"Mike Schumann" wrote in message
nk.net...
This is an artificial limit that manufacturers design into their GPS units
to force you to pay a premium for a device that can be used in an
aircraft.

That may have been true in the past. I recall marine units that had a very
low limit.

However, I have a handheld hiking unit that has a plenty high limit (don't
know what it is, but it works fine in the plane and even will show me my
speed in knots), and that explanation certainly doesn't seem relevant to the
951 mph limit mentioned previously in this thread (unless the market they
want to exclude are military and Concorde pilots).