McGregor wrote:

What you're looking for is an airway database. Even the IFR Garmins don't
have that. Those are
the domain of airliners and biz jets for the most part.

Give me a break. My ancient Northstar M3 GPS has airways. My equally ancient
Argus 7000 has airways.
Garmin just sucks.

That's why I said for the most part. But, those old, clunky boxes come up
pretty short for the most part.