Chinook - Still Hitting Back 3 (Merged)

[walter kennedy]

Here's hoping New Year's bashes have left us all with an equal handicap – hurts but was worth it!
Now, it may seem strange for me to suggest it but wouldn't airworthiness etc be better off on another thread with the other examples? As I see it, such considerations do not apply in this case as the a/c seemed to have been performing as expected. All in all an aweful waste of time, a distraction/red herring, and a flase hope for many. At least it has been thoroughly explored – unlike the other option for which there is ample evidence.
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I'd like to point out a few things that you seem to have left unchallenged and yet limit the scope of analysis:
Speed and available power;
Altitude from Carnlough to the Mull;
Waypoint accuracy.


Speed and available power
2 RAF witnesses at one of the inquiries gave their views that at 150 kts a/s (postulated as was at start of pull up manoeuvre) a cruise climb of only about 400 or 650 ft/min respectively was to be expected – (obviously with the same load) Boeing reckons 1000 easily obtainable. Further, earlier in the leg across the sea the air speed seems to have been no more than 135 kts at which that a/c should have been able to easily cruise climb at 2000 ft/min (ie no loss of speed).
So it had some grunt in reserve contrary to the picture painted? - opens up the scope a bit?


Altitude from Carnlough to the Mull
The perception is that they were very low level all the time – accommodating the alleged absence of radar data and negating possible use of navaids such as the MAZ TACAN – do you realise that there are only 3 sources of height data for the entire leg?
These were:
the yachtsman's estimate (understandably vague as was his position at the time of the sighting);
data from the encoded altimeter saved in the system some 15-18 sec before impact (and so after the position of waypoint change, very close to the Mull) giving approximately 613 ft amsl;
the position of impact (810 ft amsl).
Given the habit of mil helos doing a VFR low level over the sea of avoiding 250 – 750 ft (leaving that to fixed wing low level), common sense would suggest an altitude of at least 750 ft across the sea.
This supports the view that radar returns would have been expected at Lowther Hill (as per press article – pity the recordings aren't available as the secondary returns would have had the FL/height data). Further, with the climbing capacity they had (without reducing speed) they could easily have popped their head up a few miles before the position of waypoint change to get a fix off the old MAZ TACAN (to which the TACAN CU was set (ch 107x) and the bearing to which (028) was found on the navigator's HSI) – they'd have needed to get up to about 2500 to get LOS (wouldn't take long starting 750+ and climbing at 2000+ ft/min followed by rapid descent).
They may not have done so but as it was so easily possible should it not have been considered?


Waypoint accuracy
It has been noted somewheres that waypoint A was approximate, that it was a sloppy pos for the lighthouse, and that at least it must have been less important than the other waypoints because it did not have arcsecs/lots of digits/whatever – check out the other waypoints:
7 waypoints had been entered into the STANS route:
H N 54.47.70 W 006.36.00 spudfield
A N55.18.50 W 005.48.00
B N 56.43.00 W 005.14.00 turning point, no specific feature
C N 57.35.02 W 004.04.45 100yd swim to Ft George
D N 57.32.42 W 004.02.92 about middle of Inverness Aerodrome
B
A
V813 N 54.41.10 W006.11.89 spudfield


So comparatively, wpt A is not less accurate/important than the other waypoints just because it has less precision in the digits.
Only thing is the others are nice safe points to head for – wpt A is damn close to steep high ground, unecessarily so for use like the others – and it just happens to be the ideal spot to aim for when approaching the landing area that I have described.
While mentioning that LZ, it has a reasonable length in the direction 035 mag (at the time) and this would have been the obvious approach path; 035 was the path from the position of waypoint change to the crash area and it was on the HP's HSI course selector; one of the baro altimeters had a subscale setting that would have given the QFE at the site's elevation at the time and one of the RADALT warnings was set at the min (69ft?) consistent with an imminent landing.


So this is part of the evidence that they may have had an intention to land or closely pass that LZ, for whatever reason – they had the capability and opportunity to have popped up and taken a fix off the TACAN which they appeared to have done (navigator's HSI) suggesting that they were concentrating on local navigation in the area of the Mull – have you got any evidence at all to suggest problems with the aircraft?