To my knowledge planes don't use the gps for very much, and AFAIK they use the barometric altimeter for maintaining their flight level. A controllable, plane that can maintain altitude is difficult to crash. The GPS stuff is mostly supplemental and is relatively new.
And pilots can land with a visual approach and still have ILS.
You would still have ADSB with your altitude, and I beleive heading and airspeed.
Because of the existing requirement to be spotting traffic and being over 1000ft away from other planes, they should be fine.
ATC should still have radar vectoring for their airspace.
I assume planes use more then just GPS, and use galileo and the other networks like consumer GPS do.
And pilots can land with a visual approach and still have ILS.
You would still have ADSB with your altitude, and I beleive heading and airspeed.
Because of the existing requirement to be spotting traffic and being over 1000ft away from other planes, they should be fine.
ATC should still have radar vectoring for their airspace.
I assume planes use more then just GPS, and use galileo and the other networks like consumer GPS do.