Personal electronic devices such as cellphones, MP3 players, laptop computers and cameras have been purported to have potentially hazardous effects on flight navigation systems.
The Federal Aviation Administration, or FAA, has banned the use of cellphones during any passenger-carrying flight operating under instrument flight rules, or IFR. This includes all commercial airline flights.
Several studies, such as Boeing's 2003 study, have shown that cell phones cause electromagnetic interference. However, cell phones have not been shown to significantly affect navigation radios and instruments.
Several studies, including one in 2001 by NASA, indicate that other personal electronic devices such as computers and MP3 players do not cause significant interference with navigational instruments.
Although the in-flight use of cell phones is banned, many airlines have allowed the use of personal electronic devices other than cellphones above 10,000 feet mean sea level. Additionally, cellphones may be used while planes are taxiing or sitting at the gate.
Because of the regulations, many cell phones have a function called "airplane mode," in which the phone will no longer emit an electromagnetic signal and is therefore safe and legal for use on flights while above 10,000 feet.
