I'm not well-versed in these kinds of navigation. Could anybody offer a short explanation on how to realistically navigate with the 727? I know how to work the 707, but in the 727 it is no simple matter of setting autopilot to "NAV".

Also, is there INS in the 727? I couldn't find it, and I'm not sure I'd know how to use it. I'm just getting used to using complex aircraft systems. (I'm pretty hopeless when it comes to figuring out navigation stuff, so I apologize if I'm asking stupid questions...  ;))