Chinook - Still Hitting Back 3 (Merged)
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Walter
...sorry but there was NO RIGHT TURN after waypoint change.......
..this is a myth started I think by the Fellow from Boeing but few people bother to check his calculations........
..the only evidence for a turn to the right is the Lat.and Long. for the crash site as compared to the Lat.Long. for waypoint change.........but everyone forgets that the numbers for the waypoint change are from the GPS source........
If the A/C were at the absolute , correct and exact Lat.&Long. to WGS84 standard , when the change was made there might be a grain of truth in it ...........but we know that a few seconds later there was a significant GPS offset error of hundreds of metres , guiding them North and East of the true location.
Once we factor this in , plus the offtrack error where they had drifted to right of track (hence the heading of 018 degrees to steer to waypoint 'A' ), which is another 200 feet at least at this range , you will find that flying straight on takes one to the point of impact ...
regards to all on this sad anniversary.........
Robin....
<p>Their turn from 027 to 035 at waypoint change, for which there is evidence that it was deliberate......</p> <br />
..this is a myth started I think by the Fellow from Boeing but few people bother to check his calculations........
..the only evidence for a turn to the right is the Lat.and Long. for the crash site as compared to the Lat.Long. for waypoint change.........but everyone forgets that the numbers for the waypoint change are from the GPS source........
If the A/C were at the absolute , correct and exact Lat.&Long. to WGS84 standard , when the change was made there might be a grain of truth in it ...........but we know that a few seconds later there was a significant GPS offset error of hundreds of metres , guiding them North and East of the true location.
Once we factor this in , plus the offtrack error where they had drifted to right of track (hence the heading of 018 degrees to steer to waypoint 'A' ), which is another 200 feet at least at this range , you will find that flying straight on takes one to the point of impact ...
regards to all on this sad anniversary.........
Robin....
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Tec
I was not referring to the hypothetical turn that was said at the inquiries should have been made to avoid the high ground – I was referring to the turn that analysis has them having actually made at or near the position where they changed the waypoint in the STANS. The track from NI to the position of waypoint change was 027 mag and the track from this position to the crash site was 035 mag which was found on the HP's course selector.
Tec&Chug
Either the pilot or an AFCS is continuously moving the controls to keep these (unstable) things straight and level – I would be surprised if a Chinook would have maintained a straight track over the distance of the last leg with even one control jammed – as I would be surprised if the pilot had not waggled controls any which way if he detected a jam which would have caused a/c attitude changes – and perhaps a change of power too.
Cows
<<Walter, fantasy is believing that some for of covert demonstration went tragically wrong with the whole event being conveniently (and very securely?) covered-up. >>
As briefly as I can: they were set up to approach a known LZ in conditions that would only have allowed such with a local reference, hence the demo theory of the particular equipment I have mentioned previously;
they managed to keep from more than one inquiry and from the general public the very existence of this equipment in HC2 Chinooks all these years, did they not?;
many would agree that it was folly to put the whole team on one helicopter in the first place and the consequences of the crash were so severe for the security forces that I'll bet the MOD and RAF would cover it up – when you add to this the prospect of possible civil unrest if there was any public perception of foul play I think that you will see that it could have been more important to cover this up than, say, the lie about WMD in Iraq;
the only part of what I think about this crash that I accept may be “fantasy” is the view that the exercise may have been set up to remove an obstacle to the peace process – if a new and more enlightened inquiry exposed such an exercise, then exposing who put it together and executed it would be a step towards determining whether anything wilful happened.
Robin
Do the chartwork properly – I checked out Mitchel's (of Boeing) analysis years ago and have been recommending that anyone interested in this case use it as a framework for their own efforts – it is the only decent effort I have come across which is surprising given that the alleged pilot error implied their being unaware of how close in they were, one would have expected an “official” version whereas all we got was the fudged track presented by one of the AVMs at the HOL inquiry – you don't have to use it as gospel, but it is a useful example to follow when working it out for yourself.
<<... but we know that a few seconds later there was a significant GPS offset error of hundreds of metres >> - are you getting confused with the difference between the GPS and Doppler position data at impact? They could not have been getting processed (range/bearing info) of any use to them after waypoint change (because they had changed the waypoint to one 80+ miles away) and I do not see them being able to work out were they were precisely using the raw GPS position and a chart that close in at that speed so after waypoint change the GPS performance would have been irrelevant – besides, Flt Lt Tapper would not have regarded the SuperTANS as reliably accurate enough to have got that close in in those conditions with only it anyway.
<<... (hence the heading of 018 degrees to steer to waypoint 'A' ), which is another 200 feet at least at this range ,>> - I think you'll find it was waypoint B in the part of that report you must be using, 80 + miles away – when you go back to checking it, I think you will find that 018 was true and the mag equivalent of 025 doesn't immediately make sense – I have an explanation but am not very confident in it and would be interested in what you think of the anomaly.
I hope you have not been put up to this distraction -if you are genuine, pls check your work a bit more before posting – some points have been covered long ago on this thread and there is a thread search function that can help you get through all the waffle.
I was not referring to the hypothetical turn that was said at the inquiries should have been made to avoid the high ground – I was referring to the turn that analysis has them having actually made at or near the position where they changed the waypoint in the STANS. The track from NI to the position of waypoint change was 027 mag and the track from this position to the crash site was 035 mag which was found on the HP's course selector.
Tec&Chug
Either the pilot or an AFCS is continuously moving the controls to keep these (unstable) things straight and level – I would be surprised if a Chinook would have maintained a straight track over the distance of the last leg with even one control jammed – as I would be surprised if the pilot had not waggled controls any which way if he detected a jam which would have caused a/c attitude changes – and perhaps a change of power too.
Cows
<<Walter, fantasy is believing that some for of covert demonstration went tragically wrong with the whole event being conveniently (and very securely?) covered-up. >>
As briefly as I can: they were set up to approach a known LZ in conditions that would only have allowed such with a local reference, hence the demo theory of the particular equipment I have mentioned previously;
they managed to keep from more than one inquiry and from the general public the very existence of this equipment in HC2 Chinooks all these years, did they not?;
many would agree that it was folly to put the whole team on one helicopter in the first place and the consequences of the crash were so severe for the security forces that I'll bet the MOD and RAF would cover it up – when you add to this the prospect of possible civil unrest if there was any public perception of foul play I think that you will see that it could have been more important to cover this up than, say, the lie about WMD in Iraq;
the only part of what I think about this crash that I accept may be “fantasy” is the view that the exercise may have been set up to remove an obstacle to the peace process – if a new and more enlightened inquiry exposed such an exercise, then exposing who put it together and executed it would be a step towards determining whether anything wilful happened.
Robin
Do the chartwork properly – I checked out Mitchel's (of Boeing) analysis years ago and have been recommending that anyone interested in this case use it as a framework for their own efforts – it is the only decent effort I have come across which is surprising given that the alleged pilot error implied their being unaware of how close in they were, one would have expected an “official” version whereas all we got was the fudged track presented by one of the AVMs at the HOL inquiry – you don't have to use it as gospel, but it is a useful example to follow when working it out for yourself.
<<... but we know that a few seconds later there was a significant GPS offset error of hundreds of metres >> - are you getting confused with the difference between the GPS and Doppler position data at impact? They could not have been getting processed (range/bearing info) of any use to them after waypoint change (because they had changed the waypoint to one 80+ miles away) and I do not see them being able to work out were they were precisely using the raw GPS position and a chart that close in at that speed so after waypoint change the GPS performance would have been irrelevant – besides, Flt Lt Tapper would not have regarded the SuperTANS as reliably accurate enough to have got that close in in those conditions with only it anyway.
<<... (hence the heading of 018 degrees to steer to waypoint 'A' ), which is another 200 feet at least at this range ,>> - I think you'll find it was waypoint B in the part of that report you must be using, 80 + miles away – when you go back to checking it, I think you will find that 018 was true and the mag equivalent of 025 doesn't immediately make sense – I have an explanation but am not very confident in it and would be interested in what you think of the anomaly.
I hope you have not been put up to this distraction -if you are genuine, pls check your work a bit more before posting – some points have been covered long ago on this thread and there is a thread search function that can help you get through all the waffle.
Walter:
No doubt the gyrations of which you speak would have been plain to see, Walter. Trouble is there were no eye witnesses, only the "ear witnesses". As has been pointed out the turn could have been made at any time simply to stay clear of the coast and maintaining VMC. Only then would a control jam as proposed by Sqn Ldr Burke have manifested itself. Perhaps your gyrations then ensued, but what change in sound would have made a control problem clear to the ear witnesses?
Tec&Chug
Either the pilot or an AFCS is continuously moving the controls to keep these (unstable) things straight and level – I would be surprised if a Chinook would have maintained a straight track over the distance of the last leg with even one control jammed – as I would be surprised if the pilot had not waggled controls any which way if he detected a jam which would have caused a/c attitude changes – and perhaps a change of power too.
Either the pilot or an AFCS is continuously moving the controls to keep these (unstable) things straight and level – I would be surprised if a Chinook would have maintained a straight track over the distance of the last leg with even one control jammed – as I would be surprised if the pilot had not waggled controls any which way if he detected a jam which would have caused a/c attitude changes – and perhaps a change of power too.
I can confirm that I have already asked the MoD to look at the best way of carrying out an independent enquiry
Considering that the MoD have been the driving force behind the last 16 years of obfuscation and lies by a succession of Government ministers, isn't this a bit like asking a villian to choose the process for the police investigation and trial?
I really hope that I am wrong but I do expect another fudged response from MoD which this new Government will find a way to accept. Perhaps 13 years of Blair/Brown have made me too cynical.
If you are concerned about Wratten and Day's damning finding, pulse1, I think you might well find that a face saving formula will be arrived at and all will be well! If you are concerned that the lying stealing and cheating that is the MOD will continue to hazard the lives of those who it supposedly has a duty of care for then your concerns are well founded. The reason that a Grossly Unairworthy aircraft crashed into the Mull of Kintyre may never be known, but if ever an aircraft accident cried out for an independent professional investigation it is surely this one. The reason that it was Grossly Unairworthy can be summed up in four words- The Ministry Of Defence. I have said before that unless and until the Regulatory and Investigative Military Aviation functions are removed from this major aviation operator the needless death toll will continue. Nothing Dr Fox has said thus far hints at that changing.
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Pulse1
For once I am in complete agreement with a post here - you have hit the nail on the head.
The best chance, I suggest, for an independent inquiry would be to lobby the authorities in Scotland for a new FAI.
For once I am in complete agreement with a post here - you have hit the nail on the head.
The best chance, I suggest, for an independent inquiry would be to lobby the authorities in Scotland for a new FAI.
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Arthur Rowe
Had you spent only a fraction of the time on this subject as many here have, you might appreciate that, rarely is there a 5 minute answer. Though it may be convenient to overlook that fact having just 'dipped in' to the subject matter!
Having reviewed all your postings on this subject, I imagine it may assist, if you were to give a short summary of your opinion in this case rather than simply rubbishing the testimony of the only eye witness?
I'm obliged.
Edited to add: It may be that we have similar views, it's just very difficult to fathom what it is you are trying to establish?
I do get a feeling that on this thread it is easy to wander into the full half hour of argument rather than five minutes, to quote Monty Python. To further quote:
Having reviewed all your postings on this subject, I imagine it may assist, if you were to give a short summary of your opinion in this case rather than simply rubbishing the testimony of the only eye witness?
I'm obliged.
Edited to add: It may be that we have similar views, it's just very difficult to fathom what it is you are trying to establish?
Last edited by Tandemrotor; 4th Jun 2010 at 01:26.
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Hi Walter.........
...I am not sure that I understand any part of your post 6518........
..but.......
..the respected Mr J. Mitchell from Boeing states that there was a turn made nearly three degrees on to 022 true..
..they were navigating using the GPS source.......
..plotting all the GPS locations from the RACAL report , Aldergrove , waypoint change , last steering update , powerdown and the last unprocessed location from the Trimble GPS itself......you can see that they are all in a straight line.....
You think they turned much further..????????.....
..there was a sensor in the fuselage which reports the orientation in all three axes...and this did show some wild variations..........but I think you will agree that the direction in which the fuselage is pointing is not a reliable guide to which way the A/C is travelling , especially in a helicopter...
This does actually support my suggestion that they hit the ground briefly some time earlier and there were some wild gyrations before the main impact.... link ........
rgds Robin..
...I am not sure that I understand any part of your post 6518........
..but.......
..the respected Mr J. Mitchell from Boeing states that there was a turn made nearly three degrees on to 022 true..
it was also right of its original course
from the ATC fix to Waypoint A.
The bearing from Waypoint Change to Last Steering Command is 22.22 degrees True,
which indicates that the route of the aircraft is ~3 degrees right of the initial route
from the ATC fix to Waypoint A.
The bearing from Waypoint Change to Last Steering Command is 22.22 degrees True,
which indicates that the route of the aircraft is ~3 degrees right of the initial route
...(this does assume they were flying a track of 19.5T towards the light house)
..checking my calc. and plotting it different ways , the most I can make it is one degree...and even that depends on how you round up/down fractions of one degree..........they were navigating using the GPS source.......
..plotting all the GPS locations from the RACAL report , Aldergrove , waypoint change , last steering update , powerdown and the last unprocessed location from the Trimble GPS itself......you can see that they are all in a straight line.....
You think they turned much further..????????.....
..there was a sensor in the fuselage which reports the orientation in all three axes...and this did show some wild variations..........but I think you will agree that the direction in which the fuselage is pointing is not a reliable guide to which way the A/C is travelling , especially in a helicopter...
This does actually support my suggestion that they hit the ground briefly some time earlier and there were some wild gyrations before the main impact.... link ........
rgds Robin..
Last edited by Robin Clark; 13th Jun 2010 at 21:17. Reason: name corrected..
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Tandemrotor.
I have read this thread from the beginning. I believe that the cause of the Chinook crash will always remain unknown. The original findings of the Board of Inquiry should have been accepted by the reviewing officers. A further proper independent and authoritative inquiry into the accident should be undertaken and its findings accepted.
I have not made many posts but when I have it is to try to bring some explanation to light drawing on personal experience or knowledge. You may wish to note that I have a full personal profile while many contributors to this thread do not. It is difficult to know whether they are writing with any authority when they express their opinions.
Perhaps I should not have invoked Monty Python but it was the 'automatic gainsaying' responses of some posters that I was hoping to point out.
As to eyewitness evidence, which do you think more likely; that the Chinook slowed down to 70 Knots then accelerated to almost Vne or that the yachtsman was mistaken in his estimate of its speed? And, from your personal experience, would 140 Knots have been a dangerous speed in the circumstances?
I have read this thread from the beginning. I believe that the cause of the Chinook crash will always remain unknown. The original findings of the Board of Inquiry should have been accepted by the reviewing officers. A further proper independent and authoritative inquiry into the accident should be undertaken and its findings accepted.
I have not made many posts but when I have it is to try to bring some explanation to light drawing on personal experience or knowledge. You may wish to note that I have a full personal profile while many contributors to this thread do not. It is difficult to know whether they are writing with any authority when they express their opinions.
Perhaps I should not have invoked Monty Python but it was the 'automatic gainsaying' responses of some posters that I was hoping to point out.
As to eyewitness evidence, which do you think more likely; that the Chinook slowed down to 70 Knots then accelerated to almost Vne or that the yachtsman was mistaken in his estimate of its speed? And, from your personal experience, would 140 Knots have been a dangerous speed in the circumstances?
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Arthur Rowe
As I suspected, we very largely agree.
Having visited AAIB on a number of occasions, and 'sifted' the wreckage, and having also spoken to Mr Tony Cable at considerable length, I have absolutely no reason to suspect that the a/c impacted the ground at anything other than very high speed.
Indeed some senior officers even suggested the speed was so close to Vne that it is extraordinarily difficult to explain it within any normal regime!
On the other hand, I personally saw Mr Holbrook standing in the witness box at the FAI. He was an extremely persuasive witness! Everything he said was 'measured'. He is/was an instrument maker by trade. As an example, when he explained how he had assessed the height of ZD576, he said that he had used the height of the lighthouse, which he knew to be 300' above sea level, as a reference.
His assessment of speed was also referenced to the speed of Sea King helicopters with which he was very familiar. These are a very similar size in all respects to Chinooks.
Having personally heard his testimony, I have absolutely no doubts as to the accuracy of his evidence.
Perhaps just as importantly, as an experienced Chinook operator myself, the speed he describes ties in pretty well exactly with what I would expect in the weather conditions he outlines.
Indeed, speed just might be the most important anomaly in the entire body of evidence!
So how to explain the apparent discrepancy?
I have to say I cannot prove anything, but that does not mean the clues aren't available, and it certainly does not mean we should simply discard any evidence which does not 'fit' with some pre conceived (and unproven) notion of 'how it must have been'! Of course that is precisely what the reviewing officers felt able to do!
From personal experience, it is extremely dangerous to impact terrain at 140kts. That does nothing to explain how it came to happen?
As I suspected, we very largely agree.
As to eyewitness evidence, which do you think more likely; that the Chinook slowed down to 70 Knots then accelerated to almost Vne or that the yachtsman was mistaken in his estimate of its speed?
Indeed some senior officers even suggested the speed was so close to Vne that it is extraordinarily difficult to explain it within any normal regime!
On the other hand, I personally saw Mr Holbrook standing in the witness box at the FAI. He was an extremely persuasive witness! Everything he said was 'measured'. He is/was an instrument maker by trade. As an example, when he explained how he had assessed the height of ZD576, he said that he had used the height of the lighthouse, which he knew to be 300' above sea level, as a reference.
His assessment of speed was also referenced to the speed of Sea King helicopters with which he was very familiar. These are a very similar size in all respects to Chinooks.
Having personally heard his testimony, I have absolutely no doubts as to the accuracy of his evidence.
Perhaps just as importantly, as an experienced Chinook operator myself, the speed he describes ties in pretty well exactly with what I would expect in the weather conditions he outlines.
Indeed, speed just might be the most important anomaly in the entire body of evidence!
So how to explain the apparent discrepancy?
I have to say I cannot prove anything, but that does not mean the clues aren't available, and it certainly does not mean we should simply discard any evidence which does not 'fit' with some pre conceived (and unproven) notion of 'how it must have been'! Of course that is precisely what the reviewing officers felt able to do!
And, from your personal experience, would 140 Knots have been a dangerous speed in the circumstances?
Last edited by Tandemrotor; 4th Jun 2010 at 15:51.
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As I am on TR's ignore list, I think I had better repost my #6488 regarding the confidence of Mr Holbrook's judgement:
<<TandemRotor wrote
<<Mr Holbrook (the yachtsman) was/is an instrument maker by trade, and was extraordinarily measured in his assessments. Extremely persuasive in the witness box at the FAI. >>
BUT the judgement of the height of aircraft height and speed is difficult, especially an unfamiliar a/c against a backdrop of grey sky.
Select committee
70. Mr Holbrook explained to us that he had repeatedly but unsuccessfully asked to see photographs of a Chinook at different heights and ranges, in order the better to estimate the height and speed of the aircraft when he saw it. He clearly felt that he would have been in a better position to assist the Board had he been furnished with such information. We do not know why the Board did not accede to his request or afford him the opportunity of seeing a Chinook in flight. >>
Why the hell they would have slowed down in the area the yachtsman saw them anyway ? - were they supposed to be in difficulty there and yet carried on course a couple of miles further?!!!!
Robin
“Miller” or “Mitchell”?
Try plotting the track from one of the positions that you think they started from at or near Aldergrove to the position where they changed the waypoint; then plot the track from the position of waypoint change to the position of first impact. The difference in this track angle suggests a turn at or near the position of waypoint change.
Not only is this substantial but it also happens to fit with what was found on the HP's HoSI course selector, the instrument he would have been steering by.
Now you wrote <<..they were navigating using the GPS source....... >> - not after the change of the waypoint in the SuperTANS they weren't – as I explained previously, at their speed comparing raw GPS from the SuperTANS CDU with a map of any sort would not have been practical.
ALL
Why not go as a group up to the Mull this week and charter a small boat - stand off the Mull in the early evening and see what it would have been like - you'd be unlucky to not get it the same as those conditions were prevalent at that time of day, at that time of year. with a southerly blowing. Ask the skipper to tell you how far off you are with his radar - at several distances - you can see it but judgement of range is very difficult in those conditions.
<<TandemRotor wrote
<<Mr Holbrook (the yachtsman) was/is an instrument maker by trade, and was extraordinarily measured in his assessments. Extremely persuasive in the witness box at the FAI. >>
BUT the judgement of the height of aircraft height and speed is difficult, especially an unfamiliar a/c against a backdrop of grey sky.
Select committee
70. Mr Holbrook explained to us that he had repeatedly but unsuccessfully asked to see photographs of a Chinook at different heights and ranges, in order the better to estimate the height and speed of the aircraft when he saw it. He clearly felt that he would have been in a better position to assist the Board had he been furnished with such information. We do not know why the Board did not accede to his request or afford him the opportunity of seeing a Chinook in flight. >>
Why the hell they would have slowed down in the area the yachtsman saw them anyway ? - were they supposed to be in difficulty there and yet carried on course a couple of miles further?!!!!
Robin
“Miller” or “Mitchell”?
Try plotting the track from one of the positions that you think they started from at or near Aldergrove to the position where they changed the waypoint; then plot the track from the position of waypoint change to the position of first impact. The difference in this track angle suggests a turn at or near the position of waypoint change.
Not only is this substantial but it also happens to fit with what was found on the HP's HoSI course selector, the instrument he would have been steering by.
Now you wrote <<..they were navigating using the GPS source....... >> - not after the change of the waypoint in the SuperTANS they weren't – as I explained previously, at their speed comparing raw GPS from the SuperTANS CDU with a map of any sort would not have been practical.
ALL
Why not go as a group up to the Mull this week and charter a small boat - stand off the Mull in the early evening and see what it would have been like - you'd be unlucky to not get it the same as those conditions were prevalent at that time of day, at that time of year. with a southerly blowing. Ask the skipper to tell you how far off you are with his radar - at several distances - you can see it but judgement of range is very difficult in those conditions.
Last edited by walter kennedy; 5th Jun 2010 at 01:02. Reason: format
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Eye witnesses
The fishing boats were never traced , so much attention was paid to the evidence provided by one of the yachtsmen........
..however convincing he may have seemed his testimony was inconsistent
.ie ... when asked by the HOL what he thought the visibility was , he says 7 nm , then later states that he can see the island of Sanda (9nm) and the Irish coast(10nm)...
..also....
..everyone responds to pressure in different ways , and I do not envy him the bias he must have felt people were applying to his words....
Walter
..it is important to use all position references from the same source , hence my use of the GPS co-ordinates ........
..if you mix in real , true OS lat/long to WGS84 as well , you will get varying results as the GPS positions were all displaced 0.1NM in the alignment 55degrees/235degrees.(reciprocals).......
rgds Robin.......
..however convincing he may have seemed his testimony was inconsistent
.ie ... when asked by the HOL what he thought the visibility was , he says 7 nm , then later states that he can see the island of Sanda (9nm) and the Irish coast(10nm)...
..also....
The Ministry of Defence notes Mr Holbrook’s evidence to the Committee that the pilots would have been able to see the position of the lighthouse on approach to the Mull. But according to the evidence offered to the Fatal Accident Inquiry, at the time he saw the helicopter he believed he was about two miles south west of the lighthouse and that the aircraft was ¼-½mile away, at a height of 200-400 ft. He estimated the speed of the aircraft to be 60-80 knots, although in evidence to the RAF Board of Inquiry (BOI) he suggested that it was travelling " ….. somewhat faster than Sea Kings in level flight ….", which is typically an airspeed of some 100-110 kts. Mr Holbrook also indicated to the Fatal Accident Inquiry that he watched the helicopter for only some 25-30 seconds, during which time he was manoeuvring his yacht around fishing boats (although in evidence to the BOI and to the Committee, Mr Holbrook indicated that his sighting of the aircraft was limited to a five second view ......
Walter
..it is important to use all position references from the same source , hence my use of the GPS co-ordinates ........
..if you mix in real , true OS lat/long to WGS84 as well , you will get varying results as the GPS positions were all displaced 0.1NM in the alignment 55degrees/235degrees.(reciprocals).......
rgds Robin.......
Arthur Rowe:
I see no reason why the original findings of the Board of Inquiry should be accepted by anyone, least of all by the Reviewing Officers whose creature (as with all BoI's) it was. Therein lies the real dilemma. If the BoI is briefed to act freely and purposefully, and to truly endeavour to discover the causes of an aircraft accident, then they may possibly be discovered. Given any pressure or dissembling to prevent that and they will not. There is abundant evidence that both happened in this case and no doubt in other BoI's as well. This is a dysfunctional system as is that of expecting an aircraft operator to be its own regulator. It seems that both regulation and investigation ceased to function as they were supposed to shortly after the end of the Cold War, no doubt casualties of the "Peace Dividend". If there be no other positive outcome to the ensuing tragedies that followed than the recognition of the urgent need to separate both from the MOD and to implement the necessary reform to do so then the many lives lost would not have been entirely in vain. Airworthiness Regulation and Air Accident Investigation should be as independent of the MOD as it is of BA.
Self Regulation never works, and in Aviation it Kills!
The original findings of the Board of Inquiry should have been accepted by the reviewing officers.
Self Regulation never works, and in Aviation it Kills!
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My last ever entry on weather and speed
I have followed with interest the exchanges between Athur Rowe and Tandemrotor. What those exchanges, and others on the subject show is just how little factual information we have and just how contradictory that information is.
Arthur, I accept that Mr Hollbrook may have been wrong with his estimates of height and speed. However as an experienced sailor you also have to accept that he may well have been fairly accurate with his assessment of height, speed and weather. So less than two minutes from impact the crew were flying legally, at a sensible speed and "apparantly" under full control.
We know that the crash site was either in cloud / fog or at least on the very edge of it. We also know the aircraft impacted at or around VNE. (Mr Cable, expert witness.)
How can this be explained?
1. Gross negligence. Having seen the Mull the operating pilot reached down and selected a very large handful of throttle. He then deliberately pointed his aircraft into a cloudbank and hit the ground.
If we accept the Holbrook evidence why on earth did the crew, who had up until a few seconds earlier been flying at a sensible speed do this? Remember also the decision of the operating pilot to take this course of action was being monitored by two other experienced aircrew.
2. Major technical malfunction. Sqn Ldr Burke was right all along.
3. Pilot / Aircrew error. The crew approached the Mull at a 70 kts. They identified the Mull at an estimated 3 nms and now felt safe to accelerate to a higher speed, prior to the turn. Due to an transient error in the TANs they were not at 3nms they were at one. Victims of visual illusion. Now throw in another distraction such as a caption, they would be into the cloud before they could respond.
The likes of John Purdy and Cazatou will tell you that such a scenario is fanciful. If crews never fall victim to visual illusion or distraction, why do IFS waste so much money making films about them?
On balance of probabilities I favour 3. 2. 1.
So Baston I agree with you. Pilot error is a likely scenario.
You can,t rule out 2 or 1 though, can you.
Arthur, I accept that Mr Hollbrook may have been wrong with his estimates of height and speed. However as an experienced sailor you also have to accept that he may well have been fairly accurate with his assessment of height, speed and weather. So less than two minutes from impact the crew were flying legally, at a sensible speed and "apparantly" under full control.
We know that the crash site was either in cloud / fog or at least on the very edge of it. We also know the aircraft impacted at or around VNE. (Mr Cable, expert witness.)
How can this be explained?
1. Gross negligence. Having seen the Mull the operating pilot reached down and selected a very large handful of throttle. He then deliberately pointed his aircraft into a cloudbank and hit the ground.
If we accept the Holbrook evidence why on earth did the crew, who had up until a few seconds earlier been flying at a sensible speed do this? Remember also the decision of the operating pilot to take this course of action was being monitored by two other experienced aircrew.
2. Major technical malfunction. Sqn Ldr Burke was right all along.
3. Pilot / Aircrew error. The crew approached the Mull at a 70 kts. They identified the Mull at an estimated 3 nms and now felt safe to accelerate to a higher speed, prior to the turn. Due to an transient error in the TANs they were not at 3nms they were at one. Victims of visual illusion. Now throw in another distraction such as a caption, they would be into the cloud before they could respond.
The likes of John Purdy and Cazatou will tell you that such a scenario is fanciful. If crews never fall victim to visual illusion or distraction, why do IFS waste so much money making films about them?
On balance of probabilities I favour 3. 2. 1.
So Baston I agree with you. Pilot error is a likely scenario.
You can,t rule out 2 or 1 though, can you.
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Dalek
Just a quickie – here's one little bit of information that has been mentioned before regarding speed:
You wrote <<We also know the aircraft impacted at or around VNE. (Mr Cable, expert witness.)
How can this be explained?
1. Gross negligence. Having seen the Mull the operating pilot reached down and selected a very large handful of throttle. >>;
Well actually they had “throttled” back to an intermediate level and held it long enough for the engines to be matched – as the Boeing analysis pointed out, the resultant reduction in airspeed was masked by the increased tailwind as they approached the landmass. As the airmass pushed up the slopes, the lower layer increases in speed significantly – it also gives rise to the “ground-hugging” mist that runs up the slopes with a strong on-shore wind. Not only was this mist evidence of the strong wind, the wind speed was recorded there at 30-35 kts.
An explanation for this is frightfully simple – they had eased back to coast in towards the shoreline but were already much closer in than they had thought.
Just a quickie – here's one little bit of information that has been mentioned before regarding speed:
You wrote <<We also know the aircraft impacted at or around VNE. (Mr Cable, expert witness.)
How can this be explained?
1. Gross negligence. Having seen the Mull the operating pilot reached down and selected a very large handful of throttle. >>;
Well actually they had “throttled” back to an intermediate level and held it long enough for the engines to be matched – as the Boeing analysis pointed out, the resultant reduction in airspeed was masked by the increased tailwind as they approached the landmass. As the airmass pushed up the slopes, the lower layer increases in speed significantly – it also gives rise to the “ground-hugging” mist that runs up the slopes with a strong on-shore wind. Not only was this mist evidence of the strong wind, the wind speed was recorded there at 30-35 kts.
An explanation for this is frightfully simple – they had eased back to coast in towards the shoreline but were already much closer in than they had thought.
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Walter makes a valid point.
I would imagine an aircraft flying at 70 IAS / TAS with 100kts tailwind and an aircraft flying at 170 IAS / TAS in still air would create very similar debris paterns on the ground.
Mr Holbrook could never assess IAS / TAS he could only assess GROUNDSPEED.
Even if there was a sudden and dramatic increase in tailwind of say 30 kts over the cliff ( which incidentally would lead to severe turbulence) it can only account for part of the increase in GROUNDSPEED.
Some of the increase had to come from increased power.
I have never met any pilot, who, confronted with deteriorating weather conditions, deliberately increases speed.
I would imagine an aircraft flying at 70 IAS / TAS with 100kts tailwind and an aircraft flying at 170 IAS / TAS in still air would create very similar debris paterns on the ground.
Mr Holbrook could never assess IAS / TAS he could only assess GROUNDSPEED.
Even if there was a sudden and dramatic increase in tailwind of say 30 kts over the cliff ( which incidentally would lead to severe turbulence) it can only account for part of the increase in GROUNDSPEED.
Some of the increase had to come from increased power.
I have never met any pilot, who, confronted with deteriorating weather conditions, deliberately increases speed.
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Speed-Power
Dalek , Walter...
..just one small point here.........
..there were no power levers for the engines.........
..the whole point of FADEC is to allow the engines to respond by themselves to any need for more or less power.....in order to maintain rotor rpm within the critical range.....
..there was no evidence that full emergency power was ever used , as it starts a counter to record the fact if sensed for more than one second........
rgds Robin....
..just one small point here.........
..there were no power levers for the engines.........
..the whole point of FADEC is to allow the engines to respond by themselves to any need for more or less power.....in order to maintain rotor rpm within the critical range.....
..there was no evidence that full emergency power was ever used , as it starts a counter to record the fact if sensed for more than one second........
rgds Robin....
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dalek
Pls download and read Mitchell of Boeing "Analysis of Available Data" - the argument in that doc is robust for the a/c having maintained a steady high cruise speed over the whole of that first leg.
Robin
While you make some worthy points (which I will address after recovering from the holiday weekend here in WA) this latest post shows that you have not followed the thread nor understood the use of ""s around "throttle.." - when you dip in lightly you weaken your good points.
Pls download and read Mitchell of Boeing "Analysis of Available Data" - the argument in that doc is robust for the a/c having maintained a steady high cruise speed over the whole of that first leg.
Robin
While you make some worthy points (which I will address after recovering from the holiday weekend here in WA) this latest post shows that you have not followed the thread nor understood the use of ""s around "throttle.." - when you dip in lightly you weaken your good points.
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Available Data and VNE
Walter,
I was trying to stay out, but your last entry does need challenging. Look up the word "available" in the dictionary.
I have stated earlier I know/ knew quite a lot about low level navigation, meteorology and flight safety. I know little or nothing about computer flight simulations.
Even so I read the Boeing report and could not understand how they could replicate the final flight of ZD 756 without ADR inputs. I asked lots of "experts". They told me it was impossible to do so.
Earlier in this thread Boeing admit that the simulation shows what "may" have happened, not what "did".
HOL para 132.
" we conclude that it would be quite inappropriate to treat the results of the simulation as proven facts."
If you are using the simulation to show that Holbrook may have been wrong, fine. If you are tring to disprove his evidence it just does not wash.
Instead of trying to rubbish the evidence of the last credible witness, why don't we use the few available facts to see if he could be right.
Much has been made about the high speed transit and possible breach of VNE. We do have a Take Off time (ish). We do have a time of impact, (precise or ish) depending on the TANS. We know the distance between the two points.
Everything I have read, points to an average Groundspeed at or just above 150kts.
Let us simulate the flight:
The crew get airborne already knowing they are up against crew duty restraints. They are going to fly as fast as conditions allow.
VNE is 160 but that would involve uncomfortable vibration for the pax.
I am told by an experienced Chinook operator that an IAS of 150 is realistic and in most conditions comfortable. They are likely to choose that speed.
We have from forecast ( and some actuals) an estimated tailwind of some 15 - 20 kts.
If the crew maintain 150IAS or 165 - 170GS. They are going to arrive early at the crash site. To make T/O and impact times fit, part of the sortie has to be flown at a lower speed.
In all probability they maintain 150 until approaching the coast. In marginal conditions they would then "thr (sorry Robin), slow down" until they were certain of their position and could see the coast. Just good common sense and airmanship.
Any evidence to support this hypothesis? Well yes, MR Holbrook our eyewitness. He would have seen them at this stage of flight.
We know from the evidence of Mr Cable that impact was aroond 150IAS 174 GS.
Very few people dispute Mr Holbrooks version of the weather. The visibility was 1 - 2 nms. The crew almost certainly could see what Holbrook could see.
Arthur Rowe explains why he thinks Holbrook was wrong. But even if the Chinook was at double his (Holbrooks) minimum estimated GS,(of 60 to 80 kts GS), there still needed to be a significant increase in GS between sighting and impact. Far more than could be explained by an increase in tailwind over the cliffs.
Having slowed down from 150IAS to something between 60 and 120, why did they decide to fly faster into deteriorating weather. In all my 10,000 hours I have never encountered a pilot who choses to accelerate into worsening conditions.
To me the answer is fairly obvious:
a. They had no control over the aircraft.
b. They thought they had a lot more time to react than they did.
If I bite again on this subject, please feel free to shoot me.
I was trying to stay out, but your last entry does need challenging. Look up the word "available" in the dictionary.
I have stated earlier I know/ knew quite a lot about low level navigation, meteorology and flight safety. I know little or nothing about computer flight simulations.
Even so I read the Boeing report and could not understand how they could replicate the final flight of ZD 756 without ADR inputs. I asked lots of "experts". They told me it was impossible to do so.
Earlier in this thread Boeing admit that the simulation shows what "may" have happened, not what "did".
HOL para 132.
" we conclude that it would be quite inappropriate to treat the results of the simulation as proven facts."
If you are using the simulation to show that Holbrook may have been wrong, fine. If you are tring to disprove his evidence it just does not wash.
Instead of trying to rubbish the evidence of the last credible witness, why don't we use the few available facts to see if he could be right.
Much has been made about the high speed transit and possible breach of VNE. We do have a Take Off time (ish). We do have a time of impact, (precise or ish) depending on the TANS. We know the distance between the two points.
Everything I have read, points to an average Groundspeed at or just above 150kts.
Let us simulate the flight:
The crew get airborne already knowing they are up against crew duty restraints. They are going to fly as fast as conditions allow.
VNE is 160 but that would involve uncomfortable vibration for the pax.
I am told by an experienced Chinook operator that an IAS of 150 is realistic and in most conditions comfortable. They are likely to choose that speed.
We have from forecast ( and some actuals) an estimated tailwind of some 15 - 20 kts.
If the crew maintain 150IAS or 165 - 170GS. They are going to arrive early at the crash site. To make T/O and impact times fit, part of the sortie has to be flown at a lower speed.
In all probability they maintain 150 until approaching the coast. In marginal conditions they would then "thr (sorry Robin), slow down" until they were certain of their position and could see the coast. Just good common sense and airmanship.
Any evidence to support this hypothesis? Well yes, MR Holbrook our eyewitness. He would have seen them at this stage of flight.
We know from the evidence of Mr Cable that impact was aroond 150IAS 174 GS.
Very few people dispute Mr Holbrooks version of the weather. The visibility was 1 - 2 nms. The crew almost certainly could see what Holbrook could see.
Arthur Rowe explains why he thinks Holbrook was wrong. But even if the Chinook was at double his (Holbrooks) minimum estimated GS,(of 60 to 80 kts GS), there still needed to be a significant increase in GS between sighting and impact. Far more than could be explained by an increase in tailwind over the cliffs.
Having slowed down from 150IAS to something between 60 and 120, why did they decide to fly faster into deteriorating weather. In all my 10,000 hours I have never encountered a pilot who choses to accelerate into worsening conditions.
To me the answer is fairly obvious:
a. They had no control over the aircraft.
b. They thought they had a lot more time to react than they did.
If I bite again on this subject, please feel free to shoot me.
Last edited by dalek; 10th Jun 2010 at 21:40.