RC
Points taken, but the way I read the two reports the respective system runtimes differ by 34.2s (+/- 0.05) using the same source (GPS), with TANS having the shorter runtime.
I readily conceded the two reports jump between different terminologies at will and sometimes use the term “fix” to describe Lat/Long/Time when they possibly only mean Lat/Long.
These may be explainable but my point is they are not explained or reconciled independently. Racal were allowed to determine what data was “relevant” and, because it seemingly suited the desired outcome, no further investigation was conducted. We now have the complete Racal SuperTANS report, but most of it was heavily redacted at the time, omitting the data that would facilitate such analysis. And, as I said, Racal wrote the report on their own system, but the AAIB wrote the Trimble GPS report.
I make the same point on the toggle switch. The AAIB (who I assume everyone here readily admits are world-renowned experts) stated the switch was off at impact. Racal didn’t say it was on, they just didn’t mention it at all (again, because they were allowed to determined what was and was not in their report). While we both concede it is possible the impact forces moved the switch, yet again the BoI did not seek to resolve the conflict (if, indeed, it was a conflict; something they were also obliged to determine).
The AAIB investigator who stated it was off (Mr Cable) was not the investigator who wrote the Trimble GPS report or oversaw Racal’s work. That being so, one can read between the lines and ask why Mr Cable made a point of stating the switch was off in his single paragraph “SuperTANS” section, which merely mentioned this fact and then referred the reader to the Racal report. It was obviously the only means open to him to voice this concern; or perhaps his words were “sanitised” as the report worked its way through the system to the BoI. It is well known MoD withheld vital and relevant information from the AAIB and I strongly suspect Mr Cable would say much more now that the facts have slowly emerged.
And just to reiterate a final point. MoD and Racal stated the entire Nav system was both serviceable and accurate. (Yet I'd invite anyone to show me were it says it was cleared for use). The AAIB, in their Trimble GPS report, listed faults such as no Time of Day output and a blown FET in the power supply. I’m a mere greenie, but if I found no ToD o/p and a blown FET, there is no way I’d sign a MF731 to say it was serviceable. And the MoD investigation allowed this to slide? Indicative of a Mickey Mouse investigation into a pre-determined cause.