wrote in message
oups.com...
Peter Duniho wrote:

That is correct. The presumed 50 meter accuracy is constant throughout
the
flight. It's not as though it's additive for each waypoint (or worse, as
a
continuous function along the flight). Though frankly, even if it were,
you'd only be off by 500 meters after 10 waypoints which is still "no big
deal".

Now I know why planes occasionally land on the wrong runway in IFR
conditions )

As someone already mentioned, the error is not cumulative. Then, too,
approach GPS is a different animal from enroute.