Originally Posted by
vilas
The chart shows safety altitude north of DIXIR as 7100. The clearance given descent according to procedure. No matter from where you come to DIXIR procedure doesn't permit descent below 7500 before DIXIR.
Looking at the AIP ILS 23 plate, if you came along the DME arc from DITRE, the procedural descent starts at the MUR 051 radial and the next charted platform altitude is 4,100’ at 13DME MUR. Terrain clearance is not the issue at DIXIR as that whole segment is 4,100’ minimum - if you were using non-CDFA techniques you would be perfectly safe going to the 4,100' IAA from FL90, there is no FL75 restriction.
What would I do if I was placed in the same position as the OPs PF, 10nm north of DIXIR, flying direct and cleared for the ILS but for the purposes of the discussion still in IMC? OK, we’re outside the 4,700' 25nm MSA so can’t use that. What’s the MGA between our position and DIXIR? 5,000’ on my chart. Is there a restriction at DIXIR? Yes, 4,100’ on the approach plate (we are not flying a STAR). Right: set 5,000’ initially, then 4,100’ crossing DIXIR. Capture the LOC then the GS, carry on as normal. Depending on whether I was in the mood for a CDFA or not and our energy state, we would cross DIXIR somewhere between 5,000’ and 8,000’.
If ATC wanted us to stop descent at some level/altitude they would have instructed us to do so. As they haven’t, it's up to us to remain safe w.r.t. terrain, which the above plan does. We have been cleared for the ILS, so we can take it all the way down to DH and further if we have the required references and landing clearance.