What happened to the push for real-time telemetry ?
What happens to a satcom connection if you do not fly straight & level...
Such systems would produce zetabytes of data every day documenting fine flights, and fail exactly when it is needed.
Will one motor drive the system if the other locks up?
Yes it will, if both motors run, the speed of the spindle is nominal, if one fails it is just half of it.
Works similar to the differential gearbox in your car, just the other way round (not one engine driving two wheels but two motors driving one spindle).
Mechanically separates (ie. broken shaft)?
Concentric shafts should prevent this. Worst case you are stuck with your stabilizer position.
How is a functioning system inspected?
By a series of different tests/checks/inspections. Additionally it is regularly lubricated and from time to time overhauled.
Nevertheless, there can always be some unexpected failure, for example induced by overload in severe turbulence.
Although all attachments are dual loadpath, there can always be structural failure if you seriously overload the system. This also applies to the
pivot fittings and the according
bulkhead which had issues previously.
Additional to the black boxes, the debris will be very interesting to look at once it has all been retrieved any laid out in a hangar.
The tail section should be fairly intact, although nothing looking alike has been present in any of the pictures.