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bobtait replied the topic: TSO-C146A GNSS alt planning
Thanks for that Ryan. The phrase 'radio navigation aid' incudes RNAV/GNSS. So when you interpret AIP ENR 1.1 para 11.8.3, the term 'radio navigation aid' includes RNAV/GNSS along with ADF and VOR. So if the destination has only an RNAV/GNSS approach procedure, and you have 2 x RNAV/GNSS units TSO 145, 146 or 196 you would not need an alternate.
However, if you only had one such unit, you would still need a ground-based aid to avoid the requirement for an alternate. See part 10 of AIC H05/18 para 10.1, 10.3 and 10.4.