American Airlines expanded the availability of in-flight Internet access Wednesday, launching airborne e-mail, Web and other online services on some of its longer, nonstop flights.

The move could create a new stream of revenue as the aviation industry faces high fuel prices and other challenges, but it also could create new headaches as passengers retrieve sensitive e-mails and Web sites in confined quarters.

American tested in-flight access on two flights on June 25. With Wednesday's launch, the airline is making service available for $12.95 per flight on its Boeing 767-200 aircraft connecting New York with Los Angeles, San Francisco and Miami. American said most flights on those routes use the 767-200.

"Today the days of being cut off from the rest of the world while in the air become history," said Jack Blumenstein, chief executive of Aircell LLC, the company providing Internet services for American and other airlines.

Several other airlines have been testing or considering in-flight services.

The system will block Internet-based phone calls, giving passengers relief from chatty seatmates.

However, American and other U.S. airlines have said they will not filter sites based on their content, raising the prospect of passengers surfing pornography with kids nearby. Airlines say they already have general policies to address unruly passengers, and those would apply as they do now to passengers who browse adult magazines.

Less clear is how executives reading corporate e-mail containing confidential information will fend off snooping eyes.