Flipster #17
That is what MoD and Fleet have done....mainly - except that they decided, for reasons best known unto themselves, that the SK7 HISL was airworthy - however, they DID rescind the Service Deviation - mea culpa? Sadly, as I said, the light itself is probably ok but its concept of use is plainly not compliant with the def stan - this is in black and white and the BoI were quite right to say so. Why this was not followed up in the Inquest (and by the BoI) owes more to disingenuity and side-stepping by MoD; perhaps HM Coroner and the families may even have been purposefully misled?
I think this is a significant area given the similarities it highlights with the Mull of Kintyre accident; that staffs at a certain level are allowed to stand as judge and jury in their own case.
To summarise the above posts;
The BoI criticised the HISL
installation design (a Naval Service Modification, not an Aircraft Design Authority Modification) and the way crews were instructed in its
use (the Service Deviation).
2 years later the RNFSAIC contradicted parts of the BoI report, partly in disagreement and partly because they used forensic tools to properly analyse the mission tape. This last is critical because it completely alters the tone of the BoI report which, we now know, wrongly infers mild panic in the cockpits.
Both reports went up to FLEET who, along with the IPT, decided the
HISL design was ok (note, HISL units, not the HISL installation design and use). The significance here, in addition to Flip’s “side-stepping”, is that the BoI criticised functional safety (although didn’t use those words), but FLEET and the IPT only commented on the physical safety of the discrete HISL unit.
It seems clear the trial conducted by the BoI (whose actions I suggest were exemplary) was almost certainly the only comprehensive trial conducted thus far to assess the functional safety of a HISL installation.
Whether or not this was deliberately disingenuous is not for me to say, but it is clearly in the interests of both that the confusion be perpetuated and the real issues hidden – as it seems they were from both the BoI and Coroner. Why? Possibly because (a) the IPT is responsible for tasking and approving the HISL installation design, and (b) FLEET are the signatory to Category 1 Service Deviations?
This conflict of interests should be declared, although I confess I don’t know enough to say who would resolve the conflict. But it does seem odd that the BoI did not reconvene to assess the RNFSAIC report. Anyone reading just their report gets entirely the wrong picture.