REDHANDED (13 posts in 5.5 years, half on this thread): Well done on your rapid learning!!!!
At 08:26 you said:
Why are the authorities so against forcing the operators to monitor and use the HUMS data?
By 12:04 you have found the CAP that supports the UK regulation that requires HUMS (the Norwegian have a rule in the BSL too and EASA have published the rule to expand that across Europe):
The guidance to operators given in CAP 753 states that the period between the successful download and assessment of any primary VHM indicator, used for monitoring the engine and rotor drive system components, should not exceed 25 hours.
However that is the MEL limit not the guidance on how often to download*.
The CAA guidance earlier in that CAP is that HUMS should be downloaded ideally even during rotors running turnarounds.
Just for info, since the REDW incident, all oil and gas aircraft flying in the North Sea have to have a hums download and the data analysis before d next flight.
Though that was common practice with some operators before.
However, at this stage assumptions of what or might not have detected something and when are fantasy only.
but we went round and round this buoy at the time and it got tedious.
ahmen
* OGP don't even quote that as they still refer to a CAP that was redundant when CAP753 was issued in 2006! OGP guidelines are only for daily downloads (and I'm sure they would oppose rotors running HUMS downloads, especially offshore).