Definition
An operational area of defined vertical and lateral dimensions within an Air Route Traffic Control Center (ARTCC) for which a controller, or team of controllers, has air traffic control responsibility for arriving aircraft. The arrival sector handles aircraft transitioning from the en route environment toward a terminal area before handoff to approach control.
Plain English
A specific block of airspace inside a Center, with set boundaries up and down and side to side, that one controller (or controller team) is responsible for. The job of that sector is to manage aircraft on their way down and in toward an airport, until they get handed off to the approach controllers closer to the field.
Context Anchor
Seen in air traffic control and traffic-flow discussions, especially when arrivals are being spaced before they leave en route airspace for the terminal area.
Derivation
A 'sector' originally meant a portion or slice of something larger (from Latin 'sector', meaning 'a cutter' or 'one who cuts'). In ATC, a sector is a slice of a larger Center's airspace. The 'arrival' label simply tells you which kind of traffic this slice is built around — aircraft on their way in.
Why Pilots Care
Understanding which arrival sector is handling your flight helps pilots anticipate frequency changes, routing instructions, and sequencing expectations during the transition to approach.
Intuition Check
Do not read “sector” here as just a compass direction or a pie-shaped area on a chart. In this use, it means a defined piece of controlled airspace assigned to controllers for handling arriving traffic.
Example Sentence 1
Cleveland Center's arrival sector descended us to 11,000 and slowed us to 250 knots before handing us off to approach.
Example Sentence 2
Traffic in the arrival sector was sequenced for the ILS approach to runway 27.