What is the primary function of a flight plan?

The primary function of a flight plan is to outline the intended route, altitude, and flight details. A flight plan serves as a comprehensive document that communicates essential information about the flight to air traffic control and other relevant authorities. It includes details such as the starting point, destination, waypoints, expected flight levels, and estimated times of arrival. By providing this information, the flight plan ensures that the flight can be safely managed and monitored throughout its journey, facilitating coordination with air traffic management.

Other options, while related to aviation, do not accurately capture the main purpose of a flight plan. For instance, determining fuel capacity and maintenance checks are vital for operational readiness, but they are not the primary focus of a flight plan. Similarly, calculating flight duration is an important consideration for planning, but it falls under the broader context of how the flight plan is utilized to communicate overall operational intent.