DALLAS (NewsNation) — After more than 50 years, Southwest Airlines is phasing out its iconic open-seating policy and “bags fly free” perk.

Starting Tuesday, the airline began selling tickets for flights with assigned seating; the new boarding and cabin structure is set to launch Jan. 27.

The shift marks the end of a practice dating back to Southwest’s first flight in 1971. In its place, a more traditional boarding process with eight boarding groups replaces the long-used A-B-C method.

Southwest: Flyers prefer assigned seats

The airline has said the new model is a direct response to passenger feedback.

According to Southwest, 80% of current travelers and 86% of prospective flyers prefer assigned seating over the choose-your-own model.

However, not all passengers seem to be on board with the revamp.

“I fly Southwest because of what they were offering,” one passenger told NewsNation.

Another passenger echoed those sentiments, stating, “One of the major reasons I fly Southwest was because of that, and I’ll certainly think twice because of that.”

Southwest says farewell to free checked bags

The airline has said it’s making good on its promise of “one cabin, more options,” offering assigned seats, redesigned cabins, more legroom and new fare bundles.

As of Tuesday, approximately 250 planes have been reconfigured to offer extra legroom in the front rows, with more retrofits underway.

While the airline’s two free checked bags policy is being retired, the carry-on allowance remains unchanged.