Final answer:
Air traffic controllers are responsible for maintaining separation between flights conducted under IFR in the en route structure. This involves monitoring the positions and altitudes of planes and providing instructions to pilots to maintain the required separation distances.
Step-by-step explanation:
In the field of aviation, the responsibility of maintaining separation between flights conducted under Instrument Flight Rules (IFR) in the en route structure lies with the air traffic controllers. They use a system called air traffic control to ensure safe separation between aircraft. This involves carefully monitoring the positions and altitudes of the planes and providing instructions to pilots to maintain the required separation distances.
For example, if two planes are flying at the same altitude, they must maintain a minimum horizontal separation of five miles. If one plane is flying above or below another, the vertical separation must be at least 2,000 feet, or 1,000 feet if the altitude is less than 29,000 feet.
This system of maintaining separation is crucial to prevent collisions and ensure the safety of air travel.