What is the purpose of a flight plan?

The purpose of a flight plan is to inform air traffic control of an aircraft's intended route. A flight plan acts as a formal notification that details the planned route, altitude, and any other necessary information regarding the flight. This communication is essential for ensuring safety in the airspace, as it allows air traffic control to monitor the progress of the flight and coordinate with other aircraft.

While a checklist for pilots, weather documentation, and passenger lists are important for overall flight operations, they do not encapsulate the primary function of a flight plan. The primary aim is clear communication with air traffic control to facilitate safe and efficient airspace management.