KNOXVILLE, Tenn. (WATE) – The Federal Aviation Administration has proposed a $9,000 civil penalty for an airline passenger flying to Knoxville who berated flight attendants asking her to wear a mask.

The FAA on Monday proposed civil penalties ranging from from $9,000 to $52,500 against four airline passengers for allegedly interfering with and, in one case, assaulting flight attendants who instructed them to obey cabin crew instructions and various federal regulations. Passengers are required to wear masks in airports and on planes under a law effective February 2.

The incident for which the Knoxville-bound passenger is being fined happened February 15, on a flight from Ft. Lauderdale, Florida. The FAA alleges that a flight attendant instructed the passenger to wear her facemask over her mouth and nose as she boarded the flight. After the plane departed, a flight attendant again asked because the passenger did not have one on. The FAA report says the passenger rolled her eyes and did not put on her mask.

When the flight attendant asked a third time, the passenger is accused of putting it on without covering her mouth and nose and using an expletive in saying she would not wear it. Later, the report says the passenger came to the front of the plane to use the lavatory and sat in the exit row because the lavatory was occupied. After the flight attendant told her she could not sit in the exit row, the report says she got up, stood close to the flight attendant without wearing her mask over her mouth and nose, and screamed at the flight attendant.

When another flight attendant attempted to provide the passenger with a disturbance form, the passenger began to curse.

Federal law prohibits interfering with aircraft crew or physically assaulting or threatening to physically assault aircraft crew or anyone else on an aircraft. Passengers are subject to civil penalties because such misconduct can threaten the safety of the flight by disrupting or distracting cabin crew from their safety duties.

The passengers have 30 days after receiving the FAA’s enforcement letter to respond to the agency. The FAA does not identify individuals against whom it proposes civil penalties.