Main tank 2 and 3 becomes depleted during long haul flights causing engine 2 and 3 to shutdown

[runningdavid]

Version

latest dev

Describe the bug

During long haul flights (over 12 hours), x-feed seems not to be working properly. Main tanks #2 and #3 became depleted while #1 and #4 still had plenty of fuel, and that caused engine #2 and #3 to shutdown. Once I added more fuel in sim menu that rebalanced the tanks, engines were back up.

Expected behaviour

Fuel burn should be more balanced across tanks and when x-feed is on, engine should not shutdown even if main tanks 2 and 3 were depleted.

Steps to reproduce

1. Do a long haul flight (over 12 hours) and check fuel usage.

Additional information

This plane has been amazing and works perfect for me and very smooth to control and land. Cockpit felt ultra realisitc especially during the evening landings. It is just this one minor issue that is killing the whole great immersive experience.

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Your Discord

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[runningdavid]

One other thing I noticed that doesn't seem to be correct is that even if I switch off the X-Feed valve between main tank 1 & 2 and main tank 3 & 4, on the engine display it's showing tanks 1 & 4 are not supplying fuel to engine 1 & 4 now, but still only numbers in tanks 2&3 goes down.

[DesertRick13]

Hmmm, I hear your frustration. Are you getting any tank/engine advisories and following them? There comes a point where tank 1 is equal to tank 2, and tank 4 is equal to tank 3. At that point, you should get a tank/engine message, which would indicate shutting off the OVR switches and closing the crossfeed valves between 1 and 2, and 3 and 4. All I can tell you for sure is that I'm running 'Ole 75, the last dev version before the autoloader, and I am not experiencing anything close to what you are describing. If you have not already checked it out, take a look at the document ".fuel" to make sure you are following procedure.

[runningdavid]

Hmmm, I hear your frustration. Are you getting any tank/engine advisories and following them? There comes a point where tank 1 is equal to tank 2, and tank 4 is equal to tank 3. At that point, you should get a tank/engine message, which would indicate shutting off the OVR switches and closing the crossfeed valves between 1 and 2, and 3 and 4. All I can tell you for sure is that I'm running 'Ole 75, the last dev version before the autoloader, and I am not experiencing anything close to what you are describing. If you have not already checked it out, take a look at the document ".fuel" to make sure you are following procedure.

I tried what you suggested. Even after switching off the OVRD and X-Feed buttons, the plane still doesn't want to use fuel from tank 1&4 (only numbers from tank 2&3 are going down). Even the center display is indicating tank 1&4 are feeding into engine 1&4.

[runningdavid]

Oh never mind it started working now.. It's just started using engine from the resid tank. Thanks a lot.

[dcherrie]

There is definitely a bug with the fuel system not working as it previously did. For those of us who fly overnight (and unable to turn off the overrides at Fuel Tank/Eng), we would usually not turn on the override pumps at all so the fuel in tanks 1 and 4 would run out first and then the pumps would be left to feed off main 2 and 3. However recently the fuel flow doesn't seem to switch over to 2 and 3 which will cause engine 1 and 4 to flame out but it doesn't happen all the time.

A week ago I did this technique and both engine 1 and 4 were off when I woke up. A few days ago, all 4 engines were running fine. Then this morning when I woke up, engine 1 was off. Even after restarting engine 1, the fuel page is showing that it is still drawing from fuel tank 1 which is empty.

[Alienation80]

So, something similar happened to me yesterday.

Pumps 1 and 4 when empty. Pump 4 automatically was fed from 3.
However, Engine one died.
The only way it restarted was by turning on the over-rides to the left.