Aux fuel

[geraldmorrissey]

Wondering if any Patrol builders have or considered aux fuel tanks. Any insite or opinions appreciated. I'm close to wing final assembly so if I'm going to add fuel it's soon. Will be talking to Bob about it. Not sure it's possible or desireable but I see it being done on the 4 place. Searched the forum with no success. Most bush pilots I've read about say range is very important in their profession. Setting rivets today, 110 degrees and 10% humidity. In Seattle of all places, what the hell!!!
Gerry
Patrol #30

[Rollie]

I thought about the same thing when I was building my Patrol but decided to just make it as fuel efficient as I could instead. I went with the IO-360, instead of the O-360 for several reasons, one of which is it's supposed to burn about a gallon less per hour. Then I put in 10:1 pistons, also more fuel efficient (along with a little more power) and dual P-mags. I ended up with a cruise fuel flow of 7.7 - 8.2 GPH at 24 squared when running lean of peak. I run that power setting pretty much all the time unless I'm up too high to get 24 squared, then I'm using even less gas. 55 gallons at that burn rate gives me over 6 hours plus reserve. With the digital fuel flow (after testing and verification) I'm comfortable running right down to 6 gallons on board (45 minutes reserve at cruise power). I get 115-120 knots TAS with 31" bushwheels. 115 knots for 6 hours is 690 NM, or 793 SM for those who prefer that. See if those guys with 180's and PA-18s who are telling you that you need extra gas can go that far on what their planes carry and then you will probably want to get back to finishing your wings.

[BravoGolf]

I thought about it. In the end I considered how often I would use/ need the extra fuel compared to just carrying the extra weight. In the end I couldn’t justify the cost and weight gain. But the cool factor almost won.

scott

[Bissetg]

I'm doing a 4 B model with 200 Hp 0360. I considered aux tanks but my bladder is more of a limiting factor than aircraft endurance. (I hear the young bucks scoffing) If I get to wanting to fly too far from fuel I'll take some jerry cans with me. In my view keeping the build light and simple was a higher priority than flying for hours and hours ... but I don't live in a vast country where refuel stops are hours away.

[Mark Goldberg]

A suggestion for you that could make sense. After you close up your wings, access is limited. But the aux tanks themselves could fairly easily be installed even then. In the Patrol (& Model B) the aux tanks go in the bay just outboard of the aileron support frame and all the aileron mechanism. The transfer pump goes in the bay with the aileron mechanism.

What would be very difficult to do after closing your wings is install the fuel line that would take fuel from the transfer pump to the sight gauge in the wing root. So I suggest to builders (four place) who can't decide if they need aux tanks or not - is to install that 3/8" fuel line in the aft part of the wing from where the transfer pump would be to the wing root. And just tape off the ends.

You do add a little useless weight installing that fuel line. But it makes a future aux tank installation possible if you should find you actually need the aux tanks and their additional 19 gallons. Mark

[Gerhard Rieger]

Living in Africa we are mostly far away from fuel and with the aux tanks that give you at least 3hrs out and 3hrs back with decent reserves. Although I have not completed my build, if I work on Bob Barrows figures of more or less 8 gal/ hr lean of peak at altitudes exceeding 8000 ft. I have about 80 gal of fuel including my header tank, that will allow me to go on paper 9 hrs plus reserve, to be on the safe side lets rather say 8 hrs, allowing for wind and other factors. I also planned not to use aux tanks but when I looked at our mission goal it was making the decision for me. I agree with Mark, add the fuel line now if you are not sure, then you have the option to add aux tanks later.

[JimParker256]

Another alternative that was discussed earlier in the forums was to plumb the baggage area for a "ferry tank" (complete with a fuel transfer pump and wiring for a fuel level gauge on the panel) and install it only when the extra range is needed. Yeah, you'd be trading off baggage space for additional range...

I wanted to extend the endurance of my RANS S-6ES to 4+ hours so that I could comfortably plan for 3 hour legs, while landing with a full hour of fuel on board (personal minimums). We ordered and installed the RANS 2.75 gallon capacity "header" tank (installs under the seat - right in the middle of the CG range). 2.75 gallons is more than 30 minutes worth of fuel at any possible cruise power setting. I've had the plane for 14 months now, and have actually used that full 3-hour leg capability exactly once... And that was only because headwinds on one leg of the flight were stronger than forecast (planned 2:45 leg), and I didn't want to land where gas cost would equal a mortgage payment... By the time I got there, I was in such a hurry to find the facilities that I almost forgot to tie the plane down... LOL

Sadly, I distinctly remember one car trip where I drove 6 hours without stopping for anything – back when I was "a little younger." And I can remember flying my Commander 114 on 4+ hours flight legs... (Ah, the good old days!) But nowadays, I'm right there with Bissetg: the "human factors range" trumps the aircraft's range almost every time, and I start really wishing I was on the ground about 2:45 into a flight these days.

[zkelley2]

Another alternative that was discussed earlier in the forums was to plumb the baggage area for a "ferry tank" (complete with a fuel transfer pump and wiring for a fuel level gauge on the panel) and install it only when the extra range is needed. Yeah, you'd be trading off baggage space for additional range...

I wanted to extend the endurance of my RANS S-6ES to 4+ hours so that I could comfortably plan for 3 hour legs, while landing with a full hour of fuel on board (personal minimums). We ordered and installed the RANS 2.75 gallon capacity "header" tank (installs under the seat - right in the middle of the CG range). 2.75 gallons is more than 30 minutes worth of fuel at any possible cruise power setting. I've had the plane for 14 months now, and have actually used that full 3-hour leg capability exactly once... And that was only because headwinds on one leg of the flight were stronger than forecast (planned 2:45 leg), and I didn't want to land where gas cost would equal a mortgage payment... By the time I got there, I was in such a hurry to find the facilities that I almost forgot to tie the plane down... LOL

Sadly, I distinctly remember one car trip where I drove 6 hours without stopping for anything – back when I was "a little younger." And I can remember flying my Commander 114 on 4+ hours flight legs... (Ah, the good old days!) But nowadays, I'm right there with Bissetg: the "human factors range" trumps the aircraft's range almost every time, and I start really wishing I was on the ground about 2:45 into a flight these days.

Extra fuel is almost never about how far you can go in a single leg. It's about how far you can get from a place you can get fuel.

I use the 72 gallons in my 4 place all the time and I've never flown a 6 hour leg(in the BH) or had the need to.

I think it depends on where you live, and what your mission is.

[geraldmorrissey]

Thanks all for your input. Very valuable insite. I think I will go ahead and install the fuel line. Where would I start to find documentation on the aux tanks and installation? All I have is info on the main tank install.
Thx
Gerry
Patrol #30

[svyolo]

I want more fuel, but probably not that often. Aux tank in the cargo/back seat area for me.