I imagine the retrofit is pretty expensive as it has to connect to so many systems. I am not sure if anyone besides EC has an STC for even a minimal fit . There are some after market ones I believe for the Bell mediums.
http://www.airweb.faa.gov/Regulatory...e?OpenFrameSet
Shows 6 hits for HUMS only large helicopter is S-61 Chawick system STC owned by CHC all other are Altair systems for small helicopters
I would expect it is only available as a factory installed option for these aircraft.
Anyone got a blue book handy ?.
Is HUMS a JAR OPS requirement ?.
( edited coz i can't spell JAR)