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Old 5th Jul 2020, 12:33
  #619 (permalink)  
Easy Street
 
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Originally Posted by airsound
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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