DME is not required for an ILS approach
I wouldn't be so affirmative, me thinks it depends on the chart and what's written on.
Also for the "legal" point of view I believe that you need three things for a approach to be a
precision approach :
- axis indication (loc)
- slope indication (glide)
-
and a distance information
"with an accuracy of at least +/- 0.5 NM"
This indication had been for long provided by the markers which tend to become "old stuff", the newer and more precise DME is now the norm.
For the reference, it should be somewhere in the ICAO Publications (document 8168 - Procedures for Air Navigation Services: Aircraft Operations - Volume II: Construction of Visual and Instrument Flight Procedures)
And yes
Gomer, I know I didn't answer what shall be done in the situation described
