Hello. A few of my thoughts on HUMS for my first post.
Health and Usage Monitoring Systems are advisory, not executive. I can’t really see and alternative whilst HUM is an inexact science; and it is still far from being anything more than that. It certainly helps though, and I think most of those involved in RW (and indeed FW) engineering would agree that it currently makes flying safer, and in time will make it much safer. And cheaper – it’s on the path to CBM.
Meanwhile, it is immature technology and there are problems. Rotorcraft are hostile environments for delicate diagnostic systems, and HUMS are rarely 100% serviceable. It has to be working and someone has to look at, and understand, what it is saying for it to give protection. That person has to recognise the difference between ‘no exceedences’ and an unserviceable system. They should know that alert levels are statistical probabilities, not engineering/operating limits (unless actual fault data exists – the same fault shouldn’t be missed twice). They have to understand that alert levels will be different on similar aircraft with different HUMS and that the confidence levels in those alerts will vary, as will the criticality attached to the many cautions that their HUMS will provide.
Developments (like those at Chandlers Ford) in data mining, and possibly neural networks, to provide more accurate fault indications are particularly exciting and, from what I have seen, are very promising (google ProDAPS). However, I still think we are a few years away from allowing a vibration based diagnostic computer system to ground our aircraft without recourse to a well trained and HUMS educated engineering human brain.