DALLAS (CBSDFW.COM) – Dallas-based Southwest Airlines is ending its coronavirus pandemic-era policy of underselling flights and will put passengers back in middle seats starting Dec. 1.

“We are one of just a few airlines in the world that limits the number of seats available for sale to promote distancing onboard our aircraft, and we will continue to do so through November. This practice of effectively keeping middle seats open bridged us from the early days of the pandemic, when we had little knowledge about the behavior of the virus, to now. Today, aligned with science-based findings from trusted medical and aviation organizations, we will resume selling all available seats for travel,” said a statement in part from the airline.

But the company said it’s “pairing this change with enhanced flexibility for customers on fuller flights to rebook to another flight, if desired.”

Citing research from UT Southwestern Medical Center and the Stanford University School of Medicine, the airline said the risk of breathing COVID-19 particles on an airplane is virtually non-existent, with the combination of air filtration and face covering requirements.

Masks are still required by all passengers and airline workers.

Southwest Airlines lost $1.16 billion in the third quarter, typically a very strong period of air travel that includes most of the summer vacation season as the pandemic caused a massive drop in air travel.

Revenue tumbled 68% at Southwest, compared with a year earlier, before the global spread of COVID-19.

Combined with earlier losses reported by Delta and United, the four largest U.S. airlines have lost at least $10 billion in each of the last two quarters. It’s an unprecedented nosedive that has caused the once highly profitable airlines to forage for billions of dollars in government aid and private borrowing to hang on until travelers return.

Southwest CEO Gary Kelly urged Washington to approve more pandemic relief including a six-month extension of $25 billion in aid to airlines. Without it, he said, “we simply cannot afford to continue with the conditions required to maintain full pay and employment.”

Southwest plans to cut pay for nonunion workers in January and has demanded unions accept lower pay or risk furloughs.

Air travel in the U.S. has recovered slowly in recent months, and topped 1 million passengers on Sunday for the first time since March. However, travel is still down about 65% from a year ago. Business travelers, who fly more often and pay higher fares, have not made a meaningful return.

The airlines are still hoping for another $25 billion lifeline from Congress and the White House that American said would allow it to recall the furloughed workers.

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