Hello John;
Re,
.. which is why the Regulator concerned with the fleet mentioned above is more than happy for us to review DFDR data routinely .. if we find the box or individual parameters a bit suspect .. we fix it and the base incident/accident investigation tool is there for the rare occasion on which it might be required for such purposes ...
A healthy and positive relationship to be sure. Not sure it can be done that way in a large fleet. We do inform our mtc people on such issues.
Re,
concurrence and reasonableness is achieved through daily detail analysis
label me "an anal engineer" but it seems to me that, for the relevant parameters, a periodic inflight calibration validation is essential .. then one has some baseline real data upon which to base routine work ..
Well, I'm probably an anal pilot (or is that a redundancy?) and to the extent of my knowledge, require similar approaches only because critical safety and commercial decisions are made based upon this information and it has to be accurate. The difficulty is, the FDR carries only about 650 parameters and, as described above, our QAR provides over 1800 parameters. There just isn't any way to verify such data by employing the FDR.
However, "reasonableness" enters into this I think. Given that there are parameters which are discretes, rates, positions, and values, some are easier to "logically" validate than others. Sometimes it takes a "birds on a wire" approach - (when one can't see telephone wires, but can see birds sitting in a line, reasonable "evidence" of the presence of wire, etc) and even an experienced sixth sense, all of which go to the art of interpretation and none of which is appreciated or understood where we work, again the original reason for the question. The question is perhaps not one of acceptance of valid data so much as interest level...