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Check those tails

Mlidzct said:
Thanks to this thread I made sure to check this area on a project airplane I looked at today. Here are some pics. This makes me wonder about all the critical areas that cant be seen.








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Wow ! How many hours has this plane been flying? Perhaps another testament to the robustness of the design, but obviously this plane should be grounded and fixed. Good catch.
 
Not a flying airplane - luckily

JonJay said:
Wow ! How many hours has this plane been flying? Perhaps another testament to the robustness of the design, but obviously this plane should be grounded and fixed. Good catch.
Click to expand...

This was on a non flying project. Apparently this was done with guidance from his local eaa members/ "experienced" builders.

This illustrates that experience does not equal correct.
 
Explain

Can someone knowledgeable explain what exactly is wrong with this work, besides not per plan? Us non builders would like to learn from the example.
Is it the 3rd bolt?
The edge distance?
Distance the two good bolts are from the longeron?
Thanks in advance.
 
I never like the HS to longeron mating section on the 7A and if there was ever a spot where the matched hole tooling of the 12 should migrate to the 7 (and maybe it has), this is it.

It only take a very small (I won't even call it a mistake) "diversion from perfection" when building the HS to end up with questionable (but nothing like what I see here) edge distance at the longeron attach point.

I recall talking to Ken Scott about it and he was all like, "yeah, we see this all the time and no big deal" but it was one area where Van's seemed to accept less than standard edge distance specs.

Which, by the way, I always thought was odd considering their language in the instructions on the rear spar attach bolt of the wings to the fuselage carried all sorts of crisis warnings about edge distance.
 
Bob Martin said:
Can someone knowledgeable explain what exactly is wrong with this work, besides not per plan? Us non builders would like to learn from the example.
Is it the 3rd bolt?
The edge distance?
Distance the two good bolts are from the longeron?
Thanks in advance.
Click to expand...

The last bolt is supposed to be thru the angle flange. Tolerance here is very tight. In some photos, the flange is simply cut away! In others, the hole is so close to the end that washers hang over the edge, or there was no room for the bolt head so it was partly cut down, etc.
 
wirejock said:
I will be doing this soon. Any tips for getting it perfect?
Click to expand...

Yeah - measure about 10 times, then think a while before drilling.
Ok, that's a bit tongue-in-cheek, but one must be very deliberate when doing this job. It's not rocket science but you absolutely need to take your time.
 
wirejock said:
I will be doing this soon. Any tips for getting it perfect?
Click to expand...

molson309 said:
Yeah - measure about 10 times, then think a while before drilling.
Ok, that's a bit tongue-in-cheek, but one must be very deliberate when doing this job. It's not rocket science but you absolutely need to take your time.
Click to expand...

And maybe get another set of eyes to give everything a reality check before committing drill to metal. :)
 
Bob Martin said:
Can someone knowledgeable explain what exactly is wrong with this work, besides not per plan? Us non builders would like to learn from the example.
Is it the 3rd bolt?
The edge distance?
Distance the two good bolts are from the longeron?
Thanks in advance.
Click to expand...

Bob, I'm not that knowledgeable, but if you look at Vic's first picture, you will see that the end bolt either cuts or misses all together the longeron(where the #4 is) on the top side, which you can't see.
 
wirejock said:
I will be doing this soon. Any tips for getting it perfect?
Click to expand...

Start with #40 holes and work up in several increments.

Measure and carefully mark the edge distances on both parts.

A needle file can adjust the location of the holes as you slowly increase the holes for the AN3 bolts.

That, and the rear spar wing bolts. were the two hardest critical holes to get correct on the -6.
 
tracy said:
Bob, I'm not that knowledgeable, but if you look at Vic's first picture, you will see that the end bolt either cuts or misses all together the longeron(where the #4 is) on the top side, which you can't see.
Click to expand...


ok, I see it now.....took me awhile.
Plans call for 2 bolts each side, outermost bolt thru the longeron.
His top spar attach angle was not long enough so it had no edge distance for the bolt, so he removed top angle material to get a bolt into the longeron and thru bottom attach angle, then added a full piece spacer plate under the spar and an additional bolt.

So I can see the builder had a problem getting his parts to match the plans.
Then figured a way to compensate and carried on building.
I can see he had some logic to his plan. This logic may have been explained to his inspecting buddies to garner their approval or lack of intervention.
I am guessing the bottom line is there was most likely no engineering on this deviation from the plans and therefore unacceptable.

I am assuming the proper thing to have done was to somewhat disassemble the HS and remake the attach angle longer to get a proper fit. Then it would conform to plans and known engineering.

Knowing the build sequence and that this is a known close tolerance, seems like the plans would say to leave this part longer and maybe even notch the rib over it. Or maybe the plans do.....I need to check them today at the hangar. Thanks for posting this and making me continue to THINK.
 
az_gila said:
Start with #40 holes and work up in several increments.

Measure and carefully mark the edge distances on both parts.

A needle file can adjust the location of the holes as you slowly increase the holes for the AN3 bolts.

That, and the rear spar wing bolts. were the two hardest critical holes to get correct on the -6.
Click to expand...

To add to Gil's information if the edge distances between the angle bracket and the longeron do not line up (they don't overlap enough to give you sufficient edge distance on both) contact Van's. They have recommendations of how to build the area up based on the details.

Oliver
 
If it were me, I'd pass on it. Who knows how many other things are hidden, and fixing cracks could be a real hassle... and hopefully you'd find them in time.

As for resale value...

Ed
 
vic syracuse said:
The pictures that Rob posted show a very common fix. It works and is approved by Van's. But don't hesitate to check with them for your particular situation.

Vic
Click to expand...

Vic,

Just curious as to how YOU would fix this type of issue.

Would you:
A. drill out the top panel rivets and remake the attachment angles, redrill and
re-rivet the area or
B. perform the Vans approved fix.

Thanks for bringing this to light. I am facing this right now with my 6A.
 
gmohr said:
Vic,

Just curious as to how YOU would fix this type of issue.

Would you:
A. drill out the top panel rivets and remake the attachment angles, redrill and
re-rivet the area or
B. perform the Vans approved fix.

Thanks for bringing this to light. I am facing this right now with my 6A.
Click to expand...

Either way works if you are carfeul. The problem with drilling out the rivets is that unless you are very careful and experienced, the holes could get wallowed out and may require the next size rivet. I certainly wouldn't hesitate to remove the tail and put it on a workbench to accomplish the task. It will make access much easier.

The trick to cleanly drilling out the rivets, especially in thicker material is to just drill off the head very carefully, and then use a punch ( a heavy duty center punch works real nicely) to "pound" out the shaft of the rivet. It will leave the hole intact, assuming it is a nice hole to begin with. Sometimes you will find that the reason for the crooked rivets is that the holes aren't drilled 90 degrees to the material or are already wallowed out.

Vic
 
wirejock said:
I will be doing this soon. Any tips for getting it perfect?
Click to expand...

Larry;

I just did mine recently and it came out good.

The key was carefully marking the edge distance limits for all pieces right there clearly on top-most surface where you can see them when you drill. That takes some ingenuity because the edges of the underlying longerons are hidden.

I used several measuring schemes to make sure that I had lines drawn that reflected both inboard and outboard edges of the longeron and checked them several times before center punching and drilling a small pilot hole.

It helped to use a 12 inch bit for that first hole, too. Better able to precisely locate it.

I also have an inexpensive endoscope that lets me see on my ipad the view from underneath-- Much more handy that just using an inspection mirror.

Hope this helps.

-Ivan
 
Tail

TeamFAS said:
http://imgur.com/a/dVejP

I checked mine today, everything looks good to my untrained eye. Anybody see anything note worthy?
Click to expand...
I'll take a pot shot at this: picture #1- notch for rivet in top of angle, likely not a problem.
#2 Right side angle at lower bolt MAY have a slight notch in angle. Left angle lower bolt edge distance appears to be less than others.
#3 Multiple mangled rivet heads but probably not unsafe. Some one didn't know how to hold the rivet gun OR did not have the proper gun.
Overall I give it a 7.0 as opposed to some zeros for some of the earlier posts.
 
The rivets on the elevator push rod is not what I have seen in the past. In a RV7, there are (I believe 8) that goes around and not in one row.
 
I agree something doesn't look right on push pull tube, it would make me very nervous, also don't like the way vertical support ground out
 
RV Jerry said:
I agree something doesn't look right on push pull tube, it would make me very nervous, also don't like the way vertical support ground out
Click to expand...

I would want the factories opinion on the ground away vertical angle. It looks like they ground it out for clearance of the rivet shop head before they realized a spacer goes between the angle and HS Spar. It wouldn't be any issue if just the spacer was ground down.
Having a notch at the center line of the bolt bothers me as that is where the stress will be concentrated.

Van's designs are pretty bullet proof and often over engineered. This may or may not be a problem but I would want a second opinion.

Push rod end fitting isn't what I am used to seeing either but I am not familiar with how the 4 is done. the 6, 7, etc.... is riveted around the tube as mentioned.

Posting pics here gets you no shortage of opinions but I think you are getting some good advice.
 
Found this today on a condition inspection.

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Bavafa said:
The rivets on the elevator push rod is not what I have seen in the past. In a RV7, there are (I believe 8) that goes around and not in one row.
Click to expand...

Checked the plans, the plans call for the rivets just as they are built in the plane. I don't know why Van's changed it from a line to round with the new plans though...
 
What's the real shim size?

WingsOnWheels said:
Dan,

Per Vans, I used 0.125 2024 T3. Good eye, there is an additional 0.63 spacer in there as well. I did raise the rear spar to compensate and allow for the extra thickness of the gussets. So, without the shims the HS is located per plans.

The shims were added per the testing done by Bob Axiom and other RV-6 builders that found an .063 spacer trimmed the HS out a little better. It has been a couple years, so I would have to go back to my log to verify all this, but that is what I recall.
Click to expand...

I made the gussets like Colin was nice enough to give me the dimensions for and now am ready for the HS to be drilled and mounted. So here's the confusion. My RV-6A is a non prepunched '90's kit. In the construction manual there is no call out for a shim. On the plans sheet 34 it shows a .125 shim and in Colin's message above he calls out a .063 shim but has allowed for the gusset thickness on the rear spar. What is the current wisdom on what size shim to use?
 
pczar3 said:
I made the gussets like Colin was nice enough to give me the dimensions for and now am ready for the HS to be drilled and mounted. So here's the confusion. My RV-6A is a non prepunched '90's kit. In the construction manual there is no call out for a shim. On the plans sheet 34 it shows a .125 shim and in Colin's message above he calls out a .063 shim but has allowed for the gusset thickness on the rear spar. What is the current wisdom on what size shim to use?
Click to expand...

Follow the plans. Occasionally, I have seen folks mess with the shim thickness later if the elevator isn't perfectly in trail. However, reports seem to negate the impact of doing that. It doesn't seem to affect much and requires rework of the empennage fairing.
You would want to take into account the thickness of any added things like gussets or doublers.
 
HS shim size

Thanks for the quick reply Jon. That's the direction I'll go since the gusset is 1/8 that works out to the same as the plans. Thanks again.
 
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