ENPLANEMENTS – The number of enplanements (commercial passenger boardings) that occurred at the airport in calendar year 2019 as per FAA records.passenger enplanements, but more than 10,000 annual enplanements

N: Nonhub that accounts for less than 0.05% of total U.S.

passenger enplanements (Generally 500,000-3,500,000 total passengers).

S: Small hub that accounts for between 0.05% and 0.25% of total U.S.

This would make PDX a 'Medium Hub' by total passengers, but a 'Large Hub' under enplanements.

M: Medium hub that accounts for between 0.25% and 1% of total U.S.

passenger enplanements (Generally 18,500,000 total passengers and above).

L: Large hub that accounts for at least 1% of total U.S.

Each primary airport is further classified by the FAA as one of the following four 'hub' types: This list only includes airports designated as Commercial service – primary (P).

ROLE – One of four FAA airport categories.

ICAO – The location indicator assigned by the International Civil Aviation Organization (ICAO).

Those that do not match the FAA code are shown in bold.

IATA – The airport code assigned by the International Air Transport Association (IATA).

These are linked to that airport's page in the state's airport directory, where available.

FAA – The location identifier assigned by the Federal Aviation Administration (FAA).

This is not always the actual location since some airports are located in smaller towns outside of the city they serve.

CITY – The city generally associated with the airport.

This list of primary airports contains the following information:

Airports in the United States that provide scheduled passenger services and have over 10,000 passenger boardings per year are classified as primary airports by the Federal Aviation Administration.

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