when flying a "heavy" and you're flying a hi or lo altitude airway using both nav radios and the GPS, which is used for the MAIN navigation instrument? the nav radios or the GPS and how do you use both at the same time? william

Here is a short RW answer.High and Low altitude, (heavy or otherwise) use GPS as primary but have the VOR's tuned and used as a backup to compare information.Approaches, use VOR's unless it is a GPS approach that would require you to use your GPS as primary.Regards,Ed

hi ed, thanks very much for your reply. just what i needed to know. cya, william