Surprised no one has mentioned the perfectly legal "NDB or VOR overlay" approaches. Of course certain preconditions have to be met, but it is possible to do an NDB approach with the NDB and or ADF unserviceable if you have appropriate RNAV AND approval from your regulator.
I believe it's a US and Oz(?) thing only. Haven't seen any around Europe after a few years covering most corners of the continent. GPS approaches, yes! But no VOR/NDBs that's got GPS overlays. I guess it's possible they're filtered out through our approach plate provider if our authority wouldn't want us to do them.
I hope he doesn't do his test in that aircraft because that would result in a fail. To do an NDB approach, you have to have an ADF installed, tuned and identified. Failure to perform any of these items in a test (and in real life - because others are depending on you to do it properly) should be a fail and one of the main parts of an NDB approach is managing the nif-naff and trivia before you actually fly the approach.
Don't worry.. I know we are talking Europe.. but, in the US a student of mine did this very thing. Got a bit overloaded with all the tuning and button pushing in the G1000. Flew the VOR procedure turn and whole approach following the magenta line on the MFD instead. Examiner couldn't fail this person, it was a published "VOR or GPS" approach.
I guess the art of flying a NDB to minimums to see the runway at your 11 o'clock low is slowly fading.