Don't know how the fighter world does it, but we preflight and leave a jet in a "ready to go" state if we have to respond. There is a required response time, which usually means we're on base. Most units that have an alert mission have a temporary living facility for the aircrew on alert. Every day on alert was one active duty day, so if you could pull 3 or 4 days of alert per month, it added up to quite a nice somethin somethin at the end of the year, not to mention an extra 50+ retirement points per year. It was a good deal, but like all good deals... sooner or later, they come to an end.