Fort Worth-based American has apologized and said it's looking into the incident aboard a Labor Day weekend flight from Newark, N.J., to Dallas-Fort Worth International Airport.
Beck said on his radio show Tuesday that a flight attendant "treated me as a subhuman." Beck said the man "fawned over the other passengers" but "barked" at Beck and slammed a can of soda down in front of him.
Beck implied that the flight attendant singled him out because of his political views.
American tweeted an apology.
American is owned by AMR Corp., which last November filed for bankruptcy protection.