I think these control system discussions are a diversion. Bristow maintenance would have inspected the flight control components of the whole fleet in infinite detail following the fatal accident. I'd be more interested in exploring what may have happened electrically that may have suckered the crew into thinking they had a mechanical problem.
And as for whether a CVR/FDR is fitted and required parameters are validly recording, as a pilot I don't care about this. If a component is due for testing it with be entered in the technical log, and a maintenance guy will attend to it. If it's due and the entry is open I don't accept the aircraft. If a pre-flight check of a component is required of the pilot it will be written in the body of the RFM, or in a supplement, and I will do it as written.
I have never had reason to check any FDR, pre-flight or otherwise. Is there something the Bristow pilots needed to do pre-flight in relation to the FDR?