When must required flight crewmembers' safety belts be fastened?

The requirement for flight crewmembers' safety belts to be fastened while at their stations is essential for ensuring safety throughout the entire duration of the flight. This regulation is designed to protect crewmembers from unexpected turbulence, sudden maneuvers, or any in-flight emergencies that could occur at any time, not just during critical phases like takeoff and landing or turbulence.

Keeping safety belts fastened at all times while at their stations reinforces the discipline of safety and preparedness among flight crews, allowing them to respond quickly and effectively without the additional delay of having to buckle up when incidents arise. This practice aligns with aviation safety protocols that prioritize the wellbeing of both crew and passengers by minimizing risks associated with sudden changes in flight dynamics.