left as it is, would be VERY likely to generate a crack down the track, particularly as it runs through a tooling hole.

As a further point you might like to ask yourself a couple of questions. If the rib cracks will it be in a location where you will be able to inspect it. Maybe not.

And if it does crack will it be possible to repair/replace it without ripping half of your wing apart. Maybe not.

In this instance I suggest you don't take any notice of the advice offered on this forum...including mine. :D

If you have any doubt about what to do on structural defects such as this the prudent thing to do is always ask Vans. ;)
 
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This whole exercise of discussion of replacement of a rib is fascinating. It is obvious that you will probably replace it. But the thought process and comments of all the contributors makes me and I'm sure, other builders wonder.....what would I do? Just the contemplation is good for the build process. We all are extremely concerned about the safety for us, our family and friends.

A forum such as this in this case is great support for us fools out here trying to live our dream of building.

Steve
 
This whole exercise of discussion of replacement of a rib is fascinating. It is obvious that you will probably replace it. But the thought process and comments of all the contributors makes me and I'm sure, other builders wonder.....what would I do? Just the contemplation is good for the build process. We all are extremely concerned about the safety for us, our family and friends.

A forum such as this in this case is great support for us fools out here trying to live our dream of building.

Steve



Nicely stated. :D
 
I never reordered any parts in building of our RV-6A

When I first went to work on the F-101 Voodoo production line at McDonnell Aircraft in St. Louis I was a new inspector fresh out of a four year enlistment as a radio mechanic in the USAF. I learned that MANY errors occur in the finely controlled process of building a supersonic jet fighter and they all have to be dealt with systematically. Our system included standard repairs documented in a standard repair manual, minor problems documented on production line discrepancy reports requiring disposition by a production floor Liaison Engineer, and more serious problems requiring review and disposition by a material review board (MRB) to salvage the part or assembly. I was involved in detection, documenting and accepting the rework at all levels so I was very aware of the systematic concept of salvaging the material and maintaining the integrity of the product.

37 years later the lessons learned were not forgotten when Jeanine and I started building our RV-6A. I made up a discrepancy report form to document all discrepancies. All discrepancy reports (DRs) had an individual number, required a written disposition and satisfactory completion acceptance. This avoided the problems of "forgetting" and delays associated with trying to deal with the problem before I forgot it while working full time in a critical day job with some irregular hours and a 4 hour daily commute.

I found that forcing myself to deal with each discrepancy to develop a repair where required made me more sensitive to avoiding errors in the first place and dealing with them right there in my little garage "aircraft factory" kept up the sense of continuing progress. On rare occasions I did call Van's, like when I saw all the play in my completed manual elevator trim tab installation, as a kind of MRB action but I was able to find sources for material and make repairs when necessary in every single case. I think that if you can't reach that level of knowledge and self confidence it is going to be hard to reach your objective.

When I first saw you photo I was in the "remove and replace" camp but when I read the description I moved over to the "acceptable as is" side. A compromise that might be driven by actually seeing the part, would be to add a doubler but the need is not obvious on the face of it. Whatever you decide I think the discrepancy, corrective action and closure should be documented in your records.

Bob Axsom
 
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good question about the dremel. As propsync pointed out you need to cut down two of he ribs due to the location of the spar. This would not have happened if I used a band saw, which I don't have. A dremel tools sort of suck for the job in that it is hard to get a straight cut. Since I will have to cut stiffeners at some point, I think that I will just bit the bullet and by the band saw to save myself some grief later down the road.
 
And to Reiley: was that comment warranted. I thought that this site was a site to ask questions and get helpful responses. Sorry for not having your years and years of experience. Maybe I will just avoid asking questions on Vans Airforce and ask my questions to the tech counselor/advisor that I send questions to directly via email.

And BTW, I am going to replace the rib.
 
Don't worry about it. I too would replace, because of the depth (you say 1/2 the thickness, which is pretty deep), as well as the location intersecting a hole. As much for peace of mind as for anything else - although I'm sure a doubler would work just fine. I have elected to replace many parts, even after being told by Vans that I could leave something as is or repair. I threw out an entire horizontal stabilizer even after being told to build on.

That being said, don't worry about those who would have you believe your plane has to be mistake-free. There is absolutely nothing wrong with striving for perfection and a show-winning plane. But there is also absolutely nothing wrong with fixing occasional mistakes in an approved, well-thought out repair, and moving on. There may very well be mistakes that would be entirely impractical to replace, and almost every one of them will have a perfectly fine repair option. Ask the guy who drilled into his spar cap by mistake.

Remember that although TC's can be valuable, the two final authorities are yourself and the engineers at Vans. If those two entities are happy, move on!

chris
 
Don't be the least bit remorseful about posting the question. It is certainly pertinent, valid, and provocative. This is exactly how the rest of us morons learn. The question of Ken's is certainly insightful, at least for me. In the future I know I will be posting questions and concerns about possible mistakes. There are a lot of great minds and experienced builders on this site that are willing to share bits of valuable information.

I for one Ken am happy that you posted.

Steve
 
With the exception of Paul Dye, who told me once he only had to reorder one part when building his RV-8, most of us have a big box of parts that were reordered during the build.

Paul is not of this world, though.:D
 
Not Personal...

And to Reiley: was that comment warranted. I thought that this site was a site to ask questions and get helpful responses. Sorry for not having your years and years of experience. Maybe I will just avoid asking questions on Vans Airforce and ask my questions to the tech counselor/advisor that I send questions to directly via email.

And BTW, I am going to replace the rib.

You asked a question, I gave you an answer. When good pre-buys are performed looking over the plane in general is just a part of the process. A lot of research goes into a pre-buy, and that includes scouring the internet to evaluate the builder and their mindset during the build of the plane. You would be surprised what we find and read. It was a heads up for you. Glad you're replacing the part. :):):)
 
With the exception of Paul Dye, who told me once he only had to reorder one part when building his RV-8, most of us have a big box of parts that were reordered during the build.

Paul is not of this world, though.:D

You never asked about the pile of scrap we generated building the RV-3 however....:D
 
While this discussion has sort of drifted into a general quality issue, one thing I have not seen mentioned yet is the type of structure as a criterion for the repair/replace/leave alone decision. Sure, there are many flaws in any airplane, but not all parts are the same importance. And this one - a wing rib - is primary structure. It's load bearing and failure is a bad thing. This is not the same as a little bracket you fabricated to hang your headsets on when the airplane is parked.

So for me, I'd follow this thought process:

1) The part is primary structure, therefore worthy of an engineering evaluation;

2) It sounds structurally compromised (discrepant) and in need of repair or replacement;

3) Cost/Benefit analysis on repair or replace: Obvious replace, due to complete access and the cost of the repair will likely exceed the cost of the new part.


Yes, there are times when you should just press on with the build - but not when you have a damaged piece of primary structure in your hand that has not even been installed yet.
 
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