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

Vans calls for addition of relief notches

ILikePike said:
Rvbuilder2002,
Would you be willing to comment on the relief notches vs normal smoothed radius as it relates to FEA?
Click to expand...

Step 8 of the relevant Service Bulletin reinforcement instructions states as follows:

"Inspect the corners at the inboard end of the top and bottom fwd spar flanges on the left and right spar halves for the presence of relief notches as depicted in Figure 3.

If notches are not present, use a round file to add relief notches (first refer to the following step... adding a missing notch may be done in conjunction with removing a crack). This will require trimming the skin slightly as shown in Figure 2 to gain access for the file".

I think that's your answer.

I think it also addresses concerns raised by a number of posters that the relief notches might in fact be precipitating the problem.
 
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Stay on topic. No flame wars.

Let’s stay on topic in this thread with the service bulletins at hand.

If conversation starts dissolving into a flame/speculation wars, I’ll ban accounts permanently, regardless of the number of posts or importance you feel you might have here. This online space isn’t for talking heads on TV yelling conspiracy theories; you’re a guest in MY virtual living room.

Van’s, you rock. Thanks for looking over our shoulders here and keeping us informed.

It is very much appreciated.

I know it is special that you take the time, and make the effort, to chime into this site and help us out.

Now, back to complying with the service bulletins…

v/r,
dr

PS: No cracks on my HS. Inspecting elevators next.
 
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FYI for stats

Inspected my -8 today and found no cracks. Flying 10 years with a little over 800 hrs and mild acro. Also inspected a friends -8 and found no cracks in his either. Don't know the exact time in service. He has at least a 200 hours also with mild acro. Going back today to check the elevator SB.
 
When I look at the photos of the planes with cracks compared to mine without cracks, one thing that jumps out is the radius of the bend. On my plane the bend tucks tightly into the corners. In the photos that show cracks most of them seem to show the piece under some pre-load as if the tab were being pulled tight by the rivet.
 
No Cracks

2008 RV7 (Emp Kit from 2003 - prepunched)
980 Hr. TT
Superior XP-360
Hartzell BA
some grass
some Acro
relief notch
No cracks
 
My question is on the subject of the relief notches and the early kits (the 2/2001 DWG 3) that did not show them. I don't have the cracks, but I don't have the notches, either. Would that influence whether I should wait for the cracks to appear to take some corrective action?
 
RV10inOz said:
And accelerated stalls.

We have a video in the APS course of George Braly doing testing on the T34 when the FAA were about to ground the fleet. He had strain gauges all over this thing and was replicating flight loads. GAMI subsequently came up with what I still consider to be the most brilliant solution to any difficult problem I have seen to date.

But the funny part was he collected some video of the tail feathers doing accelerated stalls at 117kts. :eek::eek::eek:

After seeing this video you will never want to do one ever again! And I mean it.

rvbuilder2002
Imagine the same thing from Cessna....timely, $10 fix?

Vans are at the pinnacle of customer service in the industry, along with a small group of others I can think of, but it is very small. Be grateful for what we have, it does not get better, trust me. Tried Lycoming or TCM? :cool:
Click to expand...

Do you have a link to said video? thanks. Bret
 
Mike S said:
Maybe not your intent to "pound" on Scott and Vans, but it sure sounds like what you are doing to me.

From what I can see looking at this thread, Scott has been very open with information, and has tried to deal with the issue in a manner that is well balanced and thought out. The explanation of the process arriving at the SB (computer modeling etc) shows that this is well thought out and engineered solution. This type of action does not happen overnight-----takes time to develop.

Well said Jon.
Click to expand...

I bought Darryl a Snickers bar?he's not him when he's hungry! :D (He's a good dude, lots of passion?now back to the OP!)

bret said:
Do you have a link to said video? thanks. Bret
Click to expand...

Yes David, please do tell! Hoping its not proprietary APS class subject matter, and available for the greater good!

Cheers,
Bob
 
For your stats -


RV7,
IO360,
FP Sensenich prop
200 hrs. total
95% grass ops.
Notches there,
NO cracks, so I'll just sign it off and include the inspection in my annual

Mike Greene
 
2 cents

Looked at this for a long time as I am a little slow and like to think things over before sticking my foot in my mouth. This is not that big a deal if you look at the history of Part 23 aircraft. We have had a lot of Mods. come down the pipe over the years on factory built aircraft. I think post # 278 has more than addressed the issue. For my part I will hold off till the new ribs are ready and do this mod as I have the time to pull the H.S. back off and work in comfort on the bench. The hard part looks to be bucking the rivets of the fish-plates up inside the skins. Yes it will heart, but doable. This is "P.M." on my part, but I sing it off one time and the value of my work and peace of mind are good to go from that point. Mark Borns in post #290 has it going already. Good job Mark. and thanks too you Scott for fading this heat. We may need to buy you more than a single beer, but don't get your hopes up for more than a six-pack. Hope this helps. R.E.A. III #80888
 
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It would be great if we can start a poll to compile the data as how many with cracks and perhaps a breakdown of each category with/without notch, high/low hours etc.

Also let me voice my appreciation for both Vans/Scott and DR for providing an awesome service with the timely info and a venue to share them.
 
Collecting Data

I would like the thank all those who post information and especially Scott for giving some of the finer details.

I am very interested in the the data so some conclusions might be made. It seems it would serve Van's to know this information as well. I would kindly suggest sending a questionnaire to each registered owner of the effected aircraft then this data could be compiled and studied then perhaps more light might be shed on why some have the cracks and some don't. It might even show that if you don't have a crack you more than likely will not develop a crack.

I think a questionnaire could be made available online, someone told me about a site called "Survey Monkey" or something similar.

The most important thing at this point is to get the word out. I have spoken to at least 3 RV owners that did not know about the SB since they don't regularly view VAF and or Van's Aircraft. So please talk to, phone, email, text, Facebook your RV friends.

Cheers
Plan to have a happy RV day today!
 
rvbuilder2002 said:
It has been asked "Are there any theories of the cause."

Yes there is a kit modification underway. New builds will use the same type of doubler parts as are being used for the retrofit. There are new ribs going into production that will accommodate the thickness change of the spar. As already mentioned, builders working on an Emp kit should just work on other components. By the time you get to the H stab, the parts and updated plans and manual will be available.
Click to expand...

I just finished my workshop and was planning on starting my RV-8 empennage this week. Would you recommend that I wait for the redesign? Should I start my VS?

I called Van's yesterday to order the parts for SB 14-01-31 and asked about a redesign. The parts lady transferred me to a tech, and he said there wasn't going to be a redesign and to order the SB parts. Now it turns out there is going to be a redesign.

How about SB 14-02-03? Should I order that? Will it be addressed in the redesign?

I am just starting out and this is a little frustrating...

Thanks,
Gregg
 
Thank You Scott and No Cracks

RV-8
Flying since March 2008
400 hours TT
No Acro (did enough in the Air Force at UPT)
Have notches on my left and right forward spar. I put them there per plans.
My tail kit was purchased in Sep 2000. Can't speak to the RV-7 community,but
Many of my parts were 7/8 parts. So, integration had started.
Great airplane.

And on a separate note.

I used to live in Tacoma Wa while I was building my -8. Stationed at McChord AFB. Like everybody else who builds, I had tons of questions or just needed a real visual on some operation I was about to undertake. I would hop in my truck and take I-5 south for about 2 hours to Vans factory. I always needed extra parts, screws, nut plates, or whatever anyway so down I drove. I would go out back to their hangar and gawk all over their RV-8 to get my visual on what my building dilemma was. That's when I met Scott. Even though he is a very busy man working in their prototype shop and just doing general MX on all their factory demo aircraft, he always had time to answer my questions and lead me AWAY from stray. I am forever grateful. I also got million dollar tech support from Scott Risan who is now general manager of the company. Boy has he moved up! So, to have Scott M on this forum offering his pearls of wisdom and knowledge is priceless. Believe me....

So I am hoping that Scott saying "I am done here", was just him saying he was very tired for the night and just checking out for a rest. Thanks Scott for your input here and thanks for helping me out those years ago in the hangar at work. I have a flying plane because of your inputs. Now on to check my elevators for spar issues. Heck, my annual is about due anyway, so up and at it.
 
inspection result

inspection result, no notch, no cracks

RV-8 s/n 82718

TTSN 289
1st flight Sept 2009

IO-360-A1A
Whirl Wind 200RV prop
mild acro
20% of landings on dirt
hangared
 
Wood or Composite props?

Has anyone found cracks on any RVs equipped with wood or composite fixed pitch props... or composite bladed CS props?

Going thru the reports posted thus far, unless I've missed something, it seems like only those with metal props (both FP and CS) are finding cracks.
 
For the stats...

Early RV-6A (not a prepunch)
First flight in 1996
1000 hrs TT
O-360 with Hartzel CS prop.
No acro
Mostly operated on paved runways
Always use a tow bar.
Turtle wood gear leg stiffeners (anyone thought about cycles from gear leg shimmy?:rolleyes:)
Has relief notches
No cracks

Dave
 
rvbuilder2002 said:
I'm done here.
Click to expand...

Didn't mean gone from VAF... just meant done with this thread (I think I have contributed all I can at this point).

Having said that, some have mentioned waiting for the new root ribs.
On a retrofit, the skins are already dimpled. That makes it difficult to properly fit and locate un-drilled/dimpled ribs. Also your would be match drilling from dimpled holes that are slightly over sized (hopefully just from having been dimpled).
Thus, the reason the SB directs to reuse the original ribs.
 
Dave_G said:
Turtle wood gear leg stiffeners (anyone thought about cycles from gear leg shimmy?
Click to expand...

No, but the "wet dog shake" during engine startup/shutdown idea shaking the tailfeathers, especially the counterweighted elevator tips, in a cyclic manner was brought up by DanH in this thread: http://www.vansairforce.com/community/showthread.php?t=104551&page=25 specifically starting in post #248 and continuing on to the next page, has been making my brain itch. Especially since RVs with metal props seem to do that shake a lot more pronounced than those with wood or composite props.

Note that I'm no aircraft engineer by any means... just insatiably curious.
 
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I'm happy to have a little skin in this game. Just inspected mine. No cracks. 0hrs. Lots of aerobatics being moved from one space to another in the shop! I'm looking forward to getting the parts so I can utilize my expertly honed rivet removal skills :). This is going to be an easy couple hour project for those of us that have yet to install the HS. I do feel a bit sorry for those that didn't build their airplanes or otherwise have acquired the skills.
 
rvbuilder2002 said:
Didn't mean gone from VAF... just meant done with this thread (I think I have contributed all I can at this point).

Having said that, some have mentioned waiting for the new root ribs.
On a retrofit, the skins are already dimpled. That makes it difficult to properly fit and locate un-drilled/dimpled ribs. Also your would be match drilling from dimpled holes that are slightly over sized (hopefully just from having been dimpled).
Thus, the reason the SB directs to reuse the original ribs.
Click to expand...
I think you just showed that you have more to contribute. :) That's pretty important advice right there.
 
Im with you Scott! (scard) So glad I am the builder and still have all my tools etc. This shouldn't be a big deal at all! I do think I will wait until either cracks show up or the retro kits are more available and their installation is well documented. Might give me something to do in our really crappy Michigan weather :D

Scott, (rvbuilder2002), I totally understand your position and appreciate your contributions. Please don't let a few spoil it for all the rest of us, the majority who are really appreciative of your input. I will personally buy you a beer at this years Oshkosh get together, it's on me.
 
RV8 Sn80199

No cracks yet.

~298 hrs, Franklin/PZL6A350,
No aerobatics.
Paved runways only.
No pronounced relieve holes,

G
 
Data on those with cracks

Did a quick spreadsheet of the messages in this thread which gave results of cracks or no cracks. About half way through I stopped logging "no crack" results and only logged those with cracks. I did not notice any data points which stood out in the "no crack" results. There were many high time, acro, no notches in that category.

Here is a Excel matrix of those who reported cracks. I have listed message number from this thread for reference. If you want to give me any missing data, send it to [email protected]. Be sure to reference your message number.

Msg # Type A? Kit Date Date Completed Total Time Acro? Grass Strip Cracks? Notches?
37 7 A 1400 Y Y N
50 6 2000 1200 Y
58 7 A 955 Y Y Y
74 6 1200 Y Y Y
98 7 850 Y Y Y Y
125 6 560 N N Y Y
144 8 2000 1345 Y Y
162 8 1900 Y Y Y N
164 7 A 635 Y Y
229 6 A 1900 Y Y Y
257 7 1350 Y Y Y Y
297 7 600 Y Y Y

My apologies for the poor alignment. I couldn't figure out a better way to post the spreadsheet.

I also did not list any of the "batch" posts which said something like "we inspected four RV's and one of them had cracks," mainly because there was no meaningful data in the posts. If those who did this want to give me an update in this format, I will include it.



Some things which stand out to me:

1. 50% RV-7's. 33% RV-6's. 12.5% RV-8's. 33% are A models.
2. Lowest time is 560 hours. (many high timers had no cracks)
3. All but one (92%) did acro.
4. No correlation noted with notches.

-John
 
Retry

I just noticed that you can't tell which data fields are blank in my previous post. Here is a second try with "?" in the blank fields.

Msg # Type A? Kit Date Date Completed Total Time Acro? Grass Strip Cracks? Notches?
37 7 A ? ? 1400 Y ? Y N
50 6 ? 2000 1200 ? ? Y ?
58 7 A ? ? 955 Y ? Y Y
74 6 ? ? 1200 Y ? Y Y
98 7 ? ? 850 Y Y Y Y
125 6 ? ? 560 N N Y Y
144 8 ? 2000 1345 Y ? Y ?
162 8 ? ? 1900 Y Y Y N
164 7 A ? ? 635 Y ? Y ?
229 6 A ? ? 1900 Y Y Y ?
257 7 ? ? 1350 Y Y Y Y
297 7 ? ? 600 Y Y Y ?

-John

boomer said:
Did a quick spreadsheet of the messages in this thread which gave results of cracks or no cracks. About half way through I stopped logging "no crack" results and only logged those with cracks. I did not notice any data points which stood out in the "no crack" results. There were many high time, acro, no notches in that category.

Here is a Excel matrix of those who reported cracks. I have listed message number from this thread for reference. If you want to give me any missing data, send it to [email protected]. Be sure to reference your message number.

Msg # Type A? Kit Date Date Completed Total Time Acro? Grass Strip Cracks? Notches?
37 7 A 1400 Y Y N
50 6 2000 1200 Y
58 7 A 955 Y Y Y
74 6 1200 Y Y Y
98 7 850 Y Y Y Y
125 6 560 N N Y Y
144 8 2000 1345 Y Y
162 8 1900 Y Y Y N
164 7 A 635 Y Y
229 6 A 1900 Y Y Y
257 7 1350 Y Y Y Y
297 7 600 Y Y Y

My apologies for the poor alignment. I couldn't figure out a better way to post the spreadsheet.

I also did not list any of the "batch" posts which said something like "we inspected four RV's and one of them had cracks," mainly because there was no meaningful data in the posts. If those who did this want to give me an update in this format, I will include it.



Some things which stand out to me:

1. 50% RV-7's. 33% RV-6's. 12.5% RV-8's. 33% are A models.
2. Lowest time is 560 hours. (many high timers had no cracks)
3. All but one (92%) did acro.
4. No correlation noted with notches.

-John
Click to expand...
 
boomer said:
Did a quick spreadsheet of the messages in this thread which gave results of cracks or no cracks.
Click to expand...

Might want to include propeller type and material the prop is made of too.

I have a strange hunch that we may only see cracks on planes with metal props (both FP and CS) or at least that metal props have a large affect of the probability of these cracks happening. Could be totally wrong too, it's just a hunch. Actually the idea comes from what DanH posted here (http://www.vansairforce.com/community/showpost.php?p=823798&postcount=248), so he gets the credit if this indeed is the triggering cause of these cracks, since the locations have been determined to be points of elevated point load (see Scott's post here: http://www.vansairforce.com/community/showpost.php?p=850457&postcount=278)

EDIT: OK, I've done a quick search for prop type in each plane of Boomer's list above and found:

6 of them are equipped with Hartzell CS props;
3 of them are equipped with Sensenich FP metal props;
1 is currently equipped with a Catto for the past few hundred hours but had something else for the rest of its 1900 hours according to a post by the owner;
1 one has either a Hartzell CS or a Whirlwind CS prop, all I could find was one photo of the plane with the prop spinning so I couldn't really tell for certain which prop it had;
1 was indeterminable what type prop it has.
 
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Question

rvbuilder2002 said:
Didn't mean gone from VAF... just meant done with this thread (I think I have contributed all I can at this point).

Having said that, some have mentioned waiting for the new root ribs.
On a retrofit, the skins are already dimpled. That makes it difficult to properly fit and locate un-drilled/dimpled ribs. Also your would be match drilling from dimpled holes that are slightly over sized (hopefully just from having been dimpled).
Thus, the reason the SB directs to reuse the original ribs.
Click to expand...

Scott
Thanks again.
I have a question about the use of existing ribs in the SB repair.
It looks like HS-0001 spar doubler and HS-0002 rib flange angle are between the spar and
HS-405 main rib. I can't tell the thickness of the doubler but the angle is .040".
Will this added thickness make the rib bind or make the rib/ skin holes difficult to align?
I'm not an engineer pardon if this is a stupid question.
 
No cracks

2000 RV6
667 hours TT
0-360
Metal fixed pitch Sensenich
<10% grass fields
Bunch of acro, NTX 4.5 G
HS built in 1992
Radiuses fairly large and smooth
No cracks!

Thanks Scott for the good info.
 
Nope

wirejock said:
Scott
Thanks again.
I have a question about the use of existing ribs in the SB repair.
It looks like HS-0001 spar doubler and HS-0002 rib flange angle are between the spar and
HS-405 main rib. I can't tell the thickness of the doubler but the angle is .040".
Will this added thickness make the rib bind or make the rib/ skin holes difficult to align?
I'm not an engineer pardon if this is a stupid question.
Click to expand...

Scott,
The service bulletin explains it all. You cut off the forward flange of the main ribs.Then use the angle to make new flanges. Done correctly you will have perfect alignment.

Mark
 
Doh!

Mark Burns said:
Scott,
The service bulletin explains it all. You cut off the forward flange of the main ribs.Then use the angle to make new flanges. Done correctly you will have perfect alignment.

Mark
Click to expand...

Thanks Mark
I see it now.
Told you it was a stupid question.
 
scard said:
I do feel a bit sorry for those that didn't build their airplanes or otherwise have acquired the skills.
Click to expand...

Yes, this can definitely change your viewpoint on SB. I am still very wet behind the ears (just finishing up the VS on my -10), but I can say that I look at this quite differently now vs. several months ago. I will still get some experienced builders to double check my work when/if I choose to comply w/ the SB, but it is very nice to look at this with the knowledge that I have a workshop set up and working.

Nothing for nothing - I'm sure we have some Bo owners/previous owners - I believe Bonanzas had a similar recurring inspection on the tail?
 
Inspection result

No cracks.

RV-8/N898JW
680 TTSN, completed 7/2004
IO360M1B
WW200RV
rare, mild acro
paved runways only
towbar
no notch
 
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2011 RV7 205 hrs
IO 360 M1B WW prop
Mostly Grass Strips
Notches
No Cracks yet but looks like all the material removed by the notches could work against us.
 
Thanks for ur services Scott

Mike S said:
You have just made a lot of folks who had been holding their breath, breathe again
Click to expand...

Hear hear!

Otherwise no data from me as I am still in build stage (about 90% complete) but will be doing the SB
 
boomer said:
I just noticed that you can't tell which data fields are blank in my previous post. Here is a second try with "?" in the blank fields.

Msg # Type A? Kit Date Date Completed Total Time Acro? Grass Strip Cracks? Notches?
37 7 A ? ? 1400 Y ? Y N
50 6 ? 2000 1200 ? ? Y ?
58 7 A ? ? 955 Y ? Y Y
74 6 ? ? 1200 Y ? Y Y
98 7 ? ? 850 Y Y Y Y
125 6 ? ? 560 N N Y Y
144 8 ? 2000 1345 Y ? Y ?
162 8 ? ? 1900 Y Y Y N
164 7 A ? ? 635 Y ? Y ?
229 6 A ? ? 1900 Y Y Y ?
257 7 ? ? 1350 Y Y Y Y
297 7 ? ? 600 Y Y Y ?

-John
Click to expand...

I have been maintaining a spreadsheet as well, we can collaborate later. Print the sheet as a PDF and then post via picasa. Kind of a pain. My intention is a stastitical analysis of failures only. Bascially a weibull plot. The 8 seems to be off set to higher hours, but that is not significant as there are failures.
 
RV6A SN24431 First flew 1999.
O360 C/S 1060 Hours
No Aeros, Mainly flying off paved runways.
No Cracks. (praise the Lord)

Barry
RV6A F-PRVM
 
No Cracks

RV-6A SN22993
First Flight 2.8.2000
O-360-A1A
Hartzell C/S
1700 hours
Limited Aero, Paved Runways, Some Grass, Some Gravel
No Notches
No Cracks
 
SB 14-01-31

Just checked my -7 and did not find any cracks. I even brought in another A&P, IA to really confirm my findings, all clear. My parts were notched. Aircraft info: S/N 71520, 220 hours T.T., O-360 engine and C.S. prop. Acro, loops and rolls only.
mlgpilot
 
SB 14-01-31

RV-7A
2004 vintage tail kit
Flying since August 2012
132 hours
185 hp IO-360-B1AD2
Hartzell cs prop
99% pavement
No cracks... yet
:eek:
 
NO CRACKS YET

For the record:

RV-7, tip-up, #72450, Tail kit purchased Aug 2005, completed Dec 2005.
Aerosport IO-360M1, ECI comp, E/Pmag combo, 8.5:1.
Hartzell BA, balanced.
Basic weight 1085lb complete & painted, CofG 78.24 inches empty.
Plans built including notches, no mods except for Screaming Eagle tail wheel.
Total flight time 112 hours, including 2 hours of mild aeros (<0 to <+4G), 6 hours formation display (<0 to <+4G), and initial check to -3 and +6G, no inverted fuel or oil, first flight Aug 2011.
50/50 sealed/grass.
99 flights, 260 landings.

No cracks detected yet on either the forward or aft HS spars.

I intend to inspect regularly, wait for the factory options to evolve, monitor developments.

Thanks for the reasoned contributions, particularly from Scott. Thanks too to the people developing the record.

Regards
 
[/QUOTE]Nothing for nothing - I'm sure we have some Bo owners/previous owners - I believe Bonanzas had a similar recurring inspection on the tail?[/QUOTE]

As a former Bo owner, I can weigh in on this a bit. Beechcrafts were hit with several AD's, one being inspection of the spar carrythrough structure for the wing. Some high time, hard use airplanes were developing cracks in that area. The fix was horrendously expensive, the number of affected airplanes was very small. It pretty much became a non issue, with inspection required at the annual. Always sweated it a bit, but never had a problem. It never did seem to effect the resale values.

The V-tail had it's own issues, the fix for the leading edge of the ruddervators was simple and effective. But they did definitely take a hit on resale that they haven't recovered from to this day. Straight tail Bo's just command a premium.
 
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