invertron
If you read the thread far enough back, I think that you will find the visual versus instrument argument well covered – one of the points that I made was that the details of the local weather conditions and the aircrafts flight intentions were never clarified as a starting point – indeed with hindsight, it would seem like there was a conscious effort by many to keep these basics confused.
As I understand it, the conditions at low level over the sea were very good with the mist localized on the landmass ahead; taking the visibility ahead as the worst case (clear in all other directions and with the sea below in clear view) it was acceptable for a helicopter to be VFR there as close in as, say, waypoint A because a helicopter can always slow down (a point that experienced pilots on this thread could have made years ago but for some reason did not). Of course, the speed of the aircraft would be at the discretion of the pilot.
When I first pointed out this concession to helicopters under these conditions I made the mistake of describing it as part of Special VFR – I was thoroughly dumped upon for this technicality by many who suddenly appeared knowledgeable about Special VFR etc – the point is the concession is valid and appropriate to this flight.
If you want a really brief summary of what the aircraft was doing, I suggest not the simulation but the Boeing Analysis of Available Data (by Mitchell – available on the web). My personal view is that they were approaching the shoreline at low level intending to turn up that shoreline (continuing below the cloudbase in comfortable visual conditions) but simply misjudged the start of their turn – how they were judging their distance off that mist covered landmass for that start is a matter for debate. If they were not experiencing control difficulties and it was just a judgment issue then I would say that they were not relying upon visual recognition of a feature as they were heading right of the lighthouse (inland); if they could see the lighthouse, they would have gone to it or to the left of it, surely?; further, their speed was high for relying on picking up such a specific visual reference so close in. The squawk code set (7760) could offer a clue (highly contentious, as explained below under “NOTES”!) as it could have indicated that they were working off a ground transponder (located at the lighthouse helipad, perhaps) for the range to the start off that turn (very accurate normally – DME thing) – and here’s the rub: if they were, it would have had to have been giving a false reading.
Now, DME systems normally are accurate if they are working otherwise you don’t get a signal – you don’t get a wrong reading, you get a good one or nothing – but they are very easy to mess with.
If someone tampered with one, they would have to have Motive, Means, and Opportunity.
America was brokering a peace initiative needing some compromise with the IRA while this team (on ZD576) believed new military initiatives would weaken the IRA bargaining position – the team could have been seen as an obstacle to this peace process by the powers that be in the UK who saw such a process as a/the way forward.
US Navy SEALS were stationed at Macrihanish at the time (and were amongst the first at the crash scene) – they are equipped with personal communication sets that can operate in DME transponder mode exactly as portable/transportable DMEs used by many NATO countries; HC2s (as was ZD576) were fitted with equivalent avionics to CH47-Ds in respect of communicating with such ground side equipment (an RAF Chinook picked up a SAS team in Iraq recently using this system – it is a NATO standard). Despite adamant protests by contributors to this thread that no such systems are used for local navigation, radio hams (if that is the correct description) state in their literature that temporary beacons are often used, particularly by military helicopters (there are highly technical amateurs out there with very sophisticated equipment whose hobby it is to monitor military aircraft and to identify beacons – amazing, eh?). And doesn’t common sense tell you how handy such would be on that regular crossing in those all too common, indeed prevailing, conditions?
If that seems far fetched, look at the follow up: if the powers that be had decided to end the operations of that team in such a manner it would not have been much good if only part of the team had been on board (of course they WERE all on board this one aircraft) or if their precious information could have been used by another such team – well the latter point was taken care of by using the US personnel for several days to help collect the confidential documents – with the known sympathies towards the IRA of some elements of the US establishment, they could then suddenly utter a cry and say “What have we done? – we must assume all the plans and assets have been compromised – we have no choice but to go along with the American brokered truce and peace process!”.
Britain’s war on terror was lost that day.
NOTES
7760 etc – while this is in the range of codes for several countries meaning use of a ground transponder, I have no access to UK military codes and no one on this thread has been forthcoming. Further, at an inquiry this code (7760) was described as “meaningless” and that the settings were disturbed in the crash or the pilots were halfway through changing them (I have argued my view in detail in past postings that these scenarios were unlikely). However, radar recordings showing the squawk code did exist (even someone on this thread admitted seeing it but commented that it could not have been significant or he would have noted it) – one would have thought that the squawk code set and as seen on the radar earlier in the flight should have been stated in the inquiries as a starting point especially as the issue was brought up several times in direct questions. I am endeavoring to get a witness to clarify this at the moment but it is hard from here – someone on this thread could have made this easy. If it turns out that 7760 was set prior to the last part of the flight, then at the very least the inquiries were misled and this alone should be grounds for a fresh look at the crash.