Tourist
"Para 101 - It is considered by the Board that the HISL is not fit for purpose and non-compliant with the requirement in DEF STAN 00970 Vol 2 para 2.1 (Enc. 42), in that the it should be located so that the emitted light shall not be detrimental to the crew's vision."
That is a statement written by an imbecile.
As it was written and published in an RN BoI report, I assume you disagree with Bismark’s assertions about the RN’s approach to the subject!
If there is such disagreement, do the regulations not allow for the BoI to be reconvened so they can get it right? Or at least for some clarification statement to be made? I recall both DEC and the IPT took this statement very seriously, initiating the investigation mentioned above; the latter making complete fools of themselves by denying any knowledge of HISL in Sea Kings. Panic, one assumes. The retraction, in a Ministerial reply, was even more embarrassing.
I happen to agree with you, up to a point, because the limited real estate on a helicopter makes the design of such things very difficult. There have to be many compromises; but those compromises mean one has to be doubly sure about the installation design, the method/quality of embodiment and its installed performance. (Your mention of trialling only addresses the last). That means you make sure all are right through examination, testing and trialling. There is more to such an installation than the lights themselves. High Voltage Power Supplies to be located properly and lengthy cable runs that must carefully avoid (certain) other wiring. Part of the airworthiness process, before any flying takes place, is to ensure this is done correctly – one such device is the Critical Design Review, which was waived.
Was all this done on the Mk6? Are you saying the installation design is exactly the same on Mk7? I very much doubt it. No-one in their right mind would read across such an installation given the EMC and TEMPEST implications. You say it was trialled in a Mk6, but could the IPT (who denied knowledge of HISL) provide evidence of the complete audit trail to satisfy any claim of read across? There is a basic contradiction there.
While of course I’m not a pilot and cannot put myself in their position, instinct tells me there is more to this. See and be seen someone said. You also see with your radar. Is the Mk6 and Mk7 (and Mk2) the same? That is, do both have full radar capability from deck to deck? (The BoI report says not). If not, there is a major interoperability disconnect (between aircraft and ship) which cannot be read across from an aircraft that does have full coverage. The BoI report also mentions NVG, or lack of it. To me, these 3 factors are all connected. If they did not have full radar coverage and NVG, then at night what aid to visibility did they have? HISL. The forward one was off and the upper one was being viewed by the incoming aircraft through both rotor discs; which the BoI noted produced a “wooded” effect causing poor situational awareness. A Critical Design Review plus trials would have revealed all these issues.
I fully accept that you, aircrew, accept these compromises and “work around” them. But others, like me, are employed to make sure these limitations are minimised, and what limitations remain are within the acceptable airworthiness boundaries – and that you are informed of them through the RTS, FRCs etc and they are covered in training. Avoid the avoidable and manage the unavoidable. Are you sure all the avoidables were avoided in this case? As the CDR was waived, you can never be sure. THAT act was the major airworthiness failure, closely followed by the IPT apparently not knowing what was fitted to their aircraft. It follows that the Safety Case could not be validated.