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Fuel leak


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I noticed in multiple flights with the most recent version that a fuel imbalance is developing in the left inner tank:


This image was taken during descent. The APU was shut off with the APU master switch shortly after turning on the engines. I initially suspected that the APU was somehow still draining fuel, but the leak increased even when completely isolating the tank. I'm fairly sure, the leak did not occur with 1.0.6.

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1 hour ago, pmplayer said:

Saw the same at a last flight with V.1.0.8 !

cheers 😉

Yep this appears to be an issue/bug with the APU shutdown process.

Starting with the aircraft (v1.0.8) cold and dark w/ the default 6000kg of fuel in the left and right outer tanks:

- Connect Batteries 1, 2, and 3

- Connect Ground Power

- APU Master ON

- APU Start ON

- Wait for APU to spool up

- Review APU LVARS: INI_apu_n1=100, INI_apu_PSI=10, INI_apu_RUN=1, INI_apu_egt=479.99, INI_APU_CONSUMPTION=300, INI_apu_available=1

- APU Master OFF.

APU Running ECAM is removed. N1 starts decreasing until it suddenly drops to 0. APU N1 then proceeds to spool up again before announcing AVAIL. N1 falls to 31, EGT falls to 150.

- Review APU LVARS: INI_apu_n1=100, INI_apu_PSI=3.15, INI_apu_RUN=1, INI_apu_egt=149.63, INI_APU_CONSUMPTION=300, INI_apu_available=0, INI_APU_SHUTDOWN_ACTIVE=1,INI_APU_SHUTDOWN_PHASE=0

- Review external CAM. APU exhaust heat effect and noise still active.

- Monitor fuel level: Fuel continues to drain.

It looks like there is a bug with the APU shutdown process where it never fully shuts down, and continues to drain fuel as if it's still running at 100%, while the exhaust heat and noise effect remain.


Interestingly, using the EFB Panel State "Ready for Takeoff" will fire up the APU to start the engines before shutting it back down again. the N1 and PSI do correctly drop to 0, but the EGT remains at 150 on one attempt and 340 on another attempt. The heat and noise effect remains on the APU exhaust. Fuel weight in the left outer tank drops faster.

Setting the EFB Panel State to "On GPU" or "Cold and Dark" appear to correctly reset the APU to the off state. No detectable fuel flow, no heat effect from APU exhaust.




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Additional note: Unlatching and pulling the APU fire handle does not cut off fuel to the APU either when its in it's bugged partially shutdown state, even though the valve is marked as SHUT.

Edited by kevink817
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One final test: Unlatching and pulling the APU fire handle while fully running appears to fully shut down the APU (EGT drops to OAT, and N1=0), but fuel drain remains as well as the exhaust heat and noise effect.

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