Plain English Meaning

Instead of telling planes to stay a set number of miles apart, the system gives each plane a specific time to arrive at a certain point in the sky or at the runway. Pilots and controllers then adjust speed and routing so each aircraft hits its assigned time, which spreads traffic out evenly.

Full Definition

An air traffic management technique that uses calculated times of arrival, rather than distance-based spacing, to sequence aircraft to a runway, fix, or arrival point. Controllers and automation tools assign each aircraft a target time to cross a meter fix or threshold, and adjustments in speed, route, or altitude are made so the aircraft arrives at that point at the assigned time, smoothing traffic flow into busy airports.