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Air Asia Indonesia Lost Contact from Surabaya to Singapore

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Air Asia Indonesia Lost Contact from Surabaya to Singapore

Old 14th Jan 2015, 12:59
  #2001 (permalink)  
 
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Originally Posted by Owain Glyndwr View Post
@zzuf


OK, I guess I misread your intent. You obviously meant others than Gysbreght!. I spent some time with Nick also.
Funny my recollection was, despite the time stamps, Gysbreght's post was not on my browser when I selected reply. So, yes, lots of others!
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Old 14th Jan 2015, 13:06
  #2002 (permalink)  
 
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Nigel, sorry, the point I was trying to make as simply that those undertaking that type of flight were not properly prepared, briefed or understanding the consequences of what they were doing, which is something for which I agree they must bear responsibility.
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Old 14th Jan 2015, 13:14
  #2003 (permalink)  
 
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An interesting discussion would be how deep into the stall one ends up during power on, 3kts/per second
That will definitively be individual for every aircraft, and even depending on actual weight (the lighter you are, the steeper you climb and the longer the nose needs to come down). It also depends on how quickly you reduce thrust, which may significantly help to get the nose down quickly.
CS-25:
Following the stall, engine thrust may be used as desired to expedite the recovery.
It also very much depends on how and when you would define the airplane to be stalled.
(3) As soon as the aeroplane is stalled, recover by normal recovery techniques.
(d) The aeroplane is considered stalled when the behaviour of the aeroplane gives the pilot a clear and distinctive indication of an acceptable nature that the aeroplane is stalled.
(See AMC 25.201 (d).)
Acceptable indications of a stall, occurring either individually or in combination, are –
(1) A nose-down pitch that cannot be readily arrested;
(2) Buffeting, of a magnitude and severity that is a strong and effective deterrent to further speed reduction; or
(3) The pitch control reaches the aft stop and no further increase in pitch attitude occurs when the control is held full aft for a short time before recovery is initiated.
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Old 14th Jan 2015, 14:07
  #2004 (permalink)  
 
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Dismantling techniques

I presume that the investigators have authorised the somewhat barbarous dismantling that is shown in the pictures.

The assumption must be that they do not expect to learn a great deal from the wreckage. ie they already have a pretty clear idea of the cause of the incident.
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Old 14th Jan 2015, 14:10
  #2005 (permalink)  
 
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Originally Posted by oblivia View Post
The constant reference to "beancounters" as a threat to airline safety is a bit fanciful. It's not the accountants' fault if safety standards are insufficient.

If there are failings (the evidence isn't convincing) then the problem is regulation and enforcement. From food to finance, we have seen constant pressure on funding to regulators during the past few decades (not to mention the busting of unions). It wasn't beancounters who did this — it was right-wing ideologues.
A more apt user name there isn't. Ian W's response hopefully shed some light. In a competitive industry, and an industry wherein to remain in service one must earn revenue in excess of expenses or not exist, the cost of everything matters. Therefore, the bean counters are directed to analyze cost. The problem is for beancounters, not everthing pertaining to safe and effective ops can be numerically quantified to three decimal places. Sadly, between management and number crunches, that leaves Safety Critical issues like training underfunded and under-resourced. Politics have nothing to do with it. Your point on regulation being lax also is a matter of cost, in terms of how many tax dollars are allocated to that function. That's another group of bean counters at work, right?

Last edited by Lonewolf_50; 14th Jan 2015 at 14:22.
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Old 14th Jan 2015, 14:17
  #2006 (permalink)  
 
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I presume that the investigators have authorised the somewhat barbarous dismantling that is shown in the pictures.

The assumption must be that they do not expect to learn a great deal from the wreckage. ie they already have a pretty clear idea of the cause of the incident.
I'm surprised to see this dismembering too. It looks more like disposal than careful dismantling.

A previous poster mentioned that Airbus had advised on the breaking up of the tail section, and I believe this was before the DFDR was found. So I think they decided on the sawing-up before they had any other evidence. Why would this be?
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Old 14th Jan 2015, 14:24
  #2007 (permalink)  
 
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they decided on the sawing-up before they had any other evidence. Why would this be?

It could be that Airbus has been passed information that has not yet been (and may never be) released to the media. That's not a conspiracy, that's normal.
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Old 14th Jan 2015, 14:27
  #2008 (permalink)  
 
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Question Chains?

Look further on the tail pic to the left of the guy with no crowbar is - looks like a chain in that crease from the "balloon" that raised the tail - if you zoom/enhance?

Last edited by justforfun; 14th Jan 2015 at 15:04.
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Old 14th Jan 2015, 14:27
  #2009 (permalink)  
 
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After MH370 I think everyone is looking for a mystery... This looks to be straightforward with little room for conspiracy theories.
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Old 14th Jan 2015, 14:49
  #2010 (permalink)  
 
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This Getty Images photo shows a torch being used... An Indonesian worker cuts the tail of the AirAsia flight QZ8501 in... News Photo 461419122 | Getty Images
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Old 14th Jan 2015, 15:01
  #2011 (permalink)  
 
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Thanks

Ok, thanks. - missed that.

Bit worrying having some guy using a cutting torch to chop it up without - from the pics apparently - nobody in authority guiding/controlling him.

Anyway, fuselage found so hopefully some closure for the relatives on the way.
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Old 14th Jan 2015, 15:31
  #2012 (permalink)  
 
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Nigel, sorry, the point I was trying to make as simply that those undertaking that type of flight were not properly prepared, briefed or understanding the consequences of what they were doing, which is something for which I agree they must bear responsibility.
Agreed I had recently done my "CAA Check Pilot" (post-maintenance Test Pilot) on ex-Mil jets, and learned a lot re the approach, attitude and philosophy such testing needed. Perpignan then happened, and everything that (ex-)CAA & RAF TP rang ominously true.
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Old 14th Jan 2015, 17:00
  #2013 (permalink)  
 
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To justforfun, mudman

On the previous page, number 101, are posted results of photos I got last night. And can add that there are many more photos today. The mr 1 in my post is the same as mr 4 by the way.

Bit worrying having some guy using a cutting torch to chop it up without - from the pics apparently - nobody in authority guiding/controlling him.
On the first photos that you find (Google) you do not see a supervisor. I had the same question that you had. Later I found the mr 1 photo, which shows a person who appears to be supervising closely. In other photos he may stand behind the wreckage. Hope this helps.

Would be interesting to know why they cut it this way, and why in this manner. Hope to find an answer in the Prelim or Final Report.

Also note that the 'strip with windows' that I mentioned in my post on 101, was mangled further when they pulled the tail wreckage onboard the Crest Onyx. Was searching for photos that show this, and there are a few.
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Old 14th Jan 2015, 17:20
  #2014 (permalink)  
 
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On the structure found ...

I twice posted a scenario that could explain a number of questions that I had about the finds and their sequence. Both times they were rejected. So I won't post the sequence again.

Starting point was an earlier post which was accepted though. In which it looks like a 'giant hand' grabbing the horizontal stabilizer and rotating it.

In the scenario referred to, one sequence might lead to opening up the pressure bulkhead. Leading to a sequence of failures, and in line with that a sequence of specific finds.

I have not had time to think about what kind of aerodynamic forces would shape this 'hand'. Perhaps another poster would be able to shed some light on that. If not, then we would have to change over to hydrodynamic forces, and that would steer the scenario in another direction.

And perhaps there is somebody who has an idea about what kind of forces would be required for such an 'opening up', scenario. Is it realistic with a THS span of 12.45m. You can mail that to me if you dont want to post it.

It is not possible to collect and analyze and make aerodyn/hydrodyn and stress/strength calculations at the same time ...

Last edited by A0283; 14th Jan 2015 at 19:20.
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Old 14th Jan 2015, 17:28
  #2015 (permalink)  
 
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Originally Posted by A0283 View Post
I have not had time to think about what kind of aerodynamic forces would shape this 'hand'.
For my money, your second point on "hydrodymanic forces" is a good avenue of inquiry.
Such a twisting might be the result of a rotating body not hitting the water's surface in a more or less "flat" attitude (as did AF 447) but rather in a more or less "tilted" attitude.
It might not need to rotating to get a tear like that if it has sufficient ground speed and tilt, depending on the vertical velocity at impact as compared to lateral / horizontal velocity.
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Old 14th Jan 2015, 17:40
  #2016 (permalink)  
 
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Feedback to Lonewolf

For my money, your second point on "hydrodymanic forces" is a good avenue of inquiry. Such a twisting might be the result of a rotating body not hitting the surface in a more or less "flat" attitude (as did AF 447) but rather in a more or less "tilted" attitude - and it might not need to be rotating if it has sufficient ground speed vector to create torsion/shear.
Lonewolf, I started out with the aerodynamic. Then considered the hydrodynamic. But today officials stated that tail and FDR/CVR were 800 m apart, and tail and main fuselage plus wings 2,000 m. That increased the probability on the side of the aerodynamic. Also, because the vertical stabilizer still looked pretty smooth.

The damage to the lower side of the rudder area, that looks a bit like that on (high speed) AF447. Which puts another grain of salt on the aerodyn scale. Don't you think?

Last edited by A0283; 14th Jan 2015 at 17:52. Reason: add ?
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Old 14th Jan 2015, 17:41
  #2017 (permalink)  
 
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Surely how it hit the water, and what caused the damage seen is really of little matter.

It may or may not indicate if there was any control at the time it hit the water, but again, that won't help find the cause.

What is needed is the reason that caused the loss of control (not pointing to pilot involvement or not) at some 30k feet above the damage being looked at.

Maybe this is why they are not too worried about the "hacking up" of the wreckage?
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Old 14th Jan 2015, 17:42
  #2018 (permalink)  
 
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Having done a high-altitude stalling module recently, I thought it was of great benefit despite the caveat that the aerodynamic simulation might not be exact.

It showed:

a) You had to agressively reduce the AoA by pitching down to a far greater degree than in any other flight phase.

b) The engines were next to useless, given spool-up times and the thrust generated near the aircraft ceiling, so it was more a glider-style recovery.

c) You were going to lose a LOT of altitude, no matter what.

d) If you tried to level out too early, before getting to c), it was quite possible to stall again.

I would argue that the fidelity of the simulator was unimportant in getting those basic principles across. After all, every LoC / jet upset is different, especially if it has been in part caused by something malfunctioning, be it software, hardware or wetware.
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Old 14th Jan 2015, 17:48
  #2019 (permalink)  
 
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@A0283:
I see your points. Just a thought: once things fell apart, the movement of the water and "how long a given bit floats" may offer sufficient explanation for how the dispersal came about. Or not.
You are more likely right in your estimates, as you've examined it in more detail.
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Old 14th Jan 2015, 18:05
  #2020 (permalink)  
 
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That is a great deal more intact than I thought it would be. I expected component parts.
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