For those interested in the future of American air travel ...<p>Regional airlines, which carry half of pax, have been &quot;last class&quot; for decades, but they&#x27;re about to disappear.<p>The new pilot training rules requiring 1500 hours of experience have destroyed their ability to operate. The first to declare bankruptcy is Republic, but the rest will soon join it.<p>The majors have used the regionals for union-busting purposes, but those days are over.