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If I really wanted to know how much fuel was in the tanks

It’s not clear what advantage it has over a float gauge, other than there being no float to sink. If there’s any wing dihedral you can place it inboard to measure empty, outboard to measure full, but it takes two units. I think it is sensitive to the index of refraction of the fuel, e.g., different readings from av gas and mo gas. And you still need some sort of electronic correction to in-between empty and full, unless you have perfectly uniform tanks.
 
Float type senders are 1/4 of the price of those but if you don't like float type senders or don't have space to install them, like in my situation, then you might want to look at this type too.
 

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It's also designed to mount directly on top of the fuel tank - which in this case means on the top surface of your wing leading edge. Less than ideal.
 
airguy said:
It's also designed to mount directly on top of the fuel tank - which in this case means on the top surface of your wing leading edge. Less than ideal.
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Yep. I emailed asking if I could install it upside down from the bottom up where it can't be seen and they told me no because they're not sealed inside.
 
Search for the perfect sensor continues

Thanks for the comments. Didn't catch that it has to be in the top of the tank. I will go back to relying on a pencil- paper- and the time.
 
Jermechanic said:
Thanks for the comments. Didn't catch that it has to be in the top of the tank. I will go back to relying on a pencil- paper- and the time.
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I continue to be amazed by how accurate my float gauges are (not counting the top 5 gal, which they cannot see) once they’re calibrated thru the efis.
 
Jermechanic said:
Thanks for the comments. Didn't catch that it has to be in the top of the tank. I will go back to relying on a pencil- paper- and the time.
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Get a fuel totalizer.. sometimes you’ll find a stand alone FT60 pop up in the classifieds. My 23 year old floats are really accurate down towards the lower half of the scale, and the fuel totalizer is accurate to within two tenths of a gallon! Instead of changing tanks every 30 minutes, use the totalizer to change after 5 or 10 gallons. This way you know how much fuel you have AND how much remaining in each tank.
 
Taltruda said:
Get a fuel totalizer.. sometimes you’ll find a stand alone FT60 pop up in the classifieds. My 23 year old floats are really accurate down towards the lower half of the scale, and the fuel totalizer is accurate to within two tenths of a gallon! Instead of changing tanks every 30 minutes, use the totalizer to change after 5 or 10 gallons. This way you know how much fuel you have AND how much remaining in each tank.
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The fuel computer built into my EFIS, plus float senders, plus pen/paper and route planning removes a lot of the fuel mystery for cross country flight. I set the timer on my navigator to switch tanks every 30 minutes. The fuel computer is very accurate and will continuously tell me Gallons Used, Gallons Remaining, Hours Remaining, and gallons needed to get to the next waypoint. As well as miles per gallon.
 
I do the same as Tom.

I don’t trust the floats but the totalizer is very accurate. I use the totalizer and time for cross country trips. I take off on the left tank and have a timer set for 1+10 hrs, which is about the time the left tank drinks 11 gals after taxi, takeoff, climb and cruise. When the totalizer shows 31gals I switch to the right tank for cruise until TOD. Then I switch back to the left (with 10 gals) for descent, landing and taxi. We typically stop every 3 hours for breaks.

There are many techniques.

Has anyone installed Cies or other measuring devices?
 
Another vote for the totalizer, they really do work wonderfully. When I was running an FT-60 my actual gallons at fillup versus predicted gallons needed was within .1 gallons most of the time, and never exceeded .2 gallons. You'll need to play with it a bit after installation to get the K factor dialed in just right, but once that's done it's bang-on. Set your alert to switch tanks at every 5 gallons burned and enjoy.

I don't run an FT-60 anymore because I'm using the SDS, which internally calculates fuel usage based on dwell time on the injector pulses and feeds that to the EFIS - if anything, it's even more accurate.
 
No comment on this product in particular, but I am a fan of "direct" reading of fuel levels in the tanks as a hard backup to the totalizer. Dont get me wrong, the totalizer is the primary indicator, but it does NOT take into consideration any physical fuel in the tanks. On the off chance you develop a leak enroute, the information from the totalizer is flawed. That said, I am very familliar with a long standing military aircraft that has no direct reading of the fuel in the tanks and is 99% reliant on the crew chief inputting the correct fuel on board at preflight to determine fuel reserves in flight. However, even this aircraft has a certain "behavior" of the fuel system that informs the crew if the system is tracking predicted curves or not. This single data point happens at a point that the crew can make a safe landing with the fuel on board if the fuel burn is way off.

Personally, I would be happy to go away from a variable "level" indication in the tanks if I could be sure of a more robust discrete "5 gallons or less" light or timer in addition to the totalizer.
 
Toobuilder said:
... the totalizer is the primary indicator, but it does NOT take into consideration any physical fuel in the tanks. On the off chance you develop a leak enroute, the information from the totalizer is flawed.
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I use the totalizer concept on mine. MGL calls it "Calculated Fuel Tanks" if you don't have physical tank senders and uses fuel flow usage to display your "fuel tank levels", but I also time my flights so my totalizer is secondary just to confirm my stopwatch. Nothing beats a simple stopwatch.
 
Pilot135pd said:
I use the totalizer concept on mine. MGL calls it "Calculated Fuel Tanks" if you don't have physical tank senders and uses fuel flow usage to display your "fuel tank levels", but I also time my flights so my totalizer is secondary just to confirm my stopwatch. Nothing beats a simple stopwatch.
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The problem with using ONLY the totilizer or even the stopwatch method is that if you developed a fuel leak, you can run out of fuel without knowing it. The float gauges (if setup right) are very accurate towards the lower half of the tanks, and if you see a gauge reading close to zero while your totalizer or stopwatch method says you have plenty, you should consider landing earlier than normal to investigate..
 
Taltruda said:
The problem with using ONLY the totilizer or even the stopwatch method is that if you developed a fuel leak, you can run out of fuel without knowing it. The float gauges (if setup right) are very accurate towards the lower half of the tanks, and if you see a gauge reading close to zero while your totalizer or stopwatch method says you have plenty, you should consider landing earlier than normal to investigate..
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And that's why I'm also trying to install gauges in the tanks, for even more redundancy, but it's proving hard to do on an ex-military plane that doesn't have them from the factory. I'm having to design some aluminum blocks and to fabricate them I'll have to depend on others. That's slowing me down.
 
100% fuel totalizer as a necessary weapon. However, having had one fail, slowly, providing ever decreasing, and subtle, fuel flow readings, I would never rely on one exclusively.
Also, one could, accidentally, under fill, or forget to fill, a tank. The totalizer only calculates on what you tell it.
I also want to know what is in each tank at all times, at least within the tolerances of the SW senders and tank dihedral.
Time, as others mentioned, also is constantly on my mind. Every flight I am comparing the tank levels, totalizer calcs, and my own brain (such that it is) on what I think it should be for the time and power setting based off my experience.

When I fill up, I always ask myself, “how much fuel should I take?” and check that against the pump.
 
Jermechanic said:
This looks interesting from Holley. Has anyone tried this fuel level sensor in an aircraft?

https://www.holley.com/products/gau.../gauge_accessories_and_harnesses/parts/19-250


https://fb.watch/ocY8X57Isg/?mibextid=v7YzmG
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My first RV7A fuel gauge has been working flawlessly (touch wood) for the last 18 years. Setup used- Vans in-tank capacitance plates, Dynon converters & Electronics International FL-2 gauge. Accurate from full 21 gallons down to .5 gallon on each tank.
Current 6A is just as accurate with D10 EMS, Dynon converters, & Vans style in-tank plates.
 
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FUEL QUANTITY

G'day folks,

RV-7, 78 litres per tank, Dynon Skyview floats & totaliser fuel used/remaining, dip stick.

Refuel 'Full' option is 156 litres, refuel 'Pre-Set' option is 150 litres, floats indicate 60+ litres until 58 litres, then as per calibration.

I check fuel remaining often, and, if (when ?) I note a discrepancy, I would replan assuming worst case - so far, so good.

I dip before & after flight, and compare dip with the Dynon indications

Regards
 
I keep a spreadsheet where I record L float, r float, totalizer, and fuel added to each side at every top-off. I then plot that data and use it to tweak the sensor translation curves. This keeps it amazingly accurate, within a gallon or two.
 
cdeggz said:
I keep a spreadsheet where I record L float, r float, totalizer, and fuel added to each side at every top-off. I then plot that data and use it to tweak the sensor translation curves. This keeps it amazingly accurate, within a gallon or two.
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I did the same in Phase I (-7) but would expect better correlation. I get in with .2 gal on mine? I think others do too. You might want to determine the cause of variance.

For the OP theme - - I have the floats and the only reliable region is under 7 gallons in each tank. That is very accurate. If it says 2 gallons, that is what it is.

I sure wish the gages were accurate full range and that the G3X knew which tank it was on for tracking the level of each tank - -if wishes were horses . . . .

Nice post on the laser sensors, now- if it could be adapted to the RV.:D:D
 
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