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Fuel Line Location

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stepinwolf

Joined: 21 Jan 2008
Posts: 133
Location: Canada

Posted: Mon Feb 11, 2008 7:16 am Post subject: Fuel Line Location

I have just received the factory plans for my 701, and while looking over the assorted material, I noticed that everywhere fuel lines were referenced, they entered, and ran completely through the cabin area.  I must admit this is not something I am comfortable with, especially if " God forbid " a fuel leak, or ground contact might take place.



I have been in the auto restoration hobby for longer then I can remember, and it was NEVER  permitted to have anything to do with fuel lines, in any situation where occupant's might be.



Has anybody address this in the past, or it is the normal procedure to be sitting on fuel lines, or have them running 12" from your nose.



Bob the 701 scratch

_________________
Long wing + vga's, = lo & slo

cookwithgas

Joined: 06 Nov 2007
Posts: 159

Posted: Mon Feb 11, 2008 7:57 am Post subject: Re: Fuel Line Location

Hi Bob:



My 601XL fuel lines are all outside.  I don't know anybody else who did this but I was not comfortable with fittings and fuel lines inside the cockpit.  From what I have seen it is VERY common in the aircraft industry to have fuel lines inside the cockpit.  I didn't think just because that is the way everyone else does it that I should do it that way.  So far with 20 hours of flight time, my external fuel lines have worked well.  There are all sorts of arguments for both inside and outside but I chose outside.



I do have one main fuel valve that has an internal handle I can shut off from inside the cockpit.  I made an extension so the valve can be outside the cockpit and the handle can be accessed from inside.  



Scott Laughlin

www.cooknwithgas.com

Gig Giacona

Joined: 10 Jan 2006
Posts: 1416
Location: El Dorado Arkansas USA

Posted: Mon Feb 11, 2008 8:18 am Post subject: Re: Fuel Line Location

Bob, yes it is very common to the point of damn near universal in small aircraft to have fuel lines in the cabin. One thing to dry and stay away from is pressurized fuel lines in the cockpit.

Scott, where is your fuel selector valve located? I can't think how on earth you did it without lines in the cockpit.

_________________
W.R. "Gig" Giacona
601XL Under Construction
See my progress at www.peoamerica.net/N601WR

bryanmmartin

Joined: 10 Jan 2006
Posts: 1018

Posted: Mon Feb 11, 2008 8:27 am Post subject: Fuel Line Location

This is normal even in type certificated factory built airplanes.  

Short of running the lines outside in the airstream, there isn't any  

other way to run them. About all you can do is cover the lines to  

protect them and contain any leakage.



Remember that automobiles are far more likely to be involved in a  

collision than airplanes (airplanes are just more likely to kill you  

if you hit something). It can also be a lot harder to get out of a  

crumpled up steel car than a crumpled up aluminum airplane. The fuel  

lines in autos can easily be run under the body outside of the cabin  

with no affect on vehicle performance. It wasn't too long ago that  

most pickup trucks had the fuel tank mounted in the cab behind the seat.



On Feb 11, 2008, at 10:16 AM, stepinwolf wrote:



 	  Quote: 	
		   

 >



 I have just received the factory plans for my 701, and while looking  

 over the assorted material, I noticed that everywhere fuel lines  

 were referenced, they entered, and ran completely through the cabin  

 area.  I must admit this is not something I am comfortable with,  

 especially if " God forbid " a fuel leak, or ground contact might  

 take place.



 I have been in the auto restoration hobby for longer then I can  

 remember, and it was NEVER  permitted to have anything to do with  

 fuel lines, in any situation where occupant's might be.



 Has anybody address this in the past, or it is the normal procedure  

 to be sitting on fuel lines, or have them running 12" from your nose.



 Bob the 701 scratch



 --------

 Live each day, as if it was your last




	


-- 

Bryan Martin

N61BM, CH 601 XL,

RAM Subaru, Stratus redrive.

do not archive.

_________________
--
Bryan Martin
N61BM, CH 601 XL, Stratus Subaru.
do not archive.

cookwithgas

Joined: 06 Nov 2007
Posts: 159

Posted: Mon Feb 11, 2008 9:21 am Post subject: Re: Fuel Line Location

 	  Gig Giacona wrote: 	
		  Scott, where is your fuel selector valve located? I can't think how on earth you did it without lines in the cockpit. 	




Gig:



It is on the floor between the seats.  I originally had it between my feet but didn't feel comfortable that someone could kick it closed.  I have a simple ball valve in-line after the two fuel tank lines come together.  I TIG'd a new handle that has an extension up into the cockpit.  I used my mill to cut a slot in the bottom of a plate welded to the end of a small pipe that is welded to the handle.  The slot fits the valve stem then a nut secures it in place just like the stock handle.  I then powder-coated the handle red so it is really easy to find.  I couldn't find any pictures of the handle (I'll take one this weekend) but here is a picture of what the lines look like below:



http://www.cooknwithgas.com/Finishing/Fuel%20Lines.JPG



Each wing contains an electric fuel pump.  A DPDT switch can switch between pumps so one at a time will run but you can't turn both off while power is on.  



The cowl exit has been modified extensively since that picture was taken.



I'm sure there are better and other ways to do this, but this is how I did it.  



Scott Laughlin

www.cooknwithgas.com

cookwithgas

Joined: 06 Nov 2007
Posts: 159

Posted: Mon Feb 11, 2008 9:45 am Post subject: Re: Fuel Line Location

Gig:



I found a picture of the fuel shutoff handle.  I had to crop it out of a larger photo:



http://www.cooknwithgas.com/Finishing/Fuel_Handle.JPG



Scott Laughlin

www.cooknwithgas.com

victorbravo(at)sbcglobal.
Guest

Posted: Mon Feb 11, 2008 10:21 am Post subject: Fuel Line Location

There are many many FAA certified airplanes that have fuel lines running 

through the cabin and under your seat. That being said, there are also 

many many government protected wolves, rattlesnakes, cougars, alligators 

and bears that would remove you from the gene pool without a second 

thought if they had the chance.



The first biggest thing is to make sure there are no fuel TANKS in the 

cabin. The early 701's had a cabin tank conveniently located near all 

your electrical wiring. Same as my certified Taylorcraft. Use the later 

wing tanks and get those 15 or so gallons out of the cabin.



Wherever you can, route the fuel lines outside the cabin. However there 

is also some valid logic in the idea that you want as few valves, 

connections and leak points on the hot side of the firewall as possible too.



One big improvement you can make is to use "hard lines" instead of hoses 

anywhere you can. The only place you need a hose is when attaching to 

something that moves OR flexes, such as the engine on it's rubber 

mounts. Most certified airplanes have all aluminum lines in the 

airframe, and a short section of hose from the last rigidly mounted item 

(the gascolator) to the engine.



Not having studied the plans thoroughly yet, FWIW my suggestion is to:



1) Use aluminum lines from the wing tanks to the selector valve and from 

the valve to the gascolator, and then

2) Use a very good quality Teflon/Stainless "Aeroquip" line from the 

gascolator to the carburetor.

3) DEFINITELY use either the built-in or external "Firesleeve" material 

over the flex hose. 

4) Definitely make a flame shield (stainless sheet bracket or something) 

between the gascolator and the exhaust or any other flame source.Make 

sure the drain valve on the gascolator would not drip fuel anywhere near 

wiring or anything hot.

5) Make sure that your aluminum lines are well mounted to the airframe 

using "Adel clamp" type hold-downs

6) Make sure that the airframe is rigid enough that the whole airplane 

is not flexing your fuel lines back and forth

7) Make sure your fuel valve mount is not flexing and moving the 

aluminum tubes, this may require more than the minimum mount for the valve

 Spend the extra few bucks on a good Teflon type selector valve or 

something that will not bind up over time. SOME of the cheap brass 

valves will be marginally movable now and then get nearly impossible 

over time. You don't have to spend $1000 on the fanciest one, but just 

do some testing and playing with several valves to find one that does 

not leak and is easy to move. If the floor of the cabin turns out to be 

the best place for the valve, then make a little box or dam around the 

valve that will contain a fuel leak, and then have an overboard drain to 

empty that box out through the floor and away from the airplane.

9)When your fuel lines are run, clamped and secured, and the valve is in 

place and connected, cap off the gascolator side and one of the fuel 

tank sides. Make up a pressure fitting hooked up to the other fuel tank 

side. Pressurize the system to about 40 or 50 PSI of air, which is 20 

times more pressure that it would ever see in flight. Go around and leak 

test every connection with soap and water, at every valve position, 

listen to the valve very carefully, etc.

10) IMHO leave the aluminum fuel lines bare because you will see and 

smell a leak faster.

11) Read steps 2, 3 and 4 above again 



Bill



stepinwolf wrote:

 	  Quote: 	
		   



 I have just received the factory plans for my 701, and while looking over the assorted material, I noticed that everywhere fuel lines were referenced, they entered, and ran completely through the cabin area.  I must admit this is not something I am comfortable with, especially if " God forbid " a fuel leak, or ground contact might take place.



 I have been in the auto restoration hobby for longer then I can remember, and it was NEVER  permitted to have anything to do with fuel lines, in any situation where occupant's might be.



 Has anybody address this in the past, or it is the normal procedure to be sitting on fuel lines, or have them running 12" from your nose.



 Bob the 701 scratch



 --------

 Live each day, as if it was your last





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=163469#163469

Gig Giacona

Joined: 10 Jan 2006
Posts: 1416
Location: El Dorado Arkansas USA

Posted: Mon Feb 11, 2008 11:23 am Post subject: Re: Fuel Line Location

Scott, I have a couple of questions.



Do the fuel pumps allow flow if they are in the OFF position?



Do you have another pump up front?

_________________
W.R. "Gig" Giacona
601XL Under Construction
See my progress at www.peoamerica.net/N601WR

dredmoody(at)cox.net
Guest

Posted: Mon Feb 11, 2008 11:35 am Post subject: Fuel Line Location

There are DPDT switches with a center "OFF" position. I have that in my panel directing power from a fuel pump power switch in the EXP BUS.



Dred

 	  Quote: 	
		   Each wing contains an electric fuel pump.  A DPDT switch can switch between pumps so one at a time will run but you can't turn both off while power is on.  

 

 The cowl exit has been modified extensively since that picture was taken.

 

 I'm sure there are better and other ways to do this, but this is how I did it.  

 

 Scott Laughlin

 www.cooknwithgas.com

cookwithgas

Joined: 06 Nov 2007
Posts: 159

Posted: Mon Feb 11, 2008 11:36 am Post subject: Re: Fuel Line Location

 	  Gig Giacona wrote: 	
		  Scott, I have a couple of questions.



Do the fuel pumps allow flow if they are in the OFF position?



Do you have another pump up front? 	


I don't know if the fuel will flow with the pump not pumping.  I hope I never have to find out! 



No other fuel pump in front - just one pump in each wing near each tank.  



I do have a check valve (as seen in the photo) on each line so a pump can't move fuel from one tank to the other even though I think each fuel pump has an internal check valve.

Gig Giacona

Joined: 10 Jan 2006
Posts: 1416
Location: El Dorado Arkansas USA

Posted: Mon Feb 11, 2008 11:44 am Post subject: Re: Fuel Line Location

OK here is my concern. You might very well not have a problem because you are pushing fuel through the system and not sucking it. But, before you have it happen in flight I'd strongly suggest that you ground test it with one tank empty.



 	  cookwithgas wrote: 	
		   	  Gig Giacona wrote: 	
		  Scott, I have a couple of questions.



Do the fuel pumps allow flow if they are in the OFF position?



Do you have another pump up front? 	


I don't know if the fuel will flow with the pump not pumping.  I hope I never have to find out! 



No other fuel pump in front - just one pump in each wing near each tank.  



I do have a check valve (as seen in the photo) on each line so a pump can't move fuel from one tank to the other even though I think each fuel pump has an internal check valve.

_________________
W.R. "Gig" Giacona
601XL Under Construction
See my progress at www.peoamerica.net/N601WR

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