"This gets into a ticklish area," Vint Cerf, one of the Internet's chief inventors, said. "Airlines have to be sensitive to the fact that customers are [seated] close together and may be able to see each other's PC screens. More to the point, young people are often aboard the plane."
For Australia-based Qantas Airways, Panasonic Avionics Corp. is designing high-speed Internet services to block sites on "an objectionable list," including porn and violence, said David Bruner, executive director for corporate sales and marketing at Panasonic. Bruner said airlines based in more restrictive countries could choose to expand the list.
American Airlines, Alaska Airlines and Virgin America have no plans to filter Internet sites based on their content, but may choose to manage traffic and delay large downloads. Virgin also is considering giving passengers the option of enabling controls for their kids.
Alaska Airlines, which plans to start offering service on some flights in the spring, said the same guidelines apply whether a passenger is flipping through a magazine, watching a DVD on a laptop or surfing the Web.
Airplanes, however, are different because customers are in closer quarters and it is likely that children will be on board. A Harvard Law School professor has said that allowing porn could subject an airline to harassment complaints — much like an employer that refuses to clamp down on inappropriate Internet use in the workplace.
Discount startup Virgin America is also deciding what to permit Internet users to access.
"An airborne environment is a confined environment," Charles Ogilvie, Virgin's director of in-flight entertainment and partnerships, said. "You don't want 22B yapping away or playing on a boom box."
Illegal Internet activities — such as hacking and piracy — could raise new questions about which country's laws apply if they are committed on an airplane.
Airlines have previously offered high-priced in-flight phone services. On the Internet, phone calls are free or cheap, particularly for passengers already paying for in-flight access to check e-mail or surf Web sites.
Panasonic is recommending that airlines permit Internet-based phone calls only on handsets with wireless Wi-Fi capabilities — the same technology delivering access within the passenger cabin. Bruner said the company believes Wi-Fi handsets use less bandwidth than telephone software that runs on laptops.
The technology can control telephone service by blocking incoming calls — and annoying ring tones — totally, or during designated "quiet time" periods.
American Airlines and Alaska Airlines passengers will not be able to access Internet-based phone services like Skype, although exceptions may be made for crew and federal air marshals.