Navigating
One can file non RNAV routes and fly the old fashioned way from VOR to VOR at lower altitudes, but at higher levers... Well
It is not really the lack of EFIS,but using NAV equipment lacking NAV database that can cause some gray hair with both controllers and pilots alike.
Som fellows plough along using Delco Carousels with 9 waypoints, though I hear these will not be allowed after the end of the year?
JJ