As aircraft continue to age, some metal to metal joints will corrode.
RF energy can be rectified by a corroded joint into a dc voltage, particualary if the joint is of disimilar metals.
DC Voltage in the wrong place is not good for computerized airplanes....the bits can really become bits!
Often we can hear the buzz of computers on board the airplane on the Low Freq ADF system while listening to Commercial AM radio. (Our airline has the ability to pump this into the Pax Entertainment system, usually we use it for ball games.)
Try checking on this site about Razor Blade Radios.....to see how simply it is to rectify a voltage. You don't really need the coil, but you will recieve more than one station at once if many stations are nearby.
http://members.aol.com/djadamson7/articles/foxhole.html
Imagine that voltage going to the wrong pin of a cmos chip.....
Actually, the only problems I've heard of that were documented to day involve Pax rf emissions causing the pressurization outflow valve to to modulate.
I do have some concerns about these portable defrib machines. They put out a pretty good pulse, complete with (Of sorts) their own antenna leads....
Some stuff I dug up:
From
http://www.aircraftbuyer.com/featured/peds.htm
THE PROBLEM WITH PORTABLE ELECTRONIC DEVICES
Despite the familiar pre-takeoff warning - "Please turn off all portable electronic devices including laptops, electronic games and cell phones until we've reached cruising altitude" - the flying public (and some pilots, too) find it hard to believe that such innocuous devices could in any way affect the operation of an aircraft. The truth is, stray signals from these portable electronic devices, or PEDs, can, and probably have, caused aircraft to stray from course.
A regional jet flying from Salt Lake City to Eugene, Ore., received three separate warnings of discrepancies between the captain's and first officer's instruments. Once passengers turned off their PEDs, the discrepancies disappeared.
An aircraft on approach to Houston's George Bush Intercontinental Airport was advised that it was four miles off course. The captain's navigation indicator had been scalloping left and right, but 15 seconds after a passenger shut down his PED, the scalloping stopped.
These are just two of numerous reports made by pilots and flight crews in which CD players, laptop computers and electronic games have interfered with the operation of navigational equipment and communication radios. The NASA Aviation Safety Reporting System (ASRS) has received more than 50 reports involving alleged PED interference.
This has quite a few examples on it......
http://www.airnig.co.uk/emi.htm