Definition
A defined block of time within which an aircraft is scheduled or authorized to arrive at, or depart from, a specific airport. The window is used by air traffic management to balance traffic demand against airport and airspace capacity, often as part of traffic flow programs.
Plain English
A set time slot during which a flight is allowed to land at, or take off from, an airport. If the flight isn't ready within that window, it may have to wait for the next one.
Context Anchor
Seen in traffic management, airport flow control, and flight planning information when arrival or departure times need to be controlled.
Derivation
Window comes from the everyday sense of an opening in time, similar to a window of opportunity. In aviation it is combined with arrival and departure to describe a controlled time slot rather than a physical opening.
Why Pilots Care
Knowing the assigned window affects flight planning, departure timing, fuel load, and the ability to meet curfews or noise restrictions.
Analogy
It is like having a scheduled appointment time. You are not just going whenever you want; you are expected to show up within the assigned time period.
Intuition Check
Do not read “window” as a physical window. Here it means a limited period of time set aside for an arrival or departure.
Example Sentence 1
ATC issued an arrival/departure window of 1430 to 1440 Zulu, so the crew expedited the pushback to make the slot.
Example Sentence 2
Because we missed our ADW due to a late pushback, we were required to wait for the next available slot.