In the U.S., Federal Communications Commission (FCC) regulations prohibit the use of mobile phones aboard aircraft in flight. Contrary to popular misconception, the Federal Aviation Administration (FAA) does not actually prohibit the use of personal electronic devices (including cell phones) on aircraft. Paragraph (b)(5) of 14 CFR 91.21 leaves it up to the airlines to determine if devices can be used in flight, allowing use of "Any other portable electronic device that the operator of the aircraft has determined will not cause interference with the navigation or communication system of the aircraft on which it is to be used." In Europe, regulations and technology have allowed the limited introduction of the use of passenger mobile phones on some commercial flights, and elsewhere in the world many airlines are moving towards allowing mobile phone use in flight. Many airlines still do not allow the use of mobile phones on aircraft. Those that do often ban the use of mobile phones during take-off and landing. Many passengers are pressing airlines and their governments to allow and deregulate mobile phone use, while some airlines, under the pressure of competition, are also pushing for deregulation or seeking new technology which could solve the present problems. On the other hand, official aviation agencies and safety boards are resisting any relaxation of the present safety rules unless and until it can be conclusively shown that it would be safe to do so. There are both technical and social factors which make the issues more complex than a simple discussion of safety versus hazard. The debate on safety In the United States, the Federal Communications Commission (FCC) restricts cell phone usage on aircraft in order to prevent disruption to cellular towers on the ground. As mentioned above, the FAA allows the in-flight use of wireless devices but only after the airline has determined that the device will not interfere with aircraft communication or navigation. One report asserts correlations between the use of mobile phones and other portable electronic devices in flight, and various problems with avionics. Another study concluded that some "portable electronic devices", including laptops, electronic toys and laser pointers, used in the cabin can exceed the aircraft manufacturer's permissible emission levels for safety with regard to some avionics, while they were unsuccessful in duplicating any of the errors suspected to be caused by these devices' use in controlled lab conditions. Since these regulations were originally