Ironic that BA/Cosford have just chopped up the last Trident One that started all this blind landing stuff.
From the very start in BA(BEA) on the Trident and then onto most other types so equipped there were very simple tables in the Ops Manual. Three basic headings (four if you include "are the crew qualified"?), that is Ground Equipment (lighting, obstructions etc.) ILS equipment (tx monitors, OM/MM etc) and Airborne equipment (A/P, ILS marker receivers etc).
The tables were so simple. Look for what was working and extract what limits (RVR and DH) you could operate to day/night.
I find braking action poor's suggestion that " it never occurred to me that the WIP would affect the operation" amazing, assuming that Ryanair have similar tables to BA. Perhaps someone defending the crews involved could actually give us facts regarding the Ops Manual documentation that lays out revised limits/equipment downgrades provided to line crews by Ryanair.