Definition
A parameter set at each ARTCC computer that determines how long an arrival flight plan remains displayed on a controller's sector list after the aircraft has landed or the flight plan is no longer active. Once the interval expires, the flight strip data is automatically removed from the controller's display.
Plain English
A timer the air traffic control computer uses to decide when to clear an arrival flight off a controller's screen list after the flight is finished.
Context Anchor
Seen in air traffic control automation and FAA glossary material, not as a normal cockpit action or pilot checklist item.
Derivation
"Sector" is the airspace area assigned to a controller. "List" is the column of active flights shown on that controller's display. "Drop" means to remove. "Interval" is the time delay. Together: how long before a flight drops off the sector list.
Why Pilots Care
Prevents display clutter by removing aircraft no longer in the sector, allowing controllers to focus on active traffic and reducing the chance of overlooking relevant targets.
Intuition Check
Do not read “drop” as the aircraft descending. Here, “drop” means the aircraft’s information is removed from a controller’s computer list.
Example Sentence 1
The sector list drop interval was set so arrival flights cleared from the controller's display a few minutes after touchdown.
Example Sentence 2
During busy periods the controller increased the sector list drop interval slightly so recently departed traffic stayed visible a little longer.