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New fuel tank SB (13-12-19 released and effective December 19, 2013)

Great! I look forward to removing the fuel tank again! Just as I do to pink eye & cold toilet seats!

I sold my old Cessna and built the RV-12, confident that I would have a modern, cheap to fly, easy to maintain LSA. Becoming very disappointed. My plane weighs 771; paperwork, SBs & maintenance records weigh more!

Dynon is a pleasure to work with, Vans not so much, Rotax abysmal.

Jim
 
I don't have a problem with product improvements....

Are Service Bulletins mandatory Stateside?

Love the products from Vans, Rotax and Dynon... :p
 
Great! I look forward to removing the fuel tank again! Just as I do to pink eye & cold toilet seats!

I sold my old Cessna and built the RV-12, confident that I would have a modern, cheap to fly, easy to maintain LSA. Becoming very disappointed. My plane weighs 771; paperwork, SBs & maintenance records weigh more!

Dynon is a pleasure to work with, Vans not so much, Rotax abysmal.

Jim
Quick count on Van's aircraft.com showed 32 alerts, bulletins and notifications for the -8. I counted 28 for the -12. Sorry, guess I'm not seeing the catastrophe.
 
Oh well, it's a good opportunity to remove any`dangling chads' at the same time. Not that I'm particularly looking forward to opening the tank.
 
I think I may draw the line at doing this one. I am not planning on landing so hard that I splay the gear flat up against the wings, which seems to be needed to make this SECOND mod of the tank to be relevant. I am wondering if more hazard is introduced by yet another tank removal, opening, modifying, rivets, and then closing. (I have a split bulkhead and have never removed the tank, the first mod was done during construction.)

If you DO remove your tank again, add the anti-twist mod to the bottom tank connector. You can do the version that does not need more rivets, just held in place with silicone or proseal.
 
I think I may draw the line at doing this one. I am not planning on landing so hard that I splay the gear flat up against the wings, ...
That's just the point. The people who need this mod are those that don't plan on landing so hard as to twist the gear box and damage the tank.

However, an engine stoppage resulting in an off airport landing and a leaking fuel tank might just prompt you to wish you had done this service bulletin.
 
Another sign of a fuselage fuel tank design found wanting.

Maybe the anti- fuselage fuel tank crowd are worth listening to. Not a great feature of this design.

What "recent accident" are they referring to? The on-going stream of service related improvements that have, somehow, escaped reporting on this Forum, seem to indicate that 1) the service difficulty reporting system is working - quite well, and 2) there is a lot going on in the fleet that is flying under the radar for this army of operators and observers

Draining, removing, disassembling, rebuilding, re-sealing, retesting, reinstalling this tank is getting more than a little "old."

RV-12ers - Like the Seattle Mariners, a baseball team forever in the "rebuilding mode", -- they should be called the "rebuilders." Maybe the RV-12 too. Maybe RB-12.

Bob Bogash
N737G


Bob Bogash
N737G
 
Great! I look forward to removing the fuel tank again! Just as I do to pink eye & cold toilet seats!

I sold my old Cessna and built the RV-12, confident that I would have a modern, cheap to fly, easy to maintain LSA. Becoming very disappointed. My plane weighs 771; paperwork, SBs & maintenance records weigh more!

Dynon is a pleasure to work with, Vans not so much, Rotax abysmal.

Jim

Jim,

Dynon is a pleasure to work with. No doubts.

Vans are also, and had this been many other kit plane companies, there would likely be no Sb at all.

I think you are suffering the frustration, and i would too, but in the longer term I think you will soon appreciate the efforts Vans go to to produce a quality and safe product.
 
Wet wings, here I come

OK, That's it. I haven't built the stupid tank yet-been avoiding it as long as I can. Maybe I'll build a second set of wings instead. What do you say Oren Heatwole? Joe Dallas?
 
I also would like to know what "recent accident" means as stated in the SB. Was this SB prompted by the original accident in the upper midwest two to three years ago, another more recent mishap or additional testing (either analytical testing or actual destructive testing) as performed by Van's Engineering? Please?
 
I also would like to know what "recent accident" means as stated in the SB. Was this SB prompted by the original accident in the upper midwest two to three years ago, another more recent mishap or additional testing (either analytical testing or actual destructive testing) as performed by Van's Engineering? Please?

Thank you Marty, for replacing emotion with a logical question. I too would really like to hear the answer.

For those folks terribly upset by the need to apply this update, which is admittedly a PITA, you might want to consider this. You could have purchased a Cessna SLSA for twice the cost, and now own an orphaned product. Just saying.

Happy New Year to All.

BigJohn
 
David,

I'm sure you're right. And, of course, I will perform the SB. Part of my frustration is the feedback from non-aviation oriented friends & family, who say "Will that thing ever be finished? You're spending much more time working on it than you did your 53-year-old Cessna!". Plus the fact that I work alone in a (basically) unheated hangar in frigid upstate New York.

Also, I'm the one with the over-heated SV back-up battery and seem to be the only one (yet discovered!) with that problem. Hot lithium batteries scare the heck out of me.

I prefer flying to (re-) building, and am/was looking forward to flying to Sebring for the Expo January 16. Not looking so good now.

So yes, frustrated.

Jim
 
Talk about good timing

I just got my Airworthiness Certificate on Saturday morning and this SB comes out Monday AM! I'm OK until next condition inspection Dec '14. If it came out a few days earlier I ran the risk of the DAR not willing to approve without the SB being complied with.

Sometime later next year I'll likely do this SB, add the Moeller gauge and the new overflow drain (assume Van's will have a kit available by then) all in one shot. Chances are there will be one or two more fuel tank SBs by then:D
 
I just got my Airworthiness Certificate on Saturday morning and this SB comes out Monday AM!

Outstanding another RV12 soon to be flying in NJ PA area. :D

Brent Congrats on the Airworthiness Certificate and starting the new year with a flying plane. Let me know when the 1st flight is scheduled.
 
Fuel tank design

Maybe a lower profile tank with baffles inside that was made out of heavier gauge aluminium ( .040-.060 ) for extra strength/ rigidity that covered the entire baggage floor area and upon which baggage could be placed that would simultaneousy help keep direct sunlight from heating the fuel while adding strength to the airframe structure is the answer to several problems, vapor lock and structural integrity and also a little more fuel quantity!!!
 
Off the subject a little - but as long I must open the tank to do the S.B. I am going to install the mechanical gauge and new vent system. Per Van's all parts and documentation to install both the vent system and mechanical gauge are included in the two part numbers listed below.
12 Fuel Tank Mod $70.00
12 Fuel Tank Vent Mod $54.00
I have ordered both.

120622
Waiting on DAR
 
I also would like to know what "recent accident" means as stated in the SB. Was this SB prompted by the original accident in the upper midwest two to three years ago, another more recent mishap or additional testing (either analytical testing or actual destructive testing) as performed by Van's Engineering? Please?

All of the above Marty.
Re-evaluation was prompted by a more recent accident. Do an NTSB search using "RV" as the model and you should find it (If I remember right, the make/model info was inputted incorrectly).

A huge amount of resources were dedicated to this project, including, but not limited to, materials and part testing to destruction, along with a full blow dynamic test failing the gear out of an actual fuselage.

One thing I hope people will keep in mind is that there are an infinite number of overload scenarios. The failure mode is effected by impact angle of attack (relative to the ground), fwd velocity, etc. This all translates into some specific vector angle of impact.
Examples - the most horizontal vector would be clipping a brick wall with the main gear in level flight. The most vertical vector angle would be the airplane dropping straight down on to the gear (nearly impossible if the airplane was in flight before hitting the ground). The normal reality will be some where in between. In this accident, it appears the vector was much closer to horizontal than vertical.
In the end, it doesn't really matter. If a situation could occur, it needs to be designed for.
I am not going to go into any more detail than that, but I will say that because it is sometimes hard to design for loads and situations that are not fully known (Ask Boeing about that regarding their development of the 787), there is a high level of confidence (proven by physical testing) that this fuel tank mod. should have a broad margin of safety beyond the loads that have been physically tested and verified.
I understand peoples frustration, which is why everything that could be done to ease the pain, has been (designing a modification that would be as easy of a retrofit as possible, supplying the parts for free, allowing it to wait until a condition inspection is being preformed, etc.).
The RV-12 has definitely been evolving since its introduction. That has caused some frustrations along the way, but I believe most would agree that it is now reaching full maturity and stands at or near the top (depending on the criteria you are judging by) when ranked against all others in this class of airplane.
 
Thanks for the info, Scott - and to you and everyone else at Van's for continuing to improve the RV-12 for all possible encounters however they are caused....
 
A search shows that the plane mentioned, N817RV, has only one mention in this forum as a first flight. If anyone knows the gentleman, some pics of the damage would be enlightening, if he is willing to share.
 
All of the above Marty.
Re-evaluation was prompted by a more recent accident. <snip> I believe most would agree that it is now reaching full maturity and stands at or near the top (depending on the criteria you are judging by) when ranked against all others in this class of airplane.

Scott....
Thank-you for taking the time to answer the question in depth. I MUST agree. The RV-12 is AT THE TOP. It is evident that Van's Aircraft cares about their customers. There are too many examples in the industry where such is NOT the case. Please pass this compliment to Van and the engineering staff.
 
A couple of days ago, I was about to post a query along the lines that Marty did, but then decided not to in case it just resulted in more speculation and no useful information. Glad to see I was wrong. Thanks Scott, and also to Vans for providing this level of commitment to refining the design and supporting us builders.
 
RV-12 Nearing 300 Flying

Another thing to consider is that there are nearly 300 RV-12s reported to Van's as completed and flying. That number allows for quite a bit of 'flight experience' of the the RV-12 design and structure.

Accidents will happen no matter what. Van's has chosen to be pro active and has designed 'fixes' as the fleet gets more and more 'experienced'. I am thankful for that and also to all of you who have gone before me and helped Van's in developing a safer airplane.

In my opinion, all of you are part of the Van's team - and the team is doing an excellent job of improving this airplane!
 
All this tells me I made the correct decision in the RV-12! :)
Even though I bought a pre-built tank to avoid the tank stuff :D I need to do the other SB/mod anyway.

Love the updates wouldn't miss it for anything! Keep up the great work!

Bob
 
When the first tank SB came out, I already had the moeller gauge access hole installed. So I used it as an access hole to vacuum out the drill swarf from the modification and thus was able to accomplish that mod endoscopically without removing the front cover plate, resealing, etc. etc.

When some of you get the new SB parts, if you have the same moeller hole would you report on the possibility of doing this one the same way - without opening the front cover?
 
I know we've talked about it before, but this latest mod seems like an opportunity for Vans to consider a wing tank option for those of us who don't care about the wing removal issue.
 
I'm not saying it can't be done (already has been apparently), but it goes against the entire design philosophy of the RV-12 and will not likely ever come from Van's.

I am confused regarding the idea that so many seem to be thinking that putting the fuel in the wings would automatically provide a big jump in safety.
If you do a little research on accidents involving RV's and many other designs with fuel in the wings, I think you will find that is not the case. In fact, I think that after there is enough service history available, I think the RV-12 will prove to be no worse for post crash fire than other aircraft, but probably even better (but we will have to wait and see).
 
I wonder if a bladder, in the tank, would be a safety measure?
I guess weight and less volume are the trade off.
John
 
I wonder if a bladder, in the tank, would be a safety measure?
I guess weight and less volume are the trade off.
John

The baffles in the tank make a bladder next to impossible. Correct me if you think there is an alternative.
 
Scott, I agree that a busted fuel tank is a serious issue no matter where it is. My aversion to the cockpit location stems from concerns that any leak or breach is a fire hazard with no barrier between the occupants and the gas. At least you would have a few seconds protection with the fire outside the canopy, and that might mean the difference in escaping a life and death situation. I once did a very poor roll in a home built and lost the gas cap. Gas poured over the canopy for about two seconds and a little came through the canopy vents. The gas tank was just forward of the instrument panel. Fortunately nothing ignited. The fuel running over the canopy was bad, but the fuel in the cockpit was the worst.
 
How about if Vans sends me a new fuel tank with the mods done? Then I will remove my (flawed) tank, send it to Vans, and install the new one! Vans can keep the old one as their very own, and do with it as they please.

JRo
 
RV12 fuel tank

I am just getting started on my finishing kit. Looking at all of the pain and suffering that goes into the fuel tank is it worth having VANS build it for $450?
 
I am just getting started on my finishing kit. Looking at all of the pain and suffering that goes into the fuel tank is it worth having VANS build it for $450?

If you can build an aircraft, you can build a fuel tank. The mods just add to the challenge. :D
 
Regarding the accident aircraft N817RV, the first flight was 9/26/13 and the accident occurred 9/29/13 -- that's sad.
 
I am just getting started on my finishing kit. Looking at all of the pain and suffering that goes into the fuel tank is it worth having VANS build it for $450?

Ben, it's not hard, just a bit messy. Actually, if you factor out the Pro Seal, it's terribly easy. Save your money!
 
Fuel Tank Design

I'm with Bob Bogash, the fuel tank design is stupid period!
I'm sure it, along with removable wings has cost Van's a lot of sales.
 
I am just getting started on my finishing kit. Looking at all of the pain and suffering that goes into the fuel tank is it worth having VANS build it for $450?

As one friend told me while I was mulling the same question, "if you build it you will know what flaws are built into it, if you don't, you won't"... and that was enough to convince me.
 
After thinking about the accident aircraft that precipitated this latest mod to the fuel tank attachment, I'm guessing that the aircraft in question had both the frangible bolt and the gear leg mod done since the first flight was 9-26-13. If that was the case, then I'd like to know if the the gear failed and the fuel tank mount failed before the frangible bolts let go, thus the reason for the beefed up mount?????
 
I have not built an RV-12, but did build most of a Sonex. The Sonex uses a rotationally-molded polyethylene fuel tank, all once piece, mounted behind the instrument panel. I don't think the Sonex tank is mounted in an ideal location, but in accidents involving the Sonex, the only ones I am aware of involving tank rupture and resulting post-crash fires are those where the entire aircraft is essentially destroyed on impact.

It seems if Van's were to use a similar polyethylene tank on some type of rubber-isolated "floating" mounts in the current location, it might be less prone to problems on impact. If the mounts are designed to shear before torque on the tank could split it, the tank would just "float" in the baggage bay without spilling fuel, as long as the filler neck has adequate flex to accommodate the movement.

Just a thought...I like the RV-12 a lot, but some builders do seem to dislike the current tank setup.
 
After thinking about the accident aircraft that precipitated this latest mod to the fuel tank attachment, I'm guessing that the aircraft in question had both the frangible bolt and the gear leg mod done since the first flight was 9-26-13. If that was the case, then I'd like to know if the the gear failed and the fuel tank mount failed before the frangible bolts let go, thus the reason for the beefed up mount?????

That is exactly the question I have on all this. I was going to ask but you nailed it for me. Us early builders (2009) already added beefed up mounts and frangible bolts to the fuel tank. (SERVICE BULLETIN 11-12-14). Did that not do the job in this accident??

Brad Stiefvater
 
I'm with Bob Bogash, the fuel tank design is stupid period!
I'm sure it, along with removable wings has cost Van's a lot of sales.

Wow, this discussion has gone the gamet... Just a my 2 cents=The thought of having fuel around me (anywhere) in the event of a less than gentle landing is of concern; however, the machine won't fly without the stuff. There is considerable more protection having the tank internal (and well anchored) than in the thin skin of wing tanks. Have seen a flaming wreck where there wasn't any chance of getting out. Just saying I'd rather have to make the mods Van's has spent time and resources on attempting to build a "Total Performane" airplane for "older" guys.
 
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