Alaska Airlines primarily uses Boeing 737 aircraft for most of its mainline routes, including domestic flights and trips to Mexico, Canada, Belize, and Costa Rica. They also operate Embraer 175 jets through their regional partners for shorter flights or routes with lighter demand. The 737s make up the bulk of the fleet, while the E175s handle many West Coast and regional connections. Alaska retired its Airbus planes after the Virgin America merger, so the fleet is now mostly Boeing with some Embraer. The exact plane on your flight depends on the route and schedule.