What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Need Advice -- Drilled into Spar

Stalldog

Well Known Member
Need some help. While match drilling the root rib to the tank baffle, my drill stop slipped and I drilled into the spar a good 1/16" (see picture - a little hard to see, but follow the arrow).

Besides drop kicking myself into the next county for letting this happen, any ideas how I can salvage this?

 
Lightening hole :D

Vlad, interesting concept -- maybe I should add more? :rolleyes:

Prime and move on is an answer I REALLY like, but it almost seems too easy. Is there anything I should do to dress it up, although that would require removing more material?
 
Wouldn't hurt to debur it a bit, but I would also confirm with the factory that it is ok to have that extra lightening hole. Might also want to put one on the other side so the airplane stays balanced.:D

Greg
 
Ask VANs

Contact Vans to get their opinion. It's the only way you will feel comfortable with the result. I suspect they will tell you to dress up the hole a little and move on.
 
Spar hole

Spar hole or spare hole , prime and go , there will be more errors along the way.
Another thread is on build quality , no such thing as perfect , just the one with the least errors .
Tom
 
There is no question that you should supply Van's with the specific details like location, diameter and depth of defect, then let them work the issue.

Dare I say that the wing spar is one of the more critical structures, defects should not be covered up and ignored (taking a pole on VAF does not make it 'OK").

The correct way is to confess your sins and let the smart folks at Van's that know stuff (and get paid to figure this stuff out) tell you if it's ok or not. Then you take that documention from Van's and put it with your records.
 
Last edited:
Note and picture have been sent to Vans. I'll post to let you know what they say.

Thanks to everyone for the feedback -- I'll sleep better tonight.

In the meantime, I'm coming up with a better drill stop.
 
. . . . Then you take that documention from Van's and put it with your records.

Excellent point, Walt, will do just that. So far I've saved all the e-mails and responses from Vans but haven't printed them out, so I'll go ahead and print off the responses and keep with my records.
 
Documenting defects along with the engineering "fix" and including them in the aircraft records is SOP in the "certified" world. Should this area ever be opened up and this "issue" discovered, its nice to have the paperwork to show that its already been addressed and approved. It also goes along way in showing builder integrity on dealing with defects which are going to happen. As we used to say the job isn't done until the paperwork weights more that the aircraft.
 
Being a 7 or 7A, I would shoot it down ASAP on a prebuy inspection... This IS the Spar you know.
 
Last edited:
In the meantime, I'm coming up with a better drill stop.

spring-stops.jpg
 
Being a 7 or 7A, I would shoot it down ASAP on a prebuy inspection... no matter what Van's or anybody stated. Note: not a lot of folks look that deep. If Mel Asberry did your inspection, it WOULD fail! And, he is THE BEST!!! Hands Down!

:)

How is this post helpful? Did you not make any mistakes when you built your RV? As pointed out by Walt, the important thing is what Van's says.
 
Being a 7 or 7A, I would shoot it down ASAP on a prebuy inspection... no matter what Van's or anybody stated. Note: not a lot of folks look that deep. If Mel Asberry did your inspection, it WOULD fail! And, he is THE BEST!!! Hands Down!

:)
Why not let Mel speak for Mel, eh? But if The Mothership OK'd a defect such as that, and the DAR refused to issue the airworthiness paperwork because of it, there would be **** to pay, particularly if I've documentation from the factory OK'ing it.

An awful lot of people, DAR's, Tech Counsellors, CASA/FAA staff seem to think they know better than the factory. Unfortunately, oftentimes they don't. If Vans says the wingspar is 1 1/8 thickness, we don't build a spar that is 1 1/4 "just because" do we? Of course, these same people often have a lot of good ideas too. It's a matter of sorting the wheat from the chaff.

That being said, a small blemish like that anywhere else I would suggest is Ok - build on. BUT, because of where this is, arguably the most stressed part of the airframe, I would get as much detail on it as I can and fire an email off to The Mothership for an "official" blessing.
 
How is this post helpful? Did you not make any mistakes when you built your RV? As pointed out by Walt, the important thing is what Van's says.

Robert,

I was not trying to be negative OR state I know better that Van's. I was just making a point. This gent is asking for info. IMHO, there could be a resale problem here on a prebuy, even if someone gave it their blessing.

That's all folks. :)
 
this is one of those threads where I think there should be only one answer: Call Van's.

I know building our own airplanes gives us a lot of expertise, but this is a spar and the very best advice comes from the people who designed the plane. They may very well say "move on," but there are some times (very few times) when I think VAF is a poor substitute for a proper answer, and it's a good idea as part of the build to determine when the source of information is Van's and when it's another builder. I think this is one of those times.
 
Dang!!!!

Jim. I'm sorry... you must have a really bad case of bad luck! The Plans specifically say to be careful in this area and drill when the tanks are off the wing.. Top of page 7-6.

"Remove the clecoed tank assembly from the wing, and drill all rivet holes to final size. (Doing so off the wing
prevents accidentally drilling into the spar)."
 
Thats the spar cap, right? ...Right at the root? That's perhaps the most highly stressed single piece of metal on the airplane. Engineering at Vans is the ONLY opinion that matters here.

As an aside, it might not be a bad idea to slip a piece of steel in there to keep the next wayward drill bit away ftom the VERY precious spar.
 
Thats the spar cap, right? ...Right at the root? That's perhaps the most highly stressed single piece of metal on the airplane. Engineering at Vans is the ONLY opinion that matters here.

I don't know about the ONLY in your post, a soul/person is flying this aircraft and many 7's are well exercised... I personally have a different thought pattern on the build for an aircraft capable of doing acro/aero. (GGG's)

You are correct, highly stressed area for sure! Lets build safe out there. :)
 
Last edited:
This isn't the first time i've wondered about this, but I sometimes see questions like this and wonder whether it would make sense to have a database somewhere that correlates kit number with reports of "oops, I did X while building, is this okay?"

The unfortunate part is that anyone looking to buy an airplane would use it to beat down a seller's price... And an insurance company would use it to say "see, he built it wrong! coverage denied!"

But in terms of gathering information that could be analyzed and used to further the design, it would be a rather useful tool. Maybe Van already keeps such a log...

Note that i'm not judging the incident in this post... I'll let Van rule on that. There seems to be opinions in both the "build on" and "you're screwed" camps, chances are reality is somewhere in between...
 
I don't know about the ONLY in your post, a soul/person is flying this aircraft and many 7's are well exercised... I personally have a different thought pattern on the build for an aircraft capable of doing acro/aero. (GGG's)

You are correct, highly stressed area for sure! Lets build save out there. :)

If you decide to stop flying aircraft that were built with "defects", then you better give up flying (especially the ones on this List)

I wasn't kidding when I said the paperwork weighs as much as the aircraft, most of that weight is engineering orders to repair the damage that was done while building it :eek: (keep in mind most aircraft structures are built by the lowest bidder, this translates to low cost workers that really don't give a darn about what they are building, could be a Yugo for all they care)

The only difference between "certified" aircraft and homebuilt is the documentation/approval process of those "defects".
 
Last edited:
Walt, I'm not sure what point you are trying to get across with that last post, but you suggest a cavalier attitude about workmanship. We're not talking about a landing gear fairing here. As to your "list", I work in the engineering department of a major aircraft manufacturer, and I can tell you that parts like that shown in the first post don't make it out the door. On a highly stressed machined part like that, we don't even allow impression stamping for identification, let alone a wayward, random hole.

In the end, there either is enough margin left in the spar, or there is not. And while we may all have our opinions, it really is up to Van and his engineering department to make that call. He is the subject matter expert.
 
I think you misunderstand my comments. I quit my last job because I was so disgusted at the get it out the door must meet schedule mentality which was the first priority, producing a quality product was third with cost being second (I don't care what "they" say in all the meeting rooms, that was the priority on the shop floor).

Really my point was, as I said in in the beginning of this tread, that Van's engineering is the final authority on this. Other folks have said they wouldn't fly in the airplane regardless of what Van's said because this particular aircraft had a "defect". All airplanes have defects was my point (these "defects" are then repaired by re-work, part replacement or approved "as is").

Perhaps I need to have more coffee in the morning before posting :cool:

Update: I think if we started an aircraft manufacturing plant exclusively with RV builders it would produce a superior product compared to many companies!
 
Last edited:
Walt, I'm not sure what point you are trying to get across with that last post, but you suggest a cavalier attitude about workmanship. We're not talking about a landing gear fairing here. As to your "list", I work in the engineering department of a major aircraft manufacturer, and I can tell you that parts like that shown in the first post don't make it out the door. On a highly stressed machined part like that, we don't even allow impression stamping for identification, let alone a wayward, random hole.

In the end, there either is enough margin left in the spar, or there is not. And while we may all have our opinions, it really is up to Van and his engineering department to make that call. He is the subject matter expert.

I don't see a cavalier attitude in Walts post. I see a willingness to rely on the designer and his repair recomendation. So I ask, what are the specific structural issues which cause concern?

I would guess the two primary concerns would be:

1) Loss of area in the cap. While only Van's can answer this question, the loss of area appears to be very small. I would guess this tiny hole wouldn't be cause for rejection but this is clearly a decision which needs to come from the design team.

2) Introduction of stress risers. Seems like this risk could be mitigated thru deburring and polishing. The analogy of "not stamping highly stressed parts" doesn't seem applicable to this situation as doing so would likely introduce stress risers. Probably everyone would agree that introducing potential stress risers is undesireable, therefore it is not surprising this would not be acceptable in most production enviroments. It is noteworthy that Van's engraves the serial number on the spar somewhere near the root end.

It doesn't seem that a hole in the cap would necessarily render it unusable, as the cap contains lots of holes for the purpose of attaching it to the spar.

A lot of structure is "highly stressed", that's why we call it structure. So I ask the engineers, what are the correct considerations when evaluating this situation?

For the record, I'm not an engineer. I don't know Jack (except Mr. Daniels). I am not saying the cap is acceptable, I'm asking what are the specific areas of concern?
 
I think you misunderstand my comments...

Apparently I did. I thought the post "uncharacteristic" of you. Thanks for clarifying.

And I'm certainly not passing judgement on the servicability of the spar... It might be fine. But drilling into the spar cap is definately a "stop and call engineering" moment!
 
As a side note, one reason I hate drill stops. They lull you into a false sense of security. As mentioned, the sacrificial scrap piece between parts is what I prefer. Aluminum works just fine as you will feel the bit break through, unless you have a drill stop, especially one that has "slipped". I have them, but didn't use them during my build and rarely use them now.

And Walt, if we all grouped together to form an airplane manufacturing company, I worry no airplanes would ever reach the door! Way too many type "A"'s like me here that have high opinions on everything, even things we know nothing about. :)
 
Thats the spar cap, right? ...Right at the root? That's perhaps the most highly stressed single piece of metal on the airplane...

Actually, the service history of that wing design suggests that the critical strains are achieved a bit further out. That's where the factory demonstrator broke when overstressed. Also, the spar stub has a lot more material than dictated by the internal stresses so as to allow for the cross-sectional area of the wing attach bolt holes. So my thinking is that odds are good that the mothership will bless a "dress and build on" approach.

Thanks, Bob K.
 
I hope we get an answer soon. The curiosity is killing me!!

How do you think I feel? ;) I've contacted Van's support and sent some additional info, pictures, and dimensions. They've said that it may take several days to get a reply, but I will get one. The hole, by the way, is slightly less than 1/16" at the center, and less than that at the edge, made with a #30 bit. The picture below tells the story.



Also, as I was drilling the rest of the tank brackets the dang thing slipped again -- this time I had a piece of steel under the tank baffle and tape just above the drill stop. Turns out the set screw is defective. I had never used this drill stop before, not really wanting to rely on them. I replaced the set screw from another stop and it did fine after that (with the steel and tape still in place, mind you, fool me once . . . . ).

Anyway, here I sit, waiting for an answer, and I'll post it as soon as it is received. In the meantime, I might as well keep building. If it turns into a hunk of scrap, it'll be a nice hunk of scrap! :D Not being cavalier here, but I've got to keep some sense of humor about this or I'll go nuts waiting.
 
Whatever Van's tells you, you need to keep a hard copy of that info with your builder's log to show the inspector.
 
Vans

My bet will be that they tell you to smooth off the edges to prevent stress risers and build on. Fingers crossed for you!
 
These latest pictures put things in perspective much better than the first. I'm guessing that you will hear a favorable opinion from Van.
 
My bet will be that they tell you to smooth off the edges to prevent stress risers and build on. Fingers crossed for you!

Assuming they approve it I suspect it would be more like a 20:1 blend out similar to what you see in 43.13 chapt 6 for corrosion damage.
 
Delay

Just to let everyone know, I heard from engineering and they said they are very busy right now, so it could be several weeks :eek: before they can give me a solution. In fact, they had another request very similar to mine come in at the same time, so I'm not the lone ranger after all!

For now I'll just have to keep on keeping on. I'll let you know when I hear something. At this point I'm ready to start working on the tanks themselves, so I have plenty to keep me busy until I hear, plus it's work not actually on the wing.

One other question that I have not been able to resolve by searching. IF I have to replace the spar cap, are there experienced individuals around the country who can do this for me? I don't think I have the knowledge, experience, or equipment to drill out these railroad spikes and put in new. I know in the "old" days builders assembled the spar caps themselves. With the right equipment I'm sure I could install a new cap, but it's removing the old that is out of my realm. Not wanting to borrow trouble, but figured this has come up before and I could not find any such info here or elsewhere.
 
Jim,

In no way am I trying to beat you up... please understand this. I feel your pain with this mistake! IMHO, Van's has the time to respond. IMHO, their attorney is reviewing a response. Approving a spar defect would open a lot of doors that Van's as a company I would think could not and should not let happen for the company and many folks that have invested 10's of thousands of dollars in their aircraft. One bad incident could lead to a big problem for many. I would like to see your issue solved, but correctly. NO, I don't know it all that is for sure! I do technical inspections and YES, I'm pretty anal. I do not just think about the builder as I KNOW some other soul will most likely fly in the aircraft. Spank me, hate me, shoot negatives at me... whatever, I'm all about safety. Will this issue cause a problem? NOBODY can answer that question. Please forgive me if I have offended you or anyone in this thread. :)
 
Jim,

In no way am I trying to beat you up... please understand this. I feel your pain with this mistake! IMHO, Van's has the time to respond. IMHO, their attorney is reviewing a response. Approving a spar defect would open a lot of doors that Van's as a company I would think could not and should not let happen for the company and many folks that have invested 10's of thousands of dollars in their aircraft. One bad incident could lead to a big problem for many. I would like to see your issue solved, but correctly. NO, I don't know it all that is for sure! I do technical inspections and YES, I'm pretty anal. I do not just think about the builder as I KNOW some other soul will most likely fly in the aircraft. Spank me, hate me, shoot negatives at me... whatever, I'm all about safety. Will this issue cause a problem? NOBODY can answer that question. Please forgive me if I have offended you or anyone in this thread. :)


Once again, how is this post helpful?

Can you cite a specific example where Van's was unwilling to provide repair information without consulting legal?
 
No problem, Reiley, everyone is entitled to his opinion, and yours is as valid as anyone's. I agree the fix has to be done correctly -- I just don't know what correctly is. I'm okay with whatever Van's engineering says it is, assuming that the FAA agrees as well during their inspection.

You may be right, Van's and their attorneys may tell me to back up the dumpster and send it to scrap. If that happens I'll likely just sell what's remaining of my build and go buy the best four seat GA good performance aircraft that I can find and fly as long as I can. Hopefully I can finish my build and fly into the sunset, but there is life and flight without an RV, and I'll manage either way.

What I cannot do at this time is go ahead and order the scrap dumpster for the sake of keeping my "damaged" wing off the future market. This is an expensive hobby for me, and I do it because I really enjoy it, and enjoy flying. I can't just scrap this to make the world a happier place for you and all the other inspectors out there, nor should I have to. I agree with what others have said, that the decision should lie with Van's engineering, and that's what I will do.

One final note. I've reserved my tail number as indicated in my signature, and have no plans to change that. Make note of it, write it in indelible ink if you like, so that someday you'll know it when you see it. I'm fine with that. I've posted this in hopes of getting good advice, which I have received, but also to help others who may have a similar problem down the road. I've read enough posts to know that most folks do have serious issues at some time in their build. I'm not trying to hide anything or create a problem for anyone, I'm just a builder with a problem looking for help and advice. And with that, I will not post again on this thread until I finally hear from Van's. I owe that to everyone.
 
...You may be right, Van's and their attorneys may tell me to back up the dumpster and send it to scrap...

Highly unlikely. The guys at Vans have a really good idea how their structures work and what the stress distributions are and how much margin there is. And I'd bet $20 that the answer will come back pretty quick to dress it out and build on. If Van's guys had to talk to an attorney every time someone drilled a hole in the wrong spot they'd need to install a hotline to Meacham, Peigh, Bigge & Howe.

And, for the record, I did once have an operator call me about an extra hole in the aluminum wing spar of a kit sailplane that I support. I had to tell him to get a new wing. But that was a 3/8" hole that went all the way though the spar cap.

Thanks, Bob K.
 
Jim - you absolutely can replace that spar cap. It is not an easy job but it shouldn't be a deal breaker for your build. If it becomes necessary, I have a contact that may be able to help you. You are not the first and my contact has refined the procedure and tooling to match drill the wing spar fuselage assemblies. They work with Van's closely.
Those big rivets come out just like the small ones, perhaps even easier. Don't let that worry you. You can probably find a loaner squeezer that can handle them too if it comes to that.
My hope is Vans will bless the repair as Walt suggested per Ac.43. The spar is critical but I would be very surprised if it was designed so closely to tolerance that no repairs would be allowed. However, as you know, Vans is the final decision maker on this.
Regardless it shouldn't be the end of your build. I would hate to see that. If you like, PM me your info and I will put my contact in touch with you. They may not comment on the actual repair, but they might help put your mind at ease should bad news come from Vans.
 
Actual experience getting a spar fix from vans

Many of the posters here are offering unhelpful advice based on opinion. They have no facts and no experience.

I have both.

I damaged my rear wing spar during construction. I contacted Vans. I received a fix (yes it took some time). There were no Legal discussions. My rear spar is now stronger than every other rear spar flying. None of the above is opinion. It is engineering fact from Vans engineering. They are excellent people who are there to help.

I suggest that those who have nothing to add stop discouraging the OP.. I'm sure he feels bad enough.

I hope he posts the fix for those of us who want to learn.
 
I damaged my rear wing spar during construction. I contacted Vans. I received a fix (yes it took some time). There were no Legal discussions. My rear spar is now stronger than every other rear spar flying. None of the above is opinion. It is engineering fact from Vans engineering. They are excellent people who are there to help.
I hope he posts the fix for those of us who want to learn.
Me too. I flipped my aileron push rod holes as I became disoriented with my wings laying on my work table upside down. I repaired per AC.43, with a doubler on each side and put in the new holes and moved on. The repair came from a tech counselor and was reviewed by several Van's employee's ( in person ) I am not sure they even had an "engineering department" at that time.
I am very hopeful for Jim.
 
....One final note. I've reserved my tail number as indicated in my signature, and have no plans to change that. Make note of it, write it in indelible ink if you like, so that someday you'll know it when you see it. I'm fine with that. I've posted this in hopes of getting good advice, which I have received, but also to help others who may have a similar problem down the road. I've read enough posts to know that most folks do have serious issues at some time in their build. I'm not trying to hide anything or create a problem for anyone, I'm just a builder with a problem looking for help and advice. And with that, I will not post again on this thread until I finally hear from Van's. I owe that to everyone.

Amen, brother, amen. You are hearing some negative opinions from non-Van's engineers, but positive vibes from others. I am hoping Van's offers you a positive answer! Forget anything negative that a TC says, for the sake of THIS dilemma. While they do great jobs at what they do, they do NOT offer a final verdict for your specific problem. I've been a PAID member of these forums for a long, long time, and I can sense that the mod's are about to lock this thread down. I hope that doesn't happen, but I sense it based on many years of watching past posts. You are doing the right thing by awaiting an official response from Van's. Any other opinion is just that: an opinion, and worthless to your problem. Here's to hoping Van's gives you a blessing and/or an easy repair solution.
 
Last edited:
Amen, brother, amen. You are hearing some negative opinions from non-Van's engineers, but positive vibes from others. I am hoping Van's offers you a positive answer! Forget anything negative that a TC says, for the sake of THIS dilemma. While they do great jobs at what they do, they do NOT offer a final verdict for your specific problem. I've been a PAID member of these forums for a long, long time, and I can sense that the mod's are about to lock this thread down. I hope that doesn't happen, but I sense it based on many years of watching past posts. You are doing the right thing by awaiting an official response from Van's. Any other opinion is just that: an opinion, and worthless to your problem. Here's to hoping Van's gives you a blessing and/or an easy repair solution.

Was a Mod here for many years... nothing in this thread would put the move for a shut down. The negative towards TC's is a sad sign, they do their best and work for FREE. There is an easy solution, Jim will get there I'm sure. :)
 
....The negative towards TC's is a sad sign, they do their best and work for FREE. There is an easy solution, Jim will get there I'm sure. :)

I couldn't agree more about the value of the TC's! I think the TC's offer a tremendous benefit to many builders, and yes, all on their own 'dime'. I think TC's are great and said nothing to imply negativity towards them. Which is why I underlined and capitalized my statement about THIS situation.

My point, which I tried to highlight- was that in this given dilemma, a TC opinion won't give the OP a definitive answer as to whether proceed or to repair. That can only come from Van's.

I'd never speak negative about the positive things that TC's offer. Never. But I will once again reiterate that a TC opinion for this problem, is simply an opinion, not the answer.

I'd like to become a TC myself one day. No negativity was meant by my post toward the value of a technical counselor!
 
Last edited:
Simple question

Okay, for you guys that like to calculate stress & strain: What would be the effect of installing an "extra" rivet in a spar cap?
 
Back
Top