I'm just reviewing my paperwork with KDR's in preparation for my flight test, and I'll double check with my instructor, but I cannot find an obvious answer to a thought I had crop up (given I don't know exactly what the question I got wrong in the exam was, I'm pondering a few options).

I note that there are no Alternate Minimums listed on the DME / GNSS approach charts. Is this because in order to use a DME / GNSS approach, you need to be current on the 'associated' VOR / NDB approach, and as such, those procedures set the alternate minima, or do they have the 'no IAP' minima?

Thanks, that's an interesting question and I can’t find a specific answer in the documents. The following points are relevant. (AIP ENR 1.5 section 11- plus some common sense).

1 There is no alternate minima published on the DGA procedure charts.

2 The requirement is to use the GPS for distance information only.

3 The actual tracking to the destination aid must be done by reference to the ground-based navigation aid.

4 Using the ground based aid for tracking does not require you to be current (or even endorsed) on the associated instrument approach.

The DME or GNSS procedure simply means you should be able to actually track to the destination and descend to MDA. The documents don't have anything specific to say about what happens if you do not become visual at the completion of the arrival procedure.

Clearly you would have to have another approach available and you would have to be qualified and current on the use of that alternative approach. The alternate minima would then be the published alternate minima for that approach.

Maybe the AIP should have something specific to say about this. I have asked CASA for comment and I am awaiting their reply.