Chaps,

There are 2 distinct aspects to this whole sorry business:

1. There was insufficient cause for Wratten and Day to pin their finding of Gross Negligence on the 2 pilots.
2. Various senior people allegedly ran roughshod over their own airworthiness regulations whilst trying to bring the HC2 into service.

Now, one might consider that 2 may well have been instrumental in the accident, but most folk simply accept that confirmation of 1 is the more important. An independent judicial inquiry should resolve 1 fairly quickly, but would probably then lead to an in-depth investigation of 2 as more and more stones are turned over.

I feel strongly that 1 should be settled first - and quickly. Then 2 can be considered at length - but assuredly not just by some internal MoD inquiry.

I happen to agree with Beagle here. The finding of Gross negligence must be the first hurdle to overcome.

If (big If) the Gross negligence finding was overturned in favour of a "Pilot error" finding - would that satisfy ?

Weather on Mull
 

Just a query.

SFFP suggests that only the crew would have known what the weather was at the crash site.

Dalek says "Weather at the crash site. Who knows?

Some nine or ten witnesses actually on the Mull including the lighthouse keeper who was, if I remember rightly, a met observer, stated that they were in fog. One witness stated that he heard but could not see the crash but estimated he could not have been more than 100 yards from it.

If the evidence of Mr Holbrook, the yachtsman is regarded as proof that the over water weather was VMC, why is the Mull observers evidence disregarded as to the weather at the crash site?

Because he was a 100 yards away from the crash site, in fog and unable to state, without any shadow of a doubt what the actual weather at the crash site was.................simples :ok:

Beagle:
I am very aware that those who have fought the good fight from the very start have had one aim and one aim only, to overturn the finding of the AOC and the AOC-in-C and to thus restore the reputations of the two deceased pilots. That was, and is, a laudable and very understandable cause, given the outrageous injustice done in the name of the Royal Air Force to two deceased officers both of whom were highly professional pilots. The reason why that campaign failed time and time again despite support from the Scottish FAI, the House of Lords, the House of Commons and even the Secretary of State for Defence of the time is summarised succinctly by you in item 2. above.
It was not until the gross lack of airworthiness of ZD576 and its sister Chinook Mk2's as Released to Service was revealed in this very thread that some explanation for the bizarre and obdurate attitude of the MOD to what to most (!) everyone else seemed blatant injustice, as clear as a pikestaff, began to make sense. Now if it were only the reputations at stake of what are now retired senior RAF Air Officers, there might be some merit in your call to sort out 1, before moving onto 2. But 2. is the problem. 2 would mean that the whole UK Military Airworthiness process was criminally compromised at the highest levels. 2 would mean that the MOD cannot be left to self regulate airworthiness while acting as operator and accident investigator as well. Far more than Nimrod, Hercules, Tornado or Sea King, Mull shows that the MOD as Judge and Jury of its own actions will convict everytime, but never itself! The MAA and the MAAIB are its puppets. I'm sorry but this is far to serious a matter of life and death to delude ourselves to the contrary. I bore you all time after time with my mantra that:
Self-Regulation never works, and in Aviation it Kills!
for one reason only, it is a self evident truth! Unless and until Military Airworthiness Regulation is wrested from the MOD, more avoidable accidents will kill more people. That does not even make sense in military terms, let alone the needless grief and misery that come with those accidents. With respect to you Beags, and others who are so like minded, you are wrong. The imperative is 2, for if that be true many more lives remain at risk and we must succeed where Mr. Haddon-Cave QC failed. Then we can put right past injustices.

I think that the evidence of the Yachtsman for the height and speed of the Chinook should be considered carefully as it may suffer from the effects of habituation and scale. He said that he was unfamiliar with the Chinook but was used to seeing SAR helicopters. The Chinook is a much larger aircraft and it would subtend a greater angle at the eye of the observer. It would therefore give the impression of being lower than its true height. This would then result its appearing to travel a shorter distance in the same time, giving the impression of flying more slowly than its true speed.

The effects of scale in the opposite sense can be seen with radio control scale model aircraft. They appear to be flying much faster than their true speed. The Red Bull air races have more dramatic impact as a result of greater apparent speed because the aircraft which are flown in them are relatively small.

As the Chinook is about twice the size of typical SAR helicopters I think the estimates by the Yachtsman of its height and speed should be increased by a factor of about two. This would mean the Chinook would have been flying at around 140 knots, which would agree with other evidence for its speed at that stage of the flight.

Walter
sorry but I have to correct you on a couple of points........the BEL vor/dme at Aldergrove was on the northern perimeter of the airfield at the time of this flight , the frequency 117.2 is still in use although it has been moved a little SE since then .
You may be thinking of the older BEL vor on 116.2 which used to be south of Belfast and was discontinued at the time......
...on the Racal report , I think you need to read it again , the last operator input you refer to was 30 minutes before the flight departed ....

Arthur Rowe
the yachtsman was mistaken , if he really was where he thought , the Chinook would have passed about a mile away from him.......his impressions were never checked to authenticate , simply accepted..???????...
rgds Robin....

Robin
I was using 54:39':40” 6:13':48” for Bel VOR – where did you think it was?
The ATC fix was obviously referenced to their radar.
Last operator input position was 2 nmiles out on their way – I had made that last post in a hurry and may have dug out the wrong time and so will recheck when I have more time to go through the info again.
V813 and waypoint A define exactly a track of 027 mag (using mag var at the time).
Thank you for pointing out the time error.

I wholeheartedly agree that the dearth of factual evidence regarding airmanship should have been sufficient to prevent the RO’s verdict. And I accept that is the driving force behind this 16 year campaign, both to families and their supporters, of which I am one.

However, the Board of Inquiry was duty bound to address airworthiness because an Organisational failure of that process was a verdict open to it. It failed in that duty despite a compelling raft of evidence from a number of respected officers. Yet, MoD claims all “Airmanship, Technical and Legal” aspects have been thoroughly investigated. The reason why there is this 3-pronged test is because there is overlap; the three are inextricably linked.

Most contributors here express views according to their area of expertise. Mine is most definitely not airmanship, but I know enough about airworthiness to know that the Haddon-Cave report applies even more to Chinook than it does to Nimrod. Had airworthiness been addressed in 1994, or in 1991 when the new policy to cease routinely maintaining airworthiness was introduced, then the underlying causes of other accidents would (hopefully) have been resolved long ago. My view is that if these airworthiness failings had been on the table in 1994, the ROs and their fellow Stars would have quietly backed away and, perhaps, said “Cause not positively determined”. This requirement to base judgment on all the available evidence is a fundamental legal principle. Most readers know that MoD sought to hide similar evidence on both Nimrod and Hercules; the key players will tell you both cases were won as soon as (lack of) airworthiness was mentioned. I say, place all the evidence on the table and let an independent legal review assess it as a whole.

Only then would it be time to treat these failings separately.

Arthur Rowe:
Interesting theory. I can only assume you are unaware of the relative fuselage lengths of Sea King and Chinook?

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.

Bos,
I don't think anybody disregards the lighthouse keepers version of the weather. It is likely, indeed very likely that the crash site was in fog.
But take a look at some of the photos published on this site. The edges of a fogbank can be very well defined, so even an observer an "estimated" 100m from the crash site may not be able to see his nose, while 50m away there may be unlimited visibility in three directions. What we are looking for is certainty, not opinion. There was no (surviving) observer at the point of impact.
Mr Holbrook does not show conclusively that the crew were legal VMC. However, if he could see the Mull and the aircraft at ranges of around 2nms, it is likely / probable that the crew could do the same. In other words there is nothing in his testimony to show illegal low flying.

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.

Weather on Mull
 

Dalek

If the observer was an estimated 100 metres, lets be generous and say 200 metres, from the crash, then the crash was 100 (200) metres from the observer who was in thick fog. A moot point as to how the aircraft could have been VMC, 1000metres viz in all directions. However, I accept your point that, once again, there is no absolute certainty.

SFFP

By your definition, if an aircraft crashed in poor viz on the threshhold of a runway, then ATC are not at the crash site.

Looking a bit wider, prior to this particular case and thinking back to 35 years worth of reading accident reports, I'm hard pushed to think of a case in which a number of witnesses stated that a hill feature was in fog and an aircraft hit that feature, 810 ft up, yet doubt remained about the weather conditions on that feature.

Boslandew

Just a quick question:

If I were standing in a fog patch (possibly 'hill fog'), and even if others were too; how could we know what people standing outside that fog patch could see? Or indeed how far those conditions extended?

Of course if we had evidence from someone who was outside that hill fog, a yachtsman perhaps, he may be able to enlighten us??

However, if the implications of such approximation of weather were significant, perhaps we would err on the side of caution, rather than on the side of certainty, when reaching a conclusion?

- Bos - I think we are wandering away from the issue here - I cannot believe that anyone will argue that the crash site was not 100% solid IMC. That is not really the issue. The issue is how the helicopter got there. We have those who 'imply' they know it was negligence and that the crew deliberately entered IMC. We have those who do not know why (that in reality includes the BoI and the Reviewing officers).

I can see little point in any discussions revolving around the point of impact in terms of weather. I would suggest there is no-one who can claim the site of the crash was clear of fog or orographic cloud. I don't think SFFP is actually suggesting that.

Walter
Yes the current BEL vor is at the location given , north of the threshold for runway 17 , slightly east of the centreline....My old documents from 1994 give a slightly different loc. but probably due to rounding up/down the numbers...........
..more importantly , I think that is is extremely unlikely that they maintained the track of 027 mag. for long , as this would entail flying over mountains up to 1400 feet high on their way to the Irish coast.......a waste of time and the old icing questions again......

rgds Robin....

BOAC,

It is not my intention to be rude however the inclusion in red best sums up my thoughts with regard to the weather.

Weather on Mull
 

This discussion comes down, as it has always done, to what is 100% proof. We are splitting hairs extremely finely because it is only a split hair between 99.5% probability and 100% certainty.

BOAC

It seems to me that SFFP is arguing that because there was no-one who saw the actual crash and that it is conceivably possible that the aircraft was VMC, then there is no absolute proof that the aircraft was IMC and the case falls. With respect, I do think that the weather is one of the issues.

Tandemrotor

If one walker had reported being in fog, he could possibly have been in a 'fog patch'. If ten walkers on the hill in different locations all stated that they were in fog then they were not standing in a 'fog patch' but on a fog-covered hill. For the aircraft to have been operating within limits there would have to have been a corridor giving 1000 metres viz in all directions with a 250' cloudbase that was not evident to any of the walkers, never mind the guy 100 metres away.

Boslandew, a few very quick questions if I may:

1) What heights were these walkers?

2) Is it possible they were in cloud, with clear conditions below??

3) If they described visibility as 'coming and going', how might this phenomena appear to an a/c approaching this localised cloud?

4) How would you calculate a 99.5% probability?

I'm obliged

Weather on Mull
 

Tandemrotor

1 The report doesn't give heights. One walker reported that, in ten metres viz, he thought the aircraft was going to hit him but still couldn't see it.

2 It is of course possible but there is little to suggest that it was.

3 They didn't describe visibility as 'coming and going', they reported variously 'thick' or 'dense' fog, viz 15 metres, being unable to see the aircraft because it was 'up in the mist'.

4. You got me. I should have said a very high probability, see comments from BOAC and SFFP

At a slight tangent; the weather at the crash site is described as foggy; elsewhere ,largely unknown apart from Mr Holbrooks account. So,I checked with the Northern Lighthouse Board if the foghorn was in operation at that time. There appears to be no information from the `walkers`,or the Lighthouse keeper as to whether it was/was not. It should have been audible over a range of at least 4 miles ,signalling `N`, (4 secs on,2 secs off, 2 secs on,82 secs off),with a Southerly breeze it would have been heard,unless people /walkers,would have subconsciously ignored it,if they were familiar with the area/conditions.It is/was automatic in operation and triggered to specific local weather conditions,generally vis <3 miles,ambient light,moisture concentration.However,no-one mentions it in the reports,maybe the questions were not asked.Unfortunately in 2005, `foghorns ` were withdrawn,and it appears from the NLB that records were also destroyed. Another question asked was whether there were any `automatic` weather stations at the Lighthouse and foghorn at the time. The answer was that it was not known,as it would be a Met Office task; on speaking to them ,they could not give a definitive answer,required a `letter of request` to dig up the
Archives.I`m surprised that the BOI did not investigate this possibility at the time..

Boslandew

Were I to suggest to you, that none of the 'weather witnesses' were below the height of the lighthouse (approx 300' asl) and the cyclists Bracher and Ellacott were close to, if not above the accident elevation (810' asl) would you be able to quote evidence to contradict me?
But of course there was one witness to give a unique view of the weather at low level; that of the yachtsman Holbrook! He sees the aircraft clearly.

Ergo, isn't it not only possible, but likely, that weather conditions were indeed clear enough for VFR only a very short distance from our land locked observers! Anything else is little more than speculation.

As for cazatou's (K52) earlier suggestion of a 'radar fix', this is of course a complete invention, or simply 'slap dash' research. There was of course no such thing!

Please let's stick to the FACTS chaps, otherwise I will just have to keep coming along to correct you!

"then there is no absolute proof that the aircraft was IMC and the case falls." I cannot speak for Brian and the rest, but I would be very surprised if they are hanging their hats on that. The primary objections surely are that the RAF's own recommendations preclude apportioning Gross Negligence to dead crews (and as far as I know that had not happened before or after, which is interesting) and the fact that there remains no proof of the same. If indeed the fog horn was not operating that would support the belief that at sea level the conditions were not a problem.

Amazingly we seem to be going round the bouys again, hopefully for the very last time. May I remind everyone that Wratten's view, consistantly supported on this thread by John Purdey, was that gross negligence occurred at waypoint change. The only certain thing you can say from the witness evidence is that the crew would never have seen the ground where the land based witnesses were actually standing. The yachtsman's evidence suggests that they were probably in VMC when the Chinook passed him.

Anything else is pure speculation. No-one, including JP, has ever been able to say what the crew could or could not see from the cockpit at waypoint change. Neither can anyone say with any degree of certainty that they were going too fast at that time. These are the two pillars of Wratten's judgement - they were too fast under the conditions at waypoint change. Yet, in the nine years this thread and its predecessor have been running, no-one can say how fast or what the conditions were as seen from that point.

pulse,

You put into words my thoughts exactly.

:D:D:D:D:D:D

Yes, it has been noticed that John Purdey closely supports "Wratten's view". One wonders whether they are joined at the hip.

Weather on Mull
 

Tandemrotor

I’m sorry but I don’t understand your reasoning. I may have missed something, a far from rare occurrence these days.

The yachtsman said that the weather over the sea was clear and that the base of the Mull was visible up to about the level of the lighthouse. It is worth mentioning that the yachtsman did not know until later that the aircraft had crashed and his recollections of the weather are possibly less accurate than those who heard the crash.

However, the aircraft did not crash at sea or at the base of the Mull. It crashed at or close to a point that more than one observer said was in fog, five hundred feet above a point that four witnesses said was in fog and on a hill feature which all witnesses on that feature said was in fog.

Now it is not impossible that somewhere above the light house there was an area of VMC, 1000 metres in all directions and 250ft cloudbase. However, all the available evidence from those actually on the Mull is to the contrary. It seems to me to be a reasonable assumption that there is a high degree of probability that the crash site was in IMC.

Bos,

All the clues are there :ok:

I don't believe that ANY of the campaigners have any doubt (whatsoever!) that the hillside where the aircraft impacted was in IMC at the time of impact, nor that the lighthouse keeper was also standing in IMC, but the fact that the aircraft crashed whilst IMC does not mean that it had been deliberatley flown there.

It is very likely that the aircraft was under control when the Supertans waypoint was changed to a point further up the coast and very likely that this selection indicates that the crew had visual contact with the coastline at the time. What we don't know is why the aircraft did not subsequently turn the necessary few degrees to the left. A number of hypotheses have been put forward in an effort to explain what may have happened but, in the absence of ADR/CVR, we shall never know what DID happen. But we do not know, even 'beyond reasonable doubt' that the reason was the negligence of the crew.

The aircraft's supposed (high) groundspeed is used by Day/Wratten (+ JP et al) as evidence that the crew was already negligent by the time of the waypoint change, in that they were flying too fast for the conditions, but this logic is flawed. An alternative explanation is that, notwithstanding the fog at the crash site, conditions were so good that a high-speed cruise was considered by this highly-experienced crew to be entirely appropriate. Weight is lent to this possibilty (probability?) by Holbrook's evidence and by anecdotal evidence by many on this thread regarding typical orographic conditions (ie often clear conditions in close proximity to the hill fog) in the area.

The MoD could have heeded the findings of the various inquiries already held and reversed this extremely unfair finding of Gross Negligence against Tapper and Cook; this would have left everyone happy, as even Day/Wratten could have conceded that new arguments had come to light and that they had acted in good faith. Now, however, the whole ugly truth about lack of airworthiness has come out and others have been placed in the firing line - those who, in the face of the experts' advice, pushed the HC Mk2 into service in a pretty shameful state.

I agree that the names of the pilots can be cleared pretty quickly, but the new Government should not shrink from a thorough and independent inquiry into the circumstances surrounding the entry into Service of this immature aircraft and why, despite no actual evidence, messrs Wratten/Day came to their remarkable conclusion. Was it that they honestly believed that an aircraft impacting a fog-shrouded hill was proof of its crew's negligence, or might it have been a way of hiding the fog-shrouded evidence that some of their Air-ranking colleagues had pushed an immature aircraft into service?

Size and Speed
 

I am aware of the relative lengths of the Sea King and the Chinook. However, comparing their silhouettes I would still say the Chinook is about twice the size of the Sea King. Perhaps bulk is a better word. A champagne flute may be taller than a half pint glass but the latter is bigger.

I am only trying to fathom out a reasonable explanation for the alleged change in speed of the Chinook. It seems very unlikely that it would slow down to 70 knots then accelerate to Vne as it approached the Mull.

If some people believe that this was the case are they trying to say that there was some fault with the engine control system, causing the aircraft to decelerate then accelerate uncontrollably, and that this was the cause of the accident? Perhaps distracting the crew at a critical time?

I think it is much more likely that it would be maintaintaining a steady speed. Perhaps 120 knots - two miles a minute, a very handy speed for navigational purposes, although it may well have been 140 knots.

As a fixed-wing pilot with little rotary experience I would certainly not describe even 140 knots as a dangerously high speed. At that speed the turning radius of any aircraft is very small and the Chinook should have been able to manoeuvre easily at turning points. I am sure someone with more rotary-wing experience will confirm or deny whether this is the case.

Arthur

I think we will have to disagree over the relative sizes of the two helicopters. However...

If you could share with us the basis upon which you wish to discount the evidence (likely or otherwise?) of the last known witness to see ZD576, perhaps we may be able to progress any theory that may follow?

Perhaps you have other witnesses to the speed of the aircraft, or recordings?

Could the a/c have increased speed shortly before impact? I accept it's possible.

Just show me the evidence that proves it didn't.

Edited to add:
If a witness sees the aircraft at a speed that he assesses as 70kts, and it then impacts a hillside 60secs or so later at high speed, that's not an 'allegation', it is simply a statement of best evidence?

Arthur Rowe


Not being a pilot I won't offer opinion, but simply quote the Release to Service which, at the time, warned of ;


There is no detailed audit trail accompanying this warning, nor should there be in the RTS, but the wording is remarkably similar to the events experienced shortly beforehand by Sqn Ldr Burke, later given in evidence. That is, at the end of a straight run he would experience an UFCM when attempting to execute a turn. I have always thought that a perfect description of what little we know of the final seconds. Notably, Sqn Ldr Burke was actively prevented from giving evidence at the time. Inconvenient to the RO's argument you see.

Arthur Rowe
In my post 6488 I showed that Mr Holbrook was aware of his unfamiliarity with the a/c and would have liked to have seen examples, etc
Further, distance/time analysis by Boeing (not that simulation) has it that they had to have maintained that high cruise speed (over the whole of the leg from Aldergrove to the Mull) to have got there when they did and this did not allow any slowing down anytime as to have dione so would have required the time be made up with excessive (exceeding placard? whatever the term is) speed.
It was not just in the estimation of the a/c's speed that the RAF did not assist Mr Holbrook – they did not give him sufficient opportunity to expand on his view of the weather, which he did do in a subsequent inquiry, making it clear that the weather of concern was very much right on the Mull.
I say that they would have been aware of the Mull but judgement of distance to it would have been difficult had they for whatever reason been directly approaching it – further, identifying a specific point on it visually would have been almost impossible.
An ear witness on the Mull did not detect any adverse changes in noise that could have made him think that they did anything other than fly straight in.
There is nothing to suggest a control problem.
As I have put forward so often on this thread, there is plenty to suggest that they were approaching a known LZ and were using equipment that, by accident or by design, misled them.
Their turn from 027 to 035 at waypoint change, for which there is evidence that it was deliberate, put them onto the optimum approach line to the LZ (which was right by waypoint A) – had they been lined up with it, there was a safe wave-off by means of a moderate banked turn to the left initiated as they crossed the shoreline. Their mis-alignment and over-running the shoreline can be explained by their having refered to a local device that was out of position.
Of course, there are those on this thread who do not want to contemplate this scenario or perhaps see it as their duty to distract others from contemplating it. I think it was Churchill who said something like the truth is so fragile a thing that it needs to be surrounded by a bodyguard of lies – the truth in this case must be something very fragile. The families and colleagues of the pilots need to know what really happened – so does the British public – so however embarrassing or unpalateable a stuffed up exercise may be, how about at least talking about it? Someone must know something – sure as hell there was more to this than pilot error or fantastic control jams.

Eyewitness evidence
 

Unfortunately, even with an eyewitness who is being as honest as he can in his recollection of an event, it has been shown that eyewitness evidence is notoriously unreliable.

There is an interesting article here, among many to be found on the web:

Eyewitness Testimony and Memory: Human Memory is Unreliable and so is Eyewitness Testimony

I quote a short passage from the article.

''Eyewitness testimony is, at best, evidence of what the witness believes to have occurred. It may or may not tell what actually happened. The familiar problems of perception, of gauging time, speed, height, weight, of accurate identification of persons accused of crime all contribute to making honest testimony something less than completely credible.

Prosecutors recognize that eyewitness testimony, even when given in all honesty and sincerity, isn’t necessarily credible. Merely because a person claims to have seen something does not mean that what they remember seeing really happened — one reason why is that not all eyewitnesses are the same. To simply be a competent witness (competent, which is not the same as credible), a person must have adequate powers of perception, must be able to remember and report well, and must be able and willing to tell the truth.

Thus, such testimony can be critiqued on several grounds: having impaired perception, having impaired memory, having inconsistent testimony, having bias or prejudice, and not having a reputation for telling the truth. If any of those characteristics can be demonstrated, then the competency of the witness is questionable. However, even if none of them apply, that does not automatically mean that the testimony is credible. The fact of the matter is, eyewitness testimony from competent and sincere people has put innocent people in jail.

How can eyewitness testimony become inaccurate? Many factors can come into play: age, health, personal bias and expectations, viewing conditions, perception problems, later discussions with other witnesses, stress, etc.''

Is there a better explanation for the apparent change in speed of the Chinook? If so I would be very glad to hear it and give it due consideration. 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:

''An argument is an intellectual process. Contradiction is just the automatic gainsaying anything the other person says.''

''Oh no it isn't''

Walter:
How on earth would an "ear witness" be able to hear a control problem, Walter? Perhaps he/she should have heard the sounds of the pallet springs becoming detached, as indeed they were found to be at the crash site? Oh, of course they were detached by impact forces alone, weren't they? Weren't they?
Arthur Rowe:
The only Pythonesque aspect here is to accept any part of a rigged accident investigation as gospel. The reason Mr Holbrook's testimony is so easily disparaged is that there is so little of it. The one and only eye witness available was dealt with and despatched with unseemly haste. The one expert witness to the many technical shortcomings of engine and flight control in the Chinook HC2, Sqn Ldr Burke was not called at all despite putting himself forward for that purpose. Now why would that be I wonder, given that the RAF included such shortcomings in the RTS?

Chugalug
Human hearing is very sensitive to changes in sound.
The lighthouse keeper was a rotorwing enthusiast and had done some light a/c flying, as I understand. He seemed quite sure that there was no change in sound, that they went straight in.
When you watch a helicopter manoeuvre, you will surely note that it can't change much in terms of aspect, power, anything really without your ears picking up the changes in sound.
Are you suggesting that a control jam in a Chinook could have caused a turn (onto a heading that the HP just happened to have set) and allow an unstable a/c to fly over that last leg (waypoint change to impact, a significant length in such an emergency) without any audible sign of the pilot trying to regain control? Fantasy.

Walter, fantasy is believing that some for of covert demonstration went tragically wrong with the whole event being conveniently (and very securely?) covered-up.

Equally, it is somewhat 'fantastic' that the RAF managed to overlook some hideously questionable airworthiness issues when carrying-out its own investigation into the crash.

Forgive me Walter, but is it not accepted fact that there was no need to execute the turn AT the Waypoint? The point made by Sqn Ldr Burke, denied at the time, was that at the end of a straight run, he had experienced sudden UFCMs when inputting the demand for a turn. And that this sudden change could take him in the opposite direction to that intended.

Could such an UFCM have been a contributory factor? I'll leave that to pilots to discuss. What is certain is that MoD thought it prudent to hide this fact for many years. Just as they concealed the positively dangerous software. It is called misleading by omission. I wonder what an independent inquiry will make of that?

Walter:
Presumably when you watch, or rather hear in this scenario, such a manoeuvre the changes of sound would come as a result of pilot control inputs. If such inputs cannot be made, because the flight controls are jammed, what changes in sound would you expect to hear? I do not say that this accident happened because the flight controls were jammed, Walter, because I do not know, but you stated that the "Ear Witnesses" heard nothing to suggest a control problem. I simply ask what would they hear if there were one?

Although I have a son who flies them, I am not particularly an enthusiast of rotorwings and have done quite a lot of light a/c flying. What I am very familiar with is the sound of Chinooks approaching and passing very low overhead my house, especially late at night. (I love it!!). I would defy anyone who was not an expert to draw any conclusions from the way the sound changes as the aircraft approaches even when in a steady cruise.