PJ, you are seeking ‘runway braking action’; aren’t we all.
One of the issues in discussion (including reverse) involves the differences between Europe and the US.
Europe openly recognises that operations on contaminated runways involve increased risk and thus if these operations are to be conducted regularly some additional mitigation is required. If reverse is to be included then consider ‘what if’ it fails – perhaps less margin in speed, touchdown point being allowed, more GA minded.
The US apparently accepts contaminated operations as routine, or a necessity due to other limitations in the ATC / runway infrastructure. The chosen margin over ‘actual’ landing performance might only be the minimum 15%, which has been discussed elsewhere; ‘actual+15%’ might only be a better representation of what is actually achievable in routine operations, with everything working; thus in reality there is no margin.
Yes a runway excursion vice overrun, but there is a hint of complacency with thoughts of EAMS; these are to mitigate aspects of a landing which should have already have been allowed for, not an aspect of routine operations – “we don’t need more than 15% because of EMAS”. Of course EMAS has no value once off the pavement.
Did the airport calculate and broadcast braking action as per TALPA … a US inspired system.
If the pictures at #37 are representative of the runway condition – snow, slush, depth greater 1/8in, then the best braking action from TALPA would be ‘Medium’ or more likely ‘Medium Poor’. Then add to that the dew point which identifies increased risk.
Braking action also defines crosswind aspects, thus the reported wind might have been acceptable for ‘Good’, but it could be less so in ‘Medium Poor’ – even less margin for a rear engine aircraft; what mitigations would be considered for these ‘routine’ variations in wind measurment and reporting.
A key item in TALPA is that a PIREP cannot upgrade the braking action, thus a call of ‘Good’ is irrelevant as the preceding reports of "medium, worse at the end ... later said poor" remain unless there is a runway inspection. Are PIREPS considered that way, are all preceding PIREPS passed on to crews – not necessary if TALPA is used.