2 NDB on approach chart and Std mnms. What does it mean? As I understand it means that both NDBs must be operative(i.e. no NOTAMS inop status) , another opinion that we have to have 2 onboard ADFs to work with both NDBs simultaneously.
In my opinion it means both, except I would expect approval to be granted to use one ADF plus GPS in lieu of twin ADF. The problem with this type of question is what applies in general is not necessarily correct for each company or country.