Travelers flying out of San Diego are increasingly choosing Alaska Airlines over the traditional market leader, Southwest, due to aircraft size and seating layouts. The core advantage comes down to Alaska’s 76-seat Embraer E175 regional jets, which allow the airline to offer more direct routes, higher flight frequencies, and zero middle seats compared to Southwest’s massive all-Boeing 737 fleet. Understanding how aircraft capacity directly impacts passenger convenience is vital for frequent flyers looking to optimize their travel time and comfort.

How 76-Seat Regional Jets Outflank Southwest’s 737 Fleet at SAN
Alaska Airlines relies heavily on the 76-seat Embraer E175 to fly routes that simply lack the daily passenger demand required to fill Southwest’s larger 143-seat to 175-seat Boeing 737s. Operated by regional partners Horizon Air and SkyWest, these smaller, highly efficient aircraft enable Alaska to launch direct flights to mid-sized cities that Southwest cannot profitably serve from Southern California.
Operating frequent, lower-capacity flights provides a massive scheduling advantage for business and leisure travelers alike. According to data tracked by the Bureau of Transportation Statistics (BTS), offering multiple daily flights on regional jets builds better yield integrity and reduces operational bottlenecks. If a morning flight is delayed, passengers can easily switch to an afternoon departure on the exact same route.
Because Southwest uses high-capacity 737s exclusively across its network, the airline must wait to fill an entire large plane before clearing a departure. This dynamic forces Southwest to reduce flight frequencies on niche routes, handing Alaska Airlines a massive competitive edge for travelers flying out of San Diego International Airport (SAN).
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The Embraer E175 Advantage: Zero Middle Seats for Passengers
Passengers flying on Alaska Airlines Embraer E175 aircraft will never get stuck in a middle seat, fundamentally upgrading the standard domestic travel experience. The regional jet cabin features a passenger-friendly 2-2 layout in the main Economy section and a spacious 1-2 layout in First Class.
Southwest’s Boeing 737s utilize a rigid 3-3 configuration across the entire length of the aircraft. This layout automatically forces 33 percent of all Southwest passengers to sit squeezed between two other people. For a typical two-hour flight along the West Coast, the physical comfort difference between an exclusive E175 window seat and a cramped 737 middle seat is significant.
Alaska Airlines Embraer E175 Cabin Configuration:
| Cabin Class | Total Seats | Seat Layout | Middle Seats |
| First Class | 12 | 1-2 | None |
| Premium Class | 16 | 2-2 | None |
| Main Cabin (Economy) | 48 | 2-2 | None |
Winning the Hawaii Market Head-to-Head
Alaska Airlines is now the firmly established incumbent in the highly competitive San Diego to Hawaii market following its strategic acquisition of Hawaiian Airlines. This massive network merger puts immense pressure on Southwest’s island routes operating out of San Diego.
With legacy carriers like American, Delta, and United offering minimal direct competition on these specific Pacific routes, the combined Alaska-Hawaiian network dominates the passenger share governed by U.S. Department of Transportation (DOT) airspace regulations. Southwest is now forced to aggressively defend its market position from a point of weakness, as Alaska leverages a much broader network of seamless island connections.
4 Expert Tips for Booking San Diego Flights
Securing the best seat and fare out of San Diego requires understanding airline fleet mechanics and airport operations. Follow these exact steps to optimize your next trip:
- Check the Aircraft Type Before Booking: Look closely at the equipment listing on the checkout page. If the flight operates on an Embraer 175 (E75), you are guaranteed an aisle or window seat with no risk of being stuck in the middle.
- Prioritize Multi-Frequency Routes: Choose destinations that offer three or more daily flights. The Federal Aviation Administration (FAA) mandates strict maintenance safety schedules, and having backup flights ensures you reach your destination the same day if a mechanical delay occurs.
- Use Expedited Security Clearances: Bypass long terminal lines by enrolling in official trusted traveler programs verified by the Transportation Security Administration (TSA).
- Leverage Global Alliances: Alaska is a full member of the oneworld alliance, allowing passengers to earn and redeem miles on global partner airlines. Southwest operates an independent network with zero international airline partners.