How long should a flight attendant give the brace command?

The brace command should be given until the plane comes to a complete stop to ensure that all passengers are fully prepared for the potential impacts of landing or an emergency situation, such as an accident. This command is crucial for ensuring passenger safety, as it informs everyone to assume the proper brace position and remain it until there is certainty that the aircraft has safely landed and is no longer in a potentially hazardous situation.

By maintaining the command until the aircraft is completely stationary, flight attendants can help minimize the risk of injury caused by sudden jolts or unexpected events during landing or an emergency evacuation. The instruction allows flight attendants to assess the cabin environment and ensure that all passengers are ready and in the correct posture to protect themselves during any adverse situation.