A passenger on a flight from Denver to Montana could face possible federal charges after authorities say he became unruly while the plane was in the air.
Another passenger says the man appeared drunk when he started acting strangely last night, and eventually knocked on the cockpit door.
A Sky West Airlines spokeswoman says the man also threatened a flight attendant, pushing and grabbing her. At that point, some other passengers confronted the man and things got physical.
Police in Great Falls were waiting for the flight to arrive. They boarded the plane and arrested the man a little after nine p-m.
Sky West operates United Express flights in and out of Great Falls.