American Airlines flight attendants are worried about passengers surfing porn Web sites.

As the airline adds on-board Internet service, some travelers might be tempted to visit seedy alleyways off the information superhighway. So the Association of Professional Flight Attendants, which represents 19,000 American Airlines flight attendants, has talked with management about installing filtering software to keep inappropriate Web content grounded, union spokesman David Roscow said.

American is one of several airlines experimenting with Internet service. While some, such as JetBlue, are using filtering software, others, including American, are leaving it up to flight attendants to monitor.