Can someone explain to me why the aircraft loads with the NAV1 radio with both frequency windows as "INOP", while NAV 2 appears to work normally. I've tried all kinds of switches, yet no success. Thank you.

What version of navigation equipment are you using? I think with GPS NAV it's handled in the GPS unit. So tune your NAV freqs there.

Edited Friday at 09:59 PM3 days by BrianW

I found it: with the GPS option, it uses the gps frequency knob.