RNAV equipped 727-100/200's
As there are quite a few of those trusty workhorse 727s cris-crossing Canada (and many other places in the world) at night playing the cargo game, I have a little question regarding RNAV equipment on them.
As I haven't had a Fam on one (maybe because most of them are older than me and I'm funny about that sort of thing ), could somebody take the time to explain when issued an RNAV point to navigate to, what the little RNAV box actually does (as opposed to glass cockpit).
Thanks in advance.