Originally Posted by
Biggles_in_Oz
How much class G is there really in the USA ? (genuine question), because my quick searching indicates that it is mostly at very low levels (around 1200' AGL) with class E above.
ie. there is little need to mark frequency boundaries because it's either class E or whatever ATC tells you. everywhere war to restart)[/size]
Outside of Alaska and some parts of the West, not much. Most of the US has Class E airspace above 1200 AGL or lower. However, when flying VFR in Class E Airspace, you are not required to monitor or transmit on any frequency, ATC or otherwise. And that includes 121.5, there is no requirement to monitor 121.5.
You may, if you so *choose*, request VFR flight following from the appropriate ATC facility while flying VFR in Class E airspace, but that is completely a choice, as in something you may choose to do or not. There is no requirement to do so.