Which operations are classified as critical phases of flight?

The classification of critical phases of flight is important for ensuring safety and maintaining situational awareness. Critical phases of flight encompass operations where the aircraft is most vulnerable to accidents and incidents, which indeed includes all ground operations such as taxiing, takeoff, and landing.

During these phases, the flight crew must be especially vigilant to manage the aircraft's configuration and respond to any unexpected events. Taxiing involves maneuvering the aircraft on the ground, transitioning to takeoff requires precise alignment and speed management, and landing is the final and often most complex phase where many factors must be controlled for a safe arrival.

These operations require focused attention and coordination to mitigate risks and ensure safe flight continuity. Other options mentioned do not accurately reflect the definition of critical phases, as they either refer to non-flight operations, specific emergencies not encompassing routine phases, or maintenance activities, which are not flight phases themselves.