|
-
POSTING RULES

-
Donate yearly (please).
-
Advertise in here!
-
Today's Posts
|
Insert Pics
|

01-04-2014, 10:52 PM
|
|
|
|
Join Date: Aug 2012
Location: Panama City, FL
Posts: 132
|
|
Started on modifying my fuel tank today for the vent and reinforcement mods. Took about 1.5 hours to prep (removing the access panel, designated rivets, and scraping cured proseal). Working the inside corners is a PIA, lots of flashlight and mirror time to see what is going on.
For those who want more capacity and safety may I suggest you look at installing an Aero Tec Labs fuel cell. They have a nice 29 gallon aluminum tank with a foam bladder that should take care of your crash safety concerns. Its only $2,000 and 6 inches wider than the stock RV-12 fuel tank.
http://www.summitracing.com/parts/abt-suba129/overview/
Summit Racing also has several 20 gal welded aluminum fuel cell tanks with foam that are about the same dimensions as the RV-12 tank for $300, but you get to do all the engineering to mount it and plumb the fuel system.
Lastly, for someone who really wants to lead the way, have ATL make a custom fit foam fuel cell bladder for the stock RV-12 tank (less the baffles). You will most likely lose a couple of gallons of capacity, but I doubt you would ever have to worry about the tank bursting/leaking in a crash event. Cost should not be more than several thousand dollars. Here is the link to the designers worksheet to get you started:
http://www.atlinc.com/pdfs/dews.pdf
For reference the RV-12 tank is approximately 24"L x 18"W x 12"H (and not rectangular by any means). Perhaps someone will donate a tank to the cause for ATL to evaluate.
John Salak
RV-12 #120116 (EAB)
|

01-05-2014, 08:14 AM
|
 |
|
|
Join Date: Oct 2010
Location: La Feria Texas
Posts: 3,822
|
|
Now THAT is an inviting prospect, I like it plus the additional 9 gallons is a nice thing too. Does anyone familiar with this technology know how well it would work in regards to baffling and return fuel lines?
Quote:
Originally Posted by 12vaitor
For those who want more capacity and safety may I suggest you look at installing an Aero Tec Labs fuel cell. They have a nice 29 gallon aluminum tank with a foam bladder that should take care of your crash safety concerns. Its only $2,000 and 6 inches wider than the stock RV-12 fuel tank.
http://www.summitracing.com/parts/abt-suba129/overview/
RV-12 #120116 (EAB)
|
|

01-05-2014, 08:51 AM
|
 |
|
|
Join Date: Aug 2010
Location: Marshall TX (KASL)
Posts: 1,783
|
|
You would HAVE to remove such a larger, wider tank every annual to look under it. A split rear bulkhead (and starboard aft floor plate) would not help, you have to look into the channel with the fuel pump. I've seen a flat, removable 5 gallon poly tank that sits behind the pilot seat, equipped with a pump to transfer that fuel to the main tank in flight.
Scott, it was nice to hear that ideas like that were considered, even if not chosen. Thanks.
|

01-06-2014, 08:52 AM
|
 |
|
|
Join Date: Dec 2007
Location: SC & CA
Posts: 907
|
|
Checked back with Van's today about a replacement fuel tank. They are available for $755 and are on a six week back order.
__________________
Tom Valenzia
RV8 (Sold)
RV12 Jabiru 2200 Powered (Sold)
Dues contributor since 2007
Learn from the mistakes of others. You won't live long enough to make all of them yourself...Anonymous
|

01-06-2014, 05:31 PM
|
|
|
|
Join Date: Jan 2006
Posts: 905
|
|
Tank work
In response to Scott's etimated 5.5 hrs being done in Van's work environment, and with the professionals involved I have no problem with the estimate. I suspect tho that consideration should be given to the fact that 90% of us bldr/flyers out here in the other world likely require about 5 times the mod estimate usually forecast. This fact is what probably produces all the "oh s. " comments on most mods even tho we know they are best for us to make the airplane safe(r).
I will do the mod, or buy a new tank from Vans when the time comes. However, I have to wonder if there isn't a better way to secure the tank without attaching it to the very part of the structure which wants to rip the front (or possibly the rear) panel off when energized.
Dick Seiders 120093
|

01-06-2014, 06:10 PM
|
 |
|
|
Join Date: Apr 2008
Location: Davenport, IA
Posts: 1,390
|
|
One of the first solutions, after we heard of the first accident in the upper midwest was to install pins to secure the tank as opposed to bolts. The pins (headless slotted bolts) would pull thru the center section if the center section rotated due to a VERY hard landing. I am also, very interested what the downside is of this potential solution as opposed to pulling the tank AGAIN! Would appreciate ALL comments.
|

01-06-2014, 07:24 PM
|
 |
|
|
Join Date: Aug 2010
Location: Marshall TX (KASL)
Posts: 1,783
|
|
That seems to me to be the ideal solution. So the nutplate is kept and the pin screwed into it. How "tight" in the existing bolthole is this non- threaded part of the new pin? Since the member rotates rather than simply translates fore-aft, there may be some "catching" of the pin in the hold. (What is the radius of the rotation, which would determine how much potential there is for catching.) The longer the pin the more potential for this. Grease? A pin made of material that might bend a little bit but still carry the weight load? I'd sure rather pay -say - $50 for some engineered pins than install more doublers...
|

01-06-2014, 07:44 PM
|
 |
|
|
Join Date: Jul 2005
Location: Hubbard Oregon
Posts: 9,035
|
|
Quote:
Originally Posted by dick seiders
In response to Scott's etimated 5.5 hrs being done in Van's work environment, and with the professionals involved I have no problem with the estimate. I suspect tho that consideration should be given to the fact that 90% of us bldr/flyers out here in the other world likely require about 5 times the mod estimate usually forecast. This fact is what probably produces all the "oh s. " comments on most mods even tho we know they are best for us to make the airplane safe(r).
I will do the mod, or buy a new tank from Vans when the time comes. However, I have to wonder if there isn't a better way to secure the tank without attaching it to the very part of the structure which wants to rip the front (or possibly the rear) panel off when energized.
Dick Seiders 120093
|
Quote:
Originally Posted by MartySantic
One of the first solutions, after we heard of the first accident in the upper midwest was to install pins to secure the tank as opposed to bolts. The pins (headless slotted bolts) would pull thru the center section if the center section rotated due to a VERY hard landing. I am also, very interested what the downside is of this potential solution as opposed to pulling the tank AGAIN! Would appreciate ALL comments.
|
Sorry Dick, I might not have been completely clear. All S.B.'s are issued in the context of the continued airworthiness system for the S-LSA RV-12's (E-LSA's are piggy backed on that). So, the 5.5 hour estimate is what Van's will pay under warranty to an LSA service center to complete the work (that is what I meant by professionals doing the work). The ASTM that regulates the continued airworthiness process (yes, there is even one for that) requires the inclusion of the time required to complete.
Seriously, it shouldn't take anyone that had (or developed) the skills to succeed in building an RV-12 (I know that even as refined as the RV-12 kit is, it is still a big project) any more than about 8 hours to do (on a tank that has already been removed).
Using pins to hold the tank...
It might work just fine in some circumstances but probably not all.
There are failure conditions (remember I posted earlier that there is an infinite # of load scenarios) where the channel can begin to rotate and be bending the bolt (or pin if that was used), causing it to jamb in the 1/4" deep hole of the channel. This can cause a lot of friction and begin to breach the seal of the tank.
The new version bolts, along with adding the small doublers, are made so that they can take all of the required loads for the tank, but still pop the head and pull out of the channel even if they begin to deform.
So I guess the answer is that the recently released mod. has been physically tested and confirmed to work. If you choose to do anything else that seems like it should work... still might not. There are so many different variables.
Once again, I am sorry for the trouble this causes everyone, but it really isn't that bad to do, and once completed, I am highly confident you wont be messing with anything related to this problem again.
__________________
Opinions, information and comments are my own unless stated otherwise. They do not necessarily represent the direction/opinions of my employer.
Scott McDaniels
Van's Aircraft Engineering Prototype Shop Manager
Hubbard, Oregon
RV-6A (aka "Junkyard Special ")
|

01-06-2014, 07:47 PM
|
 |
|
|
Join Date: Jul 2005
Location: Hubbard Oregon
Posts: 9,035
|
|
Quote:
Originally Posted by Bill_H
That seems to me to be the ideal solution. So the nutplate is kept and the pin screwed into it. How "tight" in the existing bolthole is this non- threaded part of the new pin? Since the member rotates rather than simply translates fore-aft, there may be some "catching" of the pin in the hold. (What is the radius of the rotation, which would determine how much potential there is for catching.) The longer the pin the more potential for this. Grease? A pin made of material that might bend a little bit but still carry the weight load? I'd sure rather pay -say - $50 for some engineered pins than install more doublers...
|
Bill posted while I was typing my post. Good job Bill. You are pondering the right types of question and it is very relevant in this installation (see previous post).
__________________
Opinions, information and comments are my own unless stated otherwise. They do not necessarily represent the direction/opinions of my employer.
Scott McDaniels
Van's Aircraft Engineering Prototype Shop Manager
Hubbard, Oregon
RV-6A (aka "Junkyard Special ")
|

01-10-2014, 03:13 PM
|
|
|
|
Join Date: Nov 2007
Location: Jesup, Iowa
Posts: 1,657
|
|
Working on latest Tank SB & Vent
I am doing both tank mod and vent. I'd say 10 hours serious work NOT including removal and reinstall is about right. Not a fun job, messy as usual. Glad I did it. Waiting for stuff to dry now. By the way, one 3 1/2 Oz. of fuel tank sealant is plenty.
__________________
John Bender
Flying RV-12 - Serial #120036
Paid in May ( 5-2020 )
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
All times are GMT -6. The time now is 01:58 AM.
|