One small point springs to mind, with regard to an earlier post regarding the crew of the Cougar cab noting abnormal indications, but no visible or audible signs such as vapour trails, smoke, flames or noises.
This, when coupled with a difference of opinions we used to have at the CAA HUMS users and North Sea operators gatherings, "Should HUMS data be displayed instantaneously in the cockpit?" JimL you will probably recall this, there was opposition to the displays because it was felt that the systems back then were not mature or reliable enough to provide definative data.. e.g. would a pilot ditch due to a displayed warning only? The general feeling back then from NS crews (About 5/6 years ago) was a resounding "no".. However, with modern aircraft such as S-92, where the old methods such as "noisy gearbox" etc MAY not be so evident to the crew, and given that HUMS and FDR data collection is now much more reliable and comprehensive, do we have a case for perhaps reviewing attitudes towards the onboard information and indications available to the crew? I concede that this fault most probably would not have been detectable via the HUMS / FDR but thats not to say that as in the case of the Dauphin main ring gear back in 2004, monitoring could be extended to cover new failure modes.
The arguments on here about commercial gains taking priority over safety remind me of a statement I once heard Eric Clark from Shell make..
"If you think flight safety is expensive, wait until you kill somebody"