AAIB investigation to Hawker Hunter T7 G-BXFI 22 August 2015
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Beg to disagree with my learned friend. A defendant suffering from amnesia may not be tried if his lack of memory of the events surrounding the crime prevents an adequate defense.
Reviewing various videos of the flight, I see a slight hesitation in pitch as the aircraft is descending through the vertical. The pitch change seems to stop for just a second or so before continuing. This might be a video artifact, the pilot realising he has a big problem, or simply the angle between the camera and the aircraft.
It may be that the hesitation was an attempt to maximise airspeed in order to pull a higher G recovery in the final quarter of the loop. I don't think it has a great deal of relevance to the final outcome, but it might serve to indicate that the pilot was fully aware that there was a problem at that point and was doing his best to try and recover the situation.
It also might suggest that the pilot was trying to invent a recovery procedure without having trained for that eventuality before hand.
Lemain
I must take issue with you suggesting that the AAIB investigators were not completely competent and exercising due diligence throughout this investigation. Such comments are unworthy of this forum.
It may be that the hesitation was an attempt to maximise airspeed in order to pull a higher G recovery in the final quarter of the loop. I don't think it has a great deal of relevance to the final outcome, but it might serve to indicate that the pilot was fully aware that there was a problem at that point and was doing his best to try and recover the situation.
It also might suggest that the pilot was trying to invent a recovery procedure without having trained for that eventuality before hand.
Lemain
I must take issue with you suggesting that the AAIB investigators were not completely competent and exercising due diligence throughout this investigation. Such comments are unworthy of this forum.
The time to accelerate to cornering speed is immediately after coming over the apex; he should have had plenty of speed by the time he was going straight down. I was surprised that the AAIB report of test flights did not show any benefit of different flap settings or power changes in minimizing altitude loss on the backside of the loop. In any event, accelerating straight down and not pulling when you think you might not make it would definitely be counter-intuitive at that point.
I was surprised that the AAIB report of test flights did not show any benefit of different flap settings or power changes in minimizing altitude loss on the backside of the loop.
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Chronus
With the deepest respect, while amnesia may be considered grounds for not commencing proceedings if a defendant is incapable of mounting a defence against the charges and there is no independent supporting evidence, amnesia in and of itself is no defence against charges being brought, nor a defence against conviction in English Law. Amnesia may be taken into consideration when deciding any sentence upon conviction.
The reasons behind this are that amnesia can be faked. There is no way or reliable medical procedure for determining if the claimed amnesia is genuine or not.
Remember that a trial is intended to determine whether the accused is guilty of the offence and whether they had an intention of committing the offence before or at the time it happened. The fact that you hit your head and suffered amnesia escaping from the scene of an armed robbery would be no defence in law. Having been convicted of the offence through forensic or CCTV evidence, a judge may rule that the person so convicted serve a reduced sentence in the grounds that they couldn't remember the event. BUT at the time the event happened, that person clearly had it in mind to commit a robbery, or other offence.
So I reiterate, amnesia is no defence, in English Law and in most other jurisdictions around the world.
With the deepest respect, while amnesia may be considered grounds for not commencing proceedings if a defendant is incapable of mounting a defence against the charges and there is no independent supporting evidence, amnesia in and of itself is no defence against charges being brought, nor a defence against conviction in English Law. Amnesia may be taken into consideration when deciding any sentence upon conviction.
The reasons behind this are that amnesia can be faked. There is no way or reliable medical procedure for determining if the claimed amnesia is genuine or not.
Remember that a trial is intended to determine whether the accused is guilty of the offence and whether they had an intention of committing the offence before or at the time it happened. The fact that you hit your head and suffered amnesia escaping from the scene of an armed robbery would be no defence in law. Having been convicted of the offence through forensic or CCTV evidence, a judge may rule that the person so convicted serve a reduced sentence in the grounds that they couldn't remember the event. BUT at the time the event happened, that person clearly had it in mind to commit a robbery, or other offence.
So I reiterate, amnesia is no defence, in English Law and in most other jurisdictions around the world.
Last edited by G0ULI; 21st Mar 2017 at 01:49.
That is my opinion as well.
I may have missed it, but the accident report doesn't seem to cover the pilot's actions on the day of the accident leading up to the flight in great detail, specifically, when he ate, what he ate and how much time elapsed subsequently.
This can have a bearing on hypoglycemic events that some people will have a predisposition for.
I remember an interesting case of an F-8 wingman joining on the lead aircraft after takeoff from NAS Miramar, when he went blind during the rendezvous! Fortunately the lead got him in sight quickly and gave voice commands which he was able to follow. After a while, his vision began coming back and the aircraft was recovered into the arresting gear at NAS Miramar. The sawbones blamed the problem on hypoglycemia resulting from a coffee and donut fighter pilot breakfast.
I may have missed it, but the accident report doesn't seem to cover the pilot's actions on the day of the accident leading up to the flight in great detail, specifically, when he ate, what he ate and how much time elapsed subsequently.
This can have a bearing on hypoglycemic events that some people will have a predisposition for.
I remember an interesting case of an F-8 wingman joining on the lead aircraft after takeoff from NAS Miramar, when he went blind during the rendezvous! Fortunately the lead got him in sight quickly and gave voice commands which he was able to follow. After a while, his vision began coming back and the aircraft was recovered into the arresting gear at NAS Miramar. The sawbones blamed the problem on hypoglycemia resulting from a coffee and donut fighter pilot breakfast.
Your body has glucose stored as glycogen-if you are short of glucose, glycogen gets converted to glucose as your body obviously needs the glucose for energy. Glucose levels in non diabetic patients are well regulated by the body and carefully controlled in a narrow band.
It would be a highly unlikely scenario that a pilot with an appropriate medical category to fly a fast jet would become hypoglycaemic in the cockpit during a display.
Yes I read it - On page 11 of Appendix H it is written that "The height loss appeared to be insensitive to whether 1 or 2 notches of flap were selected and to the power setting". Which is why I wrote that I was surprised that there wasn't any benefit. I had assumed that both pulling the throttle back and adding flaps would reduce the altitude lost. I wasn't sure whether extending the speed brake would provide some benefit but that wasn't mentioned or I missed it.
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Originally Posted by Treble one
Glucose levels in non diabetic patients are well regulated by the body and carefully controlled in a narrow band. It would be a highly unlikely scenario that a pilot with an appropriate medical category to fly a fast jet would become hypoglycaemic in the cockpit during a display.
Perhaps you are still too young to have encountered the issue?
AH was no longer a spring chicken, was he? Do you know what he had for nourishment the day of the accident?
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Chronus, you're wrong and G0ULI is correct. The fact that a person cannot mount a positive defence because of amnesia would not prevent a trial. In fact there are many cases such as dangerous driving where exactly that happens.
I believe there will be charges, as the climate in the U.K. has been that way for some time. See Ouzo/Pride of Bilbao in shipping, and the recent Tiger Moth crash trial.
That both ended in acquittals does not suggest a huge chance of a conviction in this case, especially given the circumstances.
That both ended in acquittals does not suggest a huge chance of a conviction in this case, especially given the circumstances.
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Ouzo/Bilbao case was very different. The Officer On Watch saw the yacht and just steamed on without checking that the Ouzo was OK. Three yachtsmen were killed. There was a manslaughter charge made against the OOW but the jury couldn't agree whether it was the Bilbao that hit the Ouzo or another ship known to have been in the vicinity. Had the jury agreed it was the Bilbao the OOW would have undoubtedly been imprisoned.
Treble one, As we age, the close regulation becomes less effective. I see that effect in myself, although I have good scores on physicals and would probably still be medically qualified to act as a commercial pilot.
Perhaps you are still too young to have encountered the issue?
AH was no longer a spring chicken, was he? Do you know what he had for nourishment the day of the accident?
Perhaps you are still too young to have encountered the issue?
AH was no longer a spring chicken, was he? Do you know what he had for nourishment the day of the accident?
So incapacitation due to hypoglycaemia at the top of a loop? Blimey those holes in that cheese.....they really were against him.
PS if he was hypoglycaemic this would have shown in the inevitable blood test he would have had on admission to A and E after the crash. Possibly even checked on site by the attending paramedics and doctor too.
With respect to the apparent reduction in pitch rate observed on the videos of the accident manoeuvre there are a few point to consider.
When a looping manoeuvre is viewed head on, or when there is a significant planform aspect, the observer's perception of pitch rate is based on the rate of change of apparent fuselage length (nose-to-tail length measured tangential to the sightline). The relationship of this length and absolute fuselage length is a function of sine(pitch attitude). Therefore, for a constant actual pitch rate the perceived pitch rate will reduce passing a pitch attitude of 90 degrees (up or down). This is why this apparent phenomenon occurs on many of the videos.
In the report there is a plot of pitch attitude vs time to impact (Figure 13) commencing at 90 deg nose down. A straight line can be drawn through the error bars from 90 to 0 deg, indicating a constant pitch rate. Even if the data points are joined a significant pitch rate exists at 90 deg nose down. Therefore, if a reduction in pitch rate did occur it would have to have been significantly before the down vertical line in order for the pitch acceleration phase back to a significant, steady state pitch rate to be completed by the down vertical.
The aircraft had achieved a level pitch attitude before impact with a rate of decent at impact which was survivable by the pilot. The height loss data presented in Appendix H indicates that a maximum instantaneous pitch rate pull through was required in order to achieve the radius of the accident manoeuvre. Therefore, if there had been any reduction in pitch rate from this during the downward half of the manoeuvre then a higher rate of descent impact with a nose down pitch attitude would have occurred.
Based on the above, there appears to be no evidence to support a postulation of a reduction in pitch rate during the downward half of the manoeuvre.
When a looping manoeuvre is viewed head on, or when there is a significant planform aspect, the observer's perception of pitch rate is based on the rate of change of apparent fuselage length (nose-to-tail length measured tangential to the sightline). The relationship of this length and absolute fuselage length is a function of sine(pitch attitude). Therefore, for a constant actual pitch rate the perceived pitch rate will reduce passing a pitch attitude of 90 degrees (up or down). This is why this apparent phenomenon occurs on many of the videos.
In the report there is a plot of pitch attitude vs time to impact (Figure 13) commencing at 90 deg nose down. A straight line can be drawn through the error bars from 90 to 0 deg, indicating a constant pitch rate. Even if the data points are joined a significant pitch rate exists at 90 deg nose down. Therefore, if a reduction in pitch rate did occur it would have to have been significantly before the down vertical line in order for the pitch acceleration phase back to a significant, steady state pitch rate to be completed by the down vertical.
The aircraft had achieved a level pitch attitude before impact with a rate of decent at impact which was survivable by the pilot. The height loss data presented in Appendix H indicates that a maximum instantaneous pitch rate pull through was required in order to achieve the radius of the accident manoeuvre. Therefore, if there had been any reduction in pitch rate from this during the downward half of the manoeuvre then a higher rate of descent impact with a nose down pitch attitude would have occurred.
Based on the above, there appears to be no evidence to support a postulation of a reduction in pitch rate during the downward half of the manoeuvre.
In fact the aircraft was in a stalled condition during the last few seconds of the manoeuvre, with a roughly 14° nose-up attitude at impact.
Cunning Artificer
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But it was speculation that the pilot might have been under qualified or not medically fit that made the investigating team check that out.
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Hi Blacksheep
How does that make it any less speculative? All investigations - science, engineering, accident - start out at time=0 as speculation. Writing down a checklist for convenience doesn't change that. However I was really trying to make the point that as you speculate and gather facts you must challenge the facts you've gathered. Following from that, when 'facts' are introduced without critical evaluation something is going wrong.
There are a number areas where the data (information) gathered seems not to have been self-criticised by the AAIB team. e.g. the accuracy of the radar track which was introduced by the AAIB without (as far as I can see) any accuracy challenge.
Why didn't the report explain why they didn't consider the accuracy? Radars do 'lie' - well there is always some potential inaccuracy. Another poster has commented that the radar track isn't relevant and another says it is. It's EDIT:[i.e. the relevance to the accident investigation] outside my competence but I do understand radar technology quite well.
How does that make it any less speculative? All investigations - science, engineering, accident - start out at time=0 as speculation. Writing down a checklist for convenience doesn't change that. However I was really trying to make the point that as you speculate and gather facts you must challenge the facts you've gathered. Following from that, when 'facts' are introduced without critical evaluation something is going wrong.
There are a number areas where the data (information) gathered seems not to have been self-criticised by the AAIB team. e.g. the accuracy of the radar track which was introduced by the AAIB without (as far as I can see) any accuracy challenge.
Why didn't the report explain why they didn't consider the accuracy? Radars do 'lie' - well there is always some potential inaccuracy. Another poster has commented that the radar track isn't relevant and another says it is. It's EDIT:[i.e. the relevance to the accident investigation] outside my competence but I do understand radar technology quite well.
Last edited by Lemain; 21st Mar 2017 at 15:10. Reason: Added a clarification in final paragraph
Lemain,
I think that the issue here is actually the definition of the word speculation. The Oxford English Dictionary one is: "the activity of guessing possible answers to a question without having enough information to be certain". The investigation of known potential causes (ie. currency, qualification, medical category) is not 'guessing possible answers'; the answers come from facts discovered by investigation. Therefore, I think that much of the exchanges here between you and others (including me) is because you are applying a different meaning to the word 'speculation' than the rest of us. This is not a criticism but, perhaps, speculation on my part!
I also am interested in what significance you think that radar track data accuracy has upon the conclusions in the report. Again, not a criticism but curiosity on my part because you do seem to keep returning to this issue with gusto.
I think that the issue here is actually the definition of the word speculation. The Oxford English Dictionary one is: "the activity of guessing possible answers to a question without having enough information to be certain". The investigation of known potential causes (ie. currency, qualification, medical category) is not 'guessing possible answers'; the answers come from facts discovered by investigation. Therefore, I think that much of the exchanges here between you and others (including me) is because you are applying a different meaning to the word 'speculation' than the rest of us. This is not a criticism but, perhaps, speculation on my part!
I also am interested in what significance you think that radar track data accuracy has upon the conclusions in the report. Again, not a criticism but curiosity on my part because you do seem to keep returning to this issue with gusto.
But it was speculation that the pilot might have been under qualified or not medically fit that made the investigating team check that out. I realise this seems pedantic and I chose the quals and medical because it's so obvious. You cannot investigate without speculation.
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Hi LOMCEVAC
It's probably my lack of care in choosing the right words. All I'm trying to say is that evidence introduced into a report should be accompanied with a critical evaluation - if only as a footnote or appendix. It is certainly hard to read sequential posts and keep context -- one tends to pick up on specific sentences and paragraphs which then tend to take a life of their own!
I believe the AAIB report is below the standard that the victims, industry and the pilot deserve.
As an illustration of that I pointed out that the accuracy of the radar track in the report is not discussed. That is just one illustration. There are others.
I have no idea of the significance of that to the conclusions - I am not competent to comment on the flying having (sadly) never flown a fast jet.
But, the lack of scrutiny concerns me.
It's probably my lack of care in choosing the right words. All I'm trying to say is that evidence introduced into a report should be accompanied with a critical evaluation - if only as a footnote or appendix. It is certainly hard to read sequential posts and keep context -- one tends to pick up on specific sentences and paragraphs which then tend to take a life of their own!
I believe the AAIB report is below the standard that the victims, industry and the pilot deserve.
As an illustration of that I pointed out that the accuracy of the radar track in the report is not discussed. That is just one illustration. There are others.
I have no idea of the significance of that to the conclusions - I am not competent to comment on the flying having (sadly) never flown a fast jet.
But, the lack of scrutiny concerns me.
Lemain,
By your own admission you have little or no subject matter expertise. Therefore, you are not qualified to make any comment on the standard of the investigation or of the report or the competence of AAIB, although you are entitled to your own opinion. However, speculative criticism of a team who have worked long and hard for almost 2 years to produce what is undoubtedly one of the most in depth AAIB reports ever is totally unjustified. If the experts deem that an item is not relevant, eg. radar track accuracy, then why would it be included in an already large document? Reporting should follow the tenets of Clarity, Brevity and Relevance. In a complex investigation such as this, brevity stills runs to 452 pages. Any additions of irrelevant comments would make the report even harder to digest for victims, industry and the pilot.
By your own admission you have little or no subject matter expertise. Therefore, you are not qualified to make any comment on the standard of the investigation or of the report or the competence of AAIB, although you are entitled to your own opinion. However, speculative criticism of a team who have worked long and hard for almost 2 years to produce what is undoubtedly one of the most in depth AAIB reports ever is totally unjustified. If the experts deem that an item is not relevant, eg. radar track accuracy, then why would it be included in an already large document? Reporting should follow the tenets of Clarity, Brevity and Relevance. In a complex investigation such as this, brevity stills runs to 452 pages. Any additions of irrelevant comments would make the report even harder to digest for victims, industry and the pilot.