Which document must be filed for each flight to ensure compliance with regulations?

The requirement to file a flight plan for each flight is rooted in regulatory compliance, as flight plans serve multiple essential functions in aviation operations. A flight plan provides necessary information to air traffic control (ATC), ensuring that they are aware of the aircraft's intended route, altitude, and timing. This information is critical for maintaining safe and efficient air traffic management, as it helps prevent conflicts between different aircraft and aids in coordinating airspace usage.

Furthermore, filing a flight plan is a regulatory requirement in many jurisdictions, particularly for flights operating in controlled airspace or at certain altitudes. This ensures that all operational flights are documented and monitored, enhancing safety and accountability in aviation operations.

In contrast, while safety management reports and operational checklists contribute to aviation safety and operational integrity, they do not fulfill the specific regulatory requirement associated with alerting ATC and other relevant authorities about a flight's intended trajectory. A maintenance log, while crucial for tracking an aircraft's upkeep and repairs, does not pertain to the immediate regulatory compliance required for each flight. Thus, the flight plan stands out as the key document necessary for regulatory compliance for every flight.