"There are cheaper systems that will do those things. (A low cost engine monitor for example.)"
Cost are coming down, most all HUMS manufacturers today offer systems that target the tangible paybacks. Face it, the FAA software requirements make the idea of credits a reality in the far distant future bused or non bused aircraft. An engine monitor is just that an engine monitor. What about vibration analysis, are you still going to do that with portable equipment? Add up the cost of an engine monitor and the cost of a small vibe montioring system and you now have the price of one of the newer HUMS systems being developed.
"I'm sure the HUMS salespeople don't peddle the system as a tubine shi.. ingestor detector. But even there, you note that the problem was significant enough to be detected an reported by the pilot."
No the pilots did not report the high vibration situation, it was found via vibe monitoring. After teardown and the evidence of gunk on the turbine wheel and then after an investigation with the pilots, the cause of the gunk was found.
What's major intrusive on a steam gage driven aircraft? A box that for the most part reads the same signals as the engine instruments themselves? Yep, on a bussed aircraft you have a lot less wires to connect, but how does it effect regime recognition any differently than a HUMS equiped analog aircraft? Both aircraft types require one LRU and depending on the HUMS manufacturer bused or non bused can use the same LRU. Both have the same number of vibration sensors...
chuckolamofola