(NEXSTAR) — A California woman who assaulted a Southwest Airlines flight attendant in May is facing a possible sentence of 20 years in prison and a $250,000 fine.

Vyvianna M. Quinonez, 28, pleaded guilty to a charge of interference with flight crew members and attendants in a federal court on Wednesday, according to the U.S. attorney’s office.

On May 23, Quinonez had boarded a Southwest flight from Sacramento to San Diego, but violated FAA regulations by not wearing her mask properly, and by unbuckling her belt and pulling down her tray table during the plane’s final descent. When asked by a flight attendant to comply with the masking and seatbelt policy, and to prepare her tray table for landing, Quinonez pushed the flight attendant.

Both Quinonez and another passenger then began filming the altercation. One of the videos, which was shared online in May, showed Quinonez punching the flight attendant in the face and pulling her hair. A male passenger was then seen placing himself between the two women, reprimanding the passenger while the crew member stood behind him, blood dripping from near her left eye.

The flight attendant later required treatment at a hospital with a bruised, swollen eye, as well as a cut that required three stitches, according to the U.S. attorney’s office. Quinonez also chipped three of the flight attendant’s teeth, two of which needed replacing.

“The flight attendant who was assaulted was simply doing her job to ensure the safety of all passengers aboard the plane,” said Randy Grossman, acting U.S. Attorney for the Southern District of California. “It’s inexcusable for anyone to use violence on an airplane for any reason, particularly toward a flight attendant who is there to keep all the passengers safe. We are not going to tolerate violence or interference with the flight crew, and we will pursue criminal charges against those who break the law.”

Quinonez’s sentencing is scheduled for March 11, 2022.