An unruly passenger who was “physically combative” on a flight last month has been ordered to pay more $20,000 to United Airlines, according to court documents.

Alexander Michael Dominic MacDonald was on Flight 883 headed to Newark from London on March 1 when a crew member heard him arguing loudly with his girlfriend, the document state. He was asked to lower his voice and complied — but a few minutes later, he was heard yelling loudly at a flight attendant, the complaint states.

It’s not clear what happened between MacDonald and the attendant prior to him yelling.

An attorney for MacDonald did not immediately respond to requests for comment.

A crew member stood between the flight attendant and MacDonald, and attempted to calm him down, the documents state. MacDonald “continued to be verbally and physically aggressive,” asking the crew member “if he would like to ‘have a problem?’” according to the complaint.

MacDonald is also accused of threatening to “mess up the plane” and putting his hands on the crew member’s shoulders, backing them into a corner.