So, about that little red light...

[Flyby]

High over southern England, in the area of the London docks, you lead a flight of Emils, and see a climbing flight of Huricanes. Just as you're about to signal your flight to attack, suddenly a little red light comes on in your cockpit...
Sorry guys. Just want to know how much fuel the Emil has left when that little read light comes on. Perhaps more to the point, how many more minutes can the Emil stay in the air? I'm sure this question has been answered before, somewhere. But is it accurately modeled in SoW?
thanks,
Flyby out