What's new
Van's Air Force

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

Service Letter 00068

Tony_T

Well Known Member
Patron
This hinge shim mod is a welcome upgrade. Re-installing the stabilator using washer spacers, which always get knocked off, is very frustrating. The service letter illustrations and instructions pertain primarily to the iS with a note that the RV-12 hardware is different. It is quite different, in fact. On th iS stab the outboard hinge brackets can't be easily removed and replaced. On the RV-12 stabilator the complete hinge bracket assemblies can be removed and the shims installed on the bench.

I don't have the parts yet, just thinking it through.

My stabilator so the picture pertains to the classic RV-12 not the RV-12iS:
 

Attachments

  • image003.jpg
    image003.jpg
    226.7 KB · Views: 713
Tony -- Your photos will no doubt prove very helpful! Please let us know how your SB compliance process goes. -- David
 
After ordering the service letter I kind of wish they would just publish the part drawing for the spacer to make ourselves. Im at a work stoppage until I can incorporate the spacer.
 
Does anyone have that pneumatic squeezer in Figure 5? I would sure like to borrow one and avoid spending $500.

I'm in Tracy. I have the no-hole yoke and the Numatx squeezer. my Numatx is a whole assembly with a base and foot pedal and not something I would ship but if saving $500 was worth bringing your stab to KTCY I can help.
 
A number of guys have epoxied theirs in place, which is my plan during my upcoming CI. No rivets to drill out or paint to touch up.
 
A number of guys have epoxied theirs in place, which is my plan during my upcoming CI. No rivets to drill out or paint to touch up.

The downside to epoxy would be that it would be very difficult to replace the 1/4-28 plate nut in the unlikely case where that would become necessary. That assumes using the service letter shims. If I were considering epoxy I would just use washers, to allow access to the plate nut rivets.
 
Last edited:
The downside to epoxy would be that it would be very difficult to replace the 1/4-28 plate nut in the unlikely case where that would become necessary. That assumes using the service letter shims. If I were considering epoxy I would just use washers, to allow access to the plate nut rivets.
De-bonding epoxy in a place like this is a non-issue, a few seconds with a hot soldering iron on the washer and it will come apart. Regular epoxy will release at about 200f and JB Weld at 400f. Soldering iron tips are around 650f so once the heat transfers from the washer through the glue line to the base metal it releases.
 
And my friend used a sharp screwdriver and hammer to easily pop one of his off. He used slow-curing JB Weld.
 
De-bonding epoxy in a place like this is a non-issue, a few seconds with a hot soldering iron on the washer and it will come apart. Regular epoxy will release at about 200f and JB Weld at 400f. Soldering iron tips are around 650f so once the heat transfers from the washer through the glue line to the base metal it releases.

That's good to know. But we've been using glue, or in some cases epoxy, for years. Nothing new there. SL-00068 promises to be an upgrade to make servicing the stab less frustrating.

I did use JB to hold the washers last time but I think the shims installed per the SL is a better solution, especially used in combination with a stab service cart.

Contributing to the frustration though is the problem of handling the bulky stabilator off and then back on the airplane while fitting the mounting bolts. We have 3 RV12's here, possibly a fourth, and one building so I made up a stab service cart to make all this upcoming work much less frustrating.

I borrowed the idea from someone else and anyone is free to copy.
 

Attachments

  • IMG_3273.jpg
    IMG_3273.jpg
    231.6 KB · Views: 164
  • IMG_3262.jpg
    IMG_3262.jpg
    227.2 KB · Views: 201
I used the same cart with blankets to do the SB on mine. I figured that since this was the first time removing the stab in 1100 hrs that if the next time was 2200 hrs it wasn't worth making a special fixture.
 
How goes it photos for the RV12 classic; not iS which has differing structure:
Drilling rivets out top and bottom, 12 in all.
Shims tapered, countersunk, dimpled as required, riveted and primed.
Brackets ready to bolt back onto the stab:
 

Attachments

  • 7RV_4886.jpg
    7RV_4886.jpg
    253.4 KB · Views: 161
  • 7RV_4894.jpg
    7RV_4894.jpg
    278.1 KB · Views: 171
  • 7RV_4892.jpg
    7RV_4892.jpg
    256.6 KB · Views: 159
Removed and reinstalled the stabilator 3 times during the balance procedure and I can report that having the shim spacer kit installed made the tasks go easier without concern of displacing washers. If there is a need to remove the stab for a SB, painting or other reason one should consider doing the SL00068 shim kit.
 
I am looking at reworking my recently completed stabilator to add the spacers.

I don't have a pneumatic squeezer nor rivet gun to squeeze or buck the the rivets for the outboard hinges. A regular hand squeezer won't fit.

It seems like this a perfect use of the cherry nut plate rivets, CCR-264SS3-03.

By my measurements, the -03 length should be within grip range for the inner stack up (max: 0.188").

The maintenance manual says the CCR rivets can be used interchangeably, but the AN426AD rivets are preferred when possible.

Is there any compelling reason NOT to use the Cherry CCR rivets here?
 
Not sure how you’d get a puller in there for the CCR rivet either, but a number of us have successfully epoxied ours in place,
 
I have a very compact hand puller, which is certainly fine for pulling 4 rivets.

I think if I can get a drill in there to drill out the existing rivets, pulling the CCR rivets should be easy.
 
I'm at the point in my build to install the stabilator for the 1st time and debating if the SL 00068 is going to be worth the effort or just install it from the original plans. For those who have installed the upgrade what's your thoughts?
 
I'm at the point in my build to install the stabilator for the 1st time and debating if the SL 00068 is going to be worth the effort or just install it from the original plans. For those who have installed the upgrade what's your thoughts?

You have an opportunity to skip the whole washer routine from the start? I would take that opportunity. Certainly not necessary to do the SL update so "worth it" is builders judgement...but it's a nice improvement. If you are early in the build you will put it on and off a few times and IMO it would be worthwhile.
 
The latest plans incorporate the fix in the SL, so if you just follow the instructions you’ll be fine. Do however note that it calls for the use of rivets that actually aren’t included in the kit. I happened to have some from a previous build. Vans is aware and will be including some in future kits.


I'm at the point in my build to install the stabilator for the 1st time and debating if the SL 00068 is going to be worth the effort or just install it from the original plans. For those who have installed the upgrade what's your thoughts?
 
I built the stabilator 2 years ago so I'd need to drill out a bunch of rivets to do this upgrade. Wondering if it's worth all that trouble for someone like myself who at the end of their build.

The latest plans incorporate the fix in the SL, so if you just follow the instructions you’ll be fine. Do however note that it calls for the use of rivets that actually aren’t included in the kit. I happened to have some from a previous build. Vans is aware and will be including some in future kits.
 
Ah sorry, I mis-interpreted your original message.

I built the stabilator 2 years ago so I'd need to drill out a bunch of rivets to do this upgrade. Wondering if it's worth all that trouble for someone like myself who at the end of their build.
 
I built the stabilator 2 years ago so I'd need to drill out a bunch of rivets to do this upgrade. Wondering if it's worth all that trouble for someone like myself who at the end of their build.

If you have the no-hole yoke, the SL is pretty easy. There is a couple steps with tight quarters but it really doesn't take much time. I would double down on my opinion above and say that even with the stab complete, if it's off the airplane it's worth doing.

I suppose the counter-argument is that you may have the shim washers glued in place and are highly confident they will never move. Assuming that's true there is no big benefit. I don't have that much confidence in some CA on metal and I found those washers to be a giant PITA.
 
If you haven't installed the stabilator yet.. I'd advise you to spend the extra time to retrofit the new steel shims. Just make sure you have a rivet squeezer that can get to all the places you need to get to though..

I've installed, and re-installed the stab with the glued on washers... one wrong move and you can knock one of them off.. then you'll have a delay of re-gluing it back on.. waiting.. and hopefully be more careful the 2nd time.

I ended up doing the Service Letter a few months ago when the stab had to come off for other reasons...
 
I'm having to re-do the SB 18-02-02 due to the past owner not doing it correctly. So I'm also doing the 00068. My problem is the past owner didn't use but one washer on one hinge bolt.

Should I just install the 00068 as per direction, cause my washer stackup was never right in step 3? Thick spacer on both outboards and thin spacers on both inboards.......
 
My stabilator only needs one thick spacer on one side and a thin one on the other; the fit is snug, and there’s no side-to-side play. I can only attribute it to build tolerances and possibly the bearings are not perfectly parallel with each other. So, if your stabilator has no side-to-side play with one washer on one bolt, then I’d reproduce that with the shims. Again, make sure there’s no wiggle on the hinges though and there’s really no gap between the hinge mounting points.
 
Thanks Bob, great points.
I checked before removing stab and there was a big gap on the one side without washers. I think the previous owner got the wiggle out with one washer, but left a gap on one side. I will just reinstall and check what it needs. I had one of the inboard brackets build with thick spacer and was hoping it works. If not I will rebuild it again after refit if needed.
 
What are the torque specs for the (8) Hinge Brackets bolts?
I can't find it - where's it listed?
Does anyone use Loctite?

Also torque specs on the (2) Hinge Bolts?
 
Last edited:
See KAI Section 5.20 for torque values. For AN4 bolts in nut plates, I add 18 lb-in to account for nut-plate friction. That’s just what I measured with new hardware when testing during my build. You can test yourself, as used hardware results will like vary.
 

Attachments

  • IMG_1126.jpg
    IMG_1126.jpg
    420.8 KB · Views: 23
Last edited:
See KAI Section 5.20 for torque values. For AN4 bolts in nut plates, I add 18 lb-ft to account for nut-plate friction. That’s just what I measured with new hardware when testing during my build. You can test yourself, as used hardware results will like vary.

Inch pounds? :confused:
 
So, see if I got this right below............

(8) AN3-4A bolts into (8) K1000-3 nut plates
Torque - 18 inch lb + 20-25 (standard nut) = 43 max torque

AND

(2) AN4-12A bolts into (2) K1000-4 nut plates
Torque - 18 inch lbs + 50-70 (standard nut) = 88 max torque

I will verify my 18 inch lb drag which may vary.

Thanks for the help......
 
No, the AN3 will have a lower value. I measured 8.4 lb-in in nut plates in my testing. Here’s the chart I created during my build. Again, with new hardware, but not sure how much difference you’ll get.
 

Attachments

  • IMG_1127.jpeg
    IMG_1127.jpeg
    323.2 KB · Views: 55
No, the AN3 will have a lower value. I measured 8.4 lb-in in nut plates in my testing. Here’s the chart I created during my build. Again, with new hardware, but not sure how much difference you’ll get.

Great chart Bob - that helps a lot!

I'll use torque seal - did you use any loctite on the threads?
 
Torque seal, yes; Loctite, no. I might be wrong, but believe adding Loctite to the threads would make them lubricated joints, thus requiring a different torque range. At least as an electrical guy that was my assumption. And since this is locking hardware, didn’t see the need. Plus the fact Van’s doesn’t call for it in the KAIs.
 

Attachments

  • IMG_1128.jpeg
    IMG_1128.jpeg
    1.4 MB · Views: 68
Yeah, I didn't see Loctite in the KAI. I just felt that the bolts could loosen, but probably not being in a nut plate.

Good picture Bob and very nice work!
 
Back
Top