Midway revisited

[LOKE]

With the recent NTSB report placing a great deal of blame on the pilot for the SW Midway accident – I thought I would bring up a confusing subject in the hopes that experts from the technical forum could shed some light on it.
As this accident took place in the US I would appreciate limiting this discussion to FARs and/or US Ops Specs.
It is clear in FAR 121 (121.195) that an aircraft may not depart so as that it will not be able to land within 70% of the available destination (or alternate) runway length. I can find no FAR that refers to actually landing on a runway within 70% of the available length -once you have departed. In fact many of the “inflight” performance #’s provided to the pilot refer to distance to 50’ over the threshold “to stop.”
There has been a long standing Ops Specs referencing visibilities below 4000’ – which muddy the waters even further – they say
“A pilot-in-command of a turbojet airplane shall not begin an instrument approach procedure when the visibility conditions are reported to be less than ¾ statute mile or RVR 4000, unless the following conditions exist:
(a) Fifteen percent additional runway length is available over the landing field length specified for the destination airport by the appropriate Sections of the CFR.”
What do they mean by “the appropriate Sections of the CFR.” Are they referring to the landing distance specified for the destination airport before departure?
If this is true (and why do they not just specify the FAR here) then any computations of a performance computer would need to also provide the additional 30 % buffer + an additional 15% for WET and an additional 15% for the reduced Vis and from my understanding of these computers – an additional additive for braking action !!!!
Yet I have seen educated and competent Airline Pilots unequivially state that once you are inflight – this 70% requirement no longer applies.
So my question is:
What did the computer tell the pilot? Given the conditions – was he capable – of stopping only on the surface provided? Or was he capable of stopping on the surface provided, plus all of the above mentioned additives – which means that he should have been able to stop in about 50% of the runway available?
I have read many stories about this accident and have seen numerous statements that the A/C should have been able to stop on the runway surface – even with the reduced braking conditions – yet when I look at some of the performance #s it appears that they mean with no additives beyond those additives – not considering an additional 30% or the additional 15% as specified in the Ops Specs.
I used to instruct in a 737NG and as an enthusiastic Instructor would pester the Engineers with questions about the auto-magic. When they were tired of listening to me they would say “it’s in the algorithms.” It used to piss me off – but I must confess – later in my instructing career – I used to respond with that answer often. But did this pilot get led down the path with these algorithms. What is the computer really saying – that with the given conditions – he will be able to stop with his nose wheel on the end of the runway – if he did everything perfectly? Granted – this is what we do when we depart on a field length limited runway and we have an engine fail at V1 – but that is for a once in a million chances with no time to make a decision – this is a situation where there is time to make a decision – but I’m afraid most – including me do not have a clear understanding of the regulations – nor what this computer is saying.
Please specify a specific regulation when replying. Interpretations are plentiful in this area – I’d like to stick to facts. I was surprised by the harshness of the NTSB’s report of the pilot’s blame in this – if it is how I see it as far as ambiguity – I think he got a raw deal.
LK