Medora Clai Reading said she was wrongly removed from a Jan. 7, 2021, flight to Palm Beach, Florida, from Washington, D.C. after a hostile flight attendant kept demanding that she keep her mask on despite medical issues, including a heart condition and low blood sugar, requiring that she stay hydrated.
Southwest had no immediate comment, having yet to review the complaint.
Reading's lawsuit in federal court in Brooklyn differs from disputes focused on travelers who are unwilling to wear masks.
The Federal Aviation Administration said airline crews in 2021 submitted 5,981 reports of unruly passengers, including 4,290 incidents related to masks.
In her complaint, Reading said that she offered to show the attendant her medical exemption card but was told, "we don't care," and that the attendant objected to her later sipping water by shouting: "You were talking!"
Reading said a gate attendant eventually ordered her off the flight, as an unmasked pilot "laughed mockingly" as she tearfully exited.
She said nearby police helped her to a chair and offered water, while commenting that similar occurrences were "happening far too often" and "it is usually Southwest."
Kristina Heuser, a lawyer for Reading, in an interview said a "planeload full of witnesses" saw the encounter, and some may have videotaped it.
Heuser said Southwest's "hostile and abusive" conduct reflected a "COVID insanity" that should not override federal laws protecting people with medical disabilities.
Reading's lawsuit alleges violations of the federal Air Carrier Access Act and various civil rights laws.
The flight attendant, two gate officials and the pilot, none of whom is identified by name, are also defendants.
The case is Reading v Southwest Airlines Co et al, U.S. District Court, Eastern District of New York, No. 22-00265.
(Reporting by Jonathan Stempel in New York; Editing by Howard Goller)
By Jonathan Stempel