HUMS
The issue as I see it with HUMS on a new aircraft is the lack of a statistical data base. Sikorsky has to collect data to establish a base line for Go / No Go criteria. The difficulty comes with where to establish initial HUMS criteria. If you set the limits too low then you may affect operability while addressing each warnings activation. If you set the limit too high then safety may be compromised as actual component limits may be exceeded. Following the Blackhawk methodology, Sikorsky built the S-92 to a US Army safe-life criteria. Building to these criteria negated any requirement for a HUMS as the robustness designed and built into each component established relatively high component lives i.e. 5000 MGB.