With regard to JAA CPL, use of GPS is not allowed for the main navigation part
Whirlygig
Well we knew that, or if we didnt, we would have guessed.
Absolutely no reason at all why a CPL should demonstrate any mastery of "modern" avionics, as I said earlier new fangled technology, waste of space.
Mode S, thats what we want, now there you have a properly demonstrated safety case, unlike GPS where you can perfectly well avoid CAT infringements by keeping a good look out.