What's new
Van's Air Force

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

Nightmare Annual

MartinPred

Well Known Member
So my partner and I bought an RV-4 last year (two Air Force guys looking to enjoy our off time) and it's time for our annual condition inspection. I took it to Darrell Morgan at Firebird Aviation because I wanted a very thorough annual, this being our first one.

Well Darrell was more than thorough, and discovered a very serious problem with the left aft wing connection. It seems the guy who built it mis-drilled the hole. So instead of rebuilding the connection, he just drilled another hole right next to the first one. In fact the two holes overlap making them one big hole.

Darrell tells me this is very serious and could lead to structural failure, which makes sense to me. Of course, having not built one of these things, I can't say for sure.

Darrell is giving us a very reasonable rate to fix it. It's just going to take him a couple of months due to the fact that he already has a couple of long term projects ahead of us.

Have any of you seen this same mistake before? Do you have any creative fixes? I'll try to post some photos.

-Matt J. Martin
N402BD
 
Matt:

I can speak from experience here. I am building a 6A and I assume that the rear spar attach is the same if not very similar.

What happend with me is my wing shifted on me when/while I drilled that single hole. As a result, the incidence of one wing did not match that of the other. So I was faced with what to do about it.

After a consult with Van's, a plan was devised. I cut the flap brace just outboard of the bottom rear wing spar flange. This is the same flange that extends past the wing root and inserts into the mount in the fuselage.

I drilled out the rivets holding the sectioned inboard portion of the flap brace as well as the spar flange. Also drilled out all rivets holding the spar flange doubler, which along with the spar flange inserts into the fuselage mount.

The spar flange and doubler were then re-fabricated and all rivet holes were duplicated using the old parts as drill jigs.

The new parts were then riveted back on, along with the sectioned flap brace which was spliced back onto the outboard portion. Most of the rivets could be bucked by reaching in through the root rib lightening holes. Those that could not were riveted with cherrymax rivets as prescribed by Van's.

I was able to fabricate a bushing that was inserted in the hole drilled in the fuselage rear spar mount that acted as a drill fixture to center the new hole in the wing rear spar after setting the correct incidence.

In your case, however, you will need to remove the flanges that are mounted on the fuselage bulkhead, refabricate them as I did for the wing rear spar flange, and then re-install in the fuse.

All of this sounds daunting, but once you get rolling, it is not too bad of a job. If you do it yourself and have Darrell sign it off, it certainly won't take you two months and will be a heck of alot cheaper to do.


BTW...I am VERY glad I went to the above trouble, as now my wings are spot on. Was a real downer to see that I had screwed up in the first place tho....
 
I'm not going to sleap well tonight

Have I ever seen this exact problem... NO! But I have had issue with making a very important cut or drilling an important whole without having measured 10x. It's hard to imagine a builder double drilled a whole as important as the rear spar attachment. As always trueth is stranger than fiction. There are many whole in the plane you can make like this. Shhh, I double drilled the airframe ground bolt... Nobody will ever know, it's our secret ;) Spar attachments are not one of them wholes!

Removing that rear spare is probably not a gigantic task. It is large. You must remove the wings (8hrs alone), pull out the seats and drill out the decking to expose the rear spar bulkhead.

The rear spar itself is two 1/8" bars roughly 2" high by 32" long rivetted to a bulkhead. You can drill out the bar stock and re-install a new one for all of $20 in bar stock. Trouble is you'll need about $500 in tools if you dont have them. Namely, a rivet gun and probably a good right angle drill attachment (those rivets against the side-walls will get you). www.AveryTools.com

-Bruce
 
This might seem like something a lawyer would say, but have you considered demanding that the builder/seller bear the cost of this repair? This certainly was a mistake made on his part and I'd say that anybody who builds one of these things knows that this type of mistake has to be fixed to be safe. I'd wager that this area was also concealed from the DAR who did the inspection. We all have little boo-boos during building, most of which are only cosmetic, but this type of "fix" could've wound up as a big smoking hole in the dirt and I'll bet the builder knew that. I recently drilled this very part on mine and definitely measured twice (about 100 times, actually). Even so, I ended up drilling the hole at a slight angle. After much private weeping and several calls to Van's, several easy fixes were suggested. During our conversations, they pointed out that my problem was no big deal compared to the much more significant problem that your airplane has. I'm glad you've got someone to take care of it, but I think it's real B.S. that the builder half-a$$ed it this way and never bothered to mention it.
 
Pre-Buy?

Matt,

Just curious, did you have a pre-buy inspection done on this airplane prior to purchasing it?

Jeff
-8 wings
 
...BTW, I also agree with the above poster about holding the builder/seller accountable for that. It seems awfully careless to think that would be acceptable and/or safe.

It would also be interesting to see what the builders' logs say about that little procedure.

Jeff
-8 wings
 
Get help

Try to find some experienced builders in the area. I found this site: http://www.eaachapter1300.org/ (with a 3.4MB image on the home page - ouch!) There are probably some people there who can help. I also found about 30 people in Nevada in the RV white pages (http://www.vansairforce.net/db/RVWPcode/rvwp_100.asp?offset=1000) I'll bet you can get some help from them, both with tools and tips. You and your partner will learn a lot, save some money, meet some nice people, and of course get your aircraft fixed correctly.

About the original builder - Van's instructions have improved a lot over the years, and even today, they are anything but verbose. The drilling of the aft spar attach point currently rates a lot of warnings and admonishments to do it carefully. I'm sure these are not the result of amazing foresight on Van's part, but the result of builders making mistakes and calling Van's for help. It is entirely possible that this particular RV4 was built before it became common knowledge that this was a critical part of the wing attachment. I have to confess that if I didn't have the written admonishments, nor the incredible teaching power of these internet lists, I might have done the same thing as this builder, and not known it was a serious issue.

Best of luck in your repair.
 
Rear spar hole

If I remember right this hole is the source of fatal accidents in the past and Van's is serious about having 5/8" of material on all sides of it. I've heard since starting my airplane that this is a no go mistake and not to take it lightly. Please don't get your advice from us here on this one. Call Van's Monday morning and get direction from them. There is not much that they haven't seen and have created a work around for.

Regards,
 
szicree said:
...Even so, I ended up drilling the hole at a slight angle. After much private weeping and several calls to Van's, several easy fixes were suggested.

Steve out of interest what were the fixes. Steve.
 
Drilling for rear spar

Just a comment on Bryan's earlier post:

"If I remember right this hole is the source of fatal accidents in the past and Van's is serious about having 5/8" of material on all sides of it."

The plans for my RV-8 (Dwg 43) show a minimumof 5/8" fron the center of the hole to the edge of the material, not from the edge of the hole. If you can get 5/8 all around the hole, great, but in some cases you can't especially considering the pilot holes on the carry through spar attachment are already there for you, at least it was on my QB.
 
sf3543 said:
.....but in some cases you can't especially considering the pilot holes on the carry through spar attachment are already there for you, at least it was on my QB.


That sparks my curiosity! My QB was 82133, and there were no pilot holes. However, I'm wondering if they have discovered that the kits are so repeatable now that they might as well drill them, because everything fits the same. Interesting!

Paul
 
Paul
My kit was third hand, number 80227, and it had pilot holes in the two brackets that carry through the fuselage, but not on the spar on the wing.
Could be that they don't do that any more to assist in getting proper clearance. A builder frien of mine said he has seen both ways, but his also had the pilot holes. Again, his kit was a late 90's kit.
At any rate, mine came out great with a (very) little extra material all around.
 
sf3543 said:
At any rate, mine came out great with a (very) little extra material all around.

Which brings up a good point....why is it that anytime there's a hole to be drilled where edge distance is critical AND the hole isn't pre-punched that Vans give you exactly 0" of wiggle room? Geez...another 1/8" of material in a few places would make things much easier. Am I the only one that's noticed this?
 
Steve Sampson said:
szicree said:
...Even so, I ended up drilling the hole at a slight angle. After much private weeping and several calls to Van's, several easy fixes were suggested.

Steve out of interest what were the fixes. Steve.

Drilling the hole straight using a slightly larger size was suggested, but was waved off as too likely to just screw things up worse. The best idea was to use a tapered shim under the bolt head and nut. A variation on this is to use what are called spherical washers under each instead. They do the same thing as the shim, but find the right position all by themselves instead of having to be oriented while tightening.
 
Thanks - I have wondered what the solution is.

I have a block with a bunch of holes drilled in a drill press to ensure I go straight 'cos it worries me.

Thanks.
 
What about reaming it out to fit an oversize bolt? Just a thought. Like the other have said, call Vans.

-Bruce
 
Post a picture

Can you post a picture of this?

Dan B.


MartinPred said:
So my partner and I bought an RV-4 last year (two Air Force guys looking to enjoy our off time) and it's time for our annual condition inspection. .....

Have any of you seen this same mistake before? Do you have any creative fixes? I'll try to post some photos.

-Matt J. Martin
N402BD
 
Rear spar misdrilling

The same problem was written up in Kitplanes, I think. A major re-work was required to fix the "double" hole. This particular airplane (a -4) had many other errors of construction that needed attention. I hope this is the only problem you find on your annual and that you get flying soon! Bill Dicus
 
just some thoughts

Often the fix is not as bad as first envisioned. Make sure to have a plan and sort through several ideas before anyone starts fixing the problem. Do you have the drawings so you know the design tolerances, such as edge distances (often from the center of the hole)? Get the tech counselors and experienced RV builders looking at it. Get the pics to Vans, and us if you are so inclined. Get Vans advice. Have you pulled the bolt? Get some RV expert help if you do intend to pull it (drain fuel, support tip, etc). It should be no problem but keep the bolt in place when not examining the hole.

I figure-eighted my aft portion of my rear spar carry through (-9A). It did not get into the aft wing spar. $10 raw stock, 30 rivets, and eight-ten hours and it was back good as new.

((The unfortunate part is that you will need an A&P to sign off on the work)) ((This statement was incorrect. You do not need an A&P signoff as noted in the following posts)). Regards, John.
 
Last edited:
No work on an amateur-built HAS to be signed off by an A&P. An A&P (or the repairman for this aircraft) is only required to sign off on the annual condition inspection. Now in a case like this, it would be extremely PRUDENT to have an A&P sign off on it, but not required.
Mel...DAR
 
Mel, I won't disagree with you, but I do ask what you based your assertion on? That has been a matter of contention amongst the Experimental guys at WHP for quite a while.
 
My assertion is based on 7 years experience as a DAR. Every year at our recurrent training seminar this is discussed extensively. FAR part 43.1(b) states that this part (which is the FAR listing who may work on aircraft) does not apply to aircraft which have been issued an experimental certificate. As a matter of fact, your operating limitations state that the owner can make major changes to the aircraft and put the aircraft back into phase I himself.
Mel...DAR
 
Last edited:
I could not believe it but its true.

Mel said:
My assertion is based on 7 years experience as a DAR. Every year at our recurrent training seminar this is discussed extensively. FAR part 43.1(b) states that this part (which is the FAR listing who may work on aircraft) does not apply to aircraft which have been issued an experimental certificate. As a matter of fact, your operating limitations state that the owner can make major changes to the aircraft and put the aircraft back into phase I himself.
Mel...DAR
Mel is right, a second hand owner can do what ever mod or major repair they choose, with out an A&P or AI sign off. I am sure Mel does not need my endorsement, but I found this so hard to believe it drove me the call the FAA. It is true; Mel is correct. The advice about getting a A&P or AI to look it over is a good one. However a experienced talented builder may be a good substitute.

However the caveat would be the person (any one, 10 year old kid or your dog) doing the repair may need to call the FAA and possibly put it back into phase I operations if a mod/repair is significant. The only thing these second hand owners can't do is the condition inspection, and at that time and only at that time would that work or a mod come under scrutiny or need to be "signed off" (by the repairman or an A&P or AI). Since the repairman screwed it up in the first place we can eliminate that option.


The only time this work needs to be inspected is when the condition inspection is due. If the work is horrible than I suppose the person doing the condition inspection (Repairman/A&P/AI) would I hope refuse to sign it off. Till than you can rebuild half the plane or convert it into a biplane twin engined JATO assisted RV with no sign off, and fly it till the next condition inspection. Again the FAA may need to be notified if the work is a major change.

It does not make sense but it is true. I guess we should not complain about the freedoms we have.

George
 
Last edited:
A&P signoff

Mel and George, thanks for the correction. I should have known better. Regards, John.
 
Re: Nightmare Annnual

Thanks everyone for the tips. I've since spoken with the guy who built the plane and from whom I bought it. He didn't remember that particular boo boo (he built the plane six years ago). From what I've been able to peruse from the builder's instructions, there are a lot of holes you have to drill. Some it's OK to flub a little, and a few that aren't. And the instructions are not all that clear on which is which.

At any rate, Darrell at Firebird is busy working on the solution. Once he has a design he's going to send it to Van's to hack on. He promises me that the solution will be both elegant and simple, and will restore the airplane to its full design limits.

Even if I wanted to try to fix it myself, it wouldn't be worth it. The airplane is currently in Texas and I live in Las Vegas. To disassemble the airplane and ship it back here would cost more than to just have Darrell do it. But Darrell is giving me a VERY reasonable rate (the Air Force buddy discount). And I know he'll he a superlative job.

All part of aircraft ownership I suppose. I'll just have to go out and fly a lot more to make sure I'm getting my money's worth. :)

-Matt J. Martin
N402BD
 
Nobody else has mentioned this, so I stick in my two cents for what it's worth. Although this may seem horrible, it may be a blessing in disquise. I don't want to make you worried about your new plane, but if it was my plane I would be worried about other significant "boo-boos". Sloppiness tends to be a personal trait and not a one shot deal. I don't know how thorough your annual inspection was or how obvious this misdrilled hole was. However, since you are going to be doing some significant work on the plane anyway, I would probably disassemble everything that can be unbolted or removed without drilling out rivets and look at things very closely. You may or may not find something else wrong, but you'll have the piece of mind knowing that you looked, once put back together you know it will stay together, and you'll learn a lot about your airplane.
 
Back
Top