The video shows the flight attendant arguing with two women seated on a flight from Sacramento to San Diego on May 23. The airline says the argument was over the passengers not following standard landing instructions.
One woman is first heard shouting "We are going to sue you!"
The other woman then jumps up and starts punching the flight attendant in the face multiple times. Another passenger quickly jumps in between them, yelling at the woman to sit in her seat.
The woman who threw the punches was later arrested, while the flight attendant was treated at a local hospital. In the video, her face is bloody right below her left eye. She had two teeth knocked out in the attack.
Southwest Airlines says the incident started when the passenger refused to follow standard instructions given upon landing.
The airline said: "The passenger repeatedly ignored standard inflight instructions (tray table in upright position, seat belt, etc.) and became verbally and physically abusive upon landing."
"Law Enforcement Officials (LEOs) were requested to meet the flight upon arrival, and the passenger was taken into custody. We do not condone or tolerate verbal or physical abuse of our Flight Crews, who are responsible for the safety of our passengers."
The passenger was later identified as Vyvianna Quinonez, 28. San Diego Harbor Police arrested her after the flight and charged her with felony battery.
Southwest Airlines has banned her from future flights.
Sonya Lacore, Southwest's vice president of in-flight operations, said in a message to flight attendants that the airline has a process for permanently banning passengers and "the passenger involved in the most recent incident has been advised that she may no longer fly on Southwest Airlines."
PREVIOUS COVERAGE: Flight attendant assaulted on Southwest flight
The FAA says it has been observing an increase in unruly passenger behavior and it has been cracking down on such incidents with heavier fines.
Since Jan. 1 of this year, the federal agency has received about 2,500 reports of unruly passenger behavior, with about 1,900 of those related to face mask mandates.
The union for Southwest flight attendants says more needs to be done to crack down on such behavior.
"This was the final straw," Lynn Montgomery, president of the union for Southwest flight attendants, told ABC News.
"We've had a staggering amount of increase in the number of unruly passenger incidents, and when this happens to our own, that is when we really kick into gear and say enough is enough, we need to do more."
The FAA provided those numbers as it announced it was seeking civil penalties totaling $54,500 against five passengers for behavior ranging from refusing to wear a mask to assaulting flight attendants.
"I've been in the industry since 1992, and this is the worst ever," Montgomery said. "People seem to be more angry. When they're asked to do something, compliance seems to be more difficult."
Southwest and most airlines train flight attendants to de-escalate tense situations with unhappy travelers. Montgomery said those tactics are growing less effective and a small number of passengers are becoming bolder in challenging the authority of crew members.
Montgomery, the president of Local 556 of the Transport Workers Union, wrote about the weekend attack in a letter to Southwest CEO Gary Kelly.
Montgomery asked Kelly to lobby federal officials for more federal air marshals on flights and to ban passengers who violate rules instead of putting them on another flight. She said flight attendants are concerned about Southwest's plan to resume selling alcohol on board planes. Many recent cases that have caught FAA's attention involving passengers who were drinking.
The Associated Press contributed to this report.