Descending to the 25nm MSA
Situation; You are flying over an area of relatively high terain prior to your destination where the lowest safe altitude (route or grid MORA etc) is well above the destinations 25nm radius MSA and also well above the IAF altitude for the let down you will use. The weather is IMC and you will have to do the letdown to the field/rwy. The question is, can you descend below the route MEA/ grid MORA or whatever limit was the restriction en route down to a lower 25nm MSA when established inside the 25nm range to facilitate direct entry into the let down proceedure rather than maintaining your lowest possible route altitude limit to the holding pattern and then descending?
I've been using this technique for years but was recently told by a Route Instructor that the 25nm MSA is defined for 'Emergency Use Only' and therefore not available for such purposes under 'Normal Operations'.
So is this true or not ? (under JAA/OPS in Europe), and ...
If this is true, then what is the difference in the survey quality of the 25nm MSA verses the other minimum altitudes that limits it to 'Emergency Use Only'.
There's no logic in this limitation under my current understanding of the various altitude limitations. Can anyone assist ?