In article ,
says...


I have not come across this, here in European pilot publications etc.
GA would have picked this up I reckon, because we do use KX155As,
165As, GNSx30s etc.

What we are getting is PRNAV and that is a far bigger problem -
potentially.

The airlines cannot fly something that is not on an approach plate.

Does anyone have a reference for a reduced ILS frequency spacing in
Europe?

A "reference" - do you mean an example?
https://www.sia.aviation-civile.gouv...AIPparSSection
%5CIAC%5CAD%5C2%5C0903_AD-2.LFPN.pdf

This is a very commonly used approach (VOR-DME)
I could list dozens of others requiring "50KHz Glideslope"