Inflight engine shutdown, possibly caused by fuel starvation and fuel system bug

[C-Schaffhausen]

Simulator

2020

Aircraft Version

Development (8k)

Build info

{
    "built": "2025-01-16T02:30:28+00:00",
    "ref": "refs/heads/master",
    "sha": "09844348d12a460d30536ec0a543d791aa5a2102",
    "actor": "flogross89",
    "event_name": "manual",
    "pretty_release_name": "master:09844348",
    "version": "a380x-v0.13.0-dev.0984434"
}

Describe the bug

I've experienced two inflight engine shutdown recently:

1. From KLAX to YMML, engine 2 shut down inflight
2. From YMML to WSSS, no inflight shutdown
3. From WSSS to KLAX, engine 1 shut down inflight
   In both shutdowns I was able to restart the affected engine

Expected behavior

No unintended shutdowns

Steps to reproduce

Fly longhaul sectors, probably over the Pacific Ocean as that's the only thing in common from my experience

References (optional)

No response

Additional info (optional)

No response

Discord Username (optional)

c.schaffhausen

[C-Schaffhausen]

Ran into the same problem again today, from VHHH to EGLL, eng 2 & 3 shutdown inflight. It looks like the fuel ran dry for eng 2 & 3 and I was only able to restart the engines by turning on the crossfeed valves.

[donstim]

Has this happened when you complied with the MTOW of 510,000 kg? That is the weight variant we are currently simulating. We already know there may be fuel loading and other issues when operating above that weight.

[C-Schaffhausen]

I use 575,000 kg as MTOW, and I think the flights which had issues departed above 510,000 kg TOW. However I've done this since Nov and never had an issue with the fuel, as you can see from my screenshot, I think either the fuel system is not distributing fuel correctly, or the EFB is not loading the fuel correctly. I rolled back to a build from early Dec which I saved in my drive, that worked perfectly without any issues.

[donstim]

Aa I stated, fuel loading does not work properly above a certain weight. It is only assured to work correctly when complying with the simulated 510k T MTOW. There have not been any recent changes in this area

[C-Schaffhausen]

Understood, I'll stay with the earlier build which worked perfectly for now. Hopefully there'll be support of the 575,000 MTOW variant soon!

[donstim]

Roger that. But I would be surprised if you see a difference between different builds when running exactly the same flight with the same loads and routing. If you have an FDR file from one of the flights with the issue, I'd be glad to take a look at it.

https://docs.flybywiresim.com/aircraft/support/?h=fdr#fdr-files

[C-Schaffhausen]

Roger that. But I would be surprised if you see a difference between different builds when running exactly the same flight with the same loads and routing. If you have an FDR file from one of the flights with the issue, I'd be glad to take a look at it.

https://docs.flybywiresim.com/aircraft/support/?h=fdr#fdr-files

Thank you! I have 2 logs here, both of them the engines where shut down inflight
https://www.swisstransfer.com/d/2f3f3d63-43a3-453b-8054-f2f23ad14635

In all my flights I load payload and fuel imported from Simbrief, using instant load.

1. From KLAX to YMML, engine 2 shut down inflight
2. From VHHH to EGLL, engine 2 & 3 shut down inflight. I tried diverting to Munich but I wasn't sure how to do it, the aircraft freeze mid aircraft with the sim still running, no sound, then I was forced to quit.

I'm on the way to EGLL with an older build, no issues so far, will upload the fdr once the flight's complete!

[C-Schaffhausen]

And 1 more, VHHHEGLL no issues with the older build
https://www.swisstransfer.com/d/f5d0ea46-ff3c-4834-9e68-278784ec07ce

[donstim]

Sorry for the delay. The FDR files have gotten so large, I am having trouble finding software that can open them and display them properly. I'm going to be away for a week, so it's going to be a while. I may have to just try one of your flight myself when I get back and monitor it in real time to see if I can catch what's going on.

[C-Schaffhausen]

Try this load, TOW 575,000