What are the fixed distances for separation in controlled airspace from terrain and obstacles called?

The term for the fixed distances for separation in controlled airspace from terrain and obstacles is "separation minima." This concept is crucial in air traffic control, as it defines the required distance that aircraft must maintain from one another as well as from obstacles, ensuring safe and efficient operations within the airspace.

Separation minima are carefully established based on various factors, including aircraft type, weather conditions, and airspace classification, to minimize the risk of collisions and to provide pilots with a margin of safety while maneuvering at low altitudes or during various phases of flight. These minima help controllers maintain safe distances in all three dimensions—vertical and lateral—ensuring that aircraft do not come too close to each other or to significant geographical features and structures.

Other terms provided may relate to safety within aviation, but they do not accurately define the fixed distances for separation in controlled airspace. Understanding the application and purpose of separation minima is essential for maintaining orderly and safe air traffic operations.