RV-12 Wing Tanks

[joedallas]

RV 12 Wing Tanks
The RV12 is a great little airplane and removing the wings is a nice feature for some.
I believe that the number of people removing the wings more than once or twice a year is less 20%.

I also believe that if a wing tank option would be available from vans that they would sell more than 50 % with wing tanks.

There is no question that Vans could make a wing tank option better than what I came up with.

I have been working on this for over two years and have changed my mind more than a few times.

This is what I think is my final design. ( this is not for anyone to try )

http://joesrv12.com/Builder%20Log/al_06_04.htm

If anyone can see anything I have missed your comments are welcome

Thanks Joe Dallas

[DonFromTX]

Looking good Joe! I of course went with the tubular wing tanks, not necessarily the BEST solution, but regardless it is ONE solution. I just did not feel I had the expertise or time to design and build tanks like yours.

[bruceflys]

Joe,

I do not have the expertise to comment on your design, but I recognize excellent craftsmanship when I see it!

[Snowflake]

Just curious: Is there a reason you chose to go with a discrete tank mounted within the wing structure, rather than making a wet wing tank like the other RV's have? The quality of your work in those photos suggests to me that you could probably have done that with equal difficulty. Just wondering if there is a CG or other structural consideration.

[joedallas]

Good Question

My first plan was to do that however after looking at the way Vans built the
wings with the spars in a scissor configuration and the thin skins, I felt it was
a little more than my ability could handle.

Also I wanted the fuel behind the spars to help with the W&B problem that I will have with using a Jabiru 3310 ( I Hope ).

With The fuel at the back of the spars the W&B will be almost the same with the tanks full or empty.

Like I said in my post There is no question that Vans could make a wing tank option better than what I came up with.

The RV12 Wing was not designed with Fuel Tanks in mind as all the other RV's were ( Vans could fix that ) it's more than I can handle.

Thanks for your question

Joe Dallas

Originally Posted by Snowflake

Just curious: Is there a reason you chose to go with a discrete tank mounted within the wing structure, rather than making a wet wing tank like the other RV's have? The quality of your work in those photos suggests to me that you could probably have done that with equal difficulty. Just wondering if there is a CG or other structural consideration.

[rjtjrt]

Fuel in the wing would be very attractive for me as a buyer.
It is a project Van's could do much more easily and faster than most other projects they may contemplate.
It would significantly enhance the appeal of SLSA RV-12 to non builder buyers.
There is a lot of likely return for the invested development buck, probably much more than any other project they may contemplate.

[joedallas]

I totally agree
This is the reason I built the wings last, I was hoping - waiting that Vans would see the light.
If Vans offered a wing kit with Fuel Tanks, I think some builders would sell their wings and build the new wings.
The RV12 is a great it would be better if it had wing tanks

MY View

Joe Dallas

Originally Posted by rjtjrt

Fuel in the wing would be very attractive for me as a buyer.
It is a project Van's could do much more easily and faster than most other projects they may contemplate.
It would significantly enjance the appeal of SLSA RV-12 to non builder buyers.
There is a lot of likely return for the invested development buck, probably much more than any other project they may contemplate.

[rgmwa]

Originally Posted by joedallas

I totally agree
This is the reason I built the wings last, I was hoping - waiting that Vans would see the light.
If Vans offered a wing kit with Fuel Tanks, I think some builders would sell their wings and build the new wings.
The RV12 is a great it would be better if it had wing tanks

MY View

Joe Dallas

Joe, FWIW (probably not much) my view is that the RV-12 would be better if it had a bigger fuel tank rather than wing tanks per se. I know that like all aircraft the RV-12 is a compromise, and I'm very happy with mine. I don't particularly care whether the tank is in the fuselage or the wings, but having recently completed a 6,500 km trip, the 20 gallon tank is a limitation for long trips in a country as big as ours. It's manageable, but a 30 gal tank would be much better. What I don't really understand is why go to the trouble of designing wing tanks if they don't carry a lot more more fuel than the fuselage tank? The tubular tanks that fit in the wing rib cutouts seem to me to be even worse due to their adverse weight distribution as well as their limited capacity. As far as the design of your wing tanks goes, I can't add anything to what has previously been said about the loss of stiffness and strength in the affected wing ribs, which I agree with. Your workmanship is not in question, and I admire your determination to go your own way, but what advantage are you gaining with these wing tanks?

[todehnal]

I also have felt that 20 gal of fuel was a bit on the short side for our Rotax powered birds. Not that I would ever consider flying a longer leg than 20 gals would support, but the lack of the availability of a lead free fuel while traveling is an issue. I would prefer not to deal with issues that using 100LL creates. However, as soon as 100LL is replaced with a lead free aviation fuel, I think that our 20 gal tanks will be more than adequate, and I personally can't wait!!

We are still probably about 2 years away from seeing the new fuel at our local FBOs............Tom

[Mel]

Please remember, Guys, the primary purpose of light sport aircraft is for the weekend flyer. They are not specifically designed for long cross countries.
Everything is a compromise.