[thewataccount]

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.

[tim333]

GPS is used a lot to figure where planes are but I think they are still not allowed to rely in it as it's not considered reliable enough by the regulators. At least not for things like altitude settings and instrument landings.

For light aircraft getting lost in the old days one hack used to be to fly low till you came to a motorway and read the signs. I imagine most such pilots these days would pull out their phone and open the maps app. Commercial flights of course have more high tech stuff like radio beacons.