Matronics Email Lists :: View topic

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

Fuel Selector

Matronics Email Lists Forum Index -> RV10-List

View previous topic :: View next topic

Author Message

jkreidler

Joined: 13 Feb 2008
Posts: 151
Location: Sheboygan Falls WI

Posted: Wed Dec 10, 2008 11:17 am Post subject: Fuel Selector

I have had fuel selector valves on my brain, and have a few questions.  Why can't a low wing airplane draw from both tanks at once?  To me if the fuel is available at the inlet of the pump it should draw from both, just as well as a high wing with gravity working for it.  Probably something obvious I am missing....  Has anyone ever considered using an electrically activated fuel selector valve like the ones used in dual fuel tank trucks?  Switching tanks would then just be the flip of a switch.  I think the failure mode of this device would be to stay open on whichever tank is selected.  I will admit, complicating something as critical as fuel management any more than is absolutely necessary does make me nervous.  Just got stuck on my brain for some reason.....  Any thoughts? 



 Thanks, Jason Kreidler 

N44YH - #40617 Finishing - 4 Partner Build [quote][b]

_________________
Jason Kreidler
4 Partner Build - Sheboygan Falls, WI
Tony Kolar, Kyle Hokel, Wayne Elser, Jason Kreidler
N44YH - Flying - #40617

rene(at)felker.com
Guest

Posted: Wed Dec 10, 2008 11:55 am Post subject: Fuel Selector

Here is my opinion on why we can not have a “both” position……..not enough pressure (short column of fuel)  on the fuel line at the valve to insure balancing of fuel between the tanks.  This could result in the “un-porting” of one of the lines.   

   

Rene' Felker  

RV-10 N423CF Flying  

801-721-6080    

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of jason.kreidler(at)regalbeloit.com

 Sent: Wednesday, December 10, 2008 12:15 PM

 To: rv10-list(at)matronics.com

 Subject: Fuel Selector  

  

   



 I have had fuel selector valves on my brain, and have a few questions.  Why can't a low wing airplane draw from both tanks at once?  To me if the fuel is available at the inlet of the pump it should draw from both, just as well as a high wing with gravity working for it.  Probably something obvious I am missing....  Has anyone ever considered using an electrically activated fuel selector valve like the ones used in dual fuel tank trucks?  Switching tanks would then just be the flip of a switch.  I think the failure mode of this device would be to stay open on whichever tank is selected.  I will admit, complicating something as critical as fuel management any more than is absolutely necessary does make me nervous.  Just got stuck on my brain for some reason.....  Any thoughts? 

 

 Thanks, Jason Kreidler 

 N44YH - #40617 Finishing - 4 Partner Build    	  Quote: 	
		    http://www.matronics.com/contribution 	
0 	  Quote: 	
		   	
1 	  Quote: 	
		   	
2 	  Quote: 	
		   	
3 	  Quote: 	
		   	
4 	  Quote: 	
		   	
5 	  Quote: 	
		   	
6 	  Quote: 	
		   	
7 	  Quote: 	
		   	
8 	  Quote: 	
		   	
9 	  Quote: 	
		  	
0 	  Quote: 	
		  	
1 	  Quote: 	
		  	
2 	  Quote: 	
		  	
3

       [quote][b]

coop85(at)cableone.net
Guest

Posted: Wed Dec 10, 2008 3:21 pm Post subject: Fuel Selector

Jason,  

   I can’t speak with authority on why not both tanks at once, but I would suspect you would still need a left/right only option as you will most certainly get a fuel imbalance over time due to a number of factors.  I would be very hesitant to use an electric fuel valve, even if it does stay on one tank when failed, you may not realize you’ve lost control of the valve until you really need the fuel out of the other tank.    

   

Marcus  

     

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of jason.kreidler(at)regalbeloit.com

 Sent: Wednesday, December 10, 2008 1:15 PM

 To: rv10-list(at)matronics.com

 Subject: Fuel Selector  

  

   



 I have had fuel selector valves on my brain, and have a few questions.  Why can't a low wing airplane draw from both tanks at once?  To me if the fuel is available at the inlet of the pump it should draw from both, just as well as a high wing with gravity working for it.  Probably something obvious I am missing....  Has anyone ever considered using an electrically activated fuel selector valve like the ones used in dual fuel tank trucks?  Switching tanks would then just be the flip of a switch.  I think the failure mode of this device would be to stay open on whichever tank is selected.  I will admit, complicating something as critical as fuel management any more than is absolutely necessary does make me nervous.  Just got stuck on my brain for some reason.....  Any thoughts? 

 

 Thanks, Jason Kreidler 

 N44YH - #40617 Finishing - 4 Partner Build    	  Quote: 	
		    http://www.matronics.com/contribution 	
0 	  Quote: 	
		   	
1 	  Quote: 	
		   	
2 	  Quote: 	
		   	
3 	  Quote: 	
		   	
4 	  Quote: 	
		   	
5 	  Quote: 	
		   	
6 	  Quote: 	
		   	
7 	  Quote: 	
		   	
8 	  Quote: 	
		   	
9 	  Quote: 	
		  	
0 	  Quote: 	
		  	
1 	  Quote: 	
		  	
2 	  Quote: 	
		  	
3

        [quote][b]

rnewman(at)tcwtech.com
Guest

Posted: Wed Dec 10, 2008 3:41 pm Post subject: Fuel Selector

One of the issues regarding a "both" position for a  fuel selector value on a low wing plane is as follows:  

 When a tank is low, and you turn in that direction  you risk unporting that fuel pick up tube, with the selector set on both it will  not draw from the tank that has its pick up tube nicely bathed in  fuel.   As an experiment try this,  put two drinking straws in  your mouth and drink some water out of two cups,   pull one straw out  of one of the cups of water while leaving the other straw  submerged and try to suck on both straws,   you'll get nothing  but air, no water:   that's how your engine would feel   

  

  

 -bob newman

  

  

 [quote]   ---

jkreidler

Joined: 13 Feb 2008
Posts: 151
Location: Sheboygan Falls WI

Posted: Wed Dec 10, 2008 5:57 pm Post subject: Re: Fuel Selector

Bob, that makes sense....  Following that theory I have attached a picture of an experimental apparatus showing why I believe high wing aircraft are allowed to have a 'both' selection.



Thanks, Jason Kreidler



[quote="rnewman(at)tcwtech.com"]One of the issues regarding a "both" position for a  fuel selector value on a low wing plane is as follows:  

 When a tank is low, and you turn in that direction  you risk unporting that fuel pick up tube, with the selector set on both it will  not draw from the tank that has its pick up tube nicely bathed in  fuel.   As an experiment try this,  put two drinking straws in  your mouth and drink some water out of two cups,   pull one straw out  of one of the cups of water while leaving the other straw  submerged and try to suck on both straws,   you'll get nothing  but air, no water:   that's how your engine would feel   

  

  

 -bob newman

  

  

  	  Quote: 	
		     ---

Thirst4.jpg

Description:

Filesize:

5.8 KB

Viewed:

6241 Time(s)

_________________
Jason Kreidler
4 Partner Build - Sheboygan Falls, WI
Tony Kolar, Kyle Hokel, Wayne Elser, Jason Kreidler
N44YH - Flying - #40617

rnewman(at)tcwtech.com
Guest

Posted: Wed Dec 10, 2008 6:23 pm Post subject: Fuel Selector

Ahh yes!  a gravity fed system has no issues!

do not archive,



bob

---

pitts_pilot(at)bellsouth.
Guest

Posted: Wed Dec 10, 2008 7:31 pm Post subject: Fuel Selector

Bob-tcw wrote:

 	  Quote: 	
		   One of the issues regarding a "both" position for a fuel selector 

 value on a low wing plane is as follows: 

 When a tank is low, and you turn in that direction you risk unporting 

 that fuel pick up tube, with the selector set on both it will not draw 

 from the tank that has its pick up tube nicely bathed in fuel.   As an 

 experiment try this,  put two drinking straws in your mouth and drink 

 some water out of two cups,   pull one straw out of one of the cups of 

 water while leaving the other straw submerged and try to suck on both 

 straws,   you'll get nothing but air, no water:   that's how your 

 engine would feel  

  

  

 -bob newman

  

I'm not so sure ..... but I don't want to be a test pilot!!!  The straw 
	


test fails because it isn't like our fuel system at all.  Consider 

this:  I think we all agree that there's no problem in level flight.  In 

a truly coordinated turn there would be no difference from a level 

flight condition due to the dihedral.  In a slipping turn if there's 

enough 'force' to cause the 'low' tank fuel to move toward the tip, then 

the 'high' side has the same force and would (in the absence of engine 

fuel flow) have head pressure and would tend to drain toward the low 

tank.  The reverse would also be true.  As long as the engine doesn't 

suck more fuel than would flow, then the 'low' port wouldn't 'unport'.  

At least that's my reasoning.  Show me where I went wrong!

Linn

pitts_pilot(at)bellsouth.
Guest

Posted: Wed Dec 10, 2008 7:36 pm Post subject: Fuel Selector

Sorry for the multiple posts .... clock screwed up again and I didn't catch 

it!  See below.

Linn

Bob-tcw wrote:

 	  Quote: 	
		   One of the issues regarding a "both" position for a fuel selector 

 value on a low wing plane is as follows: 

 When a tank is low, and you turn in that direction you risk unporting 

 that fuel pick up tube, with the selector set on both it will not draw 

 from the tank that has its pick up tube nicely bathed in fuel.   As an 

 experiment try this,  put two drinking straws in your mouth and drink 

 some water out of two cups,   pull one straw out of one of the cups of 

 water while leaving the other straw submerged and try to suck on both 

 straws,   you'll get nothing but air, no water:   that's how your 

 engine would feel  

  

  

 -bob newman

  

I'm not so sure ..... but I don't want to be a test pilot!!!  The straw
	


test fails because it isn't like our fuel system at all.  Consider

this:  I think we all agree that there's no problem in level flight.  In

a truly coordinated turn there would be no difference from a level

flight condition due to the dihedral.  In a slipping turn if there's

enough 'force' to cause the 'low' tank fuel to move toward the tip, then

the 'high' side has the same force and would (in the absence of engine

fuel flow) have head pressure and would tend to drain toward the low

tank.  The reverse would also be true.  As long as the engine doesn't

suck more fuel than would flow, then the 'low' port wouldn't 'unport'.

At least that's my reasoning.  Show me where I went wrong!

Linn

ricksked(at)embarqmail.co
Guest

Posted: Wed Dec 10, 2008 8:00 pm Post subject: Fuel Selector

Umm...Just curious but is there something so complicated about Left-Right-Off that I'm missing? And unless you are using individual boost pumps per tank on a low wing setup...don't think your single boost pump will have the ummph to draw and provide adequate pressure off a two line system. The high wing aircraft have an age old solution to the "both" issue...it's called gravity, which if you go messing around with using a single boost pump, dual tank, low wing fuel system you may be introduced to that age old solution on terms that you may not like. Experiment away, just don't cause the rest of us to have to fight for our right to fly out of our local airports by screwing the pooch into a "congested" area.



Rick S.

40185

Paint prep

Liking the wheel just like it is, no need to reinvent!



do not archive

partner14

Joined: 12 Jan 2008
Posts: 540
Location: Granbury Texas

Posted: Wed Dec 10, 2008 10:53 pm Post subject: Fuel Selector

Rick, the supply line coming from the valve to the boost pump..... notice the verbage "line"..... not lines... it shouldn't matter whether you have 20 lines feeding into the valve, if you only have one going out.  But I'm in total agreement with the scenario of running out in one tank before the other, the system would just suck air.

 Don



--- On Wed, 12/10/08, Rick Sked <ricksked(at)embarqmail.com> wrote:



  	  Quote: 	
		  From: Rick Sked <ricksked(at)embarqmail.com>

Subject: Re: Re: Fuel Selector

To: rv10-list(at)matronics.com

Date: Wednesday, December 10, 2008, 7:59 PM



 	  Quote: 	
		  --> RV10-List message posted by: Rick Sked <ricksked(at)embarqmail.com>

Umm...Just curious but is there something so complicated about Left-Right-Off

that I'm missing? And unless you are using individual boost pumps per tank

on a low wing setup...don't think your single boost pump will have the ummph

to draw and provide adequate pressure off a two line system. The high wing

aircraft have an age old solution to the "both" issue...it's

called gravity, which if you go messing around with using a single boost pump,

dual tank, low wing fuel system you may be introduced to that age old solution

on terms that you may not like. Experiment away, just don't cause the rest

of us to have to fight for our right to fly out of our local airports by

screwing the pooch into a "congested" area.



Rick S.

40185

Paint prep

Liking the wheel just like it is, no need to reinvent!



do not archive





	
	


           [quote][b]

_________________
Don A. McDonald
40636

Albert Gardner

Joined: 10 Jan 2006
Posts: 455
Location: Yuma, AZ

Posted: Wed Dec 10, 2008 11:19 pm Post subject: Fuel Selector

I once was doing a very aggressive slip in my RV-9A trying to show my wife

something one the ground on my side of the plane while sucking gas out of

the left tank. Suddenly, the loudest no-sound I ever heard when everything

was quite. Wings level, switch tanks, boost on, the fan started up. My wife

said, "Don't EVER do that again!" I'm leaving my valve as Left/Right/Off. As

far as I'm concerned, this wheel has been invented.

Albert Gardner

Yuma, AZ



--

_________________
RV-9A N872RV
RV-10 N991RV

msausen

Joined: 25 Oct 2007
Posts: 559
Location: Appleton, WI USA

Posted: Thu Dec 11, 2008 4:06 am Post subject: Fuel Selector

The things that usually get me in the most trouble involve something motorized and the phrase "hey honey, check this out".  



Do not archive



--

jkreidler

Joined: 13 Feb 2008
Posts: 151
Location: Sheboygan Falls WI

Posted: Thu Dec 11, 2008 5:06 am Post subject: Fuel Selector

Nearly the only thing that determines how hard a pump has to suck to get fuel is the difference in height between the outlet of the tank and the inlet of the engine.  The lowest intake fuel port determines this number, not the number of lines. 

 

Rick, there is nothing complicated at all about Left - Right - Off.  That is why there has never been a pile of aluminum laying on the ground with one empty tank of fuel, and one not so empty tank of fuel adding to the fire.  Please remind those families that there is nothing complicated about Left - Right - Off.  The point of my question was simply to ask why it is done this way in low wing aircraft; I know there must be some reason I am missing, which Bob, Linn, and Albert helped me understand.  I for one will never stop asking why things are done the way they are.  I am happy to know that your airplane has been built 100% per plans, you are a flawless robot of a pilot, and are at no risk of making me have to fight for my right to fly out of my field.  Mistakes happen, there are defects in material and workmanship, and sometimes luck just isn't on our sides.  Fortunately we have places like this to ask simple questions like these to help us understand why.  Your absolutely right, the wheel is perfect, that is why I can't figure out why we ever invented wooden wheels, rubber wheels, then wheels filled with air, the stone wheel was perfect, it rolled just fine.  If it ain't broke don't fix it, I get it, but I need to understand how and why.  Sorry..... 



 Thanks, Jason [quote][b]

_________________
Jason Kreidler
4 Partner Build - Sheboygan Falls, WI
Tony Kolar, Kyle Hokel, Wayne Elser, Jason Kreidler
N44YH - Flying - #40617

bhughes(at)qnsi.net
Guest

Posted: Thu Dec 11, 2008 5:11 am Post subject: Fuel Selector

You  can tie the tanks together with a transfer pump and timer. Requires one extra  hole in your left tank unless you are already returning fuel back to the tank  anyway. The cooling loop through the right tank is not needed with avgas.  

  

 Bobby

 40116

 



   From: owner-rv10-list-server(at)matronics.com  [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of  jason.kreidler(at)regalbeloit.com

Sent: Wednesday, December 10, 2008  1:15 PM

To: rv10-list(at)matronics.com

Subject: Fuel  Selector

 



I have had fuel selector valves on  my brain, and have a few questions.  Why can't a low wing airplane draw  from both tanks at once?  To me if the fuel is available at the inlet of  the pump it should draw from both, just as well as a high wing with gravity  working for it.  Probably something obvious I am missing....  Has  anyone ever considered using an electrically activated fuel selector valve like  the ones used in dual fuel tank trucks?  Switching tanks would then just be  the flip of a switch.  I think the failure mode of this device would be to  stay open on whichever tank is selected.  I will admit, complicating  something as critical as fuel management any more than is absolutely necessary  does make me nervous.  Just got stuck on my brain for some reason.....   Any thoughts? 



Thanks, Jason  Kreidler 

N44YH - #40617 Finishing - 4  Partner Build  	  Quote: 	
		  



href="http://www.matronics.com/contribution">http://www.matronics.com/chref="http://www.matronics.com/Navigator?RV10-List">http://www.matronics.com/Navigator?RV10-List

href="http://forums.matronics.com">http://forums.matronics.com

DA40.pdf

Description:

Download

Filename:

DA40.pdf

Filesize:

42.05 KB

Downloaded:

232 Time(s)

pitts_pilot(at)bellsouth.
Guest

Posted: Thu Dec 11, 2008 5:51 am Post subject: Fuel Selector

Well, that blows my theory.  Thanks Albert, for being our test pilot!!! 

  

Linn .... hopefully with correct clock!!!

Albert Gardner wrote:

[quote] 



 I once was doing a very aggressive slip in my RV-9A trying to show my wife

 something one the ground on my side of the plane while sucking gas out of

 the left tank. Suddenly, the loudest no-sound I ever heard when everything

 was quite. Wings level, switch tanks, boost on, the fan started up. My wife

 said, "Don't EVER do that again!" I'm leaving my valve as Left/Right/Off. As

 far as I'm concerned, this wheel has been invented.

 Albert Gardner

 Yuma, AZ



 --

pitts_pilot(at)bellsouth.
Guest

Posted: Thu Dec 11, 2008 6:21 am Post subject: Fuel Selector

jason.kreidler(at)regalbeloit.com wrote:

 	  Quote: 	
		  

 Nearly the only thing that determines how hard a pump has to suck to 

 get fuel is the difference in height between the outlet of the tank 

 and the inlet of the engine.  The lowest intake fuel port determines 

 this number, not the number of lines.

True .... I use the term 'head pressure' a lot ...... but in the case of 
	


a pump sucking uphill I'm at a loss for a term.  Any ideas??

 	  Quote: 	
		   Rick, there is nothing complicated at all about Left - Right - Off. 

  That is why there has never been a pile of aluminum laying on the 

 ground with one empty tank of fuel, and one not so empty tank of fuel 

 adding to the fire.  Please remind those families that there is 

 nothing complicated about Left - Right - Off.  The point of my 

 question was simply to ask why it is done this way in low wing 

 aircraft; I know there must be some reason I am missing, which Bob, 

 Linn, and Albert helped me understand.

Well, remember that what I said was in theory .....  In Albert's case, 
	


he unported his ONLY source of fuel at that point (I hope) since he 

probably has a left/right/off selector.  I didn't think of that when I 

answered his email.  The next time he does the slippy thing I'll bet 

he'll at least select the 'inside' tank!!!  Another educational 

experience shared with the group.   

 	  Quote: 	
		    I for one will never stop asking why things are done the way they are.

I'm glad for that!!!  I can't come up with all the questions!!!  We're 
	


all still learning .... it's just that some have learned more than 

others.  Your question was a good one ..... because the conventional 

wisdom just may be 'urban legend'.  Out very tough job is to separate 

out the truth from the fiction (especially on a list) and arrive at a 

safe, sound, reasonable answer.  The answer to your question just might 

have boiled down to:  It's the 'safest' or 'simplest' or ..... 

whatever.  I've never asked the question because I just accepted it.

 	  Quote: 	
		    I am happy to know that your airplane has been built 100% per plans, 

 you are a flawless robot of a pilot, and are at no risk of making me 

 have to fight for my right to fly out of my field.  Mistakes happen, 

 there are defects in material and workmanship, and sometimes luck just 

 isn't on our sides.  Fortunately we have places like this to ask 

 simple questions like these to help us understand why.  Your 

 absolutely right, the wheel is perfect, that is why I can't figure out 

 why we ever invented wooden wheels, rubber wheels, then wheels filled 

 with air, the stone wheel was perfect, it rolled just fine.  If it 

 ain't broke don't fix it, I get it, but I need to understand how and 

 why.  Sorry.....

Hmmm.  I detect a slight 'I been flamed' reaction.  I have learned to 
	


take what I perceive as a 'negative reaction' to an email with a grain 

of salt.  I just give the writer the benefit of the doubt and attribute 

the 'nasty comment' to his having a bad day.  Whether he had one or not 

just doesn't matter. To me, he was, and I'm the one that counts!!!  And, 

it could have been ME that woke up on the wrong side of the bed ..... 

but I never do that!!! 

Linn

do not archive

 	  Quote: 	
		  

 Thanks, Jason

 *



 *

Tim Olson

Joined: 25 Jan 2007
Posts: 2879

Posted: Thu Dec 11, 2008 7:02 am Post subject: Fuel Selector

I for one am happy to have the left/right/off as an option. It

does one thing that a Both position doesn't....it ensures that

I have full control over knowing what quantity is left in each

of my tanks.  With a both position, you may not know the exact

quantity in each tank.  The pressure coming out of the tank

isn't just a function of the height of the tank outlet, but

a function of the height of the column of fuel above it, and

that column is a sloshing variable.



As for the un-porting of fuel, it's a real problem, which is

why many certified planes are placarded or have POH warnings

about minimum takeoff fuel and such.  Coordinated approaches

are very important too, and while they teach you in your private

pilots course that you can choose between crabbing on final

and kicking the crab angle out at the last second, or slipping

to keep the nose aligned with the runway, you really have to

be wary of what you do when you're carrying less than 5 or

maybe even 10 gallons in a tank.



So that is why I personally love having just left/right/off,

and not both.  I have a totalizer and two float gauges,

and can roughly mentally calculate my fuel levels that I

should have burned.  Keeping them isolated helps me

ensure that I know more positively what my tanks hold.

Incidently, even in high-wing planes, I think the "both"

position perhaps promotes sloppy fuel management in some

cases.  Myself, I don't have rarely....extremely rarely,

landed with less than 5 gallons of fuel in a tank.  Maybe

only 2 or 3 times, and 2 of them where when I purposely

ran the tank dry having a near-full opposite tank.  But,

when I am on a long flight, I alternate fuel tanks a couple

times during the flight and then as I get lower in quantity

I keep one tank set to arrive in the terminal area with

at least 10 gallons of fuel, whereas I don't mind at that

point if the other tank has only 5 or 6 gallons left.

But, being conservative, there have actually been very few

times I've landed with under 16-18 gallons, because I set

my high alarm to go off at 7 gallons per side.  Fuel and

spark are the 2 most important things to making it safely

to the ground, as far as I can tell.



It's funny that experimentals have such a nasty accident

rate in the "fuel management" category.  I can only

wonder if this is because people tend to try to experiment

on their fuel system, rather than just going with the old

proven methods.



Tim Olson - RV-10 N104CD - Flying

do not archive

jason.kreidler(at)regalbeloit.com wrote:

 	  Quote: 	
		   

 Nearly the only thing that determines how hard a pump has to suck to get 

 fuel is the difference in height between the outlet of the tank and the 

 inlet of the engine.  The lowest intake fuel port determines this 

 number, not the number of lines.

 

 Rick, there is nothing complicated at all about Left - Right - Off. 

  That is why there has never been a pile of aluminum laying on the 

 ground with one empty tank of fuel, and one not so empty tank of fuel 

 adding to the fire.  Please remind those families that there is nothing 

 complicated about Left - Right - Off.  The point of my question was 

 simply to ask why it is done this way in low wing aircraft; I know there 

 must be some reason I am missing, which Bob, Linn, and Albert helped me 

 understand.  I for one will never stop asking why things are done the 

 way they are.  I am happy to know that your airplane has been built 100% 

 per plans, you are a flawless robot of a pilot, and are at no risk of 

 making me have to fight for my right to fly out of my field.  Mistakes 

 happen, there are defects in material and workmanship, and sometimes 

 luck just isn't on our sides.  Fortunately we have places like this to 

 ask simple questions like these to help us understand why.  Your 

 absolutely right, the wheel is perfect, that is why I can't figure out 

 why we ever invented wooden wheels, rubber wheels, then wheels filled 

 with air, the stone wheel was perfect, it rolled just fine.  If it ain't 

 broke don't fix it, I get it, but I need to understand how and why. 

  Sorry.....

 

 Thanks, Jason

ricksked(at)embarqmail.co
Guest

Posted: Thu Dec 11, 2008 7:29 am Post subject: Fuel Selector

Thanks for posting that Tim, 



It's kinda what I was trying to say but not as well written.

There are certain things I feel you just shouldn't with, especially if it's not broke although I did use steel braided flex lines on my -10 but they have been proven to be reliable and I plan to have them on a time change item on my condition inmspections. If I were to do it again I may have only used the flex line from the fuselage side to the tank. It would be easier to replace. I think we need to just make sure we do it better than the certified fleet sometimes. The fiasco here in Vegas is a good reason for that. I was talking to an owner of a Aerocommander this weekend and he was so frustrated at the shop performing work on his aircraft, he went in and found a "kid", maybe 19 in his words "hacking" on his airplane. The shop has three "mechanics" and one A&P/ with IA that "supervises" all the others who are not certified. He was upset about the fact he is paying top dollar for A&P services but in the end, the A&P only makes sure it was done right and signs it off. Now I was a 19 year old aircraft mechanic at one point but I would bet that I had much more training and I know I had more direct supervsion than what was being described to me last weekend. The twin Baron (I think it was a Baron) that went down had very recently been in the shop for engine work...but they continue to focus on the experimental and student pilots as the high risk activities. I can only recall one accident related to training and that was few years ago and was the result of a stall spin after the engine failed during of all things..engine out procedures. I can tell you there have been a bunch of incidents related to certifed aircraft and I know of no other incidents except the Velocity for exp[erimentals at VGT. Guess I rambled but we can't afford to not do it better than everyone else when it comes to experimental aviation. The fuel management issue still amazes me because a large percentage of that is a result of flying with air in the tanks. 



Rick S.

40185

do not archive



---

Tim Olson

Joined: 25 Jan 2007
Posts: 2879

Posted: Thu Dec 11, 2008 8:02 am Post subject: Fuel Selector

Regarding the braided lines....I don't think that in that

case it's quite the same as changing the fuel distribution

method.  With the lines, I actually think there's a good

argument that the braided lines will be more reliable

and basically immune to flex fatigue cracking, whereas

there are many of us who found first-hand that there have

been bad batches of aluminum tubing from Van's in that

3/8" size. (and even the good batches aren't necessarily

all that fantastic)  I think that probably the best

someone can do would be to use conductive teflon lines

that are overbraided with stainless and have anti-chafe

covering.  That would probably be the ideal.  The

drawback to the braided lines is just weight.  The

additional drawback to the various rubber type braided

lines is even more weight, and a life limit.  But those

things aren't really in the same ballpark as some of

the other mods.  After all, what kind of lines are used

from the firewall forward?  No matter what kind of lines

are used, they need protection, and need to be well

secured.  I actually plan at some point to replace

my lines with braided conductive teflon, and go all

the way from tank to firewall that way with some

exceptions.



Regarding that maintenance fiasco, I think that's

just another example of how businesses react with payroll

when the economy tightens...not to mention our ever

decreasing worker quality that the country produces.

It amazes me how poor the work ethic is in many of

the people that are turned out today.  I know when

we go hiring, the "Good help is hard to find" saying

really holds true.  Funny that unemployment is starting

to be such a big thing again, yet around here we

really have trouble finding top notch skills.



Sorry for the rambling, but yep Rick, you're

preaching to the choir.  If the news could only

be balanced and give perspective to crash reporting,

people would have an entirely different opinion

about flying.



Tim Olson - RV-10 N104CD - Flying

do not archive

Rick Sked wrote:

 	  Quote: 	
		   

 

 Thanks for posting that Tim,

 

 It's kinda what I was trying to say but not as well written. There

 are certain things I feel you just shouldn't with, especially if it's

 not broke although I did use steel braided flex lines on my -10 but

 they have been proven to be reliable and I plan to have them on a

 time change item on my condition inmspections. If I were to do it

 again I may have only used the flex line from the fuselage side to

 the tank. It would be easier to replace. I think we need to just make

 sure we do it better than the certified fleet sometimes. The fiasco

 here in Vegas is a good reason for that. I was talking to an owner of

 a Aerocommander this weekend and he was so frustrated at the shop

 performing work on his aircraft, he went in and found a "kid", maybe

 19 in his words "hacking" on his airplane. The shop has three

 "mechanics" and one A&P/ with IA that "supervises" all the others who

 are not certified. He was upset about the fact he is paying top

 dollar for A&P services but in the end, the A&P only makes sure it

 was done right and signs it off. Now I w! as a 19 year old aircraft

 mechanic at one point but I would bet that I had much more training

 and I know I had more direct supervsion than what was being described

 to me last weekend. The twin Baron (I think it was a Baron) that went

 down had very recently been in the shop for engine work...but they

 continue to focus on the experimental and student pilots as the high

 risk activities. I can only recall one accident related to training

 and that was few years ago and was the result of a stall spin after

 the engine failed during of all things..engine out procedures. I can

 tell you there have been a bunch of incidents related to certifed

 aircraft and I know of no other incidents except the Velocity for

 exp[erimentals at VGT. Guess I rambled but we can't afford to not do

 it better than everyone else when it comes to experimental aviation.

 The fuel management issue still amazes me because a large percentage

 of that is a result of flying with air in the tanks.

 

 Rick S. 40185 do not archive

Display posts from previous:

	Matronics Email Lists Forum Index -> RV10-List	All times are GMT - 8 Hours
Page 1 of 1

Jump to:

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