What indicates that an aircraft must receive priority handling?

When an aircraft has declared an emergency, this indicates a situation where the safety of the aircraft, its crew, and passengers may be at risk. Emergency declarations are taken seriously in aviation, and they require immediate and prioritized handling from air traffic control. This priority is essential to ensure the prompt resolution of any issues and to facilitate a safe landing or other necessary actions to mitigate the emergency situation.

In contrast, situations involving minor issues do not necessitate the same level of urgency or emergency priority. An aircraft merely passing through or on a scenic flight does not imply any immediate risk that would require enhanced handling. Understanding the difference between emergencies and routine operations is crucial for ensuring safety in air traffic management.