Hi, (A:ENG1 FUEL FLOW PPH, pounds per hour)still give a value even with the engines, APU and everything off. Any ideas?cheers,nick

Nick,I'm so new to this xml that my brain is bustin, however, maybe what you might try is a if then conditional.If engine1 operatin and if fuel pumps on and pwr available to pumps then Fuel flow available=true els gauge shows zero. I could not even begin to suggest the code to emulate that statement.I have come across a lot of bugs in my on going build of the overhead 737-400 panel some in the fuel system but a lot in the electrics but I'm still learning.This old dog can still learn new tricks,!Douglas Ret B-707

Nick,ENG FUEL FLOW is linked to N2 rotation. When you shut down an engine using its fuel cutoff switch, the logic says this Avar should turn to zero; however this is not FS logic here :-) and it will give a positive number as long as N2 decelerates to full stop.To avoid this "inconvenience" I've coded an LVar that effectively goes to 0 at fuel cutoff.Tom

Thanks Tom. I have assigned an L:variable to each engine flow so can manipulate that to zero. However, before I did this, there was still flow with N2 at zero. Problem is, (A:FUEL TOTAL QUANTITY WEIGHT, pounds)is used as a readout, and this continues to drift downwards.Anything in the cfg or air files to set flow to zero with engines off, I wonder.cheers,nick

If I recall correctly, it's been stated before that the fuel flow never goes to zero. I don't think anyone's found a work-around to get it to stop using fuel when nothing's running.

""If I recall correctly, it's been stated before that the fuel flow never goes to zero.""In my 757 ENGn FUEL FLOW is 0 as long as N2 is 0, and at that moment there is no fuel consumption at all.If Nick or someone else reads a constant positive FF with 0 N2, then maybe a fuel var in aircraft.cfg has some kind of influence. Actually I've made such a lot of changes in my 757 engine tables that I honestly don't know which parameter could be related to this weirdness.Tom

After a lot of tweaking and testing, I found a fix for my particular problem in the air file thus.To correct for zero fuel flow with engines off. Air file. Section 1506. Mach index 0, Y axis should be set to zero. In fact, all curves (both?) should go to zero.cheers,nick

Nick, are you speaking of table 1506, CThrust Factor vs CN1? If so, then both Mach 0 and .90 should be CTF=0 for CN1=0 . Thrust is not supposed to exist when ©N1 is zero (at least in MSFS).Tom

Yes, sorry, I meant table 1506, although they look like graphs to me:-)We had a little bit of thrust set for some reason and this produced a significant fuel flow. cheers,nick