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

Well, shoot, this means I'll probably have to rebuild the entire HS, since I glassed in the tips. Pretty sucky, since it has to go into the paint shop in two months and I sold my 3x rivet gun.
 
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I just checked my rocket, 800 hours, and no cracks noted. It did get me thinking about what kinds of things could cause this to crack. Items like flight loads, edges not de burred, stresses built into the structure, etc. As I was standing there looking at it I wonder about the stresses that are caused each time you push that plane backwards using the leading edge of the HS as a place to push. The loads applied by that action would act directly at that point of the structure. I am guilty for using the HS as a place to steer and I make every effort not to apply much force there but I will go back to using my pull handle on a regular basis.
 
Just spent about 30 minutes completing the inspection. The slowest part was the due to the overspray from when the plane was painted. There were some "whisps" and "stringies" of paint. Once those were clean I put the 8MP smartphone camera to good use. I have added four very clear pictures to my condition inspection clipboard so next time, I have my comparison.

RV-8
2005-2008 build
minimal acro since phase one
300 hours
 
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Well, shoot, this means I'll probably have to rebuild the entire HS, since I glassed in the tips. Pretty sucky, since it has to go into the paint shop in two months and I sold my 3x rivet gun.

I don't understand how "glassing in the tips" would have anything to do with this inspection.
 
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Van recommends a removable empenage fairings for easy inspection. Last summer I saw an RV-6 tied down in Middleton, WI which had the fairing glassed in place. My immediate reaction was that this is not good as the area should be inspected annually. Talking to the locals it appears the aircraft was not built by the current owner. I did not get a chance to meet the owner and discuss this issue but I hope he checks VAF or Van's web site and sees this new SB. I think we owe it to the our community to discuss this SB with new RV aquantances, especially those who did not build and/or are not regularly on VAF.

If the owner is not the builder, he will have to have an A&P do the condition inspection. I can't imagine any A&P signing off an airplane where he can't properly inspect the empennage attach points.
 
We have been studying the picture sent by Vans in the SB and it is the opinion of 3 mechanics on the field that who ever built this HS did not do a very good job of dressing out the radius or the top flanges of the HS702. It is very rough in the pictures, they also noted that this HS noes not have the required rivet spacing from the flange to the nut plate. My nut plate is approximate 1 inch from the flange that meets the top. Could the crack started from not de-burring correctly?

That being said
No cracks, will do as the SB states and inspect at the next condition inspection. And repeat yearly.
Only 72 hours 5.8 G's pulled during Phase one testing once.

Jack
 
Cracks found

Cracks found on the top of both sides.

7A
955 Hours
O-360 180 HP
85 pitch Sensenich fixed
Some acro

IMG_0364.jpg
 
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Recurring Inspection

I don't think that is a correct statement.
The SB says inspect, and if cracks are found, install the doubler parts.
If an inspection is done, and no cracks are found, The SB says reinspect at the next condition inspection. So the SB has been complied with until the next required condition inspection comes due. In the industry, this is referred to as a recurring inspection.

I agree this is a recurring inspection. This would not be a complied with SB. Once a SB is complied with it can be signed off in your Logbook. The service bulletin has 35 steps.

Step 35: Make a logbook entry indicating compliance with this service bulletin.

This can not be done until:
"Inspect before further flight and at each annual condition inspection until such time that this service bulletin has been complied with in its entirety."
 
SB 14-01-31

Could the first person to perform the repair please document the process please?
I have a nice shiny unused HS hanging in my shop. Now I get to tear it apart.
I could install and inspect annually but it's easier to deal with it after my wings are done and before starting the fuse.
From reading, it seems less damaging to drill all the skin rivets and expose the skeleton. Maybe not.
I'm no engineer, but couldn't Vans make a one piece spar and doubler?
 
I wonder about the stresses that are caused each time you push that plane backwards using the leading edge of the HS as a place to push. The loads applied by that action would act directly at that point of the structure.

Never thought of it in that context. I've been planning to build a towbar. It just moved up on my to-do list.
 
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...
I agree that we should start a polling thread which will indicate:

Type aircraft
Hours flown
Cracks yes/no
One side/both sides

Others might think of some other info. Doug?

...
Vic
I would add engine size & estimated HP and FP or CS prop.

It is possible that O-320 powered RV's with FP props MIGHT not have this issue but (I)O-360 180 HP (and larger) CS prop RV's do.

The HS and VS takes a pretty good beating from the prop wash.
 
I don't understand how "glassing in the tips" would have anything to do with this inspection.

I was looking at the SB and looked like the fix would require removing the skin, but having looked at the plane, this is not an issue.

On the initial inspection, I did not see a crack at the location in the SB, but then I saw what initially appeared to be a crack in the rib. Either that or it's a scratch from the bucking bar when I shaped that rivet.

sb.jpg


Unsure, I removed the rudder (had to cut the wires to the tail light, and this'll give me the opportunity to get rid of how those wires were run and also the decision to use a snap bushing on the rudder fairing instead of slicing a spot for the wire to travel), vertical stabilizer and elevator for a better look.

I'm still not sure what it is. But I'm leaning toward it not being crack.

But as long as I've got the tail off -- in addition to starting my progressive annual now rather than in May -- I'm wondering whether it makes any sense to go ahead and just do the fix on this location?
 
I agree this is a recurring inspection. This would not be a complied with SB. Once a SB is complied with it can be signed off in your Logbook. The service bulletin has 35 steps.

Step 35: Make a logbook entry indicating compliance with this service bulletin.

This can not be done until:
"Inspect before further flight and at each annual condition inspection until such time that this service bulletin has been complied with in its entirety."

A statement of compliance log book entry should be made every year, confirming the inspection has been done and that no cracks were found.

I have signed off many AD's over the years, as complied with by inspection.
Which means it is complied with until the inspection interval comes due again. Many of these also require no further inspection if some other work is done after discovery of a problem (part replaced with a different one that isn't effected by the AD, etc.).

So I guess we will have to agree to disagree.

Regardless of what you think it means, the intent of the SB (and I am the person that wrote the main content of it) is to have owners/mechanics comply with a requirement to do a yearly inspection and confirm no cracks. A way to avoid the yearly inspection, or to repair if cracks are found, is to complete the modification.
 
I agree this is a recurring inspection. This would not be a complied with SB. Once a SB is complied with it can be signed off in your Logbook. The service bulletin has 35 steps.

Step 35: Make a logbook entry indicating compliance with this service bulletin.

This can not be done until:
"Inspect before further flight and at each annual condition inspection until such time that this service bulletin has been complied with in its entirety."

I feel that you have to comply with visual inspection of the service bulletin immediately and at each annual conditional inspection, with a logbook entry stating that you complied with visual inspection portion of the SB, until the time you either find a crack or just decide to install the doublers, at which time this recurring SB is no longer required.
 
... As I was standing there looking at it I wonder about the stresses that are caused each time you push that plane backwards using the leading edge of the HS as a place to push. The loads applied by that action would act directly at that point of the structure. ....

From looking at the pictures in the SB, it looked to me like flights loads acting on a stress riser would have more to do with those cracks than pushing on the leading edge.

Does anyone know the history behind this SB? Is Van's likely to talk about it? Is it a result of investigations into a particular accident, or accidents?
 
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Van recommends a removable empenage fairings for easy inspection. Last summer I saw an RV-6 tied down in Middleton, WI which had the fairing glassed in place. My immediate reaction was that this is not good as the area should be inspected annually. Talking to the locals it appears the aircraft was not built by the current owner. I did not get a chance to meet the owner and discuss this issue but I hope he checks VAF or Van's web site and sees this new SB. I think we owe it to the our community to discuss this SB with new RV aquantances, especially those who did not build and/or are not regularly on VAF.

I agree with Mel, but I inspected a -7A a couple of years ago. Since it was painted (I don't know how many years prior), the intersection fairing had never been removed, as the paint between the fairing and the VS was unseparated. I just inspected a J-3 that the gascolator had probably not been opened and inspected in 3-5 years. There are many "pencil whips" out there and roaming around. That may give some of us a "bad name" when we charge more for an annual because more work needs to be done than last year, but hopefully the airplane owners will value the thorough inspection.
 
Does anyone know the history behind this SB? Is Van's likely to talk about it? Is it a result of investigations into a particular accident, or accidents?

Post #40 on this thread explains the history.

"Lastly, I know it is easy to begin imagining the connection between this and a recent accident with the cause yet to be identified. This issue was detected during a condition inspection of the company demonstrator RV-7A. It is much higher time than most RV's in service. After that discovery, other occurrences were noted when doing inspections of multiple airplanes...it is unknown how many will actually have or develop the problem, but since it was found in more than one... a design changed was developed and a SB was issued."
 
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Just inspected my horizontal stab

RV7
IO-360
Fixed pitch prop
230 hrs total time
Aeros flown regularly
No cracks, log entry made to indicate compliance with SB
maintenace release entry created to re inspect at annual.

Cheers
 
No Cracks found.

1995 RV6A, Orndorf build, 1180 hrs, O320, CS, no aero w me (3rd owner, flew 430 hrs).

Carl
 
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Post #40 on this thread explains the history.

"Lastly, I know it is easy to begin imagining the connection between this and a recent accident with the cause yet to be identified. This issue was detected during a condition inspection of the company demonstrator RV-7A. It is much higher time than most RV's in service. After that discovery, other occurrences were noted when doing inspections of multiple airplanes...it is unknown how many will actually have or develop the problem, but since it was found in more than one... a design changed was developed and a SB was issued."

Thank you! I thought I'd read the whole thread. Apparently I had not...
 
RV7A inspected today. No Cracks found.
350 hrs with some acro.

Looking at the job step by step, I might be tempted to build up a new HS in my spare time rather then mess with that many critically important rivets with not so good access to them.

Something that I have not seen mentioned in this thread is what this does to the re-sale value of our aircraft. If I am looking for a used RV7 and the service bulletin has been complied with, I am not sure how I would feel about it. It would certainly mean and very careful inspection of the area would be required to see how well the job was accomplished.

On the other hand, if I found an RV that had the HS replaced with a new one that included the doublers in the build, I would like that alot better!

Maybe someone will jump in and start building new HSs with the mods included. Better yet, Van's could offer them from the quick builders for those that want to comply with the SB in that manner. If the parts costs about $800, I wonder what a newly completed HS would go for?

Randall
 
RV-6 (1997) inspected today. No cracks found.
592 hours with very little acro.

Mine does not have the stress relief notch shown and described in the SB. But I also do not have any cracks so I will simply continue inspecting. I used the iPhone mirror to capture evidence for my logs.

I also thought about resale value and compliance. Since I'm not the builder of this -6 I would not feel very comfortable doing major surgery to comply with the SB. And, if I was buying a used 6,7,8 I would want to know if the original builder did the compliance work. I'd be more comfortable than if someone else (like me) tried to do it.
 
new HS

RV7A inspected today. No Cracks found.
350 hrs with some acro.

Looking at the job step by step, I might be tempted to build up a new HS in my spare time rather then mess with that many critically important rivets with not so good access to them.

Something that I have not seen mentioned in this thread is what this does to the re-sale value of our aircraft. If I am looking for a used RV7 and the service bulletin has been complied with, I am not sure how I would feel about it. It would certainly mean and very careful inspection of the area would be required to see how well the job was accomplished.

On the other hand, if I found an RV that had the HS replaced with a new one that included the doublers in the build, I would like that alot better!

Maybe someone will jump in and start building new HSs with the mods included. Better yet, Van's could offer them from the quick builders for those that want to comply with the SB in that manner. If the parts costs about $800, I wonder what a newly completed HS would go for?

Randall

I agree.
As mine is not finished, I plan to wait a bit a see how Vans changes the HS.
I think I can build another faster and with less potential error than making this SB repair.
Still on the fence with plenty of time to decide.
I'm very disappointed but glad they found a problem and at least tried to address it.
 
Pre punched SB

I see in SB that Pre Punched is NA. I checked mine anyway RV 8 finished in 2011 680 hrs. mild acro IO 390, no cracks.
 
Inspected my 7A

Inspected my 7A today, no cracks, 212 hours, flying since 12/31/2010
 
Disconcerting

There's something quite disconcerting arising from this thread....and it's not just about the cracking.

I built my RV7A Horizontal Stabiliser in accordance with Vans DWG 3 issued on 7/20/01. That drawing clearly shows that notches are required at the top AND the bottom of the front spar on the left and right sides (ie. there should be 4 notches in total).

The requirements for these notches are quite clear. In fact there is a seperate RELIEF NOTCH detail on DWG 3. It specifically calls for the relief notch to be approx 5/32" deep and to "notch back to the tangent of the bend radius".

However when I look at the picture posted by Walt Aronow (post #37) I see no notch at all on his RV7A (he also has cracks)

Further, when I look at the picture posted by Bob Collins (post #65) I see no notch at all on his RV7A (he has no cracks yet....hardly any hours).

Additionally, when I look at the picture posted by Mark Strahler (post #74) I see that his RV6 is notched but his notches are clearly not in the right position as dictated by my drawings (notched way beyond the tangent of the bend radius...and cracked).

So what is going on here. There seems to be substantial evidence in this single thread that builders are not always fabricating their aircraft in accordance with specific details on their drawings. It's a bit of a worry.

Having said that, I am not theorizing that the lack of notches (or incorrectly placed notches) is resulting in the cracking. Obviously even aircraft with correctly placed notches are exhibiting cracks. But this thread is highlighting that there are a lot of RVs out there with construction details that may not conform with Vans drawings in crucial highly stressed areas.

The average RV has very few hours on it. However as the fleet ages and the hours build up we will probably see more of these type of stress cycle failures.
 
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I see in SB that Pre Punched is NA. I checked mine anyway RV 8 finished in 2011 680 hrs. mild acro IO 390, no cracks.

That right there confuses me.....

My RV-8 Empennage kit was purchased in 1998. It is entirely "pre-punched" as far as I can tell. When were RV-8 kits not "pre-punched"

What does Van's mean by "match-hole emp- not applicable"?
 
"Affected Models" and match-hole kits

I see in SB that Pre Punched is NA. I checked mine anyway RV 8 finished in 2011 680 hrs. mild acro IO 390, no cracks.

I read that too in the SB and it confused me a little bit. Nowhere else in the SB does it say that it doesn't apply to the match-hole kits. I would have expected some mention in the "Affected Models" list at the very beginning of the title page. But nothing.

As I understand it, and please correct me if I'm wrong, this SB does not apply if the empennage kit was a match-hole kit.
 
This tool will definitely help with the modification per the SB

This is a link to a post for a rivet removal that I posted years ago. It works and will definitely help with the task of removing the 100 or more rivets. I am not selling the tool, this is a simple modification to a tool available at Lowes, Home Depot, Ace Hardware, Harbor Freight, etc. Please take the time to view the post, you will not regret it.

http://www.vansairforce.com/community/showthread.php?t=23223
 
1993 RV-6, Tail was built in 1989-ish
417.6 hours
O-320, FP Warnke prop
Very little acro before I bought it a little less than 100 hours ago, now it gets a little gentleman's acro on a regular basis.

Does NOT have that big "relief" notch cut. I do not like the look of how it was done on the aircraft in the example picture in the SB!

No cracks. My phone takes terrible pictures, but here's an example.

IMG_20140201_135524.jpg



Log book entry made thusly:
Complied with Vans Aircraft Service Bulletin 14-01-31. Visual inspection completed, no cracks found. Due at next and subsequent condition inspections. If cracks are found doublers must be installed IAW this SB.

Sucks to see several with cracks already, sorry gents...

Doug
 
There's something quite disconcerting arising from this thread....and it's not just about the cracking.

I built my RV7A Horizontal Stabiliser in accordance with Vans DWG 3 issued on 7/20/01. That drawing clearly shows that notches are required at the top AND the bottom of the front spar on the left and right sides (ie. there should be 4 notches in total).

The requirements for these notches are quite clear. In fact there is a seperate RELIEF NOTCH detail on DWG 3. It specifically calls for the relief notch to be approx 5/32" deep and to "notch back to the tangent of the bend radius".

However when I look at the picture posted by Walt Aronow (post #37) I see no notch at all on his RV7A (he also has cracks)

Additionally, when I look at the picture posted by Mark Strahler (post #74) I see that his RV6 is notched but his notches are clearly not in the right position as dictated by my drawings (notched way beyond the tangent of the bend radius...and cracked).

So what is going on here. There seems to be substantial evidence in this single thread that builders are not always fabricating their aircraft in accordance with specific details on their drawings. It's a bit of a worry.

But this thread is highlighting that there are a lot of RVs out there with construction details that may not conform with Vans drawings in crucial highly stressed areas.

Bob,
Please don't make assumptions. My prints dated 2/28/01 have no call out for relief notches. I also suspect that these were never called out on the RV6 as my print references parts call out as HS-6xx so apparently Van's basically took the RV6 prints, made a few changes, then changed the name to RV-7.
Walt
 
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......

Additionally, when I look at the picture posted by Mark Strahler (post #74) I see that his RV6 is notched but his notches are clearly not in the right position as dictated by my drawings (notched way beyond the tangent of the bend radius...and cracked).
......

The -6 plans did not call for any sort of relief notch.

The text just says that the cutoff flange end should be "filed and polished smooth"
 
There's something quite disconcerting arising from this thread....and it's not just about the cracking.

I built my RV7A Horizontal Stabiliser in accordance with Vans DWG 3 issued on 7/20/01. That drawing clearly shows that notches are required at the top AND the bottom of the front spar on the left and right sides (ie. there should be 4 notches in total).

The requirements for these notches are quite clear. In fact there is a seperate RELIEF NOTCH detail on DWG 3. It specifically calls for the relief notch to be approx 5/32" deep and to "notch back to the tangent of the bend radius".

However when I look at the picture posted by Walt Aronow (post #37) I see no notch at all on his RV7A (he also has cracks)

Further, when I look at the picture posted by Bob Collins (post #65) I see no notch at all on his RV7A (he has no cracks yet....hardly any hours).

Additionally, when I look at the picture posted by Mark Strahler (post #74) I see that his RV6 is notched but his notches are clearly not in the right position as dictated by my drawings (notched way beyond the tangent of the bend radius...and cracked).

So what is going on here. There seems to be substantial evidence in this single thread that builders are not always fabricating their aircraft in accordance with specific details on their drawings. It's a bit of a worry.

Having said that, I am not theorizing that the lack of notches (or incorrectly placed notches) is resulting in the cracking. Obviously even aircraft with correctly placed notches are exhibiting cracks. But this thread is highlighting that there are a lot of RVs out there with construction details that may not conform with Vans drawings in crucial highly stressed areas.

The average RV has very few hours on it. However as the fleet ages and the hours build up we will probably see more of these type of stress cycle failures.

If your point is I might've screwed up, then, yep. I might've. It's the first part of the airplane to build. I don't recall the notches on the plans and I had one of the first 7A kits. I'll check to see if they were there but please wait before characterizing the workmanship of your fellow builders. Our plans are earlier than yours and I suspect that there is no notch callout and that we did, in fact, build to the plans we had in our possession.

Beyond that, I'm not sure what you're trying to accomplish here. Doesn't seem very helpful. We'll try to get it fixed and rectified. If you have some assistance to offer, that'd be just swell.

Personally, I'm kind of bummed I may have to relinquish my paint date and lose the $1000 deposit, but, hey, pile on if it makes you feel good.

Happy to hear your bird came out great.
 
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Inspected mine this afternoon. No cracks found. Everything back there seems in pristine condition

Here's the specifics:

RV-6 with original "short tail" empenage, 0.016" skins on control surfaces.
Kit dated 1999, build completed in 2003.
No "relief notches" in the location in question.
407 hours on the airframe.
O-320 160hp engine, fixed pitch prop... originally wood Aymar-Demuth for first 350 hours, changed to Sensenich ground adjustable composite prop in summer 2013.
Very little acro ever done the entire life of the airframe.
 
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I see in SB that Pre Punched is NA. I checked mine anyway RV 8 finished in 2011 680 hrs. mild acro IO 390, no cracks.

I admit that chart is confusing. It does not mean the SB doesn't apply to a prepunch emp kit.
Note that at the beginning of the chart it says "Refer to the following for guidance:"

It is trying to differentiate between kits that were supplied with a premanufactured HS-710 angle, and kits that the angle was entirely made by the builder. The entrys with N/A mean there is no drawing to in the builders plans, for making the angle (it was supplied pre-made).
 
Personally, I'm kind of bummed I may have to relinquish my paint date and lose the $1000 deposit, but, hey, pile on if it makes you feel good.

Just my opinion Bob (for what it's worth)... Considering your airplane is very low time, and the position you are in with a paint schedule, I personally would just go ahead and have it painted and do the mod. later.
Your airplane is low time and it would be unlikely for you to see any problem anytime real soon.
Doing the mod on an already painted airplane will require touching up 4 new 3/32 rivets. One top and bottom on each side just outboard of the emp fairing. As long as you could tolerate that, it would save you from losing any money, or messing with the painting schedule.
 
Oddly enough, I was given the heads up when constructing my Rocket that it would be a good idea to reinforce the forward HS spar, which I did. So there's been some indication of this type of problem floating around for a while, albeit in a more stressful application.


EMP_0016.JPG
 
Bob,
My prints dated 2/28/01 have no call out for relief notches. I also suspect that these were never called out on the RV6 as my print references parts call out as HS-6xx so apparently Van's basically took the RV6 prints, made a few changes, then changed the name to RV-7.
Walt

Walt it might be that Vans included the relief notch detail for the first time when they reissued the RV7A HS drawing on 7/20/01.

What strikes me as strange however is that Mark Strahler (post #74) has obvious relief notches on his RV6.
 
I have confirmed that there are no notches on the rib in early drawings. You'll note that the SB references DWG3PP on "early" RV 7/7A. There was no such drawing on the really early drawings. Only **DWG3.

SO now we're faced with trying to get Van's to tell us whether we need to upgrade our planes to the revised drawing also.

This is one of those times when I wish Van's tech support had an active presence on VAF.
 
Just my opinion Bob (for what it's worth)... Considering your airplane is very low time, and the position you are in with a paint schedule, I personally would just go ahead and have it painted and do the mod. later.
Your airplane is low time and it would be unlikely for you to see any problem anytime real soon.
Doing the mod on an already painted airplane will require touching up 4 new 3/32 rivets. One top and bottom on each side just outboard of the emp fairing. As long as you could tolerate that, it would save you from losing any money, or messing with the painting schedule.
I've taken everything but the HS off to get a better look at the area. I guess the question is what's the estimated time to complete the fix. Since everything is apart, it might make sense to go ahead with the fix.

Gotta retool to do that, though. No 3x gun nor right angle drill.

Would be nice if Minnesota's polar vortex would retreat north, too.
 
I have confirmed that there are no notches on the rib in early drawings. You'll note that the SB references DWG3PP on "early" RV 7/7A. There was no such drawing on the really early drawings. Only **DWG3.

SO now we're faced with trying to get Van's to tell us whether we need to upgrade our planes to the revised drawing also.

This is one of those times when I wish Van's tech support had an active presence on VAF.


I have DWG-3PP with my RV-8 tail kit, dated 3/96, it had rev. 1 & 2, but not rev. 3.
 
I guess the question is what's the estimated time to complete the fix
1st thing is the lead time for the kits from Vans. As others have said, type the part number into the Web Store and it comes up as "nothing found".
 
Good call - Thanks!

My RV7 EI HUM Serial 70588-1 has approx 850 hours since I built it, lives on a grass strip and does a lot of aerobatics. O-320, sensenics Fixed Pitch Prop.
I found cracks both sides, possibly 2 x cracks on the Stbd side.

General view for those who have not yet studied this:


At least 1 x Crack on Stbd side (will examine closer & report back when it comes off):


Another crack port side:

 
Great pix Hum!

Hum, thanks for the great pictures, including the wide shot to help with orientation.

Could your port side also have a crack at the bottom?

Carl
 
More cracks?

Thanks Carl, I think its just dirt on a low-res photo taken on a mobile phone.. but I will be taking a close look there also.. :)
 
Question:
What is the best way, when I just began to build my first RV7 Empennage ? Wait for better components from VAN'S ? Include the extra sheets ? Continue building ... ? :confused:
Thanks, Achim
 
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