Which scenario describes when flight crew members must wear their seatbelts?

Flight crew members are required to wear their seatbelts when at their assigned station to ensure their safety during any unexpected movements of the aircraft. This regulation is in place to protect crew members from potential injuries caused by turbulence or abrupt changes in the aircraft's motion while operating on the ground or in the air.

Wearing seatbelts at their stations enhances safety protocols, ensuring that crew members are secured, which is particularly important during critical phases of flight or in circumstances that may jeopardize their stability and safety. This rule applies not only during flight but also while the aircraft is taxiing, when there might be unexpected maneuvers; however, the highlight remains on being secured in their designated position, particularly in preparation for various phases of flight.

In contrast, other options do not encapsulate the comprehensive requirement for wearing seatbelts. For example, while heavy weather and taxiing can necessitate the use of seatbelts, these conditions may not universally apply at all times, as there are other safe scenarios where wearing a seatbelt is still a requirement. Similarly, only wearing seatbelts during flight maneuvers fails to account for the need to stay secured at all times while stationed, irrespective of whether the aircraft is in-flight or on the