During which conditions are flight crew members required to keep their safety belts and shoulder harnesses fastened?

Flight crew members are required to keep their safety belts and shoulder harnesses fastened during all flight conditions to ensure their safety and the safety of passengers and crew. This requirement is grounded in the principles of aviation safety and risk management, as unrestrained personnel are at a higher risk of injury during any phase of flight.

Keeping safety restraints fastened helps minimize the potential for injury in various scenarios, including unexpected turbulence, sudden changes in altitude, or any operational emergency that might require swift action from the crew. While takeoffs, landings, flight in turbulent air, and emergency situations all present particular risks that necessitate the use of safety restraints, the overarching safety regulations dictate that these should be worn at all times during flight to prepare crew members for any unforeseen circumstances that may arise. This comprehensive approach underscores the priority of maintaining safety standards throughout the entirety of the flight.