Originally Posted by
A and C
The reason for the FM immunity regulations was that the aviation authoritys in europe had let commercial radio transmitters to broadcast right up to the bottom end of the aviation band.
While, I believe the statement is true (i.e. stations up to 107.9 are used in the UK), it still doesn't quite answer the question of why Europe with an FM allocation of 87.5-108 has a real risk of 'airplanes crashing' while the US using 87.9-108 (107.9 FM is commonly used) doesn't seem to feel there is a risk.
Is it US transmitters are better, N-Reg planes are better wired, American pilots are better at identifying interference, the US just accepts a level of IFR 'debris' falling around the country? or is it European Gold Plating?