What Next,
Just out of curiousity: Where and how do those airliners fly? In my part of the world BRNAV-capability (e.g. RNP-5) has been introduced as a mandatory requirement for IFR flying from 1998 on
That's a good point. I do note that 82% of European airways above FL90 have an RNAV requirement[*] and yes, anyone flying any half-serious IFR in Europe is assumed to be BRNAV capable, your typical bugsmasher included (I wonder how many UK IR instructors know that, let alone train their students for).
[*] Don't have a reference at hand for the exact number, sorry. I read it in some Eurocontrol publication.