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Hawker Hunter Crash at Shoreham Airshow

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Hawker Hunter Crash at Shoreham Airshow

Old 25th Aug 2015, 15:40
  #361 (permalink)  
 
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Thanks Courtney. To be clear though, once you discount a bunch of causes you are left with just a few to decide between - I do think that the video provides enough to make some very clear deductions. I will not post the conclusions that I arrive at because I am conscious that they are then open to misquoting, or could be used maliciously - but over a beer among fellow-professional I think we could arrive at a 'most-likely' explanation already, notwithstanding some inevitable (but only contributory) unknowns. And we must, of course, consider all options, and not shy away from some just because we feel that it is an insult to us or our colleagues. We have similar experience btw.

Bottom line is that it is bloody awful. Per ardua.
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Old 25th Aug 2015, 15:57
  #362 (permalink)  
 
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There was a comment made about age and GLOC potential. In all of the aviation medicine research into g tolerance there is no indication that increasing age results in an increase in susceptibility to either loss of vision or loss of consciousness.

After some incorrect comments on the use of flap in the Hunter I think that most of them have been corrected. However, to summarise:

There are no g or rolling restrictions with flap selected. When any flap is lowered a nose down pitching moment occurs. The speed limit using up to 4 notches/38 deg of flap is 300 KIAS/0.9M. If 300 KIAS is exceeded the flaps start to blow up and no structural damage occurs. If 0.9M is exceeded (a high level problem only) the aerodynamic loads on the elevator exceeds the output force of the elevator hydrobooster and 'jack stalling' occurs such that the elevator cannot be deflected trailing edge up and so the aircraft continues to pitch nose down; the recovery is to select flaps up, idle and airbrake out. NB that the elevator (and ailerons) and not fully hydraulically powered but are manual controls with powerful hydraulic boosting.

Pitch control is via the elevator and pitch trimming is by deflection of an electrically driven all moving tailplane. When flap is lowered and the aircraft pitches nose it is countered by an aft stick/elevator input. This is often done whilst manoeuvring and therefore no trim input is made. Even in this case, so long as the IMN is less than 0.9 you will always reach the stall before full back stick and so this trim change never limits pitch control authority at low altitude.

As has been said, lowering flap increases drag which is why, in general, 2 notches are used when manoeuvring with flap. 3 or 4 notches give you an increase in lift/instantaneous turn performance but the advantage is outweighed by the increase in drag.

It is quite usual to use flap for some looping manoeuvres in Hunter displays and there are, quite justifiably, different techniques used by different pilots.
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Old 25th Aug 2015, 16:08
  #363 (permalink)  
 
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Wingswinger

This really is the most outstanding post and explains the problems faced by the pilot in very readable terms. It also seems to mirror the opinion of Winkle Brown regarding the accident.
Captain Hill is on the A320 aircraft flying mainly short haul, but as BA are short of pilots at the moment on the fleet, your comments re fatigue could be quite relevant.
I'm not sure if a previous post was an implied comment about Winkle Brown but in my aviation social circle, if he talks, people listen,
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Old 25th Aug 2015, 16:26
  #364 (permalink)  
 
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But, Robert F Jones, there is no evidence whatsoever for anyone to start writing or saying in public any personal evaluation about pilot error. winkle Brown and Leslie Hatcher should both no better than to make unprofessional, unsubstantiated accusations in public.
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Old 25th Aug 2015, 16:29
  #365 (permalink)  
 
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Capt Hill is on a 50% part time contract i.e. half a months flying.(40 hrs a month?)
Fatigue should not be a factor.
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Old 25th Aug 2015, 16:33
  #366 (permalink)  
 
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But, Robert F Jones, there is no evidence whatsoever for anyone to start writing or saying in public any personal evaluation about pilot error. winkle Brown and Leslie Hatcher should both no better than to make unprofessional, unsubstantiated accusations in public.
Thats not true, there is a lot of evidence. Without wishing to repeat some others who hold a similar view (see post 327). That guy knows what he is seeing as will many others. Its a badly executed figure and flown as such was always going to loose height if he continued to pull, which ultimately he does all the way to the buffet and subsequent stall.
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Old 25th Aug 2015, 16:44
  #367 (permalink)  
 
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Pittsextra,

Even if you accept the judgement of others who either saw the display or the video, they have no way of knowing whether Andy met his gates (which stand regardless of entry altitude), whether there was a technical issue with the aircraft or numerous other things that I really do not need to rehearse here all over again.

You simply do not know if Andy "poorly performed" the manoeuvre or whether there were any other factors. Without that knowledge neither you nor anyone else can attribute the accident to pilot error.

Utter, inappropriate supposition at this stage.
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Old 25th Aug 2015, 16:46
  #368 (permalink)  
 
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CM - absolutely correct, IMHO
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Old 25th Aug 2015, 16:54
  #369 (permalink)  
 
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I agree, Wander. Pittsextra is yet another armchair expert who is happy to make a completely unsupportable claim of pilot error with out any of the evidence that the investigation will reveal.

Pittsextra, instead of poorly performed by the pilot, have you considered the likes of control restriction, systems failure, pilot incapacitation (other than g-loc), disorientation or a dozen other possible factors that eye-witnesses and videos will not have shown? If not, you should before making inappropriate judgements about a man in a coma who is unable to respond to your accusations.
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Old 25th Aug 2015, 16:57
  #370 (permalink)  
 
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CM - you are absolutely right we do not know what other factors may be involved and whilst data will be available to the relevant authorities I don't know his planned sequence etc. So I agree that and agree it isn't fair therefore to say the cause of the crash.

That said you can the 1/4 clover was poor however. We can see that with our eyes, OK we might not have in in super quality HD from Planes TV feed or whatever but you can see things as clearly as is needed.

Now i'd agree with you once again that it isn't known if Andy "poorly performed", but that isn't what I said. I said the figure was poorly flown, if there are other factors at play we do not know at this stage but the people looking at 1/10th's of seconds before impact are looking in the wrong place. The issue to this started way before then.
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Old 25th Aug 2015, 17:03
  #371 (permalink)  
 
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Pittsextra is yet another armchair expert who is happy to make a completely unsupportable claim of pilot error with out any of the evidence that the investigation will reveal.

Pittsextra, instead of poorly performed by the pilot, have you considered the likes of control restriction, systems failure, pilot incapacitation (other than g-loc), disorientation or a dozen other possible factors that eye-witnesses and videos will not have shown? If not, you should before making inappropriate judgements about a man in a coma who is unable to respond to your accusations.
You are unable to read my post on this. I said there was plenty of evidence available via the video and that (quoting myself) " Its a badly executed figure" - which it was. As I have added in the second post perhaps there were other factors which caused this to be so? Perhaps.

You are quite wrong however to suggest that questions around the way the machine was flown are not "inappropriate" given the history of display pilots and this type of crash, its claimed many before.
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Old 25th Aug 2015, 17:04
  #372 (permalink)  
 
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And, again, nobody can say why. And that is why nobody can start making wild accusations about pilot error.

One last thought. Has anyone here even seen Andy's display plan? Does anyone know what manoeuvre he was supposed to be performing. I know what we think it was, but who knows for sure and who knows what may have happened during the manoeuvre? More supposition.

Oh, and one more thing. Any unproven accusation about pilot error is always inappropriate. In this case based purely on the supposed expert opinion of someone else without all the facts available - That, by the way, is pretty much everybody at the moment.
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Old 25th Aug 2015, 17:11
  #373 (permalink)  
 
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And, again, nobody can say why. And that is why nobody can start making wild accusations about pilot error.
CM - Given what we can see in the video whilst there maybe other factor it is a million miles away from WILD accusation. And again I didn't say it was pilot error, I said it was poorly flown (as you say perhaps there are other factors but the pilot is at least one of them). I respect your posts and views and so I'll leave it there.
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Old 25th Aug 2015, 17:13
  #374 (permalink)  
 
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Looping

Whatever the reasons, in laymans terms "insufficient altitude to complete a loop" has been seen so many times on so many types.

Is it time to re-consider whether this move (and similar ones) are inherently risky, perhaps a bit too risky?

What are the actual margins here? Even if you make your gate at the top - what margins exist for a technical issue or even just a control error in the 3rd quarter of the move?

It seems the speeds and energies at play here leave very very little room for error when performed close to the ground. Perhaps it is these moves and their inherent danger that need to be under the microscope, rather than the type or pilot experience.

The reds do it regularly of course without it seems difficulty, however I recall the thunderbirds had a terrible multi fatal accident from a loop. From the wiki it seems this was a technical issue (rear stab jammed) though I find it slightly odd all the video evidence was destroyed - a different time/culture perhaps.

https://en.wikipedia.org/wiki/1982_T..._Diamond_Crash
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Old 25th Aug 2015, 17:18
  #375 (permalink)  
 
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@Courtney Mil

This is a copy of Chris Heames' hunter display routine taken from classicjets.co.uk which curiously is now seemingly non functional so the below has been lifted from google's cache of the page a week ago.
POSSIBLY it might be the same as the one of Andy's at Shoreham - or it might not.

Chris Heames Hunter display routine.
B Axis run in,
Clover to A Axis,
Derry wing over,
Barrel Roll,
Cuban,
4 point roll,
Max rate turn,
Derry to A axis,
Wing over,
Slow roll,
Reverse Cuban (lazy),
Canadian break to land.
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Old 25th Aug 2015, 17:22
  #376 (permalink)  
 
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Thank you, DSC.

Quite a lot of stuff with connections to this are suddenly deleted.
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Old 25th Aug 2015, 17:23
  #377 (permalink)  
 
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The T7

As an ex engineer with somewhat limited servicing experience (RAF) on various Mk's of hunter and seeing the remains being lifted on to transporters did it not look as though the rear section (tail unit) broke away at the transportation /engine removal/fit break point, if so always thought with the ring of bolts that it was a major strong point of the fuselage, not speculating on any cause just would like opinions, rgds, PH.
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Old 25th Aug 2015, 17:35
  #378 (permalink)  
 
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Experience on manual reversion requested

Jazbag made a post on the R&N forums about Hunter manual reversion. He is interested in others who experienced the same malfunction.
During one of my flights on the Hawker Hunter I had a manual reversion of the controls. One of the two switches in front console just tripped off. This was due to a momentary drop in hydraulic pressure ...

I was wondering how and when this could be linked up to this accident. If anyone else has had such an incident please do post your experience.
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Old 25th Aug 2015, 18:42
  #379 (permalink)  
 
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The Hunter's hyd pump wasn't capable of maintaining pressure to the hydroboosters if other services were operated at the same time at low throttle angles. So idle thrust, airbrake in and landing gear down at the same time when rolling out downwind off the break would invariably cause manual reversion until the airbrake and landing gear had completed their operation.

VERY unusual for a 'momentary drop in hydraulic pressure' for any other reason, apart from inadequate maintenance, possibly?
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Old 25th Aug 2015, 18:55
  #380 (permalink)  
 
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JFZ has hit the nail on the head with his comments, such as the aircraft ran out of height, was the display to risky and what were the margins.

For those professional pilot's on here, we all know about factoring in margins for take off and landing performance (1.33/1.43). There are number distractions which can happen at critical moments during displays, such as bird strikes, loose items, sun in your eyes, malfunctions and of course an engine malfunction.

In the case of the later, whether a total or partial loss of power, would it no be reasonable to always have the energy to position the aircraft away from congested area? I'm really not sure what the display philosophy is here.

Regarding the other post regarding 'pilot error', this is an outdated term used by the media, the preferred term is human error, as no one factor in isolation causes an accident. As as we may find that the humans responsible for display authorisation may be one of the factors in this accident. I think a review in display authorisation was well overdue, the argument that there hasn't been a display accident involving civilians for 63 years is flawed statistically.

I can think of two well documented fatal air accidents in the UK, a B737-400 in the 80's and Viscount in the 90's where the FOI (CAA Flight Operations Inspector) were identified by the AAIB as one of the causal factors.

I think I'm right in thinking that the FOI, in the aftermath of the B737-400 accident was redeployed by the CAA to be a CAAFU Examiner and ironically then she became a CRMI Examiner!

Last edited by athonite; 25th Aug 2015 at 19:22.
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