When using lateral separation, must the lead aircraft always be the same speed or faster?

Answer: B — No, it is not necessary

Lateral separation does not require the lead aircraft to maintain the same speed or a faster speed compared to the following aircraft. This is because lateral separation relies on maintaining adequate horizontal spacing between aircraft to ensure that they do not conflict with each other, regardless of their relative speeds. As long as the required lateral distance is maintained, it is permissible for the lead aircraft to fly at a slower speed. The ability to allow the lead aircraft to be slower means that air traffic controllers can strategically manage traffic flows and spacing without the constraint of requiring all aircraft to operate at similar speeds. This flexibility is particularly useful in varied air traffic scenarios where altitude and space are prioritized over speed.