8 airliners Americans are most likely to board, and the US airlines that fly the most of them

Passenger jets on US routes range from regional aircraft to long-haul widebodies. Fleet listings and company releases from Southwest, American, Delta and SkyWest show which types carry so much of the traffic. Here are eight types that recur across those fleets, each paired with the airlines that lean on it.

1. Boeing 737 MAX 8: Southwest’s Workhorse Gets Bigger

In the fleet listing cited here, Southwest flies 310 Boeing 737 MAX 8 jets, each with 175 seats, and has 186 more on order. That makes it the largest 737 MAX operator.

The airline has said it will be an all-737 MAX operator by 2031, so passengers should expect the type to appear more often over time. The order count is a planned figure rather than aircraft in service, and Southwest’s overall fleet stands at 800 aircraft in service. Because the airline’s fleet is so uniform, boarding one of these jets is the most probable outcome for a Southwest ticket holder, and the standard seat count keeps cabins predictable.

2. Boeing 737-800: Older 737s Still Fly Daily

As of March 2026, Southwest flies 196 Boeing 737-800s with 175 seats each, one of several 737 variants in its fleet.

American Airlines lists 303 of the same model, seated at 172, as of June 2026, so that carrier holds the larger 737-800 fleet. The seat counts differ by only three, which means travelers face a similar cabin on either airline. Southwest also operates 294 737-700s alongside them. The mix of older and newer 737s means the aircraft on a given route can vary, and the similar seat counts make the difference hard to notice from a window seat.

3. Airbus A321: American’s Big Airbus Narrowbody

American Airlines flies 203 A321-200s, the largest operator of the type, plus 74 A321neos, with 190 to 196 seats depending on version.

Together those 277 aircraft make up more than a quarter of American’s 1,030-plane mainline fleet as of June 2026. A passenger booked on the carrier therefore has a fair chance of boarding one, and the seat range means cabin size varies by subtype. Passengers choosing between subtypes can check the seat count on a booking page, since the A321neo and A321-200 differ within that 190 to 196 range, and the difference is felt mostly in the cabin.

4. Airbus A319: The Small Airbus Still Flying

As of June 2026, American Airlines flies 126 Airbus A319s with 128 seats each.

That cabin is noticeably smaller than the 190 seats on an A321-200 or the 172 on American’s 737-800, so the A319 tends to signal a thinner route or a smaller-capacity flight. The source lists no retirement schedule, so the count is a snapshot, not a trend. The fleet figure is dated, and American’s plans for the type may shift, so the count should be treated as a snapshot as of that month rather than a permanent number.

5. Boeing 787 Dreamliner: American’s Long-Haul Dreamliners

American flies 37 Boeing 787-8s, the type’s largest operator, and 22 787-9s, seating 234 and 285 passengers respectively as of June 2026.

The 51-seat gap between the two variants means the subtype matters when choosing an international flight. American’s other widebodies in the same listing include 47 777-200ERs and 20 777-300ERs, so the Dreamliners share long-haul duty with older twin-engine jets. Dreamliner cabins are the ones most travelers on American’s overseas routes are likely to see, and the two subtypes give the airline flexibility in matching capacity to demand on routes that vary widely by season.

6. Airbus A220: Delta’s Homegrown Launch Type

Delta was the A220’s American launch customer and is its largest customer and operator, with 119 on firm order as of January 2023.

The figure comes from an Airbus release about Delta firming an order for 12 additional aircraft. It counts aircraft on firm order in early 2023, not the current fleet, so deliveries since then are not reflected. Passengers on Delta’s smaller-jet routes are the ones most likely to meet the type. Delta’s early commitment to the type explains why an A220 sighting is so tied to that airline, and the launch-customer role gives its order unusual weight in the type’s history.

7. Embraer E175: Regional Jet Behind Four Brands

SkyWest, which flies for United, Delta, American and Alaska and carried 42 million passengers in 2024, ordered 60 more Embraer E175s in June 2025.

Because SkyWest works under partnerships with four major airlines, a passenger on a regional connection may be aboard one of its jets while holding a ticket from any of them. The figure counts new aircraft on order, and the size of the existing E175 fleet is not stated in the source. Regional flights operated by SkyWest are often sold under the mainline airline’s name, so the aircraft type may differ from what the ticket brand suggests, and the E175 is central to that pattern.

8. Bombardier CRJ: Regional CRJs Face Replacement

SkyWest still flies CRJ700s and CRJ900s for Delta, and 16 replacement E175s will take over from 11 CRJ900s and 5 CRJ700s starting in 2027.

The swap points to the CRJ’s gradual exit from that Delta service, with the Embraer type taking the seats. The release covers only those 16 aircraft, so CRJs in other service are not addressed, and travelers on Delta regional routes may see either type until the transition runs its course. Delta’s 2027 timeline gives travelers a rough window, though a release describes intentions rather than guarantees, and schedules can shift as aircraft deliveries arrive.