Unsolved Automatic forward fuel transfer system not working in 4.37?
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Hi all. Sorry to spam bug reports, but I find them as I go through the manual. Please be patient with me.
Now, to quote the manual,
The automatic forward fuel transfer system operates only when the FUEL QTY SEL knob is in NORM and the total forward fuselage fuel quantity indication is less than 2800 pounds. In the C, forward fuel transfer starts when the forward heavy fuel differential drops below 300 pounds and stops when the forward heavy fuel differential reaches 450 pounds.
yet, both in TR_BMS_02_Navigation (after a few minutes of AB flying to clear out the wing and almost emptying the fwd tanks) and TR_BMS_04_ILS_Navigation (which already starts with a bad aft CG), there is no sign of any automatic fuel transfer from aft to fwd. I confirm that FUEL QTY SEL was set to NORM and the ENG_FEED was set to NORM as well. In this setup, fuel is drained equally from the FR and AL systems, FR completely empties first (as it starts way lower, at the beginning of my tests), both in AB usage and MIL flight.
Out of curiosity, I checked out how DCS handles this. Although there is no active pumping visible (flying at idle for a long time), in the same setup, only the AL system is drained until reaching 450pounds below the FR system, then they both get used at the same rate, with AL always emptying first.So is this a TE issue, or a 4.37 issue, or was this never implemented in the first place? I know how to manually balance my tanks, but that’s a different topic.
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@karamazovnew said in Automatic forward fuel transfer system not working in 4.37?:
Hi all. Sorry to spam bug reports, but I find them as I go through the manual. Please be patient with me.
Now, to quote the manual,
The automatic forward fuel transfer system operates only when the FUEL QTY SEL knob is in NORM and the total forward fuselage fuel quantity indication is less than 2800 pounds. In the C, forward fuel transfer starts when the forward heavy fuel differential drops below 300 pounds and stops when the forward heavy fuel differential reaches 450 pounds.
yet, both in TR_BMS_02_Navigation (after a few minutes of AB flying to clear out the wing and almost emptying the fwd tanks) and TR_BMS_04_ILS_Navigation (which already starts with a bad aft CG), there is no sign of any automatic fuel transfer from aft to fwd. I confirm that FUEL QTY SEL was set to NORM and the ENG_FEED was set to NORM as well. In this setup, fuel is drained equally from the FR and AL systems, FR completely empties first (as it starts way lower, at the beginning of my tests), both in AB usage and MIL flight.
Out of curiosity, I checked out how DCS handles this. Although there is no active pumping visible (flying at idle for a long time), in the same setup, only the AL system is drained until reaching 450pounds below the FR system, then they both get used at the same rate, with AL always emptying first.So is this a TE issue, or a 4.37 issue, or was this never implemented in the first place? I know how to manually balance my tanks, but that’s a different topic.
I believe in this TE you fly a D version aren’t you ?
Have you created an imbalance first ?
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@Mav-jp Yeah, I’m dumb. It is indeed the D version in those TE missions. I should’ve read the manual more carefully. Ups.
C Normally, the forward tank fuel quantity is 0-600 pounds greater than the aft tank quantity. D Normally, the aft tank fuel quantity is 700-1350 pounds greater than the forward fuel quantity.
In conjuction with:
This system does not correct a forward fuel imbalance since it only transfers fuel from aft to forward.
it explains why I wasn’t seeing any effect on those missions.
However, found something weird in the C version. One time it worked just fine. But then I’ve tried the following scenario a few times, with the same results:
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custom mission with one F-16CM-52
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jettisoned all stores
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here’s the fuel dial, notice AL at 2800
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ENG FEED switch to FWD
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flew around with afterburner in circles until FR dropped to 600.
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dropped out of afterburner assumed around 3000-4000 pph
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ENG FEED switch to BOTH
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here’s the fual dial immediately after that:
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flew around and noticed that the AL needle was stuck at 2800. Flew until FR went to zero
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here’s the fuel dial (NORM):
(notice here the 3000 total indication, which is NOT 2800+0) -
here’s the reservoir situation (RSVR)
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quit out of the mission and rejoin it immediately
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here’s the fuel dial (NORM)
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and here’s the reservoir (RSVR)
All normal, and notice the total of 3000 indicated before we quit the mission as well.
Is this the bug you found?
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@karamazovnew said in Automatic forward fuel transfer system not working in 4.37?:
@Mav-jp Yeah, I’m dumb. It is indeed the D version in those TE missions. C version seems to work fine. Flying at idle clearly raises the level in the FR system. I should’ve read the manual more carefully. Ups.
C Normally, the forward tank fuel quantity is 0-600 pounds greater than the aft tank quantity. D Normally, the aft tank fuel quantity is 700-1350 pounds greater than the forward fuel quantity.
In conjuction with:
This system does not correct a forward fuel imbalance since it only transfers fuel from aft to forward.
it explains why I wasn’t seeing any effect on those missions.
Have you actually discovered a bug, or where you just pulling my leg?
ok i confim no bug, i was testing in FULL AB where the system didnt have the time to transfer LOL
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@Mav-jp Sorry, I was editing the previous comment, please read it again.
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@Mav-jp Oh, and I just tried again, this time in a mission without external fuel. Only this time, I flew a lot to allow the total to get below 2800. The AL needle started dropping. I exited the mission at AL = 2000.
Just before mission exit, notice FWD FUEL LOW caution light is on:
After re-entering the mission, notice caution light is now correctly off again:
I can’t stress enough that I was careful to put the ENG FEED back to BOTH after creating the imbalance. I also tried with idle power, up to MIL so as not to overwhelm the pumps. Time compression was off when making the changes, only stick inputs were done on time compression.