Geico266
Well Known Member
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Van's Air Force
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RV-12: Fuel Tank Information / Modification
- Thread starter Geico266
- Start date
DonFromTX
Well Known Member
I doubt it. I smeared a large amount on the rivet from the inside the tank, I doubt that it would keep it from leaking though.
vernhendershott
Well Known Member
Hi,
I do not think that the tank sealant we are using would work as it gets to hard and will crack when disturbed.
I think you may be on the right track though, I do not know what it was but in WW2 they had sealer that would fill in bullet holes in tanks that might fill in for the pulled rivets that pulled through the tank.
I think the first step will be a tank end made from thicker material and perhaps a backing plate as it looked like that rivets did their job and the tank skin failed if the rivets held and the tank end just deformed we would have less chance of a problem.
Best regards,
Vern
MartySantic
Well Known Member
Has anyone received any recent assurances from Van's that they are still pursuing a solution to the fuel tank breach issue. As I have mentioned previously, a solution may take a bit of time, but, would sure like to know if a solution is still being pursued.
Or is the accident considered to be an anomaly and the design will remain as-is?
If calling Van's for another issue ask. Also, might be time for the rest of us to call and ask about this issue.
Or is the accident considered to be an anomaly and the design will remain as-is?
If calling Van's for another issue ask. Also, might be time for the rest of us to call and ask about this issue.
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DonFromTX
Well Known Member
I wonder if we are seeing the downside of ELSA types. If they change it they open themselves up to all those done before the change essentially admitting it was a faulty design. If they do nothing, that admission is not there. I can only guess at how much paperwork would be required to change the SLSA design criteria.
Bob Kuykendall
Well Known Member
I was briefed on a solution while I was in the area working on part of my glider project two weeks ago. But they swore me to secrecy, so I can't tell you about it to any degree of specificity. Rest assured that they are aware of the issue and working diligently towards a practical solution.
Thanks, Bob K.
MartySantic
Well Known Member
Thanks Bob!! Was hoping for THAT answer!! I received another e-mail today indicating Van's will NOT pursue a solution. Time will tell.
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Bob Kuykendall
Well Known Member
Well, if you received the email directly from Vans, that probably trumps my two-week-old info. But I still think they will come up with something good.
MartySantic
Well Known Member
No, the e-mail was not from Van's, so that info may NOT be correct. Hoping not.
E. D. Eliot
Well Known Member
Improvements
My opinion here - I have to disagree that if Van's 'improves' their product, that it an admission of faulty design. I have built a number of things (no RV-12 yet though) and I haven't yet built anything that couldn't be improved. Sometimes, money or time are the factors and if I had spent a little more time or money then the product would have been better - but most of the time, the 'experience' of using the product leads to 'improvements'. In my opinion, that is what we have here and Van's will fit it asap.
Personally, I would like to see a completely new fuel tank - spun glass/epoxy - maybe 24/25 gallons. Just my humble opinions.
My opinion here - I have to disagree that if Van's 'improves' their product, that it an admission of faulty design. I have built a number of things (no RV-12 yet though) and I haven't yet built anything that couldn't be improved. Sometimes, money or time are the factors and if I had spent a little more time or money then the product would have been better - but most of the time, the 'experience' of using the product leads to 'improvements'. In my opinion, that is what we have here and Van's will fit it asap.
Personally, I would like to see a completely new fuel tank - spun glass/epoxy - maybe 24/25 gallons. Just my humble opinions.
su27sushka
I'm New Here
Tank inside a shell
I don't know if anybody already expressed this or similar idea, but here is my 2 cents. Would it be possible perhaps to create an aluminum shell, say 1 inch larger than the tank in each direction, and attach this shell firmly and exactly as the current tank is attached to the frame? Then put some kind of isolation/rubber/foam/soft plastic, or whatever else exists, appropriate material inside the shell, and then put the tank in it. This material should have even pressure around the tank during normal use, and hold the tank in place. During the crash the outer shell will be damaged/opened, but the actual tank inside will be intact. I guess this material should be much firmer underneath the tank, since there will be constant down pressure during normal use. This is just a general idea, I didn't think much about the details though...
I don't know if anybody already expressed this or similar idea, but here is my 2 cents. Would it be possible perhaps to create an aluminum shell, say 1 inch larger than the tank in each direction, and attach this shell firmly and exactly as the current tank is attached to the frame? Then put some kind of isolation/rubber/foam/soft plastic, or whatever else exists, appropriate material inside the shell, and then put the tank in it. This material should have even pressure around the tank during normal use, and hold the tank in place. During the crash the outer shell will be damaged/opened, but the actual tank inside will be intact. I guess this material should be much firmer underneath the tank, since there will be constant down pressure during normal use. This is just a general idea, I didn't think much about the details though...
tim walter
Well Known Member
racing fuel cell
That's essentially what racing fuel cells are.
I think it would be a great idea to adapt one for the 12.
That's essentially what racing fuel cells are.
I think it would be a great idea to adapt one for the 12.
Racing fuel cell
As I posted previously in this thread, Fuel Safe, ATL , etc. have ready made bladder type fuel cells available. Can someone please post the dimensions of the RV-12 fuel tank per plans. I would bet that one is available that could be used "off the shelf".
As I posted previously in this thread, Fuel Safe, ATL , etc. have ready made bladder type fuel cells available. Can someone please post the dimensions of the RV-12 fuel tank per plans. I would bet that one is available that could be used "off the shelf".
LittleJoeA
Well Known Member
Hi all,
I just received the finishing kit and was dry fitting the fuel tank. Just a random comment, but for something that is supposed to contain a flammable liquid it sure has a lot of holes.
I just received the finishing kit and was dry fitting the fuel tank. Just a random comment, but for something that is supposed to contain a flammable liquid it sure has a lot of holes.
Custom fuel cell bladders by Fuel Safe are not that expensive, relative to 60,000 to 65,000 dollars for a n RV-12 complete kit, considering the safety margin they provide. Fuel Safe will build to your specifications. Any shape or size. I have had them build a number of them for long travel sand rails. They do very good work.
Overturning tank restraint
I modified my tank per Van's repair kit and added this change to the ELT antenna bracket to contain the tank in case a similar event occurs and the plane flips over too. The material is 0.150" thick aluminum and the net weight increase was 1.8 oz. I extended the length of the bracket one inch in each of the fore and aft directions. A piece of rubber separates the top edge of the tank from the bracket. My original intent was to make the thicker piece a doubler so I opened up the center. I then felt that the thicker piece was sufficient by itself and added a thinner cross piece to hold the antenna.
I modified my tank per Van's repair kit and added this change to the ELT antenna bracket to contain the tank in case a similar event occurs and the plane flips over too. The material is 0.150" thick aluminum and the net weight increase was 1.8 oz. I extended the length of the bracket one inch in each of the fore and aft directions. A piece of rubber separates the top edge of the tank from the bracket. My original intent was to make the thicker piece a doubler so I opened up the center. I then felt that the thicker piece was sufficient by itself and added a thinner cross piece to hold the antenna.
If the main landing gear gets forced aft in a crash, the heavy center channel rotates. That causes the baggage floor to be raised about 4 inches. The fuel tank will also be raised 4 inches. This happened to the RV-12 whose tank ruptured. Any obstruction above the tank that prevents the tank from being raised could damage the tank.
John Bender's nylon strap restraint allows the baggage floor and fuel tank to move in unison.
Joe Gores
John Bender's nylon strap restraint allows the baggage floor and fuel tank to move in unison.
Joe Gores
JerryG150
Well Known Member
$ OUCH!
Surprise, surprise ... my first annual inspection (plus 100 hour Rotax Inspection) takes 5 1/2 weeks and still counting and will cost about $3,000.00. Approximately 1/2 of the expense was Service Bulletin #11-12-14. As you know, this bulletin was issued December 14, 2011 in response to an exceptionally, unfortunate hard landing of an RV-12, when a breach of the RV-12's 20 gallon fuel tank occured ... but having built my plane as an ELSA, I believed I did not have to comply.
The FAA refered me to document AC65-32 to back up my case for non-compliance. Lockwood Aviation, my FBO performing the annual inspection disagree with their interpretation and insisted the Special Bulletin had to be performed... Perhaps, if I had taken the ELSA Repairman's Course ... and was performing the annual myself ... I could have decided to practice my landings instead of upgrading my fuel tank.
But many months ago, I decided my building days were behind me ... and only piloting days were in my future. I'm now realizing the only way to save money in aviation is "once you're a builder, you're a builder for life" ... not my intentions.
In all my years of association with Lockwood Aviation, they have always been 100% professional and fair on in the care and feeding of my Rotax 912ULS and repair of my RV-12 as well as my Sport Pilot Certification. So I ordered the $20.00 gas tank repair kit which arrived about a week later. Upon the arrival of the repair kit and the susequent removal of my perfectly good non-upgraded gas tank ... it was determined it would cost more to perform the upgrade than to order a new, completely assembled gas tank from Van's Aircraft The new fully assembled tank cost $755.00 plus about $100.00 for shipping and took another week of waiting for the new tank to arrive ... It just arrived this morning.
I won't share my personal feeling about SB #11-12-14 ... I'm the furthest thing from an aeronautical engineer ... I just have my common sense to guide me ... I do know my cross-country to AirVenture 2012 will have to be put on hold for another year since my plane won't be done till next week sometime.
Disappointed and broke in Sarasota, FL ...
Surprise, surprise ... my first annual inspection (plus 100 hour Rotax Inspection) takes 5 1/2 weeks and still counting and will cost about $3,000.00. Approximately 1/2 of the expense was Service Bulletin #11-12-14. As you know, this bulletin was issued December 14, 2011 in response to an exceptionally, unfortunate hard landing of an RV-12, when a breach of the RV-12's 20 gallon fuel tank occured ... but having built my plane as an ELSA, I believed I did not have to comply.
The FAA refered me to document AC65-32 to back up my case for non-compliance. Lockwood Aviation, my FBO performing the annual inspection disagree with their interpretation and insisted the Special Bulletin had to be performed... Perhaps, if I had taken the ELSA Repairman's Course ... and was performing the annual myself ... I could have decided to practice my landings instead of upgrading my fuel tank.
But many months ago, I decided my building days were behind me ... and only piloting days were in my future. I'm now realizing the only way to save money in aviation is "once you're a builder, you're a builder for life" ... not my intentions.
In all my years of association with Lockwood Aviation, they have always been 100% professional and fair on in the care and feeding of my Rotax 912ULS and repair of my RV-12 as well as my Sport Pilot Certification. So I ordered the $20.00 gas tank repair kit which arrived about a week later. Upon the arrival of the repair kit and the susequent removal of my perfectly good non-upgraded gas tank ... it was determined it would cost more to perform the upgrade than to order a new, completely assembled gas tank from Van's Aircraft The new fully assembled tank cost $755.00 plus about $100.00 for shipping and took another week of waiting for the new tank to arrive ... It just arrived this morning.
I won't share my personal feeling about SB #11-12-14 ... I'm the furthest thing from an aeronautical engineer ... I just have my common sense to guide me ... I do know my cross-country to AirVenture 2012 will have to be put on hold for another year since my plane won't be done till next week sometime.
Disappointed and broke in Sarasota, FL ...
Not saying what is "prudent" but service bulletins are NOT mandatory on experimental, (or any other part 91 aircraft, for that matter).
Now the person performing the inspection can refuse to sign it off due to "safety of flight" issues, but SBs are NOT mandatory!
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KALEWIS
Well Known Member
We did the fuel tank upgrade on our pre-built tank a few months ago, before we installed it. Took about an hour overall...very straightforward. Although SB'S are not mandatory for exp....why not do them?? If you can build the RV-12, the tank upgrade should be a non issue. Surprised to hear that a 20$ upgrade kit from Van's ended up in the decision to buy a brand new tank 
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Fuel Tank Cap
I first finished my tank about 2 years ago and put construction on hold between then and now. I completed the tank modification a few days ago and allowed the proseal to cure. Yesterday I aimed to test the tank but the cap will not hold a seal when I try to inflate the balloon. In fact, when I pump air into the tank, I can hear it escaping around the cap and the cap has moved due to the pressure.
I cannot find the information that was provided to adjust the cap. (Can someone capture these directions for me?) There doesn't seem to be any latitude to adjust the cap further. Any suggestions?
The fuel neck seems to be fine and nothing has been done to it since first test 2 years ago.
Scott Lane
#120043
I first finished my tank about 2 years ago and put construction on hold between then and now. I completed the tank modification a few days ago and allowed the proseal to cure. Yesterday I aimed to test the tank but the cap will not hold a seal when I try to inflate the balloon. In fact, when I pump air into the tank, I can hear it escaping around the cap and the cap has moved due to the pressure.
I cannot find the information that was provided to adjust the cap. (Can someone capture these directions for me?) There doesn't seem to be any latitude to adjust the cap further. Any suggestions?
The fuel neck seems to be fine and nothing has been done to it since first test 2 years ago.
Scott Lane
#120043
WingedFrog
Well Known Member
When you made the test 2 years ago, your cap was sealed. After the test you were instructed to drill a hole in the cap to avoid putting the tank in depression as the fuel drains. You need to plug this hole: disassemble the cap and put electric tape, it should work.
good luck
Addendum: the hole is visible from under the cap, you don't need to disassemble the cap to plug it.
good luck
Addendum: the hole is visible from under the cap, you don't need to disassemble the cap to plug it.
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Geico266
Well Known Member
MartySantic
Well Known Member
Scott,
Buy or find a short (4-5") piece of 1 1/2" PVC from Lowes or Home Depot and a PVC cap. Cement the cap and attach it to the top of the tank with the supplied piece of tank to neck hose and a couple of worm drive clamps.
(I think it was 1 1/2", might have been 2". Is in the hangar!!)
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loose fuel cap
Thanks for the suggestions. I know one will work.
My other concern is the looseness of the cap. I can rotate it now even when it is clamped down on the neck. I've tightened the nut, untightened it, tightened it again, all with no positive result. Do the cap adjustment procedures address this? I've not been able to find mine yet.
Scott Lane
Thanks for the suggestions. I know one will work.
My other concern is the looseness of the cap. I can rotate it now even when it is clamped down on the neck. I've tightened the nut, untightened it, tightened it again, all with no positive result. Do the cap adjustment procedures address this? I've not been able to find mine yet.
Scott Lane
