Fuel Quantitiy Indication

[CoachTom]

Does anyone know if there are any secondary fuel level indicators within the M20K fuel tanks? 

I believe, that when we fill the tanks to the bottom of the anti-siphon plate in each tank that we would be at 72 gallons total. But due to the needs of weight and balance, less fuel might be required and is there a "split ring" or "tabs" that might be below the Siphon plate (I can't see any..) that might indicate a specific volume of fuel?

I guess the second or follow on question might be "has anyone ever calibrated a fuel level dipstick" to use on a M20K?

I always am too worried about fuel spilling on my wings or if the full service fueler is scratching the wings with the nozzle, or if i have my credit cards on me or enough cash in my pocket to pay for the fuel... To condense my usual fueling experience; i always forget to see how much extra fuel can be put into the tanks above the siphon plate.  Would anyone ever have measured that quantity?

 

Thanks in advance!

 

TMcD

 

[chrisk]

Bumping this 4 year old thread, as I have the same question.  The POH makes no mention of a visual gauge in the tank. I guess they expect us to use the sight gauges on the wings.  --I'm not real comfortable with that.

[Cris]

The POH will say to use the fuel guage on the wing as it is more accurate on the ground than the panal guage. However it is still a rough estimate and the best bet is to use a dipstick that is calibrated for your specific A/C. You can get one from any number of sources such as Sporty's or Aircraft Spruce. Once you do the calibration you can determine the exact amount of fuel at say the bottom of the tabs or a rivet half way up the restrictor so you won't need the dipstick. In some cases like my long body the dipstick will be zero with plenty of fuel left in the tank. It simply is dry at the fill point so the wing guage or fuel computer is the only alternative.    

[Bob - S50]

Our group did not want to fill our J to full or 50 gallons.  We wanted to fill to 30 gallons.  We've done two things:

 

1.  We installed an Aerospace Logic FL202.  It has proven to be very accurate in level flight.  However, since the plane sits nose up on the ground, it reads higher than actual on the ground.  Just the opposite during descents.  When you install it you put the plane in a level flight attitude, drain the tanks, add the unusable amount, then calibrate it in 2 gallon increments until it is full.  You have to do that with both tanks.  This has allowed me to run a tank down to 3 gallons during flight and leave the fuller tank for the pattern and landing.  Sure enough, it had 3 gallons in it when I landed.

 

2.  We made our own fuel stick.  We took a piece of wood that was long enough to be our stick.  After running a tank down to 5 gallons during our flight home from SQL, I opened the cap and there was no fuel below the cap.  I then put in one gallon and there was then fuel below the cap.  I put the stick all the way in until it hit the bottom of the tank while holding it upright against the inboard edge of the hole and quickly pulled it out.  I made a mark on the stick at that level.  I then added 2 gallons and made another mark.  I continued to do that until I got to the 50 gallon tab.  For that last fill, I judged if adding one gallon or two was closer to being exactly 25 gallons.  I then marked the last mark as 25 gallons and counted backwards and marked all the other marks.  We now have a stick calibrated from 6 to 25 gallons in mostly 2 gallon increments.

 

By the way, I've been told you want to use wood because it floats!  If you drop it in the tank by accident, it will be much easier to retrieve.

 

Bob

[The-sky-captain]

I use the following site references and it runs pretty close with my JPI.

To the tab- 25 gallons- per POH

To the "shelf" on the outboard edge of fuel tank-20 gallons

To the corner, where the bottom of tank meets the side of the tank- 10 gallons

[201er]

Make a fuel dipstick. Run the tank dry in cruise. At the pump fill in 1 gallon increments, stop and measure on dipstick. Make a chart.

[BigTex]

Make a fuel dipstick. Run the tank dry in cruise. At the pump fill in 1 gallon increments, stop and measure on dipstick. Make a chart.

Anyone that has the 54 gallon bladders and want a chart... let me know.  I created one for my plane.  it's pretty accurate.  The only issue is that there's 5-6 gallons in each tank when the stick reads zero.

[dham1956]

3.2 gal per tank above flapper m20k

[Bob - S50]

Make a fuel dipstick. Run the tank dry in cruise. At the pump fill in 1 gallon increments, stop and measure on dipstick. Make a chart.

Don't bother making a chart.  Just use a piece of wood for the dipstick (so it will float if you drop it).  After each time you dip it, mark it with a pen at the level of the fuel.  After the tank is full and you have the top mark (for which you know the number of gallons) work backwards labeling each mark.  After that you won't need a chart, just dip the stick and get the reading directly off the stick.

 

Bob

[rbridges]

 

 

By the way, I've been told you want to use wood because it floats!  If you drop it in the tank by accident, it will be much easier to retrieve.

 

Bob

 

that's a good idea.  In dentistry, we tie floss around small tools so it won't go down the throat.  You could always tie some string around the end of whatever you use to measure the fuel.