Study: Cell phones a hazard on flights

Despite the U.S. ban on cellular calls on airplanes, air travelers have a hard time keeping their hands off their mobiles and often make calls during critical stages of the flight such as final approach, according to a research team from Carnegie Mellon University.

As part of the study, released Monday, the research team filled their hand luggage with a broadband antenna and spectrum analyzer and boarded random airplanes crossing the Northeast United States. Picking up signals from cell phone calls onboard, they found that an average of one to four calls are made on every U.S. commercial flight.

"These devices can disrupt normal operation of key cockpit instruments, especially Global Positioning System receivers, which are increasingly vital for safe landings," Bill Strauss, an expert in aircraft electromagnetic compatibility at the Naval Air Warfare Center in Patuxent River, Md., and one of the researchers who conducted the study, said in a statement.

Strauss said risks are caused by radio emissions from cellular calls that are higher than previously believed.

The tests were aimed primarily at tracking emissions from cell phones, but they showed that other electronic equipment used on planes, such as laptops and game devices, also send out potentially harmful signals.

The report adds to the debate that was generated last June after the Federal Communications Commission proposed lifting its 1991 cell phone ban, letting passengers use their phones and other electronic devices while flying.

The ban was originally put in place to prohibit calls aloft from interfering with cell phone conversations on the ground and planes' radio communications, a risk that the FCC claimed might be outdated thanks to technical developments.

But lifting the ban is a bad idea, according to the Carnegie Mellon researchers. They recommended instead designing special tools for flight crews to track the use of electronic devices during critical stages of the flight.

The FCC proposal at the time elicited negative reactions from the Department of Homeland Security and the FBI, which expressed concerns that wiretapping guidelines would not be met.

The FCC said its move was triggered by the public's wish to make calls while flying, but not all air travelers agree. A National Consumers League survey last year showed that most passengers want to keep the ban in place, to avoid annoyance from yapping seat neighbors and trouble hearing emergency announcements.

The ban could be lifted as early as the end of this year.