Mxsmanic wrote:
Since it is possible to fly without voice radio equipment, and given
that (if I understand correctly) pilots are supposed to have their
altimeters set correctly to a reference located not more than 100
miles from their position, how does an aircraft without a radio keep
its altimeter properly set as it travels?

In my experience planes w/o radios can't go much more than 100 miles
between stops. It was a bit of a stretch in the Aeronca and worse in
the J-3