Definition
A computer display format used in air traffic management that shows aircraft and events arranged along a horizontal or vertical time axis, allowing controllers and traffic flow specialists to see when each aircraft will arrive at a fix, runway, or sector boundary. It presents traffic in time order rather than geographic position, making it easier to spot conflicts, sequencing problems, and arrival rate issues.
Plain English
A screen that lines up aircraft along a time scale so you can see, at a glance, what is going to happen and when, rather than just where each aircraft is on a map.
Context Anchor
Seen in air traffic control and traffic management systems, especially when managing the order and timing of aircraft moving toward busy airports or airspace.
Derivation
Timeline comes from arranging events in the order they occur in time. Graphical User Interface refers to a screen that shows information using pictures and shapes you can interact with, rather than just text. Together: a time-ordered picture of traffic on a screen.
Why Pilots Care
Pilots rarely use this display directly, but it drives the speed assignments, holding instructions, and arrival times that controllers issue. Knowing it exists helps explain why ATC sometimes asks for a precise speed or crossing time at a fix.
Analogy
It is like a schedule board that shows flights in time order, except it is interactive and built for managing live air traffic.
Intuition Check
Do not read this as just any timeline on a screen. In this aviation context, it means a specific traffic-management display used to organize aircraft by planned time and sequence.
Example Sentence 1
The traffic management coordinator used the timeline graphical user interface to sequence arrivals into the airport during the morning push.
Example Sentence 2
Maintenance personnel used the Timeline Graphical User Interface to review the sequence of inspections performed on the aircraft over the past month.