I hope this is the correct forum!  I am trying to find info on when to use the NAV button flying the Learjet 45. Any help or reference would be greatly appreciated.

If the NAV/GPS switch is in the GPS position you'd use the NAV button to make the airplane follow the pink line on the GPS, wherever that may be leading. That could be a "direct to" waypoint or airport that you've selected in the GPS, it could be a flight plan that you've made with the flight planner, or it could be an approach that you've loaded for a specific runway at a specific airport.

 

If the NAV/GPS switch is in the NAV position you'd use the NAV button to fly directly to or from a tuned VOR on a given radial that you select with the Course knob. Also in this mode you'll get lateral guidance on a tuned ILS, if you also want vertical guidance (glideslope) however you'd use the APR button instead of the NAV button.

Thank you. That clears up alot.  Do you happen to have ant links to download Learjet  45 Operators Manual?

I don't know of any off hand but I haven't really searched for any to be honest. The learning center has some basic info if you haven't seen that. Look on the "Site Map" tab about halfway down under Aircraft Information, then on the Lear page there's a link at the top for Flight Notes.

thanks much!  I never really looked at "site map" before. A world of info.

Do a Google search for Learjet manuals - many results:  Both real world & sims - Fly Away Sim has a D/L of a Lear 45 checklist & some pics of the main panel...