RAT et al, re #285.
The weakness with the monitored approach and safety calls for even more monitoring, depends on having parameters of relevance and accuracy, which can be monitored meaningfully.
It is the lack of these that are part of the hazards of NPAs. Either there is no glide-slope or if FMS generated (RNAV / GPS) it might not be sufficiently accurate below MDA.
A table of altitude distance is very useful during the initial approach, but less so when closer to the runway due to its resolution - accuracy requires threshold referenced DME and use of Rad Alt which may not be precise due terrain.
When below MDA, what might the head down pilot (PM) look at, and why. Airspeed, yes. Attitude, VS, Hdg, might vary when manoeuvring to line up with the runway - NPAs do not guarantee precision.
What boundaries should be placed on any ‘deviations’, what is the norm, cf estimated glide path, actual wind speed/direction, and expected VS, … .
Alternatively if the PM looks up this might this help avoid cue misidentification, or help cross check the flight path with respect to the runway, use of external cues - those used for a visual landing. It still necessary to monitor airspeed, split scan, acceptable for two crew operations just as it is for single pilot ops.
There is no ‘perfect’ solution or procedure due to the ill defined context and situation.
An alternative is to provide crews with knowledge and guidelines of how to assess situations and manage the inherent variability, highlight potential hazards of situations - as should happen every flight. However due to the uncertainty of ‘the world’, human performance, people - crew, management, regulator; and procedures, equipment, weather, … …, then occasionally the variability overwhelms the crew’s ability to manage the situation.