Why Can’t You Use Cell Phones on Airplanes?

[podcast]http://www.scienceline.org/wp-content/uploads/2010/02/Cell_Phone_Plane-11.mp3[/podcast]Could something as harmless as a phone call actually crash a plane? Or is the pre-flight announcement to “please turn off all portable electronic devices” simply to create a sense of calm and focus for the passengers as a glistening hundred-ton hunk of metal implausibly takes off into the air?

With wireless Internet now making its way onto many flights, couldn’t you technically call someone using Skype? Would anyone stop you?

There are two regulatory agencies in the U.S. who have jurisdiction over cell phones on planes. They each have independent, unrelated rules about them.

The Federal Communications Commission — controller of the nation’s airwaves — bans cell phones on planes to protect cell phone towers. They simply aren’t designed to handle calls from phones traveling tens of thousands of feet in the air at hundreds of miles an hour. Traveling through the air, your phone can contact many towers at once, confusing the networks and reducing their capacity. So the FCC ban is intended to protect the wireless cellular phone infrastructure.

The Federal Aviation Administration — which regulates flight safety — has safety concerns about cell phones. Because of this, they have rules against their use during takeoff and landing. It’s because of electronic interference. Cell phone interference could cause the pilot to lose contact with ground control or knock the plane off course. While the chance of this is low, the potential consequences are grave enough for the FAA to maintain a ban on all electronic devices during takeoff and landing.

“If it saves one crash every decade, it’s worth doing,” said retired NASA astronaut Jay Apt. Still an active pilot, Apt was involved in a review of cell phone related safety incidents reported by pilots to the FAA. During the review the committee found cases of cell phones interfering with an airplane’s Global Positioning System, which is used for navigation. Because the GPS satellites are far away, it’s easy to lose their signal. “It’s like trying to hear someone whispering in the middle of a crowded football stadium,” Apt explained.

Using your cell phone on a plane is a little like yelling right next to the person trying to hear the whisper in the stadium.

All electronic devices emit electromagnetic energy. Requiring them to be turned off during takeoff and landing is like asking everyone in the crowded stadium to be quiet.

While all electronic devices can interfere with aircraft equipment, cell phones pose a particular risk because they are active emitters — they transmit electromagnetic energy long distances to cell phone towers miles away.

The FCC assigns cell phones their own frequency channel to ensure they won’t interfere with things like radio stations. Phones should only emit at the channel they are assigned, but energy can leak to others — like those that airplanes use to communicate with air traffic controllers or for navigation.

Surprisingly, the FAA has no specific ban on cell phones once planes reach cruising altitude. Instead, they leave it up to the individual airliners to determine if they are safe, according to a 2006 advisory. Safe or not, the FCC regulations prohibiting cell phone use on planes still holds.

Even without the FCC ban, most commercial airliners would probably err on the safe side and prohibit use of cell phones when the wheels are up. Conducting more research on how cell phones affect airplane operation would be expensive and time-consuming, so it’s easier to just keep the ban.

Besides, nobody is really complaining about the quiet atmosphere.

New technology may soon change the social landscape of the airplane, however. “Picocells,” which can be installed on planes to act as miniature cell phone towers, route phone calls to terrestrial systems via satellite link. This means customers can use their own cell phones for the price of an international call. Airliners in other countries, such as Lufthansa, Air Asia and Ryan Air, have already started offering this service on some flights.

In-flight cell phone technology is similar to the in-flight wireless Internet service already provided on Continental, United, American and Delta flights by Aircell, a company based in Itasca, Ill.

While the U.S. has embraced wireless Internet on planes, there is still a lot of resistance to cell phones. Says Aircell spokesperson Brenda Chroniak, it’s because of  “passenger aversion to the idea of many people talking loudly on flights.”

In fact, a passenger could place a call from a plane via the Internet with a service like Skype. Chroniak says they block that capability at the request of the airliners. However, there don’t seem to be any FCC or FAA rules against it — just a general consensus that it would be unbearably annoying.

Rep. Peter Defazio, D-Ore., is so passionate about the issue he is sponsoring a bill to ban cell phones on planes — called Halting Airplane Noise to Give Us Peace Act — or HANG UP.

For astronaut Apt, lifting the cell phone restriction would be “another nail in the coffin of civilized air travel.”