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Shoreham Airshow Crash Trial

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Shoreham Airshow Crash Trial

Old 4th Jul 2020, 09:37
  #601 (permalink)  
 
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Trial Verdict suited the 'system'

Indirectly the 'system' was on trial in this case and therefore by only charging the pilot (who was rightly cleared of the charge) it effectively closed the book and did not expose the real gaps that existed. Remember this was an 'authorised' display not an ad hoc event, and therefore as such should have been subject to compliance with the then rules governing the day.
The fact that the DA was deficient, and that the final back stop (the ability to stop the display if required) was not implemented, are in my mind the most significant factors which allowed this accident to happen. Both these situations were present BEFORE the actual failed manoeuvre took place, and in the case of the STOP call the obvious failure in this not happening when the display machine was well below its initial height at the display start was again BEFORE any G induced element was possible. On the day not only did the pilot fail to observe the requirements, and safe practice, but the system in place to act as the overall regulator failed in equal terms to do its job. Whether this is relevant to an inquest I am unsure, but it was relevant to the event on the day and therefore in my mind should be part of the decision process to give a proper picture of what went wrong.
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Old 4th Jul 2020, 10:11
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I heard at the time (but am not sure) that Andy Hill had his DA for the more powerfully engine Hunter FGA9, not the T7 which he flew? I recall it reported at the time that he stood in at short notice for the intended display pilot?

FB
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Old 4th Jul 2020, 11:25
  #603 (permalink)  
 
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Originally Posted by Finningley Boy View Post
I heard at the time (but am not sure) that Andy Hill had his DA for the more powerfully engine Hunter FGA9, not the T7 which he flew? I recall it reported at the time that he stood in at short notice for the intended display pilot?

FB
DAs are not type specific, let alone sub-type specific. They are category specific, however.
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Old 4th Jul 2020, 11:55
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Originally Posted by KarlADrage View Post
DAs are not type specific, let alone sub-type specific. They are category specific, however.
A good example of the disparity in rigour between military and civil display regulation.

Last edited by Easy Street; 4th Jul 2020 at 12:24.
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Old 4th Jul 2020, 13:11
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Just as a matter of interest, did anyone ask in court when this CI started?

Was it when he did the preflight checks? After he took off? When he was running in? When he was too low and slow into the accident manoeuvre? When he was too low at his gate height and didn't act? When he didn't attempt an escape maneouvre.....I don't know.

When was it?
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Old 4th Jul 2020, 13:33
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Originally Posted by KarlADrage View Post
DAs are not type specific, let alone sub-type specific. They are category specific, however.
I am afraid that, as a DAE with Category G on my approval, I must correct you. In Category G (single engine jets) DAs are type specific. Therefore, AH would have had a DA for 'Cat G (Hunter)'. They do not differentiate between different Marks of a given type. DAE approvals are by Category only and not by type. Please note that since this accident Cat G has been further subdivided into G1 and G2 for straight wing and swept wing single engine jets although this makes no practical difference to the award of a DA but it does with respect to currency..

The difference in maximum thrust available between Hunters with Avon 200 series engines (F(GA)9, F58 etc) and those with Avon 100 series engines (eg. T7) makes no real difference to how you fly a display. I have practised in a T7 for a F(GA)9 display without any changes to how I flew, other than considerations for the reduced external view to the right due to the cockpit and canopy shape. A manoeuvre flown in a 200 engine Mark at full throttle should be capable of being flown in exactly the same way and from the same airspeed in an aircraft with a 100 series engine. If it cannot then, in my opinion, insufficient safety margin has been allowed.
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Old 4th Jul 2020, 13:47
  #607 (permalink)  
 
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Apologies for the duff info, Lomcevak. Is Cat G the only one which that applies to? I'd always been led to believe that DAs were not type specific.
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Old 4th Jul 2020, 14:11
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No Problems. CAP1724 Chapter 9 gives the details of the Categories and Groups. However, some categories are also annotated by type and this table could be misleading! I will try to find where in this CAP it states that.
Rgds L
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Old 4th Jul 2020, 15:58
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Originally Posted by Treble one View Post
Just as a matter of interest, did anyone ask in court when this CI started?

Was it when he did the preflight checks? After he took off? When he was running in? When he was too low and slow into the accident manoeuvre? When he was too low at his gate height and didn't act? When he didn't attempt an escape maneouvre.....I don't know.

When was it?
I would be surprised if many contributors to this thread are not yearning to get answers to your questions. We can only hope that the Coroner is similarly minded!
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Old 4th Jul 2020, 17:22
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Originally Posted by megan View Post
I hope you are not inferring that Derry knowingly exceeded limits, from what I understand the issue was design flaw in the wings leading edge D section. The coroner's jury recorded that Derry and Richards had "died accidentally in the normal course of their duty", and that "the deaths of the spectators were accidental", adding that "no blame is attached to Mr. John Derry".
Badly worded, Megan. I remember vaguely reading a report on the accident that on a previous Mach One pass, it was noticed that some structural deformation was apparent. It was mentioned by his observer. Of course Derry didn't know his aircraft was going to disintegrate. Nor did the design team. Life was cheaper then. Joe Bloggs was a nobody and claims direct didn't exist.
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Old 5th Jul 2020, 09:13
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Does the fact that the display was started using a "bent loop" manoeuvre indicate that the venue was unsuitable?

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Old 5th Jul 2020, 10:26
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Errors were made from the start, before any extra forces to the body were applied.
Errors were undoubtedly made - but not from the start. They seemed to have started at a point a few minutes into the display that came to be known as Point X.

Once again, you need to have been present in court to know that sort of thing. Except that, for this particular set of evidence, there was a very good local press report by Michael Drummond of the Shoreham Herald. His report ties in with my own contemporaneous notes. It refers to the evidence of Dr Steve Jarvis, a well respected aviation human performance/safety specialist. Dr Jarvis was a defence expert witness, but his credentials had been confirmed by Wg Cdr Nicholas Green, an RAF Av Med consultant, who was an expert witness for the prosecution

Dr Jarvis listed between eight and twelve inexplicable and unconnected errors made by AH. They all occurred in a period of 22-23 seconds. He said that the chances of so many independent errors occurring like that were very remote.
https://www.shorehamherald.co.uk/new...says-1-8824257

Incidentally, this also goes some way to answering Treble one’s question
Just as a matter of interest, did anyone ask in court when this CI started?
And if you want to deduce when Point X was, I suggest you look at Fig 11 of the AAIB report, and correlate it with Dr Jarvis’ trial evidence.

airsound

Last edited by airsound; 5th Jul 2020 at 13:03. Reason: fcatual correction
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Old 5th Jul 2020, 10:35
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Airsound

I know you know a lot more about the trial than I do so I have another question.

Were any of AH’s previous Hunter sorties examined in so much detail?

Is it possible that all the inexplicable errors on the accident sortie were actually the actions of an inexperienced and ‘maxed out’ pilot? Is it possible he had made similar mistakes before that were never caught?

I’m not here to put AH on trial again but, since you are in a position to answer questions, I thought you might help to assuage some of our concerns.

BV
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Old 5th Jul 2020, 12:33
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Originally Posted by airsound View Post
Dr Jarvis listed between eight and twelve inexplicable and unconnected errors made by AH. They all occurred in a period of 22-23 seconds. He said that the chances of so many independent errors occurring like that were very remote.
This is the particular piece of evidence that I and many other FJ pilots have a very great deal of difficulty in accepting. The sequence of errors is absolutely characteristic of someone who has gone off ‘the plan’, inadvertently or by design, and is devoting an increasing proportion of their mental capacity to getting back on ‘the plan’. All the time this is going on they are at increased risk of making further errors, some directly related and some not. This is not even something you need to be especially experienced to recognise: a first tourist ‘creamie’ QFI is expected to be able to diagnose it. It is just the sort of thing that happens (frequently) to student pilots - fortunately with the large safety margins applied to such flying. It’s also quite common in air combat, in which it can often readily be discerned from the other aircraft. Throttle mishandling (one of AH’s apparently ‘unlinked’ errors) is not unusual when struggling for capacity with attention mostly focussed outside the cockpit. Ask any Tornado back-seater how many times they had to chivvy their pilot to put the wings or manoeuvre flaps in a more suitable position while “dogfighting” - it is just these sort of things that get missed under stress by pilots of all experience levels. For a more accessible example, anyone who has taken music lessons will know how the tiny mental distraction created by one error can sometimes set off a chain of further random errors that ends with your learned routine breaking down entirely - that’s how I experienced it in cockpit, and as professional musicians do, you learn to recognise the mental signs and do something about it. But importantly you never become immune to it.

In the latter regard I struggled hugely with Dr Jarvis’s reference to AH’s level of experience as making such a sequence of errors a “very remote“ possibility. Setting aside the question of how much of his experience was relevant, it seemed to me to fly in the face of 40 years’-worth of progress in HF which has largely succeeded in persuading senior airline captains, 4000hr QWIs and consultant surgeons that they are far from infallible. If such individuals make fewer such sequences of errors it’s mainly because they’ve learned how to stop the initial (inevitable) error from cascading. There’s the rub: that a pilot as supposedly experienced as AH continued the display for so long while off ‘the plan’ is something that might easily have seen him convicted had Dr Jarvis’s “very remote” assessment been more effectively challenged to reduce the weight it lent the CI argument.

I accept that the case is done and AH has been given the benefit of the doubt to which he is entitled. But I am very interested to see how these matters will be handled at the inquest, by HF research and teaching and ultimately by regulatory systems in years to come.


Last edited by Easy Street; 5th Jul 2020 at 13:51.
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Old 5th Jul 2020, 13:08
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Were any of AH’s previous Hunter sorties examined in so much detail?
Yes. Three or four Hunter displays were shown in court, from a combination of internal and external videos. None of the errors was present in any of the displays.

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Old 5th Jul 2020, 13:43
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Airsound

Thanks for your reply. I suppose it was inevitable they would have looked at previous sorties.

I need to be careful I don’t sound like a stuck record (I’m sure I do already).

You’re absolutely correct that, having not been at the trial, I am not in possession of all the facts. I still cannot believe however that one bad sortie out of 4 or 5 from an ‘experienced’ pilot is definitive evidence of a medical event.

We’ve all had bad days in the cockpit. I would say, circumstantially, that those bad days are/were more prevalent during our earlier days on a particular type.

I would argue that few, if any, of those bad days could be attributed to an instance of oxygen starvation induced CI. But then, who knows? I’m not a doctor.

BV
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Old 5th Jul 2020, 16:22
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Originally Posted by LOMCEVAK View Post
A manoeuvre flown in a 200 engine Mark at full throttle should be capable of being flown in exactly the same way and from the same airspeed in an aircraft with a 100 series engine. If it cannot then, in my opinion, insufficient safety margin has been allowed.
Are you really saying that a jet being flown with 10,000 pounds of thrust, at full throttle, can be duplicated by a near identical aircraft using only its max thrust of 7,500 pounds of thrust. Example : pulling up for a loop at say 350 knots and 4 g.with 10 k of thrust will certainly not produce the same speed and dimensions when using only 7.5 k of thrust.

I have never flown a Hunter but the JP3 and 4 had similar thrust variations, 1750 and 2,500 pounds, simply no comparison, particularly in vertical manoeuvres. I find what you say hard to believe.. Perhaps you could explain and at least satisfy my curiosity.
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Old 5th Jul 2020, 16:33
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As I understand it before he started the maneuver he was well below the minimum height above ground specified in his authorization and in level 1G un-accelerated flight. How was this not a conscious choice made by the pilot ?
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Old 5th Jul 2020, 17:40
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Originally Posted by RetiredBA/BY View Post
Are you really saying that a jet being flown with 10,000 pounds of thrust, at full throttle, can be duplicated by a near identical aircraft using only its max thrust of 7,500 pounds of thrust. Example : pulling up for a loop at say 350 knots and 4 g.with 10 k of thrust will certainly not produce the same speed and dimensions when using only 7.5 k of thrust.

I have never flown a Hunter but the JP3 and 4 had similar thrust variations, 1750 and 2,500 pounds, simply no comparison, particularly in vertical manoeuvres. I find what you say hard to believe.. Perhaps you could explain and at least satisfy my curiosity.
For low level looping manoeuvres in a Hunter I entered with sufficient speed and used maximum thrust to exceed the gate height by a comfortable margin and to apex at a mid range speed. If I then flew a version with less thrust available I could either pull the same g and have a slightly lower apex height and lower apex airspeed or I could slacken the pull in the second quarter and make the same apex height with another airspeed reduction. Theoretically, I could enter with the higher thrust version at a lower IAS than I did and make a lower apex height and airspeed, and if I attempted the same pull up profile in a lower powered version the apex height and airspeed could be marginal for safety or even fail to make the Gate Height. However, I never entered loops in a Hunter with so little safety margin with respect to pull up airspeed or thrust; perhaps others did. The only exception to this was that for an upward half loop I was prepared to enter 20 KIAS slower in a large engine version than in a small engine one although with that amount of thrust I never really had to unless the cloudbase was marginal such that I needed an absolute minimum apex height.

With respect to pull-up heights, you can pull up for a loop from the flypast minima on your DA and AH was not below this although air display permissions will restrict the area where you can come below the SERA 500 ft minima. Obviously, if you pull up lower you need more speed to make the same apex height and airspeed.

The videos shown in court of other displays and practises by AH did not, as airsound has said, show any of the critical errors that occurred in the Shoreham accident display. However, they did show errors such as inadvertent airbrake out in the upward half of a loop, infringing display lines etc. As BV has said, we all make mistakes so everything needs to be put into context and in the case of this accident that is very complicated, and simple conclusions relating to potential CI on the accident display cannot, in my opinion, be made based upon the other videos.

The errors listed by Steve Jarvis also need to put into context. Some were errors of judgement such as the pull-up point for the manoeuvre, the angle rolled through etc. Again, these are errors that are easy to make in a display depending on the visual cues available to the pilot. Therefore, whilst there most certainly were some totally inexplicable errors made during this manoeuvre, some can be explained as known HF issues associated with display flying.

One aspect that has been commented upon very little is training related to displaying a Hunter. At the time of the accident CAP403 referred to training for 'escape manoeuvres' only as a ground training 'emergency' item. There was no requirement for a pilot to practise them during training for the award of a DA on a specific type or in a specific category, and no requirement to demonstrate proficiency in them as a requirement for the award of a DA. Unless specific training has been given regarding rolling a swept wing jet at low airspeed and then such a manoeuvre practised a pilot almost certainly would lack confidence in flying a rolling escape manoeuvre in a Hunter at 105 KIAS and, therefore, may be reluctant to do so. The AAIB report indicates clearly that a Hunter in the display configuration flown at Shoreham can be rolled safely at 80 KIAS so flying an escape manoeuvre at Shoreham was totally feasible. The report also indicates that it was possible to extend at least 4 seconds past the apex with a maximum instantaneous performance pull and then still perform a safe rolling escape manoeuvre.

With respect to Gate Heights and the requirement to respect them in looping a swept wing aircraft such as the Hunter, another essential aspect of initial display training for someone whose display experience is mainly on light aeroplanes for which a Gate Height protocol is not applicable for simple looping manoeuvres is to really emphasise this additional requirement and not to use established habit patterns from previous types.

Nothing that I have said above is new with respect to this tragic accident. However, I felt that, perhaps, it was worth refreshing upon some aspects.

Rgds
L
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Old 5th Jul 2020, 19:34
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Originally Posted by airsound View Post
. Three or four Hunter displays were shown in court, from a combination of internal and external videos. None of the errors was present in any of the displays.

airsound
I'm not a medical expert, but does this not suggest therefore that that particular display routine / aircraft physiological regime was not severe enough to cause AH an issue - under normal circumstances. Therefore, the issue is what made the Shoreham display different? Was it that AH's physiological tolerance was lower for reason or reasons unidentified or was it just a bad day in the office?

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