4dogs... yikes! You've asked some pretty awkward questions that Pans Ops isn't exactly geared up to answer. Indeed, as I'm 500 NM away from my books right now - and for the next week as well - I'll have to go from memory on the finer points. However I'll preface this by saying that the sort of questions you've asked are the very reason why airlines need to do their own sums for their particular aircraft, philosophy and SOPs.
I don't know that ICAO consider missed approaches to be "emergency situations" so much as "unusual".
The point here is that you can only expect 100 feet of obstacle clearance, in the intermediate segment of a straight missed approach and 164 feet in a turning missed approach. That's a bit of a simplification, but it is still the basic fact. The ICAO
Obstacle
Clearance
Panel came up with those values based on experience and a statistical probability of the number of times a particular missed approach would need to be flown, versus the number of times it would not need to be flown.
It is, therefore, a risk management exercise, based on the expectation that the missed approach would be used infrequently and, therefore, a lower level of risk is achieved. This allowed the OCP to determine that a very small amount of obstacle clearance is necessary in a missed approach. Yes, I'm doing a bit of second-guessing here, but no other explanation seems to make sense when considering this quite small amount of obstacle clearance.
Does the PANS-OPS missed approach design offer sensible lateral containment?
This might depend on the philosophy in the particular country. Pans Ops says that a straight-ahead missed approach splay can be the same as the final approach splay. I know of a number of countries that apply that statement verbatim. This requires track guidance from the azimuth aid used for the approach, so it begs the question about how much lateral protection do you have if the navaid failed?
In my dark corner of the world, that is a very real consideration, so I do not routinely apply it. Thus, I am forced to use the alternative Pans Ops missed approach splay, for DR Nav., which has a splay that expands at 15 degrees, rather than the 10.3 degrees for NDB guidance or 7.8 degrees for a VOR. Clearly, the extra degrees that I must allow for will bring more terrain into the missed approach area and this can, often, control the MDA for the whole procedure.
As to the matter of what is "
sensible". I suspect the answer here is that beauty is in the eye of the be(er)holder!
How far down range is the aircraft before it is re-established in a missed approach configuration for which climb data is available or can be determined?
This depends on the maximum speed allowed in the missed approach and that speed will be different for every category of aircraft that is authorised to use the particular procedure. I can't give a direct answer here but the following is a guide that uses a fairly typical situation in my part of the world...
All values for 2000 FT AMSL, ISA+15 and, before the purists jump down my throat, these values are approximate because I don't have my books or calculation routines with me. However, these values will be about right and will give an idea of the sort of allowance that must be made.
Cat A (110 KIAS) 0.8 NM
Cat B (150 KIAS) 1.1 NM
Cat C (240 KIAS) 1.6 NM
Cat D (265 KIAS) 1.8 NM
The above distance is required for transition to climbing flight, after pilot recognition of the missed approach point. There might need to be an additional 0.1 to 0.3 NM to add on, to allow for pilot reaction time after recognising the MAPt.
What options exist for safe flight paths below the landing minima and for missed approaches from circling?
This is a HUGE question that falls in the category of the "preface" comment, above. The simple answer, as far as Pans Ops is concerned, is ... none. Indeed, for circling, all bets are off because the missed approach is designed to start at the missed approach point, not at some unknown point within the circling area. Thus, the pilot is on his/her own if there is a need to initiate the missed approach from anywhere beyond the MAPt.
Will reduced lateral tolerances for VMC operation provide better options?
Undubtedly! Your only problem here is trying to convince the ICAO OCP of it. Of course, if the weather is VMC, the likelihood of hitting a hill you can't see is usually much reduced.
What is an acceptable level of risk for operations in difficult terrain, recognising that complete and guaranteed safety for all contingencies will not permit flight operations at all?
Strewth!!! How long is a piece of string? This is the VERY reason why airlines MUST crunch their own numbers - or get someone to do it for them.
Most of the above is pretty academic anyway. The reality is not so much the State compliance with Pans Ops - insurance premiums are based, in part, on the assumption that all instrument procedures comply with either TERPS or Pans Ops criteria. If any State regulator moves away from that criteria, there could be significant insurance premium penalties on airlines that operate to, from and within that State.
And, in the event of a prang, there's a pretty good chance that the procedure designer and the State will share liability. I don't know of any State regulator that will let that happen so, unless ICAO modifies the criteria in any of the ways you're suggesting, I don't see any contracting State regulator sticking its' head on a chopping block.
I hope this clarifies the situation for you.
Happy New Year!