Definition
A published system of fixed, organized routes through high-latitude airspace north of approximately 78°N, designed to provide efficient and predictable transit between North America, Europe, and Asia in regions where conventional navigation references and air traffic services are limited.
Plain English
A set of pre-planned flight paths over the polar region that aircraft follow to cross the top of the world safely and in an orderly way.
Context Anchor
Seen in international flight planning, oceanic or remote-area operations, and clearances for flights that cross high northern latitudes.
Derivation
Polar refers to the area near the Earth's poles. Track means a defined path through the sky, and structure means the organized layout of those paths. Together: an organized layout of flight paths over the polar region.
Why Pilots Care
Allows safe, efficient transit through polar airspace where compass errors, limited ground facilities, and converging great-circle routes would otherwise create separation and navigation problems.
Intuition Check
Do not picture a physical track or a single fixed highway in the sky. In this term, track means a planned flight path, and structure means the organized set of those paths.
Example Sentence 1
The dispatcher filed the flight via the Polar Track Structure to take advantage of the shorter routing between New York and Hong Kong.
Example Sentence 2
Because winds had shifted, ATC reassigned the flight to an adjacent track within the polar track structure.