What altitude requirements exist for eastbound flights below FL410?

The correct answer focuses on the standard altitude assignment for eastbound flights below FL410, which is that eastbound traffic is assigned odd flight levels. This is in accordance with the general rules of altitudes set by aviation regulations to help organize air traffic and maintain safe vertical separation among aircraft.

For eastbound flights, the odd flight levels provide a clear structure that separates them from westbound flights, which are assigned even flight levels. This system helps reduce the risk of collisions and ensures a smooth flow of air traffic, as aircraft flying in the same direction are consistently separated in altitude as well.

The structure aims to enhance safety and efficiency in the air traffic management system. In this case, since the question pertains specifically to those flying east, the correct assignment is for these aircraft to maintain odd flight levels, ensuring clear demarcation from the overall flight pattern, which simplifies navigation and communication in busy airspace.