If a aircraft forms a faraday cage (I'm thinking the pressurized comair types) then how would a mobile phone effect a external signal? Or does a comair form a faraday cage (im thinking now of everyone who immediately busts out their mobile as the flights lands,,,)??Essentially what avionics package does a mobile operating 800/900/1800/1900 (and whatever other common rf mobiles use) interfere with?
Restrictions on cell phone usage has nothing to do with avionics or aircraft navigation devices. It is a FCC (Federal Communications Commission) rule that prohibits use of mobile phones from airplanes, NOT the FAA.
At the wavelengths used by mobile phones, the signal goes through the windows which are non-conducting and mesh-free. I would hope that nothing on a modern plane is vulnerable to consumer electronics - radiated RF from laptops, cellphones transmitting at full power, or some idiot with a 5W VHF. If you are designing avionics, or anything for military applications, you put it in a shielded case with conducting gaskets and filtered feed-thrus. Then test it to make sure it still works with a radar pointing at it.
Jet Doc is correct, the cell phone restriction is an FCC regulation - cell phones are licensed for ground usage. Cell phones operate on line of site, and once airborne your phone can see and connect to hundreds of towers at once, not the 2 or 3 connections the network was designed for. The restriction dates back to to time when cell phones were not as common, and the network not as capable. The FCC considered removing the ban, but most of the public comment was in favor of continuing the ban. It turns out no one wants to be forced to listen to the stranger in the next seat run their yap . The current ban is more an enforced courtesy than a technical requirement. The FAA does ban all electronics during take off and landing, and cellphones have very limited service in cruise, as the altitude is typically greater than the range of the phone. Even if FCC ban is lifted, there would only be a limited time in the flight were they could be used
