What is the primary purpose of a flight plan in IFR operations?

The primary purpose of a flight plan in IFR (Instrument Flight Rules) operations is to inform Air Traffic Control (ATC) of the intended flight. When a pilot files a flight plan, they provide essential information such as their departure and destination airports, planned route, altitude, and estimated times. This information is crucial for ATC to manage the safe and efficient flow of air traffic. By having a detailed flight plan, ATC can coordinate movements among various aircraft, provide necessary support, and ensure that safety protocols are followed.

The other options do not align with the primary purpose of a flight plan. While passenger comfort and fuel management are important considerations for flight operations, they are not the focus of a flight plan in the context of IFR. Scheduling maintenance is a separate aspect of aircraft operation altogether, focused on ensuring the aircraft's airworthiness rather than daily flight operations.