1. What electrical bus(es) provide power to the combined recorder?
The DC Essential Bus
2. What failures would shed that bus? Are they automatic or manual?
Loss of DC Power from both Primary DC Converters (TRUs) without the APU running and the Backup DC Converter on. The Primary DC Converters are powered by the AC Generators, the Backup converter is powered by the APU Generator.
The Bus is not 'shed' in the conventional sense - it ceases to be powered, which is a slightly different thing.
3. Where are the generators on the S-92? Assumption would be one on each engine and one on the transmission.
Two Primary Generators powered directly by the transmission and cooled with oil, one APU Generator powered when the APU is on.
4. Is it an incorrect assumption that other recording devices (HUMS, QAR, etc) are on less reliable power sources than the CV/FDR?
NO
The CV/FDR also has a 'g switch' set to stop recording at 10g - this is to prevent over writing data in the event it remains powered following an accident (also has an immersion switch, for same reason.)
So, the loss of electrical power to the recorder 'scenario' seems quite plausible as the AC Generators have proved already that they will fail when hot - which they would be if no longer cooled.
Crab,
allowing the pilot to return the helicopter to safety in the event of a catastrophic oil loss
They are clearly referring to a complete oil loss following combat damage, so I doubt spin is involved! The Cyclone is NOT an S-92. It is FBW for starters.