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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 26th Jan 2015, 05:49
  #2541 (permalink)  
 
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Not happening for the moment

Looks like the weather abruptly changed so attempt to raise the fuselage has been put on hold. Don't know if it will resume today.
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Old 26th Jan 2015, 06:20
  #2542 (permalink)  
 
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to bob1vt

He believes that there is a combination of circuit breakers that can be pulled to shut down enough computers to force Direct Law. He also thinks there is a document in the cockpit that describes how to do this, and given a few minutes, he could make it happen
It is no circuit breaker, but you need to push three of five buttons on the overhead panel for the Flight Control Computers (2 of 3 prims and one of 2 secs).
As you rightfully point out: A task not suitable for sudden extreme emergency situations.
Boeings FBW can be overridden (some sort of direct law) by applying force on the yoke. The Primary Flight Computer will then be bypassed and the signal directly sent to the Actuator Computers.
This is well suited for such situations and is one of the main criticism i voiced, mainly by asking for a "red" or "hot" button on the Airbus-stick to get to Direct Law in adequate time.

to Machinbird

If a properly experienced pilot was hand flying in direct law, at the time of the problem, alert and hooked up, would he stand a better chance of maintaining or re-gaining control than the electronics (purposely broad) ?
Most certainly. Today most training departments and the manufacturers suggest in extreme upsets to initially steer between 0 and 2 degrees nose up and some 80% of N1.
This is however only possible IF the system allows the pilot to do so.
The main difference between the two philosophies is that Airbus will only do give you this full authority (when the protections feel otherwise) when in Direct Law. This state is however rarely automatically achieved when in extreme upsets and to achieve it: See above.
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Old 26th Jan 2015, 07:04
  #2543 (permalink)  
 
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recovery from extreme situations

Last week I expressed my humble opinion about the "inability" of professional pilots flying advanced aircraft (Bus/ Boeing) to recover from a stall or spin... And I did not mean you were to silly to do it!!! I still have the greatest respect for you.
I got serious beating by a few guys here and; accused of having no idea what I am talking about and the mods taking my posts offline... It is correct, I had no idea that the advanced a/c can basically not be recovered; and that surprised and worried me a lot. Now, a few days later, the same professionals debate about how this should be possible, should be trained, etc. You even add another perspective, that an airbus can't be hand flown in an instant (when the pilot decides to), but requires quite extensive elaboration and switches..., something impossible in an emergency situation.
Previous "professional" statements like "better don't get into such situation" or "I know how to avoid a stall" or "the aircraft can't stall" are all very obviously incorrect. Both AF and Air Asia crashes involved a stall...
"Happy" at least that my "PPL view" of last week is now shared by a lot of professional drivers as well...
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Old 26th Jan 2015, 07:18
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A friend of mine suggested this is might be a partial repeat of the XL888T crash at Perpignan. Not the flight testing part obviously, but that part where water gets into the angle of attack sensors, freezes them in place, so computers think the plane is descending and command an ever increasing pitch up untill it stalled out and plummeted toward the water.

Not being technically minded, I thought I'd throw it out there to you wolves to tear apart.
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Old 26th Jan 2015, 08:10
  #2545 (permalink)  
 
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I see no reasonable way the fuselage could have been raised
It could have been easily done with a large crawler crane mounted on a large barge, and using a "spreader bar" with multiple slings.
I feel the Indonesians are seriously lacking in technical skills and knowledge in this area, or they have simply not canvassed the available options - by way of people with appropriate knowledge, and by way of local companies who possess such equipment - for effective recovery of the likes of the fuselage and wings.

The attempts to drag aircraft components bodily from the water using winches, a la fishing nets, is doing nothing to promote their desired image of competence in recovery techniques.
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Old 26th Jan 2015, 08:53
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Gigi Cocok 100 Persen, Dua Korban AirAsia Dikenali | -nasional- | Tempo.co

...sorry not in English...but you can decipher quite a bit via the numbers...

...and regarding the rescue effort...the Indonesian SAR...are in no way shape or form trained professionals...nowhere near western standards are used...and likely for most involved here...this is their first kick at a major accident and they're learning on the go - it is what it is...welcome to Asia and the way things get done.
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Old 26th Jan 2015, 09:25
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I take it the artistry is exaggerated as from the condition of the radome the aircraft either did not hit the water nose first - or for some reason it separated before impact.
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Old 26th Jan 2015, 09:39
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Leightman957 said "
The largely intact wings really present a puzzle. When we think of wings being pulled off by aerodynamic loads, and how relatively easy that is... "

What makes you say that... how many instances are there of that from
aerodynamic loads alone these days?
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Old 26th Jan 2015, 09:55
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The largely intact wings really present a puzzle. When we think of wings being pulled off by aerodynamic loads, and how relatively easy that is... "
The wing to wing spar /body joint is the strongest part of the aircraft (often called the wing box). It has to lift the entire weight of the aircraft plus maneuvering forces of up to 6 times that weight.

It will be the last thing to break. You will see the fuselage fall off and the wing ends fall off before any break in that part.
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Old 26th Jan 2015, 10:52
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It could have been easily done with a large crawler crane mounted on a large barge, and using a "spreader bar" with multiple slings.
I feel the Indonesians are seriously lacking in technical skills and knowledge in this area, or they have simply not canvassed the available options - by way of people with appropriate knowledge, and by way of local companies who possess such equipment - for effective recovery of the likes of the fuselage and wings.

The attempts to drag aircraft components bodily from the water using winches, a la fishing nets, is doing nothing to promote their desired image of competence in recovery techniques.
Indonesia has plenty of capacity in this area. It has a sizeable offshore oil and gas industry and salvage operators would not be ignorant to salvage techniques. It's much more likely to be an issue of access to resources. Do people think the kind of specialised resources suitable to this type of offshore salvage are just waiting around in close proximity on call to respond to this kind of event? it can take weeks to mobilise specialist resources,which more than likely will already be tied up in current and planned commercial operations.

There has to be a weighing up of costs and benefits and availability of resources. And maintaining current morphology is not actually essential for incident investigation.

Most of you are living in some kind of fantasy land. Sad, traumatic and important as this is, it's not something the world stops for.
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Old 26th Jan 2015, 11:17
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Bahasa

Kaki = feet
Menit = minute

Basically started at 32k kaki. Started climbing 400, the 1400, until hit 11000 fpm. Max height 37k something feet.

Then fell

All based on radar observation I believe
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Old 26th Jan 2015, 12:38
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Originally Posted by onetrack
...spreader bar...
yes, exactly, that was omitted in the example i mentioned and presumably missed here

anyone who doesn't recognise the term should not be involved
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Old 26th Jan 2015, 12:43
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Indonesia has plenty of capacity in this area.
Mmm we are talking Indonesia here.. All other countries in the region I would agree but this is the country with the biggest `we know best` chip on the shoulders... In other words politics and ego´s over best practice is not uncommon. I have not been on the site and know NOTHING about salvage so I refrain from commenting on this case in particular but having worked in the region a lot I was not surprised with any screw up like this
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Old 26th Jan 2015, 12:45
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Artistic Licence or ?

I am a little confused by Blankbox's post ( the graphic therein). As far as I knew 8501 had requested a weather diversion to port which was initiated some time before experiencing the zoom climb. As far as I knew, the attitude of the A/C was still in left bank ( or some facsimile) until reaching apogee. Am I wrong ? The graphic shows a turn to starboard, before the zoom and that is news to me. Anyone ? .
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Old 26th Jan 2015, 13:18
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Global

The Indonesians have a large offshore oil & gas sector that works subsea all the time - they probably know as much about it as anyone else and the kit they've deployed looks better than most countries could come up with
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Old 26th Jan 2015, 13:52
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The pictures of the radome show some marks & evidence that lightening strike & radome separation shouldn't be discounted.....if it had indeed been blown off by such a strike it would have had an interesting disruptive affect too on the sensors that measure AOA & pitot static pressures ...

Lightening in this region is some of the strongest I have ever seen.

Last edited by ramble on; 26th Jan 2015 at 20:37.
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Old 26th Jan 2015, 14:19
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Here's a video of divers getting right up close to the fuselage. You can get an appreciation of how difficult it is for the recovery team to enter the fuselage and search for bodies given the poor visibility and limited sunlight reaching down to that depth. On top of that, you have a tangled web of wreckage, metal fragments, cables and wires to deal with. The footage also shows what appears to be the top of the left wing (with spoiler still deflected up) where the over wing emergency exits are.

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Old 26th Jan 2015, 14:26
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The Radome also has a split at the very front, which could have let air pressure build up inside the dome... just a few psi over pressure could cause it to pop its rivets.
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Old 26th Jan 2015, 14:45
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Question WINGS OFF ??

LEIGHTMAN TODAY @ 15:50 SAID " When we think of wings being pulled off by aerodynamic loads, and how relatively easy that is,'

Relatively easy ?? Suggest you review your comment- its not easy with a maintained airplane. As to surviving water impact, the load direction with forward motion is mostly fore to aft- sort of like a water ski. The engines come off probably at the pylons which leaves the inboard mostly intact as shown.
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Old 26th Jan 2015, 14:51
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RE video in #2575

The wing spoilers appear to be deployed. Would deployed spoilers remain up after the aircraft coming apart like this? Or are they just floating freely, as their is no pressure in the hydraulic lines?
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