 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
ogdenk
Joined: 05 Feb 2007
Posts: 41
Location: Syracuse, NY
|
 Posted: Mon Mar 04, 2019 5:45 pm Post subject: (EXTERNAL) Re: Plumbing in some extra fuel capacity |
 |
|
Carl,
Thanks for your insights, I feel like I'm at least on the right track. I did think about disconnecting the extension plumbing from the Tee and capping when not in use, I would just have to get under the copilot seat which will be a bit of a nuisance but that would cure the issues I raised.
I did consider the commercial 'tip' tanks but I agree they don't add much capacity for the cost/complexity plus the added weight will always be in the plane. My plane will be heavy as it is since I have air conditioning so I want to keep any more added weight to a minimum.
I do like the collapsible tanks as they can be stored in a sack, plus no vent is needed. They look to be plenty durable but I suppose any auxiliary tank could develop a leak so that's something to be wary of since it's inside the cabin.
I have no plans to fly over the poles, it blows my mind that somebody could put that much fuel in a Lancair to do that! I have some dreams for some long distance flights but I'm uncomfortable flying over a big lake let alone an ocean. Who knows though, Europe may be possible!
Kent
| Quote: | >> Carl Froehlich <carl.froehlich(at)verizon.net> 03/04/19 5:58 PM >>>
|
Interesting timing, I just discussed this with another RV-10 builder earlier today. Some thoughts:
- There are commercial wingtip tanks that add 15 gallons or so of fuel, but I ruled this option out as it added a lot of complexity, weight and has a huge price tag. Add to that the obvious “Van’s did not consider this in the wing design” aspect.
- My neighbor at Dogwood is the guy that flew his specialty build Lancair IV over both the North and South Poles. He had a total of seven fuel tanks added to the plane (380 or so gallons). Five of the tanks he custom made using carbon fiber board to fit all the contours of the plane, the aft large one strong enough to support the one large and one small badder tanks like that you reference. He had a very straightforward approach to fuel plumbing to mitigate risk of something going wrong - yielding a forced landing in the Arctic or Antarctic. He had a single, simple 90 degree isolation valve for each tank going to a Facet pump. The transferred fuel only goes to the 10 gallon header tank that has a clear sight glass for fuel level. He transferred fuel every hour or so like Limburg did in the Sprit of St. Louis.
Stealing from the above and ruling out the header tank or extra wing tanks leads to a 20+ gallon ferry tank that gets mounted in place of one or both rear seats. The ferry tank being one of many composite racing tank options (I would not consider the badder tank for this application). I have this set up for my new RV-8 project, the tank being fed into a T on the right tank fuel line before it goes to the fuel valve. The T will be normally capped when not being used for this connection. Ferry tank vent will go to the wing root area or aft to exit the bottom of the fuselage. Operation will be to burn 20 or so gallons out of the right tank, fly on the left tank, open the ferry tank isolation valve and turn on the Facet pump (with check valve) to transfer fuel to the right tank. My Lancair buddy tells me the change in noise from the Facet pump when the ferry tank is dry is obvious - but you will also get the right tank fuel sender increasing as a positive indication.
My thinking is that 99+% of the time having more than the five hours of gas will not be needed, so the ferry tank will spend most of it’s life on the shelf in the hangar. Make it easy to get in and out of the plane.
If you want to get fancy you can build a couple of tanks out of carbon that exactly fits the rear seat floor area, moving the ferry tank weigh a little more forward toward the center of gravity.
No other changes to the standard fuel system other than this T is done. While I did build the right tank with an extra fuel fitting for this purpose I decided a T on the inside of the fuselage line was more practical.
For the RV-10 you lose one or both back seats depending on ferry tank size, but the added weight of the fuel translates to not carrying four people.
Carl
On Mar 4, 2019, at 4:03 PM, Kent Ogden <ogdenk(at)upstate.edu (ogdenk(at)upstate.edu)> wrote:
| Quote: | All,
I would like to build in some fuel plumbing to allow for optional extra capacity, perhaps using tanks like these:
https://www.turtlepac.com/products/collapsible-aircraft-ferry-tanks/
A 25 or 33 gallon tank would add significant range for the occasional long distance flight or allow for improved range at high speed cruise.
I am trying to notdesign in a weak point in my fuel system though, as it is so critical and there have been some accidents related to fuel system issues.
One idea is to add a 'T' AN fitting to the fuel line under the copilot seat, that would then have an aluminum line run along the right side of the cockpit to the right rear seat, and would normally hide under the side cover next to that seat. I would put a shutoff valve there that would normally be closed, and on the other side of the valve put an appropriate fitting that could attach to the ferry tank that could be strapped to the seat. To use, take the side cover off, connect the ferry tank, bleed the air out of the system, then during flight fuel could be pumped into the right tank while running the engine on the left tank (or maybe the right tank, might not matter). When the ferry tank is nearly empty, shut off the pump and close the valve.
One concern is that the extension plumbing would have air in it until it is used, and air bubbles could conceivably find their way into the main line. The extension line could be filled with fuel too, but that would sit there stagnant for possibly long periods of time (is that an issue?). I had also considered adding a check valve to prevent fuel from flowing from the main tank side back into the extension plumbing (in case of a leak in the extension), but that would be generally uphill so gravity would be on your side there.
Another possibility is to plumb directly to the tank, but the tank is finished and I'm not sure I'd like to poke any more holes in it, which would probably leave some aluminum bits inside to boot. I can't just plumb into the vent line since there is no way to let the displaced air out of the tank when pumping in fuel through that line.
I don't want to start a debate about the RV-10 range etc, just want to hear thoughts on what's likely to work without adding too much extra complexity and risk.
Thanks for your thoughts!
Kent Ogden
#40710
|
| | - The Matronics RV10-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV10-List |
|
|
|
| Back to top |
|
 |
ArmstrongJackson
Guest
|
| Posted: Tue Aug 25, 2020 6:35 am Post subject: Re: (EXTERNAL) Re: Plumbing in some extra fuel capacity |
|
|
Not my type of site which I would choose again. I made the biggest mistake by coming here at plumber granada hills, it was full of useless stuff, to be honest. I think they need to do more work on this site to make it worth your time.
| | - The Matronics RV10-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV10-List |
|
|
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
