 On the other hand, flights where there is a change of aircraft (change of gauge) may require that passengers disembark and stay at a holding area for security reasons and a proper headcount.In relation to this, a direct flight with stopovers may or may not involve a change in the flight crew.Airlines may also market connections to a consolidation airport, usually an airline hub, where the continuation of the flight from multiple aircraft is to a single aircraft listed under several flight numbers.