An irate United Airlines passenger knocked out a gate attendant at Washington DC-area airport, hospitalizing the employee and earning himself a one-way ticket to the airline’s blacklist.

A United Airlines gate agent was punched unconscious by a Maryland passenger during boarding at Washington Dulles International Airport late last week, prompting the passenger’s arrest.

Christopher Stuart Crittenden, 54, has been banned from flying United Airlines after he allegedly punched a gate agent on Thursday, March 13, in a video that has since gone viral. Crittenden was arrested and charged with assault and disorderly conduct.