Definition
A publicly owned commercial service airport that enplanes 10,000 or more passengers per year on scheduled air carrier flights. Primary airports are categorized by the FAA into four hub-size classes — large, medium, small, and nonhub — based on their share of total annual U.S. passenger boardings.
Plain English
An airport that is open to the public and handles a meaningful amount of scheduled airline passenger traffic each year. The FAA uses this label to identify airports that are busy enough with paying passengers to count as 'primary' in the national airport system.
Context Anchor
Seen in FAA airport information, airport planning material, and acronym lists where airport categories are abbreviated.
Derivation
Primary' here means 'first rank' or 'main,' from the Latin primarius. In FAA usage it doesn't mean 'most important' in a general sense — it means the airport meets the threshold to be ranked among the principal commercial-service airports in the country.
Why Pilots Care
Determines eligibility for certain federal funding and affects the level of services and facilities available.
Intuition Check
Do not read “primary” as meaning the best airport, the pilot’s preferred airport, or the main airport for a particular flight. Here it means the airport meets a specific FAA passenger-traffic category. Do not read “commercial service” as meaning any airport with businesses on the field. Here it means scheduled passenger airline service.
Example Sentence 1
Because the field qualifies as a primary commercial service airport, it receives federal funding under the FAA's airport improvement programs.
Example Sentence 2
Pilots checking airport directories will see PR next to any primary commercial service airport.