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Testing the Water; RV-12 Aux Tank

Jetguy

Well Known Member
This thread is about testing the waters about the Market for a Removable Aux tank for the RV12. I am currently testing such a tank. Some points about the tank.
Remove it in 1 minute
Weight of all components including empty tank 9lbs
Labor to install all needed components 1 hour
Tank quantity is 6 gallons
Tank transfers its gas into main tank, time to transfer all 6 gallons is approx 9 mins
Inline fuel filter with clear case that can be seen from pilot seat, to verify when fuel transfer is complete
This will add 1 hour of extra flying time.
Fuel cost savings by not having to buy fuel when increasing flying time out and back for fly-ins which are farther away or if you live in remote regions of the US
Can actually remove Aux Tank to take down to local auto gas station to get gas to transfer back into main tank at hanger or on a X-Country
Aux tank is Fuel proof to ethanol
Aux tank is strapped down when installed
Kits contains hardware, fuel pump, wiring, tank, filter, fuel line, and directions for installing
So would this be something RV12 flyers would be interested in?

Thanks John
RV12 N1212K:)
 
What sort of cost and install are we talking about? What is it going to do to my CG?

The ones that I would be intrigued by would be wing-mounted tanks inside the holes in the ribs. If you could keep it CG neutral, it would be a fantastic way to do it I'd suspect.
 
YEAH

Let's see some details I like you idea a lot. That extra tank could add more versatility to the 12. Obviously less weight than the 'baggage'. Please keep us apprised of your progress.:cool:
 
I like the idea, but would be even more interested in a larger tank (say 20 gal.) that is custom sized for the -12 to easily go in and out for extended solo flight.
 
I like the idea, but would be even more interested in a larger tank (say 20 gal.) that is custom sized for the -12 to easily go in and out for extended solo flight.

If you are talking about an additional 20 gal in the baggage compartment, that would not be possible. Even the tank John is talking about pretty much consumes all of the remaining baggage compartment weight capacity (see Scott's post). An additional 20 gal of fuel would far exceed the weight capacity of the baggage compartment (20gal X 6lbs/gal=120lbs plus weight of tank- baggage compartment can hold only 50 lbs so it would be at least 70 pounds over).

Jeff
 
I have one now!

I have a pair of aux fuel tanks. Sometimes, when I travel, I load them up empty. When I need gas, I borrow the airport car and go fill them, fuel plane, air them out, and resume flight. My plane is almost a 100LL virgin. On cross countries, I fly 2.5 hrs untill I have 8 gallons left, then refuel 10 gallons from aux tanks. At KOSH, I fueled in the ultralight area with 91.

Best of all, they only cost $7 each, so I give them away sometimes. They are free with the mogas-> avgas price difference.

Whats the difference between my lawnmower and my RV-12? My RV-12 takes 2 red gas cans and my lawnmower only needs one!

87 hrs, happy, N120R John
 
This is my preferred way to get auto fuel :)

SVtrip8.jpg
 
Testing the Water: RV12 Aux Tank

You could consider my setup as a Accessory to the 12.
A few more Advantages for its use.

Longer runs between Oil changes by not running 100LL (25hrs)

Being able to run pure synthetic oil like Mobile One which can be bought at Sams right off the shelf (50hrs)

Tank does not take up all the room in the baggage area, just imagine the 20 gallon tank cut down to 6 gallons.

CG is not going to be a problem in most cases, if you have a flying RV12 then you will know what I mean!

Sometimes you may not even need to have any fuel in it at all on the way to a friends house or a fly-in but after you arrive then you could use the courtesy car to go pick up 6 gallons to transfer right after take off or on the ground to the main tank to get you home without using 100LL.
An example would be a 2 hr flight out which would leave you with 10 gallons left over for your flight home. Now take you empty aux tank down to 7-11 for 6 gallons to make it back home with reserve fuel left over.

Yes as Scott says if you go with the aux tank full then you could only take a small over night bag if there are two persons in the plane but if you are not staying overnight then its not a factor. If its only one person then its not a problem at all. We UPS our bags to OSH this summer when we took the 12 there with no aux tank installed.

This would be mostly used by guys that are already up and fly not building.

Not going to build a bigger tank so that out for me, But could go with a smaller one say 3 gallons. But that doesn't really make sense cause you just put 3 gallons in the 6 gallon tank. Again plenty of room still left over with the 6 gallon Aux tank.

Ok, What do you guys think something like this would be worth($) to you to increase you 12 capabilities?

Thanks for your thoughts

John
RV12 N1212K
 
Last edited:
The integration is everything. The fellow in the next hangar over is putting a smoke system into his RV. It's got a cute 2.5 gallon plastic tank, a little pump, and a quick attachment method to the fuselage.

But the hoses are not quick disconnect, and neither is the vent line.

And it's pretty expensive.

With this tank that you're thinking of, I'd expect that the integration to the existing airplane is everything. Whether the completed unit is a kit or ready to install, won't affect the price or desirability much.

Carrying about 40 pounds of awkwardness from gas station to airplane, then wrestling it into the baggage area, could be a feature that people might not use often.

Get it done, make it slick, and price it out and see what it'll cost to manufacture it. Then, especially with photos, you'll have a better idea if it'll sell.
 
Testing the Water: RV12 Aux Tank

The fellow in the next hangar over is putting a smoke system into his RV. It's got a cute 2.5 gallon plastic tank, a little pump, and a quick attachment method to the fuselage.

Just change out the tank to 6 gallons

But the hoses are not quick disconnect, and neither is the vent line.


Mine does have quick disconnects and the tank can be removed in 1 min.

Its installed now and being tested.

John
RV12 N1212K
 
CofG

The published CofG for "baggage" is further aft than the fuel tank, although it occupies the same front-to-back space, and hence CofG range. I assume this is a safety factor in case folk put heavy stuff back against the bulkhead.

If an auxiliary tank is located as far forward as possible with a vertical (as opposed to horizontal) orientation, ie tall and thin, it must be possible to put more than 50 lbs there and still remain forward of the aft CofG limit. It would of course still have to be weight limited to comply with the gross weight.

Cheers...Keith
 
If you are talking about an additional 20 gal in the baggage compartment, that would not be possible. Even the tank John is talking about pretty much consumes all of the remaining baggage compartment weight capacity (see Scott's post). An additional 20 gal of fuel would far exceed the weight capacity of the baggage compartment (20gal X 6lbs/gal=120lbs plus weight of tank- baggage compartment can hold only 50 lbs so it would be at least 70 pounds over).

Jeff

Nope. I'm talking about custom fitting a 20 gal tank to take the place of the passenger seat position. Make it easy to put in and take out, returning full functionality to the passenger seat when not needing extended range.
 
Removable fuel tank!

Diamond, My system would work fine for this application. Just use a bigger tank. How does 15" W x 28" L 12.37" H 20 gallons, just strap it down with the seat belts. It would be rigid plastic tank and you would transfer the fuel in it to the main tank after you burn off some fuel. Figure about 1 min 20 seconds to transfer 1 gallon of gas.

John
RV12 N1212K
 
Actually,

Since my RV-12 is a long way from completed, my plan is to fly it for awhile and then if I want more fuel capacity, I'll build myself a larger tank and remove the 'stock' one.

I plan to take exact measurements of the 'stock' tank and then just make one that is a bit bigger. All that dependent on my flying experience with the 'stock' tank.
 
OK so I can see the usefulness of the tank if you want to stay Mogas but then again is it that useful, landing at an airport and taking the tank out to get in a courtesy car and go fill it, maybe if you are spending the night but if not if its just a stop over thats going to add an indeterminate amount of time to the stop.

To Extend range? Even pushing it you can get 4 hours flying, how many of you have been flying for four straight hours in a very light aircraft in anything less than a light breeze? The longest I have flown in light to moderate turbulence is 2.2 hours and I was beat by the time I landed.

I think If I was buying something to get max range and speed I wouldn't be building a twelve.

That said I see some usefulness in it like flying from AZ to CA and having enough as to get back without paying CA prices.
 
Testing the Water: RV-12 Aux Tank

Again this is just a tool or accessory to add to the 12 for all the reasons I stated earlier. Yes the 12 is not the best plane for doing a lot of x-country but its not bad for the occasional one if you want to go somewhere. Start at sun rise or just before Sunset for the smooth ride, Kick on the AutoPilot, turn on the XM music and enjoy the ride. If you need extra fuel then use the Aux tank if you dont then leave it behind. One thing about the 12 is after the big investment in it, the operating cost is one of the lowest out there!

John
RV12 N1212K
 
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