Why do air craft still rely on archaic pitot tubes?

[wolram]

Main Question or Discussion Point

If GPS is or can be so accurate why do air craft still rely on archaic pito tubes? sure keep one as a back up, but for your PRIMARY instrument no way.

 

[russ_watters]

GPS provides ground speed, not airspeed. If you were in an airliner and had a 100kt tailwind, GPS would think you were going supersonic.

 

[jaap de vries]

Yes for stall and flight characteristics the indicated airspeed is the most important. I don't know if for navigation they use INS (Inertial Navigation System) with laser guided Giro's, or GPS for speed calculation.