Blue
Thanks for the reply, interesting reading.
m&v
I think we are saying the same thing in a roundabout way. Here in the UK with my Ops Manual we can depart down to 125m RVR with certain a/c, crew and airfield requirements met. If the airport is CATIIIb operational then we could undoubtably make an approach to minima if we required to return to the field using the published CATIIIb minima (usually 0' or 14' DH and 75m RVR), but only, and this is the point I was trying to make, if the a/c, crew and airfield were to meet the operational minimal requirements. It therefore follows that the T/O alternate has nothing to do with the departure minima but is there when a return to this airfield is precluded due to downgrade of equipment meaning that the revised minima would not get us back in; the example I used was in the EFATO scenario where we could not make an approach to autoland if the engine had failed before arming the APPR mode, therefore a suitable departure alternate is required within a certain distance/ flight time with weather conditions forecast as good as or better than the required minima dependant on the approach aid to be used at that field.
Phew, hope that clears my feelings up on this matter!
PP