Cazatou
<<All of these calculations show a remarkable similarity …>>
You post is an excellent summary of the data that is available on the speed and makes this point clear – the picture is that they flew on with no change to their speed until the last moment - I would say until they realized how close they had got. I also add that they not only did not make the left turn as indicated was required by their SuperTANS (for the next distant waypoint on their route) on waypoint change but made a small steer demand to the right at that point.
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Arkroyal
<<Since we have no idea why the aorcraft subsequently climbed into cloud and impacted the Mull …>>
BUT it did not climb into cloud.
The cloud base was about 1000ft (as I recall off the top of my head – correct me if I’m wrong) – and that was well above the height at impact.
The mist on the slope did merge into the cloud higher up but the first fuzz they entered would surely have been the mist itself.
Had they climbed high enough to reach the cloud base a little while before impact they would have been high enough to have got a reading from the MAC TACAN (or DME, whichever it was at the time) to which their TACAN CU was set. If you do a transaction from the TACAN or the DME site to their track on the last part of this approach you will see that they would have been able to get it just below the cloud base that day.
And perhaps would have realized just how close they were getting.
It has been my suggestion that they had started a cruise climb for the very purpose of getting a “second opinion” from the MAC TACAN but they had already got too close ( you know, this is quite upsetting – if my theory of the ill fated test is correct, they were actually displaying prudence and, in the circumstances, good airmanship by this manoeuvre – this precautionary climb actually almost saved them giving them that extra bit of height before their realization of the situation and their subsequent flare, only another 50 feet or so and they would have cleared the small cliff that their rrrss end clipped in their final flare – and yet they got all that scheet heaped on their names).
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<<Quote:
Please read what the 'lone yachtsman' said. The features on the coast were certainly not clearly visible
Well, the crew were somewhat closer to it, so would have had a better view>>
It is surely very reasonable to assume that the “view” would have been very common conditions there – ground detail indistinct – you could see it but not judge distance off well – especially approaching at speed. This is what it is so often like in that area at that time of day, at that time of year, with that wind. One of the things that you could be sure about would be the view of the Mull they had out of the windscreen – you could have predicted it the previous day with a typical met forecast for the area.
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John Blakeley
<<How do you know they did not try to transmit an emergency call? As I recall the IFF squawk was 7760 - close to the emergency one of 7700 - was it being changed at the point of impact or was this the last squawk requested by Belfast? In my limited basic flying training I was always told that the first thing to do in any emergency was to fly the aircraft (assuming it to be flyable at that point) and not to worry about the radio etc until afterwards, and in two real Pan calls later in a Lightning and Tornado that was exactly what happened - with no emergency call from the captain until the offending engine had been shut down, the emergency FRCs had been checked and we knew what we were doing.>>
And this is exactly the point I made some time ago that it was not recommended to change SSR code in the immediate emergency (I got this from ATC sources); the other option for it being meaningless is that it got like that from the impact – this would have required just the middle two wheels to have been disturbed, one by 1 position and the other by 2 – highly improbable, in my opinion; as I have said in previous posts, get yourself a bean bag and sit in an old airframe with the same kind of selectors and try to get that result – good luck!
It just happens that in some systems the “anomalous” 7760 is compatible with the exercise callsign F4J40 used by ZD576 in this flight.
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<<Why not start by assuming the pilots knew what they were doing, had a good flight plan and were following the rules and procedures to the letter …>>
Well if they had a good flight plan they certainly did not leave a copy – the excuse for a flight plan that was found (that would have been impossible to follow in the HC2) and that it was not able to be definitely ascribed to them is ridiculous – either there was a major neglect of procedure or the actual flight plan went missing along with any recollection a usual outbrief – I do not believe that these particular pilots would have been slack in this respect and so I believe the latter.