After being purchased last year by American Airlines, TWA and its callsign ceased to exist, but not airplanes with its livery. Although all previous TWA flights are using American as their callsign, the airplanes still have TWA markings. The former TWA airplanes will be repainted in American colors, but the changeover is expected to take several years. Until then, operators are cautioned to be alert to this situation to avoid misidentification of TWA-painted airplanes both on the ground and in the air and prevent potentially dangerous incidents.