Re: endurance - depends on acft type and the mission requirements, but, often, not a lot! Generally they'll call min/emerg fuel with APP, but, sometimes they'll call it while they're still in the exercise area (especially if APP have told them to stay there/clearance not yet available - due to trying to get you lot on the ground first!)
You'd have to ask a pilot for the specifics (and they probably wouldn't be allowed to tell you anyway).
