So let me put "our believe" together:
They fly an onboard approach like NDB, ATC is using the onfield PAR system and is giving glideslope and course informations.
Next question:
How come, that neither the NDB procedure was flown as published and the glideslope and course information given as info was wrong as well?
Why did the crew plan and execute a glideslope-orientated approach instead a stepdown approach, which is imho much more suitable in WX like that? With a MDH of 100 meters you have to make the decision for a go at around 140 meters not to bust the min, whereas you can do a drive in at the minimum of 100 meters.
franzl