My understanding of PANS-OPS (the law) is that we need to have raw-data displayed at all times unless we're operating (B)(P)RNAV procedures. The FMS and ND on conventional routes (SID's, STAR's) are just tools to our disposal but we are meant to cross-check.
My take is also that by law we are required to tune and identify a station which defines a holding fix on the arrival.
On the line I see this all rarely done, and I am fully aware that the FMS can be relied upon. But the letter of the law (doc 8168) says different.
Interested in opinions.............
Well OPEN DES, I think you are perfectly right in case your ACFT has GPS PRIMARY LOST or is not equipped with it.
In these cases I select even enroute as many NAV aids as possible to make sure I'm not flying around with a map shift.
With GPS primary active, I leave the RAD NAV page blank during the cruise flight and descent. For T/O and approach I select the most appropriate NAV aid in case I'm restricted with terrain and/or traffic (e.g. FRA/CDG etc)
Example: T/O in ZRH in IMC: With the high terrain surrounding the field I even use the STBY tuning function for my EOSID in case everything goes to hell incl. communication.
On the other hand: In good VMC weather at a field without any high terrain or high traffic my RAD NAV page stays blank as well during the approach.
So in my opinion you it's ok when you adapt to the present situation - from backing everything up as good as possible to leave everything managed and autotuned.
How is it called at TOU..."use proper level of automation"...or something!
W.