American Airlines flight attendants are urging the world's largest carrier to filter its in-flight Internet service to block access to pornography and other Web sites the workers said were inappropriate.

Union leaders discussed the issue with management, without making a formal request to bar specific sites, David Roscow, a spokesman for the Association of Professional Flight Attendants, said yesterday.

"We've heard a lot of complaints from flight attendants and passengers" about travelers pulling up objectionable Web pages, said Roscow, who didn't cite any examples.

In-flight Internet use is a new challenge for airlines as they balance their cabins' close quarters with the push to offer more amenities to win business and boost revenue from sources other than fares. AMR Corp.'s American began selling access on some cross-country flights on Aug. 20.

The "vast majority" of travelers use good judgment in what they look at, said Tim Smith, a spokesman for Fort Worth, Texas-based American. "Customers viewing inappropriate material on board a flight is not a new scenario for our crews, who have always managed this issue with great success."

American offers Internet access for $12.95 on 25 flights daily.

The program is in a three- to six-month trial period, Smith said. When American reviews usage and feedback, "we will obviously assess this concern as well, including the number of actual incidents reported and any other related issues."