Return Fuel Line Quantity

Re: Return Fuel Line Quantity

by Bill Hertzel » 7 years ago

Bill Hertzel

13 1.95k 8k

There are a bunch of variables that are involved here.
Fuel pressure, Orifice Size, Temperature, Etc. that make it difficult to give an accurate answer.
But 3-5 gallons per hour would be a reasonable ballpark number.

The fuel pressure is regulated at 3-5psi so the engine RPM is immaterial.
If you have an electric AUX Fuel Pump, you will be returning fuel even with the engine OFF.

---

Bill Hertzel
Rotax 912is
North Ridgeville, OH, USA
Clicking the "Thank You" is Always Appreciated by Everyone.

Re: Return Fuel Line Quantity

by Bill Russini » 7 years ago

Bill Russini

5 9 0

Thank you Bill, those figures would confirm what I am experiencing right now. I only have a supply line transducer and the indicated fuel burn w/o a return line transducer are close to 50% greater. For example, my actual burn on my last two flights was 4-5 The fuel flow burn indicated 8 gallons +/- on both flights. I think it’s time to install the recommended return line transducer to get a more accurate burn. Thanks again

Re: Return Fuel Line Quantity

by Bill Russini » 7 years ago

Bill Russini

5 9 0

FYI, after collecting a considerable amount of fuel burn data, ‘K’ factor corrections for the most part useless w/o the return line transducer

Re: Return Fuel Line Quantity

by James Ott » 7 years ago

James Ott

22 342 411

Its interesting you find K factor corrections useless. I have just a supply line transducer on my 912uls (no electric aux pump) and once I got my K factor calibrated for my normal cruise conditions it has been quite accurate and very usable for over 600 hours now.

Re: Return Fuel Line Quantity

by Bill Russini » 7 years ago

Bill Russini

5 9 0

Fortunately I/we only fly at most 2 hour segments and stick the tanks b4/after. My original float gauges are accurate fm 1-3 gallons.

I’m happy to read ur ‘K’ adjustment(s) worked...thanks for ‘jumping in on the forum’.

Btw, tech support fm Flight Data have been wonderful in their support.