What term is used to describe critical phases of flight like surface movement and flying below 10,000 ft?

The term used to describe critical phases of flight, such as surface movement and flying below 10,000 feet, is known as "sterile flight." This term refers specifically to periods when the cockpit is considered to be "sterile" from non-essential communications, emphasizing the need for crew members to focus on safety and operational tasks. During these phases, flight attendants and pilots must remain attentive to their responsibilities, as these stages are particularly crucial for ensuring passenger safety and handling any potential issues that may arise.

In contrast, "active flight" typically pertains to the overall journey and may not convey the same level of restriction on communication or the critical safety focus that is essential during these specific phases. "Passenger service" relates to the interactions and services provided to passengers throughout the flight but does not specifically address critical safety phases. "Emergency protocol" refers to procedures followed during an emergency situation rather than routine operations, making it distinct from the concept of sterile flight. Therefore, sterile flight is the most appropriate term that encompasses the heightened focus required during these critical phases of flight.