What is the correct definition of a "sequence" in aviation?

In aviation, a "sequence" refers to a series of flight segments that an aircraft or crew operates over one or more days, culminating in a legal rest period back at the crew's home base or domicile. This definition encompasses the entirety of the flight activity and includes not just the flights themselves but also the necessary rest periods mandated for crew members to comply with regulatory requirements.

The idea of ending with a legal rest in domicile is particularly important because it aligns with safety protocols that ensure that crew members are rested before operating another flight, thus preventing fatigue-related incidents. This structured approach maximizes operational efficiency while ensuring compliance with aviation safety standards.

While other definitions concerning itinerary or single flights (options like a single flight completed in one day or a planned itinerary for the aircraft crew) touch upon flight operations, they do not capture the comprehensive nature of a sequence, which emphasizes both the flights and the mandated rest periods. The option that describes a flight plan approved by the company focuses on planning aspects rather than the broader context of operational sequences.