Hello to all,

Do most modern aircraft rely on the GPS for navigation, and to what
extent do they rely on it?

And is it true that such aircraft's navigation systems use maps
'optimised' for GPS?

And finally, if I may, what level of positional accuracy must aircraft
relying on GPS for navigation work with at typical altitudes
(presumably 20,000 to 40,000 ft)? Are we talking tens of metres, or
over a hundred metres?

Thanks very much in advance.


Regards,

David,
England.