Still thinking about the awfull accident of the airfrance plane, i was lying on the couch and thought, why are these pitot tubes used, and why is this the only way they measure it. By all means i am not a aviation expert, but i have common sense, which says you should never relay on one measurement if you can do it in other ways as well.

So my questions to those smart aviation people out there; why is the speed of the plane not measured by GPS; those systems ARE in place, maybe not as accurate, but it would be entirely possible to read the speed of the aircraft in this way combined with other techniques this should be able to give pilots warnings a long time before it becomes a real issue.

By al means, if you feel you can explain this, please do.