Under what circumstances must all passengers wear seatbelts?

The requirement for all passengers to wear seatbelts primarily focuses on ensuring safety during critical phases of flight, specifically during taxi, takeoff, and landing. These phases are when the aircraft is most vulnerable to sudden changes in speed or altitude, and the risk of injury is greater in the event of unexpected turbulence or maneuvers.

Passengers under 2 years old are typically exempted from wearing a seatbelt in some circumstances, often instead being secured in a child safety seat or held by a guardian. It’s crucial for flight safety that all other passengers remain secured during the mentioned phases, as this reduces the risk of being displaced inside the cabin and potentially being injured.

In other phases of the flight, such as cruise, the requirement may be less stringent; however, it is always advisable for passengers to wear their seatbelts whenever seated. Options that suggest seatbelt use only during turbulent flights or exclusively for takeoff and landing do not capture the comprehensive safety guidelines intended for flight operations. Thus, the answer that includes all passengers wearing seatbelts during taxi, takeoff, and landing provides the most accurate scenario aligned with aviation safety practices.