Section 29A - Oil Tank Brace

Section 29A additional oil tank brace posted on the mothership update site. Result of cracking in some aircraft. I wonder if Van's are going to send this additional brace? A check to be done on all RV12's I think.

I think this is the link

http://www.vansaircraft.com/pdf/revisions/RV-12/29A-16.pdf

John

Looking at the new drawing, there is also a diagonal brace riveted to the lower front firewall that must be a fairly recent addition. At least it's not shown on 29A-01 Rev 0. My older kit doesn't have the brace, and the stiffener indentations pressed into the firewall are a different pattern to mine as well, obviously to accommodate it. Does anyone know why the brace was introduced?

Edit: On thinking it over, there is a fair bit of weight in the oil tank and battery sitting up there on the firewall shelf, so I assume the angle brace has been introduced to stiffen up the lower firewall under the heavily loaded area and help dampen out any flexing.

From the mothership.....

RV-12 Drawing 29A-06...Our applogies for the confusion on the Oil Reservoir brace. The drawing showing the extra brace (see link below) was posted prior to a related Service Bulletin. Service Bulletin 13-04-05, which describes the change, has now been posted on our website. Please review the Service Bulletin on our website. It should answer any questions that you might have regarding this change. Please note that RV-12 builders do not need to contact Van's to receive the upgrade parts for this SB. Van's will be sending out the necessary parts to all affected customers...no charge.

Link to SB http://www.vansaircraft.com/pdf/sb13-4-05.pdf

Some folks will also notice that the related drawing revision (29A-06) depicts a diagonal stiffener on the firewall that is different from the current configuration. This is a modification that we will be incorporating into future Fuselage Kits. It is not a manditory change nor will a Service Notice be issued regarding this change. If builders choose to incorporate the change, there will be a modification kit available soon. (PN# 12 STIFFENER KIT). The diagonal brace is intended to add a bit of extra stiffness to the firewall.

Again, sorry for any confusion. SB 13-04-05 is now posted in the RV-12 section in Service Information and Revisions.

Just when I thought my condition inspection was finally done!

Yeah, John

and I just HAD everything off to do the gear SB. Oh well, I'll have the 200-hour inspection sometime this summer. I guess us early guys will never be "finished: with our birds.

Wayne 120241/143WM

rgmwa said:

Looking at the new drawing, there is also a diagonal brace riveted to the lower front firewall that must be a fairly recent addition. At least it's not shown on 29A-01 Rev 0. My older kit doesn't have the brace, and the stiffener indentations pressed into the firewall are a different pattern to mine as well, obviously to accommodate it. Does anyone know why the brace was introduced?

Click to expand...

This diagonal brace was developed for -12's like mine that "grumble". The firewall below the oil tank " oil cans" so much that it produces a very noticeable grumble. I have chased this noise for awhile and recently found that this vibrating firewall is the culprit.

In the mail

Received the parts and directions for this 'fix' last week. Whata company!!! Thanks, Van's.

Received mine from Vans, today. It's a small manila envelope that comes via regular postal mail. No big boxes or anything, in case folks are waiting on FedEx or UPS.

SB 13-04-05

I received my kit yesterday, at the same time as a Tight Fit Drill Kit that I had ordered at Aicraft Spruce, anticipating that I would need it. As I had not yet installed the oil tank I was able to skip the first 5 steps of the SB. I had no problem drilling and match drilling F-1201E-R but accessing F-1201E-L to do the same operation did not seem possible with the engine in place, particularly drawing the pattern shown in Figure 4 to position the holes. I then realized that the rib was sitting on the battery support and was quite stable once the holes drilled on the right side were clecoed. I decided then to reverse the sequence for the left side. I first drilled the holes in the rib, positioning them as they were match drilled on the right side. I then match drilled these holes into the F-1201E-L. This last operation can only be performed with the Tight Fit Drill or some very compact drill head as you have to operate from inside the battery cavity. Just in case I am going to put the rivets in a position that allow to drill them out the same way... you never know

E. D. Eliot said:

Received the parts and directions for this 'fix' last week. Whata company!!! Thanks, Van's.

Click to expand...

Are they gonna put it in for 'ya???

Bob Bogash
N737G

In due time!

I'll get it done eventually - as my 12 will be built 'eventually'. Right now, I'm having a lot of fun (not) finishing up a house rebuild. Take care.

NASA515 said:

Are they gonna put it in for 'ya???

Click to expand...

It wasn't a big deal, even with the engine installed. I had no oil in the canister yet which made it a bit easier and, most certainly, cleaner.

http://torstensrv-12.blogspot.com/2013/04/sb-13-04-05-completed.html

You can pull the oil tank full of oil without any problem. How do I know? I've done it a few times already. I plastic bag the oil lines to stop the drips and make a buckshee oil tank holder out of a cardboard box. It's really quite easy.

I sure wouldn't drain the tank as suggested.

Bob Bogash
N737G

NASA515 said:

You can pull the oil tank full of oil without any problem. How do I know? I've done it a few times already. I plastic bag the oil lines to stop the drips and make a buckshee oil tank holder out of a cardboard box. It's really quite easy.

I sure wouldn't drain the tank as suggested.

Click to expand...

And I personally wouldn't pull the cowl to do for the service bulletin, unless I had some other maint. work to do.

The required time of compliance for this S.B is at or before the next required condition inspection.

Consequently, it is assumed that owners will wait until some other maintenance interval (such as an engine 100 hr inspection which includes an oil change) to do the required work for the service bulletin (some level of thought is put into these things).

With the oil drained from the tank, the tank can easily be repositioned without disconnecting either of the oil hoses.

Per Rotax's service documentation, any time the system is opened (hose disconnected), the Rotax SI-912-018 oil system purge procedure must be done. The SERVICE BULLETIN 13-04-05 document recommends that it be done even if you don't disconnect the hoses (since the tank has been repositioned) as extra insurance.

I installed the oil tank brace without removing the oil tank or disconnecting any oil lines. I suspended the tank from a 2" x 2" laid across the top of the engine.
Joe Gores

I installed the new oil tank rib similar to the way that WingedFrog did in post #10 above. I match drilled the right side of the rib per the plans. Then flipped the rib upside down so that the left side of the rib is now on the right side.
Then match drilled the left side of the rib through the previously drilled holes in F-1201E-R. Now all 8 holes have been drilled in the new rib.
I flipped the rib right side up and clecoed the right side.
Now here is where I differed from WingedFrog. I match drilled all 4 holes into F-1201E-L from outside the right side of the fuselage using a 12" drill bit. Two of the holes were drilled through the previously drilled holes in F-1201E-R. (Oil the drill bit where it passes through F-1201E-R) The other two holes were drilled though the big 3" battery box lightening hole. The rib flange is in the way so the two holes are not drilled exactly perpendicular to the surface, but it is good enough. It is better than pulling the engine.
It sounds complicated but is relatively easy. Below is a picture of drilling F-1201E-L through the battery box lightening hole.
Joe Gores

Too clever for me - I'm jealous ;-)

I used a right-angle drill on the port side drilling from right to left, I also installed rivets from right to left.

Cheers...Keith