Ah, OK,that explains it. I was wondering what the crossfeed had to do with it... You know that begs the question; How was fuel load handled in real life? I just even everythng out (same amount on a ll three). I don't think this will matter as the plane will automatically handle tank selection, but just curious what an ops manual would say about this on the real plane. Form what I can see, it really should not matter as the fuel will always be drawn from teh wings... Anyway, thnaks for the explanation DaveMALTBY D wrote:You've stumbled on a peculiarity of the model.
If you have the pumps, valves & crossfeed set normally, setting the centre tank level down to zero will always result in a fuel cut off in FS.
The fuel system works quite realistically on the 1-11 model, but it's an illusion.
The real thing only ever feeds the engines directly from the wing tanks, but pumps refill the wings from the centre tank.
So under normal running, although the engines take fuel directly from the wing tanks, only the centre tank empties.
To simulate this, the model will actually take fuel directly from the centre tank if it has any fuel. So, suddenly empty the centre tank & the engines cut in FS.
There is some XML code that secretly switches the FS fuel feed from the centre tank when it's near empty. But when the level is suddenly set to zero it can't switch the supply quickly enough to avoid the engines cutting out. It's only a microsecond of fuel starvation, but that's all it takes.
So, if you want to empty the centre tank it's best to leave a small amount (2%) in there & let it drain itself.
Under normal running there's never any need to open the crossfeed when the centre tank runs dry.
Or, if you're on the ground you can just start up again without touching the fuel system.
Nearly every 1-11 flight I do with the CBFS va starts with a fuel cut off.
DM
regards,
Macs