The current air navigation systems work, lots of redundancy, what with the various forms of nav available. I think GPS is brilliant, slowly becoming the de facto preference.
However....
Brussels is spending billions on a satellite system described as a stupid waste of money by the company developing it – Telegraph Blogs
Interesting article. I hope it does go ahead. ADF technology is, I think a bit obsolete these days, bearing in mind there seems to consensus towards more RNAV.
So, do we need another GNS?