Definition
A computational process used by air traffic management systems to calculate and predict an aircraft's future flight path in four dimensions — latitude, longitude, altitude, and time — based on the filed flight plan, current position, performance characteristics, winds aloft, and other known constraints.
Plain English
It is the computer's best prediction of where an aircraft will be at each point along its route, including how high it will be and when it will get there.
Context Anchor
Seen in air traffic control and traffic-flow planning, especially when systems help controllers plan spacing, sequencing, and arrival flow.
Derivation
Trajectory comes from the Latin trajectus, meaning 'thrown across.' Modeling means building a working representation of something. Together, the term describes building a working prediction of the path an aircraft will be 'thrown across' the sky.
Why Pilots Care
Accurate trajectory modeling supports efficient routing, fuel planning, and conflict avoidance in both cockpit automation and air traffic control.
Grounding Statement
If an aircraft slows down or gets a new route, the system recalculates where that aircraft is likely to be in the next several minutes.
Intuition Check
Trajectory modeling is not just drawing a line on a map. In this context, it also includes time, altitude, speed, and expected aircraft behavior.
Example Sentence 1
Traffic flow managers used trajectory modeling to identify a likely arrival overload at the destination an hour before the first aircraft entered the terminal area.
Example Sentence 2
Controllers used trajectory modeling to confirm the two aircraft would remain separated.