Definition
An air traffic control decision-support tool used by approach controllers to merge and space arriving aircraft into an efficient, properly separated stream as they transition from en route airspace into the terminal area and onto final approach.
Plain English
A computer system that helps controllers line up arriving airplanes in the right order and at the right distance from each other as they approach a busy airport.
Context Anchor
Seen in discussions of modern air traffic control, busy airport arrivals, and procedures used as aircraft are being guided toward landing.
Derivation
Terminal' here refers to the terminal area — the airspace immediately surrounding an airport where arrivals and departures are handled. 'Sequencing' means putting aircraft in order. 'Spacing' means setting the correct distance between them. Together the name describes exactly what the tool does in that airspace.
Why Pilots Care
Reduces delays, fuel burn, and the need for last-minute speed or path changes during approach.
Grounding Statement
Picture several airplanes approaching the same busy airport, with controllers using a planning tool to decide who goes first and how much room to keep between each airplane.
Intuition Check
Terminal does not mean the passenger building here. It means the airspace around an airport. Sequencing and spacing do not just mean a casual line; they mean controlled order and planned gaps between aircraft.
Example Sentence 1
Controllers at the busy approach facility used Terminal Sequencing And Spacing to merge arrivals from three different routes into a single, evenly spaced final approach stream.
Example Sentence 2
Terminal Sequencing and Spacing helped the tower maintain safe intervals without vectoring aircraft into holding.