Thanks for the meaty answer, L B.
Why not ask the CAA?? That would not generate questions and answers from oodles of instructors and examiners.
Interestingly enough, one of the CAA examiners told me that Lat/Long from the GPS (or Loran) was perfectly acceptable for the diversion section of the navigation.
Same examiner also told me that, if the aircraft was suitably equipped (RNAV - KNS80 for example) it was perfectly acceptable for candidate to move a VOR to the diversion and then track direct to it.
I'm curious now about an Arrow I flew recently - had two Garmin 430 GPS's on board. One click of the buttons would give me a page of the SIX nearest VOR's (or whatever) - with frequency, ident, bearing and distance.
None of these were identifiable through morse code idents on the audio panel - you just have to believe them to be accurate. So, if you are going to believe the GPS derived distance, why not believe the GPS derived radial/bearing and accept the information without identing the same stations on the VHF section of the receiver.
If you DO ident the station, through the VHF portion, and the CDI/HSI (whatever) gave you a different reading than the GPS screen, which do you believe?? The digital, accurate, GPS radial/bearing or the not so hot, moving, selectable CDI/OBS indicator on an HSI that doesn't slave 100% accurate with the equally unreliable magnetic compass?
Also wonder about the aerials/antennae on that aircraft. I don't remember seeing a VOR (wire coat hangar style) aerial on the tail - but did see ONE VHF and TWO GPS antennaes on the roof.
Does that suggest that the two VHF (speech) transceivers are fed through a combined antennae, and does that single antennae also get the VOR signal - or do the two standard VOR indicators receive their signals from GPS derived data - in which case GPS actually IS the primary means of navigation - but displayed in a conventional way?