SO GPS can only be PRIMARY mean of navigation until the integrity issue is solved.
This is now covered by WAAS (wide area augmentation system) in the USA.
In addition, with our ops we certainly had (and still have) more than 95% integrity, so this seems to satisfy the regulatory authorities in the enroute and terminal modes of operation.
WAAS does so with approaches, if fitted.
Couldn't say regarding EASA, however, in Euroland it apprars that the 'not invented here' syndrome is fully operable.
