Fuel Gauge for Jab SK

[Downunder]

A Fuel flow meter, regularly checked for accuracy works well....

 

Cross checked against original dip, time, gauges and known fuel burn while in flight.

 

 

[turboplanner]

Fuel exhaustions are not unknown in GA but seem to be prevalent in RA.

 

Facthunter made the important point about not flying to the extent that a fuel exhaustion may occur.

 

Some of the lessons I learnt is that you may have to spend an hour or more diverting around a storm, or you may be faced with a situation at your destination where an aircraft had flopped down gear-up right in the middle of it and you have to find another airfield.

 

The story of the two RPT flights heading for Adelaide where they flew around the holding points (in Bruce's "Vacant" CTA) that they had to make an emergency diversion to Mildura, and then found it was socked in, with one pilot just getting enough ground visibility to land and then running out into the middle of the runway and talking the second aircraft in just by the sound of its engines (I wonder where that report's at) shows that sometimes not even the mandatory reserves are enough.

 

 

[Downunder]

Perhaps this is a solution 

 

http://www.beliteaircraftstore.com/fuel-probe-system/

 

They also sell the gauges....... not particularly cheap though. ...

 

 

[facthunter]

You can NEVER operate a plane legally just by what the gauges  say. You must start from( observed) full or use a proven dipstick or add a quantity (accurately) from empty or remove an accurate quantity from full. Flow meters( if accurate) help.. Unfortunately, in flight, one might wish to have a more trustworthy indication to reduce the pucker factor. Long thin wings present a particular difficulty. I have found the best gauges are the simplest . A glass tube each side and you can rock the planes wings to observe the changes at least giving you some assurance. Such GAUGES? are affected by pitch of the fuselage on the ground with tailwheel planes, an allowance must be made. There's sometimes two scales in different colours..  Nev

 

 

[Bruce Tuncks]

Banggood has a marine fuel gauge sender which looks as if an external float goes up and down a stainless steel tube. No mechanical connection is obvious. It says the output varies 240 to 30 ohms. The whole thing looks robust and easy to fit. I sure would appreciate some comments. I don't understand how it would work. Maybe reed switches inside the tube? This would reduce the accuracy a lot. You would only get as many possible values as you had reed switches. Maybe it has some other operating principle. Capacitance appeared good to me but it suffers from being sensitive to the type of fuel.

Before noticing this banggood sender, I was thinking of having a U tube where the outer end returned to the tank top, and the inner side to a tube which entered the top of the tank and extended to the bottom. To read the level, you would have to pump some air into this tube until it blew bubbles from the bottom of the tank. The reason for the far end to be in the tank is because the whole tank pressure would be cancelled out and the u tube would only show the difference .

But... what fluid to put into the u tube? probably would have to be avgas because of the risk of the contents of the u tube going into the tank. And where to put the thing? Maybe the side of the fuse near the tank but where it would be easily seen... Would it add to the fire risk ? Yes but not much is my guess.

This whole thing is a bit messy but would be very accurate. The banggood gauge on the panel would look more professional.

[Downunder]

This one?

https://m.banggood.com/KUS-300mm-240-33ohms-Boat-Marine-Sender-Car-Truck-Gauge-Water-Level-Sensor-p-1382871.html?rmmds=search

 

Not sure how it works.....a magnet it the float?

[facthunter]

Even the most sophisticated fuel Qty Gauges I know of don't permit sole reliance on them. They all can fail as well. A fuel leak (SOMEWHERE)or a motor using above normal fuel can cut your margins. From a practical viewpoint I prefer a float mechanically linked OR a sight gauge on each side or to be able to SEE the level in a clear panel on the end of the tank. You ARE required to calibrate your QTY indications and know what fuel is unuseable..

If you can see the sight gauge you can also rock the wings unbalanced (skid it) to get a better assessment when fuel is low what you have remaining. You are better to land with power than try to stretch it and have to land without it and without much choice of where when the engine quits or a finer control of your touch down point which you have with power. Nev