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SB 14-01-31; RV-6, 7, 8

Doing "the Fix"

It took forever to try and figure out what the drawing "Figure 7 (RV-8)" was trying to tell me.
The note about the 'rectangle' "Match-Drill #30 Then Cleco, 8 Places", is not a part. It is showing the eight holes that are to be drilled. Poor drafting.
This line should be something other than a solid line.
Next: Steps 17 & 19 are too many words for what needs to be done. I am sure that a picture would be worth a thousand words, but these steps not clear. Confusing. Mainly Step 17-4 (paragraph, that is) and then Step 19 - 2.

I have figured it out, but took too long.

Ed
 
Last edited:
Ken Martin said:
Step 13 calls out a final drill of the fwd most hole in the top and bottom flange of the main ribs. No problem, I bought some #27 bits. However, on page 19 of 20 in Figure 11, the rivet callout for this location is still AN426AD3-3. If this is the case, why increase the size of the hole from the original callout? What am I missing?
Click to expand...

When you squeeze the -3 in the #27 hole you get a perfectly double flush rivet that expands just enough to fill the hole and hole the rivet in the exterior skin. That rivet is no longer holding anything just plugging the hole after the spar flange is trimmed away.
 
Just finished my SB on RV8 that is under construction

I was just about ready to mount my HS on my 8 QB. I decided to just go ahead and do the SB. Since I did not have to remove the HS it was just the repair. Total time was 22 man hours. Not quite as bad as I thought it would be. It takes a while to understand the directions. The hardest part was drilling out the -4 rivets inside the spar.

If I knew how to post pictures I would do so.
 
after talking with an engineer at van's who was repairing the cracks on his -7 at the time, he said the finite element analysis program clearly showed a fatigue problem on the forward spar and that the fix he engineered was strong enough to handle the spars loads all by itself. apparently [my understanding of what he said] when loads are placed on the spar the top edge wants to act like a hinge, since the bottom is bolted to the fuse, and moves forwards and back, bringing on fatigue. he said about 15% of the high-time planes were having cracks.
 
kjlpdx said:
after talking with an engineer at van's who was repairing the cracks on his -7 at the time, he said the finite element analysis program clearly showed a fatigue problem on the forward spar and that the fix he engineered was strong enough to handle the spars loads all by itself. apparently [my understanding of what he said] when loads are placed on the spar the top edge wants to act like a hinge, since the bottom is bolted to the fuse, and moves forwards and back, bringing on fatigue. he said about 15% of the high-time planes were having cracks.
Click to expand...

What is the explanation for the cracks on the low-time aircraft?
 
I didn't ask. our meeting was the first I had heard of it. I was giving him a hard time about how much he[an engineer] works on his plane compared to me[a carpenter]. so, this carpenter needs to do some inspections soon, because I have 1600+ hrs and used to fly aggressively.[like 5G stalls messing with an AOA meter for instance].
 
1994 RV-6A

Empennage slow-built in '94.
No notches, no cracks found.
O-320 160hp FP Sensenich
almost all ops on turf, mild acro. 890 TT

Like most 16 year old RV's, she's showing age elsewhere - but not in the elevator spar :) We did discover three loose jam nuts, two on the elevator and one on the rudder. No cracks there, either.

-Bill Boyd
 
tail kit 1993 (?) first flight 1997
1600+ hrs O-320 160hp sensenich FP
lots of aerobatics, spins early on
no hard landings ever
5G stalls [messing with the AOA, wish now I hadn't]
no notches [I didn't build the empennage]
H spar crack [tiny]
 
Does anybody have a tally or chart yet? I wonder what percentage of >1,500 hr planes have cracks and what percentage of <1,000 hr planes do. It sure seems relatively high and quite low respectively.
 
I have cracks

I have a 700 hour RV8 and found the dreaded cracks. I'm thinking of going the Anti Splat.com fix. It seems less intrusive and uses stainless steel plates. Any ideas out there?
 
Doing "The Fix"

David,

I recommend doing the Van's Fix.
1. It is not that difficult. The most difficult part is drilling out the heads in the interior portion of the stab. And it was only time consuming.
2. Riveting the structure together was easy.
3. When it comes time to sell, you will thank yourself.
4. You built this whole machine. You can most certainly do this fix. This really is a mind over matter procedure.
5. Just do it Dave. (and everyone else)

Ed
 
One more data point

N898DK
Hours: 571
SB14-01-31 No cracks found (no relief notches specified in plans)
SB14-02-05 No cracks found
Engine: O-360-A1A

Chris
 
The fix

Thanks Kevin and Ed

I really appreciate you guys chiming in to help me clarify the issue for me. The work involved was never an issue. Just my ignorance. Kevin, thanks for posting the related links that I needed to read. The factory repair it is.
 
"The Fix"

David,

Way to go. There was one thread that had a dozen pictures of the procedure. It was called "SB 01-31-14 Completed", but I have not been able to find where it disappeared to. I know it gave me confidence after viewing.

So can anyone help find this site?

Ed
 
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Kevin Horton said:
I recommend you read all the comments on this thread. In particular, pay close attention to posts 23, 25, 27, and 42.
Click to expand...

Well, engineering vise and responsibility vise this whole thing is beyond belief when applying normal industrial norms and conduct used everywhere in every industry on this planet.

The owner/builder has sole responsibility for the structural integrity of the aircraft, no one else. Vans is in this case only a subcontractor, a consultant and a supplier of parts.

In any other industry, Vans SB would be considered only an idea, a vague suggestion. It will remain so until Vans idea was substantiated by Vans showing actual calculations. Actual calculations put forward in a report showing the weakness of the original design and the improvement of the new design. This is the normal way because Vans has no responsibility whatsoever in this matter. It is the manufacturer, the owner/builder, who is to decide if these calculations are good enough, are they done correctly, are they done with appropriate software, and most importantly, are they done by someone with adequate training, experience and understanding. This is not for Vans to decide or mean or suggest anything about, they are only doing a job here.

I'm not saying Vans mod is bad or anything, it probably is as good as it gets - probably. The point is that the whole process is NOT an engineering process based on facts and data. It is a system based on believe and hope and something I would call misplaced awe of Vans and blind faith. Again, the builder/owner is sole responsible here, Vans have no responsibility.

Now, there are some aeronautical engineering types here as well as very seasoned and experienced mechanical types. They have looked at the two suggested mods, and their impression is that Vans mod is by far the better one. That carries some weight, because you don't need to do a full FEA to see the basics of the two mods. The structure is not that complex. But, the complete lack of visible and obtainable facts and data and number crunching engineering is still here, so it is still a system of believes, far away from the engineering world I am used to.

OK, I got that of my chest :) I see this in many other parts of the experimental scene. An open system of sound engineering and practical experimentation being replaced with an obscured system of believe and blind faith towards some kit manufacturer who has no responsibility whatsoever for anything but the profitability of his company. This is wrong on so many levels.
 
In my case, I don't think its "misplaced awe and blind belief"; I think its "trust". Since I am not an aeronautical engineer or want to spend a lot of money paying one to review this fix, I have to trust Vans. For me, I am comfortable trusting Vans based on their record.
 
SvingenB said:
Well, engineering vise and responsibility vise this whole thing is beyond belief when applying normal industrial norms and conduct used everywhere in every industry on this planet.

The owner/builder has sole responsibility for the structural integrity of the aircraft, no one else. Vans is in this case only a subcontractor, a consultant and a supplier of parts.
Click to expand...

Did you require Van to supply a full engineering package before you started to build your RV-4? Or did you trust that he had properly engineered the design?
 
SvingenB said:
This is the normal way because Vans has no responsibility whatsoever in this matter.
...
An open system of sound engineering and practical experimentation being replaced with an obscured system of believe and blind faith towards some kit manufacturer who has no responsibility whatsoever for anything but the profitability of his company. This is wrong on so many levels.
Click to expand...

It may be blind faith and optimism to say this, but I don't even remotely believe this is the case. Whether Van's has any legal responsibility is irrelevant. As Engineers Van and his staff have an ethical responsibility to report a problem in good faith when they find one. They have a further responsibility to put forth a solution for said problem only after analysing it to the best of their abilities. That they have published a solution suggests to me, as a fellow Engineer, that they have done their due diligence. As an Engineer, i'd love to see the calculations and numbers, for personal interest. But I don't need to see them to be confident that they exist.

In short: I trusted them to design the airplane I trust my life to, I think it's a small stretch to trust them to design a fix for it.

As for concerns over profitability, the impression I get from talking to Van and his staff is that this isn't their driving motivator in life. It's just a happy side effect of having designed the most successful kit plane in the world. If profit was their concern, the repair kits would cost more than $15.
 
Snowflake said:
It may be blind faith and optimism to say this, but I don't even remotely believe this is the case. Whether Van's has any legal responsibility is irrelevant. As Engineers Van and his staff have an ethical responsibility to report a problem in good faith when they find one. They have a further responsibility to put forth a solution for said problem only after analysing it to the best of their abilities. That they have published a solution suggests to me, as a fellow Engineer, that they have done their due diligence. As an Engineer, i'd love to see the calculations and numbers, for personal interest. But I don't need to see them to be confident that they exist.

In short: I trusted them to design the airplane I trust my life to, I think it's a small stretch to trust them to design a fix for it.

As for concerns over profitability, the impression I get from talking to Van and his staff is that this isn't their driving motivator in life. It's just a happy side effect of having designed the most successful kit plane in the world. If profit was their concern, the repair kits would cost more than $15.
Click to expand...

There is nothing wrong with Vans. Vans has stood the test of time, and so have all of Van's aircraft. Obviously Van is a top notch designer of airplanes, and a very talented business man. I have no reason to believe that every single one of Vans aircraft is anything but top aircraft designs. I'm just very surprised at many peoples reactions to the SB and the process around it. It shows a way of doing things, a way of operating, that is far away from any standard way in "the real" engineering world. I don't think it is healthy.

The producer of the aircraft do not have enough facts, experience or knowledge to decide if a mod is the correct mod, and the producer of the mod have no legal responsibility whatsoever in the aircraft, not even an obligation to factually verify that the mod is a sound one, not to the owner/producer of the aircraft or anyone else.

It is a system of belief and hope and faith. It is not a system of facts and openness and trust. It is not the engineering way of operating. As it is today, the producer of the aircraft is reduced to a blind consumer, yet he has all responsibility. The manufacturer of the kit is void of any legal responsibility and obligations of any kind, still he has all the authority.

I just find it very strange, that's all.
 
Step 12 Question

In step #12 the plan shows a 2/32" offset from the rib's center line for the 4 holes which are to be drilled to attach the flange angle.
The upper most hole is 38/32" away from the center line while the lowest most hole is 36/32".
I don't question that, but can't see an obvious reason for it since the rib is symmteric.

More over, to me it looks that those measurements shown in figure 5 are taken from the web side of the rib. From L and R rib web's side? Correct?
 
...As for concerns over profitability, the impression I get from talking to Van and his staff is that this isn't their driving motivator in life....

having just had a van's engineer volunteer to come to my cold hangar in the rain and freezing ice on a sunday and inspect my spars for cracks should quickly clear up any questions of ethics and motivations. talking with him about the FEA modeling for the fix convinced me that they are on track besides.
 
No cracks

N25TS 1992 RV6
O360/hartzell CS, 10.5 pistons
2258 hours
Lots of high speed cross country racing
Lots of recent acro to 4G
No cracks.
 
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mspenc45 said:
Hmm, where does it say pre puched is NA?
Click to expand...

The table at the bottom of page 3. I agree it is misleading, but has already been addressed. I forget what the verbiage is actually intended to mean (do a search). But what it doesn't mean is that the SB is N/A for match-hole emp.
 
Cracks all around

With well over 3000 hours and always a flyer---never a hangar king, Randy Richmond found cracks in all four locations during my annual this week. Louise and Paul say that I'll be having some surgery after I get out to Nevada next month. :(
 
New HS405 ribs being shipped now to replace old HS-405?

Just got my SB kit and I ordered a set of HS-405 root ribs to replace my old ones (long story). The ribs that came are part # HS00005 and look different than the old. The rib flange has 3 serrations and these is no joggle on the flange front.

Has Vans changed the root rib design for the SB now for newer emp kits being sent now? The SB instructions don't show the newer rib style if this is the case on pg 8.

Anyone else receive this new style and do you have pics of it in assembly yet?

Thanks,
 
60av8tor said:
The table at the bottom of page 3. I agree it is misleading, but has already been addressed. I forget what the verbiage is actually intended to mean (do a search). But what it doesn't mean is that the SB is N/A for match-hole emp.
Click to expand...

Hmmm.....

Does anyone have a copy of DWG-3pp, Rev. 3? Perhaps they could scan and post the figure 2 detail from the dwg, that the SB talks about so we could see it.
 
N748RV No Cracks!

Did my inspection today and found no cracks in my RV8. Started in 2002, finished in 2009, 350 hours, no cracks and no reliefs :)
 
I've got cracks

verdi9.jpg
[/IMG]

I have 3 cracks in my RV-8. (Lower R, Upper R & L)
Kit 875 delivered and built in 1998.
1210 hours on airframe.
0-360 with Hartzell CS.
Extensive Acro, formation, off paved surface ops.
Notches were present.

Findings are:

Initial inspection found nothing. Second set of eyes noted a small crack on my lower right corner (picture somehow got flipped upside down). Stripped paint (Imron is tough), used die-penetrant and verified a crack emanating from notch much like the SB shows. Also noticed that I had'nt done a great job smoothing the notch. You can see the beginnings of a crack next to the micro-nick on the left side of the notch. It's obvious that this was in the group of first parts that I made. Not the workmanship level I try to achieve now that I know more.

Ordered repair kit and waited two weeks. Finished the rest of my conditional inspection. This was not a fun finding but couldn't have come at a better time.

Received kit and disassembled empenage. Found 3 of the 4 #3 bolts that attach rear horiz spar to vertical posts were not torqued properly. :eek: Installed over 10 years ago, torqued to spec and torque seal applied. Every annual I checked to see the torque seal was not indicating movement of nut and bolt. Torque seal was intact. Apparently over 10 years of use since painting and installing parts, the rather thick coats of paint on all parts had shrunk and reduced the torque without any external evidence. I hadn't used the proper method of securing torqued parts. :mad: All mating surfaces should be free of paint to avoid this issue. Be advised.

After removal of the ribs I found two more cracks on the upper right and left that had been covered by the rib flange. A little scary to think that I had those cracks and were it not for the SB I would have never seen them. For that matter I don't believe that I would have seen the original crack during my conditional inspections due to its small size and being covered with paint. That's why the SB has you remove paint before inspecting.

Drilling out the reinforcing bars proved to be a two-man operation. I had no problem popping off the heads and driving out the rivet shank with a punch. After filing the required notches (I already had notches from original build. Don't remember putting them in but they were there. Non pre-punched kit) I was able to remove two of the cracks and the third had propagated to the rib flange attach hole.

I installed all the parts but used a slightly different method to align the parts. I was able to cleco the bars to the VERTICAL stab forward spar attach points and then align the reinforcing plates. This made it easy to ensure alignment of the bend angles and proper clearance for all the parts to fit rather than the measure method that the SB described. I was able to make sharpie pen marks on the doubler plates through the existing holes in the bars.

2q3akoo.jpg


I then clecoed the doublers to the HORIZONTAL spar web, re-aligned the doubler plates using the sharpie marks and side-grip clecoed them in place. Triple re-check everything aligned and commenced to drilling from center to outboard tip, clecoing every hole to keep it tight. Before removing to debur I slipped the main rib into place with the new attach angle side-grip clecoed in place through the lightning hole. Match drilled the 8 attach holes (4 in rib, 4 in spar web) into the attach angle all while clamped in place rather than the SB method of removing to drill. All parts drilled in place before removing or riveting anything.

To date I have hand squeezed the rivets in the center section. Awaiting my next day off to tackle the ones inside the HS. Looks like my offset rivet set and a nice tungsten bar will work fairly easily.

Sure am glad I did this. :) As always, I found more than I was looking for.
 
Gonzo24 said:
Just got my SB kit and I ordered a set of HS-405 root ribs to replace my old ones (long story). The ribs that came are part # HS00005 and look different than the old. The rib flange has 3 serrations and these is no joggle on the flange front.

Has Vans changed the root rib design for the SB now for newer emp kits being sent now? The SB instructions don't show the newer rib style if this is the case on pg 8.

Anyone else receive this new style and do you have pics of it in assembly yet?

Thanks,
Click to expand...

Yep, they have changed the HS 405 to HS00005. It is different. Trying to work out what way it goes around ? Not any docs or pics of it. Any takers ?
 
Mick.B said:
Yep, they have changed the HS 405 to HS00005. It is different. Trying to work out what way it goes around ? Not any docs or pics of it. Any takers ?
Click to expand...

The HS-00005 (if I am remembering part #'s correctly) is not relevant to doing a field installation of the S.B. on a finished horizontal stabilizer.
It is a slightly shorter rib to account for the added thickness of the HS-00001 or HS-00003 Doubler so that trimming the fwd rib flange and replacing it with a piece of bent angle is not necessary.
It is intended for new builds only because of the difficulty of properly positioning and match drilling to skins that are already dimpled.
 
So, has anybody used the antisplat mod for the HS? Can we hear from some engineers about this?

I would like to hear back privately.

Jim Bower
RV-6A flying since 2011
 
Last edited:
Hello VansAirforce community. This is my first post! My wife and I have just started building our RV7 empennage that arrived just a week after the service bulletin was issued. Luckily I got all the new parts but unfortunately I'm a guinea pig for the new Horizontal Stab build. Here are some pictures of the work in progress and of the new drawings. Unfortunately, I've found quite a few errors in the drawing/instructions based around these new parts and have called Vans for clarification. I THINK what I've done up to this point is right.

Here are some links to my drawings and a couple shots of the new parts:
http://n928dd.files.wordpress.com/2014/03/sam_2899.jpg
http://n928dd.files.wordpress.com/2014/03/sam_2898.jpg
http://n928dd.files.wordpress.com/2014/03/sam_2899.jpg
http://n928dd.files.wordpress.com/2014/03/sam_2901.jpg
http://n928dd.files.wordpress.com/2014/03/sam_2902.jpg
http://n928dd.files.wordpress.com/2014/03/sam_2880.jpg

PM me if you'd like pictures of anything specific or if you're in the area and want to check out the build in progress.

Feel free to check out my build site to see other details on the new HS Front Spar (Link in Signature).
 
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Gonzo24 said:
Just got my SB kit and I ordered a set of HS-405 root ribs to replace my old ones (long story). The ribs that came are part # HS00005 and look different than the old. The rib flange has 3 serrations and these is no joggle on the flange front.

Has Vans changed the root rib design for the SB now for newer emp kits being sent now? The SB instructions don't show the newer rib style if this is the case on pg 8.

Anyone else receive this new style and do you have pics of it in assembly yet?

Thanks,
Click to expand...

Mick.B said:
Yep, they have changed the HS 405 to HS00005. It is different. Trying to work out what way it goes around ? Not any docs or pics of it. Any takers ?
Click to expand...

rvbuilder2002 said:
The HS-00005 (if I am remembering part #'s correctly) is not relevant to doing a field installation of the S.B. on a finished horizontal stabilizer.
It is a slightly shorter rib to account for the added thickness of the HS-00001 or HS-00003 Doubler so that trimming the fwd rib flange and replacing it with a piece of bent angle is not necessary.
It is intended for new builds only because of the difficulty of properly positioning and match drilling to skins that are already dimpled.
Click to expand...


I just finished doing the SB and I'm in a position to comment on this. I have some pictures, too. My HS had the older HS-405 ribs. I got them all drilled out and proceeded to cut the end flanges off, per the directions. Like a big dummy, I cut off the wrong end on one of them. (This is easy to do, they look so similar. Pay attention and be careful!) Rather than rivet a new flange on both ends, I opted to just buy a new one from Vans. I didn't know they had changed to new HS-00005 until I went back to work and noticed the differences.

The older style didn't have the relief notches that the new one has. It required more work to bend the flanges to 90? and flute them to straighten out the rib so it wasn't warped or twisted. The new style is very nice in this regard. The flanges are perfectly bent at 90?, no fluting required.

These parts are among the few in the kit that aren't pre-punched, so Scott is right... there is potential difficulty in positioning and drilling to skins that are already dimpled. If you've ever noticed, dimpled holes become slightly larger than the drilled #40 hole, so careful drilling techniques are necessary to make sure the new holes you drill are centered under the dimpled holes in the skin.

I wish I had known that these new ribs are slightly shorter to account for the thickness of the doubler. The first thing I did when I got back in the shop was to cut off the forward flange and proceed with the directions. I could have saved myself all that trouble! Anyway, it's done and here are some pictures:

The start of the project... lots of rivets to drill out. Here are all 4 ribs after successfully removing them. (I know... I have mis-matched primer. New builder at the time :) )

P1000956%20(Custom).JPG


Here's the new rib, being carefully drilled into place. It was nice not to have to do any fluting or bending of the flanges. Note that the doubler is already positioned and clamped in place as well.

P1010027%20(Custom).JPG


Later on, the rib is now deburred, dimpled, and primed as normal. The doubler has been riveted in place. Now comes the clamping and drilling of the new end flange piece. As I said above, I wish I had known that I could have avoided this if I had known that the flange was made a bit shorter to accommodate the thickness of the doubler!

P1010036%20(Custom).JPG


When I got all that work finished and the new flanges riveted to the ribs, here they are before final installation back in the HS. Interesting side-by-side comparison of the new with the old.

P1010038%20(Custom).JPG


P1010039%20(Custom).JPG


And finally, here's the new rib, riveted in place.

P1010051%20(Custom).JPG


Just for comparison, here's the old one back in place as well, on the right side.

P1010053%20(Custom).JPG


In the end, it turned out great. I'm very happy to have this done.
 
Got the skins on only to find issues with the new set of instructions/plans. In the newest plans, Vans has you trim the HS-702 back:

20140315_164728-e1394930211599.jpg


But the HS-00005 flange doesn't extend as far enough forward to get to the hole that used to attach to the HS-702. To make things more confusing, Van's new set of drawings doesn't show the hole that is causing me grief.

Old Plans:

20140315_164836-e1394930440190.jpg


New Plans:

20140315_164712-e1394930496975.jpg


The results are me scratching my head, wondering I did something wrong, and moving onto the Vertical Stab until I can get through to Vans on Monday.

sam_2913-e1394930602599.jpg


Does anyone who has played with these new parts catch if I missed something?
 
Last edited:
mcydrake said:
Got the skins on only to find issues with the new set of instructions/plans. In the newest plans, Vans has you trim the HS-702 back:

20140315_164728-e1394930211599.jpg


But the HS-00005 flange doesn't extend as far enough forward to get to the hole that used to attach to the HS-702. To make things more confusing, Van's new set of drawings doesn't show the hole that is causing me grief.

Old Plans:

20140315_164836-e1394930440190.jpg


New Plans:

20140315_164712-e1394930496975.jpg


The results are me scratching my head, wondering I did something wrong, and moving onto the Vertical Stab until I can get through to Vans on Monday.

sam_2913-e1394930602599.jpg


Does anyone who has played with these new parts catch if I missed something?
Click to expand...

These holes are abandon when doing a SB retrofit to a finished horizontal stab. (holes get filled with a rivet set in the skin only).

The holes aren't shown in the new drawing because they have been deleted from future skin production. Because of parts still in inventory, it looks like you got a skin that has the unused holes. They are not a factor structurally, and will be hidden under the emp. fairing so not a factor visually. You can leave them as is (less desirable because there will be future questions whether something was forgotten), dimple and insert rivets, or slightly machine countersink and install NAS1097 3-3 rivets (the method I would use).
 
Brand new to forum. Just completed 14-01-31. Down for a month. Disassembled empennage, then delivered horizontal stab to to expert IA that repairs Cessna jets for a living. Took him 16 hours total to do the repair under ideal conditions. Came out beautiful.

Originally couldn't find the crack. Took the IA 2 minutes to find it with flashlight and mirror. After disassembly, the crack picture of my horizontal stab is identical to the picture on the Service Bulletin.

IA reports that the service bulletin was clear and understandable, and support from Van's was excellent. He was able to talk to engineers directly.

Happy to be back in the air.

Tom McGee
 
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