Longer Legs

[MarkD 53]

My model C extended speed wing only has one 18 gallon wing tank in the right wing and the stock half gallon header tank behind the seat on the starboard side.  With the engine and prop set up I have I figure on 5gph burn rate for cross country rides.  That gives me about 3 hours of real flight time and enough time to find a gas station.  I would like to have a bit longer legs for getting out of backcountry strips.  

 

Has anyone added any kind of larger header tank behind the seat whilst not impacting the folding wing self storing aileron arrangement?  I would like some ideas or pictures of possible set-ups for extending fuel capacity that does not involve ripping apart wings.  If I could add 5 to 6 gallons of additional fuel I could manage 4 hours of real flight time.

 

Need longer legs,

 

MarkD

[1avidflyer 1983]

A friend of mine has an A model Avid, and he put a 5 gallon tank behind the seat. He maybe has to undo the one flaperon rod when he folds the wing, my memory is thinking that for some reason. Here are a couple of pics. He used an electric pump to move the fuel up into the main fuel tank in front of the instrument panel. You could maybe use this as a large header tank in place of your small pipe one. Jim Chuk

PS looking at the pics, I see he does have to undo his flaperon rod to fold the wings which he does every time he flys as he keeps the plane at home.

Edited 12 Jun 2015 by Jim Chuk

[EDMO 1078]

Some of the Cubs had a header tank located behind the rear seat at the top of the fuselage - So don't only think about a floor location - "More than one way-------"!  There were a couple of tanks on ebay recently that might work - not as cheap as a plastic jug....But no pump needed if up high.

If you fly mostly solo, there is plenty of room for a portable tank in place of the passenger.

Plastic boat tanks would be good - and all the fittings are already there...maybe quick disconnect in line?

EDMO

A passenger weight is usually equal to 20 to 30 gallons of fuel.

Edited 13 Jun 2015 by Ed In Missouri

[EDMO 1078]

Mark,

      Check out this ebay ad for a PPG 5 gallon fuel tank # 111694908113 - Kool, with sight gage too...

but you might find something like it locally and save shipping.

Still, a lot cheaper than the $168 + shipping that Kitfox gets for their 1 gallon plastic tank!

EDMO

Edited 14 Jun 2015 by Ed In Missouri

[MarkD 53]

I think the dimensions of the 5gal plastic tank are outside of what I need.  I have to keep the simplicity of the folding wing feature intact because I intend to keep the plane at home in a pole structure and trailer to the field when I have the opportunity to fly.  I had a friend who weld aluminum come and help me measure the available space and we think we can remove the original 2.5 "diameter X 20"long header tank and fit in a 7" dia X 24" long tank.  That will give me an additional 4 gal.  I could get 5 gallons by going with a 30" long tube.  It should mount in the same location and the aileron connecting rod will clear it when I fold the wings.

 

I have to source material and see how much this is going to cost and if it is really worth it.

 

MarkD

[ChrisBolkan 130]

My MKIV had one wing tank too. When I was doing longer trips solo where fuel was going to be a problem, I seat belted 6 gallons into the seat next to me. Worked great.

[EDMO 1078]

Mark,

     The Avids use tubes, but you could also consider something like Larry put in his Kitfox 4 - a tapered rectangular aluminum  tank that fits behind the seats - Maybe one that fits all the way across seats - Look at his photos in Kitfox IV, or go to Kitfox catalog to see the plastic one I have - I could take a photo, but it is not in my plane yet.

EDMO

Chris, the blue PPG tank I posted above will fit right in a seat - quick disconnect to fuel lines would make it practical too.   My 4 wing tanks are more than my old bladder can handle - Maybe when I was younger?

Edited 15 Jun 2015 by Ed In Missouri

[nlappos 413]

I have a Mark IV, and added a tank in the baggage compartment. The concept would be the same in any model, just finding an acceptable place (behind the seats, to the sides, would work. I plumbed it into the main tank, to avoid contaminating the fuel lines with any bubbles. I transfered fuel after the main tank was down below half, so the normal vents cleaned up the transferred air. Here is the tank and pump:

 

 

 

I tapped into the main tank so the transfer fuel would just add to the main, and not contaminate the fuel system with bubbles. I used a 1/8" NPT to 1/4" hose barb fitting. I drilled a 3/8" hole in the tank, careful not to drop drill tailings into the tank. I used Permatext Epoxy Fuel Tank repair putty, wrapping the fitting threads with it, and screwing the fitting into the hole. It hardened solid and entirely leak-proof.

Edited 9 Nov 2015 by nlappos

[aktango58 1]

Are you sitting longer than three hours at a time?

 

If not, carrying extra fuel in a jug might work for you.

 

Some considerations: If you have a problem and the plane bends, often it will stop tail high; where will the extra fuel go? Will you be covered in fuel?

 

The cub community has been getting away from the rear header tank, or at a minimum going to a heavier aluminum to prevent crash leaks onto passengers and pilot.

 

What about a belly pod and a couple of six gallon Alaska Bushwheel bags put in it. You can keep your load centered more easily, and keep fumes out of the cockpit when flying around. You might have to build a pod for your needs, but be like building a tank.

 

I ran a combo pod on a cub for years. Hated putting it on, (job requirement), but once there would never take it off. Fishing gear lived in there, no worries about water inside. Fuel went there so I had lots of range... and no loss of speed.

[rdooley79 28]

This is a problem for me as well.

 

My KV-IV has a single 13gallon wing tank and has been "upgraded" with two of the header tanks for a total of:

13 + 1.9 + 1.9 = 16.8 gallons 

 

Typical morning flights this isn't a problem. BUT I plan on flying with the wife and doing cross countries. My engine (Rotax 670, 94hp!) burns about 4.5gph so that get's me 3+ hours with some to spare. Not bad but I'd like more for multi day trips. 

 

The two options I have are;

          1. add a wing tank

          2. expand the header tank.

 

I'm kindof leaning towards the expanded header tank option considering I won't need to cut in to the wing and the "bagage" area in a KV-IV is helariously limited. You can hang a couple duffle bags from the bars behind the seat and that's about it. 

 

Has anyone found a good header tank alternative? Poly is preferable for weight and weight. I'd also consider adding a "drop tank" under the belly as that would help keep the CG forward. I'm wary of adding another tank in series to the system now and keeping it vented properly. 

 

Carrying a can in the passengers seat is an option but not when the wife is coming along. 

 

Any thoughts guys?

[EDMO 1078]

Did you catch the posts just before yours on Bladder/pillow tanks by Dusty, before we started talking about mountains and tigers.

There was an ultralite ad posted for some 5.5 gal football plastic tanks to hang on the struts, or in turtledeck, or somewhere.

There was a blue plastic tank on ebay a week ago, with sight gage, fittings, filter and hose, and it didn't sell for $30 plus $20 shipping..  

EdMo

Edited 9 Jul 2015 by Ed In Missouri

[MarkD 53]

I have considered removing the 2.5" header tank and adding in a 7" dia 24" long tank in the same location.  That would give me an additional 4 - 4.5 gallons but I think the CG penalty might be an issue.  I also am considering a couple of plastic tanks that attach to the lift struts.  I would use them as transfer tanks not tied into the main fuel system and make the attach fittings so they could be easily removed and reinstalled when needed. 

 

See the attached link. 

 

http://www.ultralightnews.ca/fuelsystem/wingtanks.htm

 

I'm still in the thinking stage but the idea of carrying a 6 gal tank on the passenger seat is not my favorite idea. Some type of low profile belly tank, 10 gallon plastic or bladder, might be another way to go as a transfer tank.

 

MarkD

[EDMO 1078]

Check out West Marine, Cabelas, Bass Pro for boat tanks. 

Some time ago, someone on here was supposed to get plans, photos, etc of a belly cargo pod that was not round like Kitfox???

EdmO

Edited 9 Jul 2015 by Ed In Missouri

[EDMO 1078]

There is an ultralight poly tank now on ebay for $75 - Odd configuration - You would have to see it to understand.

ebay # 121 697 675 060 in Aviation Parts and in Experimental Aircraft fuel tanks.,Looks like a seat tank - holds 10 gallons - put it in wife's side!

 and a Swift aux tank that I didn't check out, and some Ercoupe tanks.

EdMO

Edited 9 Jul 2015 by Ed In Missouri

[RobS 52]

This Rans 7 has the wing tanks Mark referred too. Looks like a reasonable (although pricey) solution for those times when you need extended range.

http://www.stoneylake.org/pipcom/RANS%20COURIER_files/image016.jpg

[Dusty 126]

rdooley

The header tank in my opinion is just that! I wouldn't be comfortable flying off it.as quantity can't be easily checked in flight!

It should be treated as an emergency only((basically in sight of a suitable landing field)

Any additional fuel should be transferred to the main tanks so an accurate visual check can be made.

Sounds like you have similar range issues as I do.

How do you find flying with 13 gallons in one side only?

Edited 9 Jul 2015 by Dusty

[EDMO 1078]

Dusty,

     If you put a bladder in your locker with 5 gallons fuel, and a 5.5 gallon football under the other wing, you would balance out well - But, don't think that 5 gal more in one wing will make any difference in flight.

EDMO

Edited 9 Jul 2015 by Ed In Missouri

[Dusty 126]

Balancing act might work, or possibly a bungy?trim on the flapperons.

I was curious as a passenger so near the centre makes a difference, 5gallons at 1/4 span may be worse!

[rdooley79 28]

I've found that 13 in the right wing even with two guys in the cockpit makes no difference in balance. I only notice it slightly when it's 100% full. Even then it's only barely noticable. 

 

The strut tanks look like a winner to me but I'm concerned about putting extra load on the struts. That just weirds me out for some reason. Maybe It's not a big deal. They do have the added advantage of being visually checked. No gauges or senders. Even if you had to transfer fuel to the wing tank with a facet fuel pump, that would be just fine. 

 

*IF* I went with a larger header tank, I'd put a fuel level gauge in the tank BUT I am with you, I consider the header as the reserve and only to be used in a time of war (quote from "Hunt For Red October", love that movie) 

 

The strut tanks seem to be the best option without cutting in to the wing.

 

I do like the bladder fuel bag that would fit in to my left wing locker. I need to be able to store extra oil for my 2 cycle Rotax 670 engine. I think this one would work nicely. kinda pricey but it is in AU dollars. Shipping would make up any savings in conversion though.

http://liquidcontainment.com.au/cartpage/viewproduct/223/15-litre-Touring-Jerry-Can

 

We now know where Bush Wheels gets their fuel bags from )

 

Is there any reason I should be wary of putting the strut tanks on?

 

Those football tanks could also be mounted on the belly side by side but filling them would be a problem. They need to be fillable at any random airport on the ramp without tools.

 

Kinda leaning towards the strut tanks. Again is there any reason I should be wary of adding 30lbs per strut?

Edited 9 Jul 2015 by rdooley79

[rdooley79 28]

How do you order anything from ultralightnews.ca?

[EDMO 1078]

IMO - If you mount the football tanks just below the jury struts, then there should be no load on the struts - 

          See the photo of the RANS.

EDMO

[Dusty 126]

Thanks regarding 13gal in one wing,good to hear not a major unbalance!

Regarding strut mount ,visibility in the circuit would be a problem? Even my droop tips seem to always be in the way,

The hunt for the red october! one of the all time great movies

[TJay 1041]

Hey guys it only takes about 5 minutes to cut the fabric and drop in another wing tank.

[C5Engineer 1170]

For those wanting more range for cross country trips.... Have you ever flown an Avid full of gear more than 3 hrs? It's not exactly a pleasant experience. I've done 3-4 hr legs and have logged over 10 hrs on the hobbs in a single flying day covering nearly 600nm. The last leg of that trip was just over 4 hrs. I was ready to claw my way out of the plane. Not tryin to be discouraging but unless you are flying to Alaska 2-3 hrs is plenty in an Avid. The only time that having 28 gallons has came in really handy for me is in the Idaho backcountry where I can fly almost all week without having to make the 11,500ft trip out to McCall for fuel.

[rdooley79 28]

Joey, I totally agree. I don't need 28 gallons. I just need another 5 for 21 total. The wife and I really want to go camping and it would be nice to have enough fuel for that purpose. Really as it sits now 13 gallons usable is enough for the vast majority of the flights.

 

I can't for the life of me find where to buy the football tanks. Aircraft Spruce used to carry them, no more. Ultralightnews.com is an information site and their prices are old. No way to actually get the strut mount tanks. Does anyone know where to order them?

 

I would like to drop in another wing tank but with a wing locker that is harder than you think because the 45` internal strut is in the wing. In the KF's the tank is part of the wing structure. Without a tank and having a cargo compartment there needs to be an internal strut to stiffen the wing. I really don't want to loose the cargo compartment. It's very handy. 

 

What would be the best would be a teardrop tank that could be belly mounted and then use a facet fuel pump to transfer fuel to the wing tank. The only problem would be filling the belly tank. THe thought came to mind of plumbing from the header tank to the belly tank with a valve. Simply fill up and open the valve to fill the belly/aux tank and turn the valve off when done. Venting could be done with a simple breather line and a check valve after the fuel pump just before the wing tank supply just to ensure fuel will only go one way when transferring fuel. Also I haven't been able to find a poly tank that would be appropriate for a belly tank.