englishal
I haven't reread the doc, but I think you will find that VFR flight in the middle of nowhere gets dragged in around 2007/2008.
keef
I think the only relevant thing for GA traffic with "enhanced" mode S is because it "squitts" your position in 3 dimensions. I get the impression the only thing "bog-standard" mode S does in the GA world is provide a unique key which can be used to look up your tail number and send you a letter for busting restricted airspace. I'm not sure how the EU is going to find out where you are in 3D without using that nasty US GPS system which is totally unsuitable for EU aviation purposes (like approaches)
Mode S is obviously not required for GA because there is model out there where mode S is obligatory for TCAS (even for on demand part 135 charter operations), and huge numbers of VFR planes not using it is irrelevant.
My airline pilot friends tell me that in the low level airspace where you find swarms of VFR traffic, squawking mode C is perfectly adequate for their situational awareness purposes. They also tell me they would rather you squawk mode C than turn your transponder off and not be able to see where you are. They can filter out all the VFR traffic in busy terminal areas, just like ATC can.
With some digging, there is some good stuff to be found on the FAA web site, and the CAA doc has a bilbliography. Years down the line this technology could be very useful for GA because the mode S (or more likely ADS-B) groundstations will be able to transmit positions of conflicting traffic to you in real time. I think this has been demonstrated in the US, but they are still working out (ie consulting
) how this will affect the WHOLE aviation sector.
All this is all from a very basic understanding, others will know more.
Cheers