Originally Posted by
Sallyann1234
Has anyone yet demonstrated or reported actual interference to altimeters, of an extent to require these restrictions?
Are these restrictions to be maintained indefinitely, in the absence of proper tests?
Electro-Magnetic Interference can be very difficult to measure and evaluate. Even documented cases of EMI often can't be duplicated in the lab.
I recall one case many years ago - a flight crew on a Boeing aircraft started observing some very unusual avionics behavior. The cabin crew observed a passenger playing a gameboy type device - when they had the passenger turn it off the problem immediately went away. The airline actually purchased the computer game from the individual and gave it to Boeing to investigate - and Boeing could find nothing unusual about the device or duplicate any sort of unusual behavior
That being said, the FAA and FCC have done a horrible job of handling this issue...