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-   -   Fuel Tank Mods - With A Twist (https://vansairforce.net/community/showthread.php?t=83785)

WingedFrog 03-13-2012 12:25 PM

Quote:

Originally Posted by Gagarin737 (Post 639096)
The main reason for me to install the Moeller fuel gauge is that you can see the fuel level during refueling. You can't see the sight glass during refueling or during flight when you have luggage in the compartment. The mechanical fuel gauge is always visible.


Although my fuel tank is still on the workbench waiting for the sealant to cure, after looking at a friend's -12 sight glass, I agreed with his statement as well as Gagarin's that it is useless during refueling and hardly useable for pre-flight check. I am wondering though if for refueling some contraption using a miror could help. This would require just to view the top 3 windows, i.e., those to check when topping off. the mirror could hang from the top of the tank and reflect toward the filling neck. Just an idea...

gblwy 03-13-2012 01:36 PM

Fill the tank
 
When would you not want to fill the tank? I always aim to fill the tank. Minimises the risk of condensation, and you can always estimate the amount of fuel used based on time flown. I typically fly at 100+ knots at 4700rpm burning 16 or so litres an hour. I calculate based on 17 litres an hour. The float fuel gauge is my backup indication, and the contents based on the fuel flow is my second backup indication.

Cheers...Keith

gasman 03-13-2012 02:04 PM

Quote:

Originally Posted by gblwy (Post 639277)
When would you not want to fill the tank? I always aim to fill the tank. Minimises the risk of condensation, and you can always estimate the amount of fuel used based on time flown. I typically fly at 100+ knots at 4700rpm burning 16 or so litres an hour. I calculate based on 17 litres an hour. The float fuel gauge is my backup indication, and the contents based on the fuel flow is my second backup indication.

Cheers...Keith

I think the problem is over filling the tank. You can't see the fuel level down the neck.

ArlingtonRV 03-13-2012 02:07 PM

But you can hear it. I can tell by the sound when mine is full.

Tony_T 03-13-2012 02:36 PM

Fuel Tank mods & refueling
 
Quote:

Originally Posted by WingedFrog (Post 639257)
Although my fuel tank is still on the workbench waiting for the sealant to cure, after looking at a friend's -12 sight glass, I agreed with his statement as well as Gagarin's that it is useless during refueling and hardly useable for pre-flight check. I am wondering though if for refueling some contraption using a miror could help. This would require just to view the top 3 windows, i.e., those to check when topping off. the mirror could hang from the top of the tank and reflect toward the filling neck. Just an idea...

Actually, the sight window is not intended for use during refueling since it can't be seen from the starboard side at all. Even if you could see the sight gauge and even if you have the Moeller gauge on top of the tank, it won't register the top gallon or two, putting the last gallon or so into the tank is the problem especially if you are using 100LL out of an av gas refueling pump. Those nozzles put out a fast flow that is hard to control and the opening on the 12 will just spray out fuel if you are not super careful. With a hand pump setup you can go very slow at the final last gallon and actually hear the fuel coming up into the filler neck. When away from my home airport and using an airport filling station I place a thin rubber pad over the filler opening to avoid the chance of a spill on the lexan window:

The picture shows the pad in place and my home base refueling setup. I normally run on car gas from the local Chevron.

The point of all this being that even with the Moeller gauge in the tank, please be really careful putting in the last couple of gallons to avoid fuel burping out on you and the airplane :o.

Without the Moeller gauge, a quick glance at the Dynon fuel gauge before shutdown will tell you how much fuel you will be putting in (obvious, I know).

Regarding preflight, if you look at the sight glass window, you will NOT see the fuel since the fuel is clear. If you place your hand on the trailing edge of the wing and gently shake the wing up and down while looking at the sight glass you WILL see the fuel bobbing up and down (obvious, again), unless the tank is chock full.

All that said, I am seriously considering installing a Moeller gauge since I have to pull the cover off the tank to do the Service Bulletin reinforcement. But by gosh I would be keeping my sight glass, so I can visually check my fuel at preflight.

I don't think I have driven the thread off topic since the point of the thread was installing the Moeller ;).

Tony

Ausflyer 03-13-2012 02:50 PM

Dip stick
 
I agree - the sight glass is next to useless. And I too can also hear when the fuel level has reached the bottom of the filler neck. I have a moeller fuel guage installed. But I always rely on my old fashioned dipstick when I do my preflight or to know how much fuel the tank will take when I refuel.

The tanks are all the same. so the dipsticks should all be the same. Except mine is in litres.

I know Tony at Pt Macquarrie has one too.

Mine is made from a flexible plastic tongue. The joiner that goes between sheets of particle board flooring. Mark the divisions with an automatic centre punch.

Anybody else use a dipstick?
Rod

N223JH 03-13-2012 04:51 PM

Dipstick
 
3/16" dowel from Aviation Dept at Home Depot. Darker color wood shows fuel level better. I beveled one end to use as a cap pry device. Pencil markings in 2-gallon increments. Pretty high-tech.

Jim
RV-12 N233TX
flying 98 hours

rgmwa 03-13-2012 07:18 PM

Quote:

Originally Posted by Ausflyer (Post 639316)
Mine is made from a flexible plastic tongue. The joiner that goes between sheets of particle board flooring. Rod

Rod, isn't there some potential risk of static discharge using a plastic dipstick?

Threetracker 03-13-2012 08:02 PM

Rod is almost exactly right...
 
Rod is almost totally correct. He feels that the sight glass is almost totally useless; when in reality it is totally useless. The Moeller guage unit is the only smart way to go.

Carrie and I do quite a bit of cross country flying and when we do we try and plan 200-250 mile fuel stops for two reasons. First, my bladder range is less than my airplane full fuel tank capability and 2) I really like to have a 1.5-2.0 reserve aboard when cross country.

I carry a couple of folding nice plastic gas cans that I can use to buy premium uleaded enroute (that's what courtesy cars are for) and the line staff have never complained about an ice-cream sundae on return (nor has the pilot).

Whe we fly less than 2 hour legs we rarely top off the tank...why carry around the extra weight...and the Moeller reading full is over 15 gallons in our airplane. When we aren't going cross-country, our dog Harriet almost always occupies the baggar compartment and she weighs about 45 lbs. after we stop for the $100. hamburger..

I look at the Moeller before every flight...I use the Moeller whenever I fuel the aircraft and I read the Moeller inflight any time I am showing under 6 gallons on the Dynon reading. I am wayyyy more trusting of the Moeller than any other method of determining my fuel onboard.

Jay Sluiter
N124CS
550 hours on the tach
Love our Moeller...

DonFromTX 03-13-2012 08:31 PM

Mind telling me where you got the folding gas cans? I need a couple myself.

Quote:

Originally Posted by Threetracker (Post 639406)
Rod is almost totally correct. He feels that the sight glass is almost totally useless; when in reality it is totally useless. The Moeller guage unit is the only smart way to go.

Carrie and I do quite a bit of cross country flying and when we do we try and plan 200-250 mile fuel stops for two reasons. First, my bladder range is less than my airplane full fuel tank capability and 2) I really like to have a 1.5-2.0 reserve aboard when cross country.

I carry a couple of folding nice plastic gas cans that I can use to buy premium uleaded enroute (that's what courtesy cars are for) and the line staff have never complained about an ice-cream sundae on return (nor has the pilot).

Whe we fly less than 2 hour legs we rarely top off the tank...why carry around the extra weight...and the Moeller reading full is over 15 gallons in our airplane. When we aren't going cross-country, our dog Harriet almost always occupies the baggar compartment and she weighs about 45 lbs. after we stop for the $100. hamburger..

I look at the Moeller before every flight...I use the Moeller whenever I fuel the aircraft and I read the Moeller inflight any time I am showing under 6 gallons on the Dynon reading. I am wayyyy more trusting of the Moeller than any other method of determining my fuel onboard.

Jay Sluiter
N124CS
550 hours on the tach
Love our Moeller...



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