Air Asia Indonesia Lost Contact from Surabaya to Singapore

[NigelOnDraft]

capt log

NB for Perpignan, the BEA said:This absence de
reference to the use of the trim is also mentioned in AAIB report into a serious
incident to a Boeing 737 on 23 September 2007(59).In short, any pilot, with full power, full forward stick yet nose high and getting higher should not need (and will not notice) a small "Use Man Pitch Trim" message. They should be trained to know that Pitch Trim may be needed, but in both cases, IIRC, the Pitch Trim was not the whole issue, but the high power as well?

It certainly didn't help 2 very respectable pilots on D-AXLA A320-232 over Perpignan when THS stayed nose up, with the combination of the AOA sensors freezing and normal law dropping out they were unable to save it with the above aforementioned method. After reading the report, i was worried by the lack of notification to the pilots, in that moment id expect 'USE MAN PITCH TRIM' to be slapping me round the face. We do need to remember they ignored numerous signs that the AoAs were incorrect, they failed to follow every safety procedure in the test they were doing. I am afraid there gets a point when the crew have to be "accountable" (even if it their training or management the ultimate cause), rather than just blaming the systems / manufacturers because their aircraft are not "uncrashable" :ugh:

[Owain Glyndwr]

@zzuf


OK, I guess I misread your intent. You obviously meant others than Gysbreght!. I spent some time with Nick also.

[Jwscud]

Nigel, that flight amongst other incidents and accidents (the upset to G-EZJK comes to mind) was why the procedures, discipline and training requirements for post-maintenance check flights have been substantially changed.

[A0283]

It looks like someone has taken a welding torch to it. One wonders also what exactly the guy with the huge crowbar is hoping to achieve.


After the fuselage was lifted from Crest Onyx to shore, at some stage, there was a guy using a torch. He was cutting at at least two places.

Have not seen that before. Will be clear though during reassembly that it was not from the crash.



Picture 1 -Torch is handled by a man with a medium dark blue shirt with logo “ST” on it. He is closely observed by another man in civvies (@ I found later that this man is from KNKT). Cutting is vertical on the side of the first frame between the last window and the lavatory section, on the'inside' of the lavatory section.

Picture 2 –Cutting itself not observed. But ashore, 10 guys putting the structure up, you can see a very long horizontal scorch mark. Running from the door to the fuselage painted word “Fly”. Part that was cut away was a strip with 5 windows and PK-AXC registration letters. That part was still there in daylight when Crest Onyx was already in Kumai port in daylight. That same (lefthand aft part of fuselage – watch out, it is lying upside down) strip was hinged about 135 degrees outside when still on deck.

Picture 3 –The man with the long crowbar. You can see torch marks on the longitudinal stiffener just below his torso.

Picture 4 –The man making the vertical cut, view from outside, ... have seen the picture.. (@ later -same torch operator as in Picture 1)

[A0283]

I found one good picture of the QZ8501 CVR after recovery.

Cockpit Voice Recorder = Model FA2100, L3communications
CVR carried Emergency Locating Beacon = TELEDYNE BENTHOS

Other CVR configuration information like serial, manufacturing number, and HW and SW config nrs were clear for parts. I wait till I get a better picture before posting that.

[NigelOnDraft]

Nigel, that flight amongst other incidents and accidents (the upset to G-EZJK comes to mind) was why the procedures, discipline and training requirements for post-maintenance check flights have been substantially changedAppreciated, but I do not understand the point?

Any pilot conducting any test flight should be aware of some basic principles, well documented well before this accident, and probably before WW2. There is no point in testing something if you are betting your life on the test succeeding? Surely you test "High AoA protection" on the assumption it might not work?

As the BEA report stated, another crew had done a similar profile and:During take-off, a series of messages appeared on the ECAM and the aeroplane switched to alternate law. The CHECK GW message appeared on the MCDU. The crew decided not to continue the flight, which had lasted thirty-six minutes. and next flight:The programme available to the crew indicated, for this weight and in clean configuration, a V alpha prot of 171 kt (+/- 4 kt) and a V alpha max of 152 kt (+/- 4 kt). The PF placed the thrust controls in the IDLE position while keeping one hand on the trim wheel. The crew noted the absence of autotrim shut-off and decided to continue verification. The alpha floor function was not activated. The PF noticed that the speed was ten knots less than expected V alpha max. The crew felt the aeroplane sinking and the Captain decided to stop the check. The PF carried out a manoeuvre similar to a stall recovery. There was no stall warning.Somewhat nearer ideal :ok:

[zzuf]

@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!

[Jwscud]

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.

[Volume]

An interesting discussion would be how deep into the stall one ends up during power on, 3kts/per secondThat 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.

[wheelsright]

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.

[Lonewolf_50]

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?

[AirScotia]

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?

[oldchina]

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.

[justforfun]

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?

[wheelsright]

After MH370 I think everyone is looking for a mystery... This looks to be straightforward with little room for conspiracy theories.

[Mudman]

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 (http://www.gettyimages.ca/detail/news-photo/an-indonesian-worker-cuts-the-tail-of-the-airasia-flight-news-photo/461419122)

[justforfun]

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.

[NigelOnDraft]

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 :ok: 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.

[A0283]

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.

[A0283]

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 ...

[Lonewolf_50]

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.

[A0283]

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?

[Msunduzi]

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?

[FullWings]

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.

[Lonewolf_50]

@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.

[JamesT73J]

That is a great deal more intact than I thought it would be. I expected component parts.

[AirScotia]

No sign yet of front part of fuselage, ie cockpit?

[HarryMann]

Let's face it... hydrodynamic forces would be capable of anything
imaginable and unimaginable entering water at speeds from 100 kts
upwards. Including twisting and if the tail struck first, tearing it off.
lets see

[A0283]

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?


My impression is that 'losing control at high altitude' would happen more often (probability wise and statistically), than things getting 'out of control' ( either by weather events (that's one reason why we have pilots who can put things right), or SA loss leading to a flip like the 747 years ago (where the pilot provided both cause and solution, albeit after a significant drop) ). If that is so, then you would have to divide the flight path in altitude steps, call it a 'ladder'. And ask for each step of the ladder what happens, and what the pilots' options are. Like posters do in the interesting stall discussions here. And that also includes the final splash. The whole plane hitting the water or large separate sections ... that points to different possible causes. Which you test by going up the ladder again. Both top and bottom of the ladder are relevant for 'solving' this accident.

On hacking up. Nobody knows what the cause was. Real hacking up would not start until after reading and analyzing the recorders and the investigation being further along the line. The only reason for hacking up now would be transportation requirements (bridges, roadwidth ..etc ... the diameter of the fuselage is 4.14 m ... one lane on western highways is something like 3 m...isn't it?)

[snowfalcon2]

Maybe this is why they are not too worried about the "hacking up" of the wreckage?

I tend to agree. Before the tail was recovered, there was an official statement that the rescuers first priority was finding the casualties, the second was the black boxes.

The main interest in the wreckage, as reported, was about the position of the control surfaces (or "tail flaps" as it was reported) which could give valuable information about the airplane's last flying moments. Based on that information, the interesting pieces would IMHO be the actuators and the THS jackscrew.

Presumably the rescuers also took enough underwater photos and videos to enable them to establish the pre-recovery condition of the wreckage. I'd assume that to be standard practice in this kind of salvage jobs.

[A0283]

@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.

At first thought. There might be two 'theoretical reasons' that could explain the 2,000 m. First floating, and second forward speed. But both start with hitting the water and losing the THS and the bottom of the tail with the APU.

On the first, floating. So you have an open tube ... which if it fills, will fill quickly ... if not, the plane might be weighed nose down and keep the open end up for a while (until the swell flows in) and might float around a bit ... at the 1-2 knots published current that distance would take roughly 30 minutes to 60 minutes.

On the second. The forward speed would combine losing the tail followed by skimming over the surface like a flat stone. At say 60-120 knots that would be roughly 2,000 m in roughly 0.6-1.2 min. The impression is that the plane went up and down quite vertical (not far from LKP) and pretty fast. So, that seems to be less probable.... In spite of the fact that the lower aft section may still have been attached (as mentioned, the aft top panel stayed connected to the tail/rudder section).

What it does not explain is the apparent stripping of most interior components..... Which gives a bit more probability on the side of a higher speed and above break up. Also, skimming has lower probability, when reviewing earlier widebody waterlandings.

Theory and practice can be quite different of course. But it gives some idea I guess. And no more than 'some' idea ... at this stage and with the publicly available information.

[rog747]

the wreckage looks very much less fragmented then i/we were expecting

reminds me of 2 tridents that went down with little or no forward speed

PI and ZT both had wreckage/fuselage compacting that looked somewhat like this with wings attached

[glendalegoon]

someone mentioned clearing the BEANCOUNTERS from responsibility, blaming instead a lack of required standards

SO


Back in the beginning, there were no standards and we learned the hard way what had to be done to keep things safe and assure passengers there was as good a chance to get from A to B on an airliner as on a train, ship, car, or horse.

And they did it.

And then the regulators codified many of those same things.

BUT THEN came the cheapos. IF THE FAA or over seas version hasn't mandated it, then WE DON'T HAVE TO DO IT and can save money.

THE OLD GUYS shook their heads...they knew better. We are learning the same things over and over again that we knew 40 years ago.

all at the cost of passengers and crew.


So it is beancounters, because they have an excuse, an ENABLER in local regs that aren't as tight as a drum.

[Boomtown]

Given the remarkable condition of the fuselage, an attempted but unsuccessful "controlled" ditch in gale conditions?

[Chronus]

There has been some discussion on hydrodynamic forces as cause for apparent damage.

By way of a reminder I would say that my understanding of hydrodynamic force is the forces acting in fluids in motion and not objects that impact fluids such as water. Accordingly unless someone pulls a stunt such as flying into Niagara Falls at their full fury then the question of hydrodynamic force does not really come into play.
The damage sustained to an aircraft impacting against any surface is caused by the dynamic force of the travelling aircraft and not by movement of the surface or depth of the water.
In this instance my money is on the in -flight loss of the empennage as a result of aerodynamic forces imposed upon it beyond its structural limititations.

[JamesT73J]

in this instance my money is on the in -flight loss of the empennage as a result of aerodynamic forces imposed upon it beyond its structural limititations.

I just would not have expected the remainder of the airframe to survive anything like to the extent it has. It appears borderline surviveable, and the fuselage (what is visible) still looks circular.

[island_airphoto]

Boomntown - doubt it. You would need a failure that left the pilots flying, but all radios disabled.

[rh200]

A bean counters job is to count beans, not dictate morality and standards. Their jobs is to the best of their ability to come up with ways to legally save money. Failure to do that is not doing their jobs.

Its other peoples jobs to evaluate those recommendations and consequences of, and they should do that to the best of their abilities.

If some thing is serious enough, as a society we codify it.

[DrPhillipa]

Wasn't there a theory going around that the inflated rear exit slide was at first attatched to the severed rear section causing it to float away while the main body sank immediately. The slide subsequently detatching in the swell so that the tail section sank some distance away?

[glendalegoon]

QUOTE:in this instance my money is on the in -flight loss of the empennage as a result of aerodynamic forces imposed upon it beyond its structural limititations.END QUOTE



Can anyone tell me if there has ever been a failure of the empenage in ANY Airbus Product? ;-)

[BJ-ENG]

@A0283:


With respect, nothing that I have seen so far leads me to believe that the main body of the aircraft was separated from the aft section prior to impact with the surface of the ocean. If it had separated then one would expect to see a more intact empennage; no burst bulkhead and more of the aft floor section still attached, or some remnants of floor frame. During a water impact, the hydrodynamic scour that occurs forces the floor section upwards, and in the process causes it to become detached from the side frames – exactly what we see in this instance. Ok, the floor frame complex could have pulled out in one if aerodynamic separation was the cause, but that still does not explain the burst bulkhead. The most likely reason for the distance in separation is probably down to the fact that since this part of the intact aircraft probably made first contact with the water ( ie: the aircraft is in a pitched up attitude), the break that occurred between it and the main section was well developed by the time the lower skin of the the main fuselage failed, thus allowing hydraulic surge (impulse) to flow through the cabin in fractions of a second, particularly to the now open ended rear – scouring everything in its way. Given that the APU and other heavy bits appear to have detached, plus maybe some level of buoyancy remaining (inflated rear exit slide ) in the aft section and a 5k current, it is not difficult to imagine the aft section drifting apart from the heavier main body. The rear end of the fuselage, as seen in latest photo, appears to show floor frames – presumably pulled out from the missing aft section once the connections to the side frames failed. There is also the evidence of one of the data recorders being found under the wing. If the aft had detached in the air, then is it probable that the recorder be found under the wing?

Chronus: The terms used in the literature (NASA Langley Research Center – vertical drop tests) for an airframe impact with water are often referred to as Hydrodynamic impact loading. In the past I have also come across the terms Hydrodynamic Ram effect or Hydraulic surge.

[Roseland]

Can anyone tell me if there has ever been a failure of the empenage in ANY Airbus Product? ;-)

American 587 is the most obvious with an in-flight loss of the VS, although in several instances (AF447, Perpignan) it was found floating alone after impact. Of course, that's not the full empennage...

[NigelOnDraft]

In this instance my money is on the in -flight loss of the empennage as a result of aerodynamic forces imposed upon it beyond its structural limititationsBasic stability means there is a downforce on the horizontal tailplane.

By definition therefore, if the horizontal tail is lost (as you say), the aircraft bunts - hard. Significant negative 'g'. In turn this would likely lead to a very high speed, near vertical impact. Not sure the wreckage supports that at all?

In fact, loss of tailplane can impose sufficient negative g that the wings then fail.

[SAMPUBLIUS]

your 14th Jan 2015, 12:56 post evidence of one of the data recorders being found under the wing

I suspect that report was made by someone strictly based on the shape of debris it was under. After all, the horizontal stabilizer is shaped very much like a wing and works the same way. To the casual observer or from a underwater photo of part of the structure, the differences would not be obvious without some sort of scale or other information.:ugh:

[BARKINGMAD]

"Most comments on stalling are by those who have never stalled a swept wing jet at high altitude except once or twice in a simulator....."

Before we even get to attempting to practise stalling, in sims of dubious fidelity, how many airline crew posters on this forum have NEVER hand-flown their 'frame, at max mass for the max cruise altitude for that mass?

The "bungee cord" flight controls effect plus the momentum versus control effectiveness is indeed impressive, as is the "fright factor", in S&L controlled flight.

Yet I get the impression, due to some perceived prohibition on hand flying in RVSM airspace, that there are out there now, both F/Os and CAPTAINS who have never controlled their allocated craft in such conditions.

If this is indeed true, then we're all on our way to hell in a handcart if that is the xAAs and airline training departments' official policy.

Please, those of you out there still practising the art of airframe manager, prove to me that I'm wrong, and that EVERY current airline pilot has had the opportunity to hand fly a line aircraft full of SLF at max certified altitude/mass until he/she/it are fully aware of and comfortable with the handling characteristics.

If there are any exceptions to this fun experience, may I challenge whether that is a sensible state of affairs?

Which begs the question, per airframe kilometres/nautical miles, are we seeing a real increase in high-altitude LOC incidents/accidents since the introduction of RVSM and the perceived lack of practice in this environment, or is it just my (false) impression? :suspect:

[RetiredF4]

More pictures there in the link.

Pictures & News Photos | Getty Images (http://www.gettyimages.ca/search/more-like-this/461334352?assetType=image)

[Leightman 957]

Would those posting photos please cite the source address? Thank you RetF4.

Tail location where discovered is no strong indication of impact location. Partial bouyancy, highest just after impact, is all that is required for drift. With any buoyancy at all the assembly would have been a vertical sail in the current. Some corroboration would be the current direction. Distance could be nothing more than rate of loss of buoyancy until seabed anchoring overcame current.

[Australopithecus]

Barking Mad wrote

"Before we even get to attempting to practise stalling, in sims of dubious fidelity, how many airline crew posters on this forum have NEVER hand-flown their 'frame, at max mass for the max cruise altitude for that mass?"

I have never done that in my current bus for the stated reasons and SOP and for reasons of both practicality and courtesy to my passengers. If I ever had to it would be briefly while clearance to a lower altitude was acquired. I do it in the sim from time to time, but only for a few minutes between tasks.

Having said that, in normal law in smooth conditions it is easy. Add complications and it becomes harder quickly. Add cognitive overload and it becomes very hard indeed.

I have hand flown several other transport jets at max level for prolonged periods without problem, but that requires a current agile scan rate and younger reflexes to make it appear effortless.

[RU4Real]

Interesting to see an unpackaged life vest in the new photo thread from previous post

[Leightman 957]

RE various posts:
FDR CVR recovery will tell some things about what the aircraft did, and what the pilots did, but not why the pilots did it, which is what prevention really needs to know. What 'new' money would be assigned to finding why pilots acted as they did in future incidents?

RE Algol, last seen at #1966 (though currently pg 99 will not load): ”Having seen the aircraft after the event, and spoken with my colleagues, it was no ordinary CB. NASA commented that the flight probably only penetrated the outer edges before they turned/got spat out. They also speculated that further penetration would almost certainly have resulted in a breakup.”

Virtually all forum comments to date treat cb's as dangerous but infer some kind of ordinariness about them. A quote such as “There are cb's in Europe too” infers European cb characteristics are within a range of characteristics that include ITCZ cb's, enabled by a wide but vague inclusivity of cb characteristics, that also manages an equally wide acceptance of moisture complexities near the equator.

Re FullWings perma:
http://www.pprune.org/rumours-news/553569-air-asia-indonesia-lost-contact-surabaya-singapore-102.html#post8825000
“You had to agressively reduce the AoA by pitching down to a far greater degree than in any other flight phase.”

Given the factors of narrow cruise speed range, limitations of live weather info, and inability of aircraft or pilots from recovering from wx caused or faulty instrument upsets outside of a narrow AOA range, 'more training' suggested by many seems to offer very few benefits.

[porterhouse]

I personally am far from certain the accident was even related to a CB. Maybe, maybe not. We are only days from knowing the truth, I would refrain from spinning theories that may have little to do with reality.

[aterpster]

porterhouse:


I am personally am far from certain the accident was even related to a CB. Maybe, maybe not. We are only days from knowing the truth, I would refrain from spinning theories that may have little to do with reality.

You are "spot on" as to what caused the accident.

Having said that, I remain skeptical that we will learn the truth considering the country that has the recorders.

[Blake777]

As yet, we don't even know for sure whether there were two functional pilots in the cockpit at the start of whatever chain of events led to this catastrophe. The greater probability is that there were, but nothing can yet be ruled in or out in that regard.

All we know is that a seemingly very experienced captain in terms of handling conditions in that part of the world, and his FO, ended up in the drink.

I hope the interpretation of the FDR and CVR is more accurate than the head of Barsarnas has been of late.

[glendalegoon]

aterpster

I just learned that indonesia is trying to decode the boxes themselves instead of sending them to established and respected labs in other countries.

Highly disturbing.

I am unaware of how things work in that part of the world. But would always like to know how money is flowing, from who to whom...if the cause of the accident completely exhonerates the airline...wellllllll

[Almostfamous]

Photo from the NY Daily news purports to show an "Airbus Investigator". Interesting, rather low profile.

http://assets.nydailynews.com/polopoly_fs/1.2074263!/img/httpImage/image.jpg_gen/derivatives/article_970/indonesia-airplane.jpg

[olasek]

I remain skeptical that we will learn the truth considering the country that has the recorders.
I disagree, I think we will learn the truth, Indonesia did have their share of air accidents and their investigative body each time did sufficient job. Perhaps their final reports are not as polished and comprehensive but no one ever questioned their main results.

[A0283]

Latest official information is that both recorders were found under the right wing and/or right wing/fuselage combination.
Latest official information states that only the right wing was located.
Officials have not provided information on the left wing, the cockpit, or the second engine. Spotting the first engine was mentioned earlier. But there is no mention of actual location yet.


BJ-ENG. Thanks for your reply. You introduce some interesting points that I would like to look at.

Before doing that, my line of thinking on water landing (before I read your reply, so there may be some duplication in it) was roughly thinking about two different and both basic scenarios.

First scenario, the pilots somehow regained control after losing it (losing it for whatever reason). Then they would probably try a ‘mild’ pitch up approach (would be interesting to know what kind of procedure AirAsia has for water landings). Which might lead to a ‘tail separates first’. The Hudson landing was one of amazing airmanship, but luckily not in ‘open water’. Even there, significant tail damage is visible (there were some good posts on that earlier, thanks). Damage that looks similar but, at first sight, not of the ‘same type’.

Second scenario, they did not regain control, or not enough. Which would probably lead to a ‘one wing first’ (there is quite a swell in the area...), followed by a slam on the water, leading to a break ‘somewhere forward of the wing’, and the - by then rotating aircraft (along the longitudinal axis) - losing the horizontal and thereby wringing the lower part of the tail section off.
The widebody jet crashing close to a beach in Africa was not recovered as far as I know. If there is information, that would be interesting.

The second option appeared more probably to me. It would also explain something of the ‘giant hand’ damage on the aft section, pressure bulkhead and some other parts. What made it less probable – at least to me, and until now – was that I would expect the second scenario to lead to quite a different debris field from the one we have. A surge through the fuselage would sweep out a lot of material that floats. Hope you can give your views on that.

Also hope they find the cockpit and the other wing, which will tell us more.

[ventus45]

We need a detailed large scale Debris Field Map/Chart, with accurate coordinates.

There has been plenty of time for the Navy to publish an accurate and up to date one.

I can not find one.

Does anyone have one, or a link to one, other than the basic one posted a few days ago ?

With regard to the airframe itself, it seems very odd that all that seems to have been located so far is the tail, cvr, fdr, and the central part of the wing/fuselage. So far as I can gather, three of the traditional four corners are still missing, the nose, and both wing tips. What about the main engines and pylons ?

The reports that the cvr and frd were found with "the wing" is odd.

The ths looks like a wing to most people, especially to a navy diver in the murky depths, or perhaps it is a language translation issue, perhaps even a "jounalist" issue.

It seems likely that they were with the missing sector of the pressure bulkhead, since they were attached to the structure right next to it. Did that part, remain with the bottom of the fuselage as it fracured longitudinally, and subsequently folded under the remnants of the rear fuselage and wing as it sank and settled on the bottom (in which case the "under the wing" may make sense and be correct), or did that section separate and go with the ths, apu and the remainder of the bottom of the rear part of the empenage ?
So, have they found the ths and/or apu or not ?
Can anyone clear that up ?

Next point.

An engine has been mentioned, but which engine, and where is it ?
Was it the apu ?
Was it a main engine ?
If so, where is the other main engine ?

Why have they apparently wound back the search as reported ?

Are they assuming that the recoders will tell all, so no further recovery is required ?

[Lazerdog]

As HarryMann said a few pages back, anything is possible hitting the water at anything over 100 knots airspeed. A wing low at impact could cause a cartwheel, breaking off the tail, cockpit, and a wing which all float and then sink at different rates being carried by the current.

[MountainBear]

I just learned that indonesia is trying to decode the boxes themselves instead of sending them to established and respected labs in other countries.

Highly disturbing.

Why? It's exactly what they did in the Russian crash two years ago.

https://en.wikipedia.org/wiki/Mount_Salak_Sukhoi_Superjet_100_crash

I won't say the report was the best thing I've ever read but they did a good enough job with it. I have full confidence that the Indonesians can handle this crash investigation properly.

[Lookleft]

It wont just be the Indonesians looking at the FDR and CVR information. There will be Airbus reps, Australian FR/CVR specialists etc.

We need a detailed large scale Debris Field Map/Chart, with accurate coordinates.

I'm not sure who "we" are but the official report should be able to provide that info. The public does not have a right to this stuff before the investigators complete their work.

[chefrp]

I disagree, I think we will learn the truth, Indonesia did have their share of air accidents and their investigative body each time did sufficient job. Perhaps their final reports are not as polished and comprehensive but no one ever questioned their main results.

I agree. I think all must understand that Indonesia has a new, highly progressive President: Joko Widodo. (http://en.wikipedia.org/wiki/Joko_Widodo)It is in his and the countries best interest to improve air safety in Indonesia and repair their image abroad.

Corruption runs rampant in Indonesia, and it seems that this has been unearthed in the Aviation sector. Expect major clean-up, including criminal investigations by the highly effective KPK (http://en.wikipedia.org/wiki/Corruption_Eradication_Commission) (corruption eradication commision).

[NSEU]

Interesting to see an unpackaged life vest in the new photo thread from previous post

Not really. Flimsy plastic lifejacket containers designed to be opened in a hurry are not going to be crashproof. Aircraft accidents have been known to strip layers of clothing off people.

I haven't seen the photo, but perhaps it was an attendant's demo life vest? ;)

[marconiphone]

@glendalogoon: 'I am unaware of how things work in that part of the world. But would always like to know how money is flowing, from who to whom...if the cause of the accident completely exhonerates the airline…wellllllll'

Tony Fernandes (Air Asia) is not an idiot. He's running a sophisticated, international operation.

[Ranger One]

If you want an insight into the forces and effects involved, have a look at this crew:

-The Bluebird Project | Home (http://www.bluebirdproject.com/K7/#)

They have done an astonishing job, and that includes very detailed forensic analysis of what happens when water meets metal at high speed.

(It's a fascinating project and website in any case)

[Lost in Saigon]

Interesting to see an unpackaged life vest in the new photo thread from previous post

Do you mean this photo? (cropped)

Sorry, I don't find it interesting at all considering the condition of the wreckage.

http://i2.photobucket.com/albums/y17/msowsun/photo%20stuff/Photo15/461271096.jpg~original

[Volume]

I have not had time to think about what kind of aerodynamic forces would shape this 'hand'.It is very hard to imagine that a horizontal stabilizer fails due to overload (or a "hand").
Having significantly less span than the wing, high "twisting" loads due to roll are impossible, the wings will stop the aircraft rolling fast enough to create significant loads on the stabilizer.
Any high up or down forces would immediately result in big AoA changes, at cruise speed that would mean enormous g-loads, which would most probably rip of the wings before the stabilizer.
So the only aerodynamic scenario I could call remotely likely would be an asymmetric actuator fault, meaning one elevator deflecting up and the other one deflecting down (commanded by the computers to counteract the pitching moment caused by the faulty actuator). Given the fact that there are two actuators per elevator, and we never experienced such scenario, I would not consider this likely.
Thinking of the Alaska Air trim actuator accident, a scenario like that might be possible, but that would have most likely also resulted in an in flight breakup and a much wider field of much smaller debris.

So I do (so far) not believe in any horizontal stabilizer failure scenario. It all looks more like the Aircraft hit the water first with the tail, which caused all the damage.

With respect to cutting the tail section, I found the upper skin panel just behind the pressure bulkhead very interesting (don´t have the link to the photograph currently): All stringers are buckled, so obviously there has been high up-bending loads on the tail. Either due to high forward momentum from the VTP with high horizontal deceleration, or due to impact forces on the tail from below, indicating an impact with high AoA. Cutting in that area is probably destroying some evidence...

[cats_five]

someone mentioned clearing the BEANCOUNTERS from responsibility, blaming instead a lack of required standards

SO


Back in the beginning, there were no standards and we learned the hard way what had to be done to keep things safe and assure passengers there was as good a chance to get from A to B on an airliner as on a train, ship, car, or horse.

And they did it.

And then the regulators codified many of those same things.

BUT THEN came the cheapos. IF THE FAA or over seas version hasn't mandated it, then WE DON'T HAVE TO DO IT and can save money.

<snip>.


We have codification not only in transport but currency, food and many other areas of life because there have ALWAYS been 'cheapos', scammers, fraudsters and the rest of them. Don't kid yourself the past is a halcyon period where everyone did everything right without scrimping. Some areas it hurts the pocket, others it has often been lethal - food for example.


BBC News - 10 dangerous things in Victorian/Edwardian homes (http://www.bbc.co.uk/news/uk-25259505)

[Australopithecus]

For those of you born too late, Google "MD 80 test flight crash" to find a youtube video of a intentional hard landing. The tail separates, and that's at about 1200 fpm descent from memory. Imagine hitting water instead of a runway with the gear down and its not too hard to expect to see exactly what is being seen in this debris field.

[VR-HFX]

If the EASA emergency AD relating to blocked AOA probes is relevant then this investigation could get very messy. I guess we will know soon enough.

[Low Flier]

I just learned that indonesia is trying to decode the boxes themselves instead of sending them to established and respected labs in other countries.


What, exactly, does "trying to decode" mean?

[OldLurker]

An important learning point for SLF arising from the Ethiopian crash off Comoros mentioned above (Ethiopian 961 in November 1996) is that there were a few survivors, but it was reported that many more might have survived but that they inflated their lifejackets before exiting, so couldn't get out (and probably blocked others). We're always told "don't inflate before exiting", and that's why,.

[Gysbreght]

What, exactly, does "trying to decode" mean?The DFDR memory module contains a long string of 0’s and 1’s, called “bits”. Twelve bits comprise a “word”, many words are contained in a 1-second “subframe”, 4 subframes form a “frame”. The meaning of the thousands of words in a frame is defined in a “Decoding Document” that is submitted to the authorities when an airplane obtains it registration. The first word in each subframe contains the date and time of the subframe. Each of the subsequent words is dedicated to one or more of the thousands of parameters recorded.

[Mad (Flt) Scientist]

The DFDR memory module contains a long string of 0’s and 1’s, called “bits”. Twelve bits comprise a “word”, many words are contained in a 1-second “subframe”, 4 subframes form a “frame”. The meaning of the thousands of words in a frame is defined in a “Decoding Document” that is submitted to the authorities when an airplane obtains it registration. The first word in each subframe contains the date and time of the subframe. Each of the subsequent words is dedicated to one or more of the thousands of parameters recorded.

In addition, before you can get to those 1s and 0s, you need to decompress the data, which is stored in a special and proprietary format which compacts the data to be able to store as much as possible in as small memory as possible.

The decoding document above is basically an OEM thing, but the FDR manufacturer is the one who knows how it's compressed. that's another set of special software required, with the right decoding info too.

I believe the 9/11 truthers have been trying for 12+ years to decode one of the "raw" FDR files from one of the aircraft that they somehow acquired, with no success because no-one who knows how to do it - which is a pretty closed community - has any interest in providing the information required. In this case, it's won't be the same reluctance, but it's a bit of an art, so if you've never done it before, even with the right info it might take a while ...

[wheelsright]

Quite some number of contributors have expressed the opinion that location of wreckage after and ocean accident is not particularly important. These opinions also extend to the relative importance of investigating the primary cause of the incident versus the blow by blow analysis of every aspect.

I think these attitudes are probably statistically appropriate, but they do not accurately reflect the general consensus and policy that has been adopted more or less since the start of aviation.

The statistical chances of surviving ditching in the ocean are very small. Yet, every passenger aircraft has life jackets, rafts, passenger safety briefings and so on. Clearly, it is the intention of the air travel industry to give the passengers at least a reasonable chance of surviving a ditching event.

In those circumstances, I find it extremely difficult to understand why a practical and effective systems to locate ditched or crashed aircraft have not been mandatory for many years. If you survive a ditching you will not survive for long in the ocean without rescue. Surely location is a vital ingredient? In addition, a collateral benefit would be to reduce resources being wasted on SAR.


For those that suggest that it is difficult or impossible to design an effective device for locating an ocean crash site; I would suggest you are as wrong as wrong could be. It would be a simple project even in grade school.


If it is our intention to abandon aircraft and passengers at sea, in the event of ditching, then please remove the emergency safety equipment and stop these pointless passenger safety briefings.

[Lonewolf_50]

For those that suggest that it is difficult or impossible to design an effective device for locating an ocean crash site; I would suggest you are as wrong as wrong could be. For the scenario you draw up, there are ELT's and rafts. A survivable water landing and successful exit has been provided for. Now, is it sufficient to the task? In New York it was, but that was not "out at sea" but on a river in the biggest city in the nation. How many at sea ditchings have happened in the last 40 years that were survivable? What were the cues that got search and rescue teams to the location?

[Airclues]

If you survive a ditching you will not survive for long in the ocean without rescue. Surely location is a vital ingredient?

All transport aircraft are required to carry Emergency Locator Transmitters that can be manually deployed by the crew after a ditching. Therefore your point about the delayed rescue after a successful ditching are invalid. However, I'm not sure about the regulations regarding automatically deployed beacons that would be useful in the case of a crash rather than a ditching.

Distress radiobeacon - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Distress_radiobeacon)

[BJ-ENG]

@A0283: "Before doing that, my line of thinking on water landing (before I read your reply, so there may be some duplication in it) was roughly thinking about two different and both basic scenarios."


I’m not sure how much more I can add to my previous post without getting too far away from the evidence we have seen so far.

Either of your scenarios are possible, though judging by the condition of the fuselage (slightly pancaked – side bulge flattened top) as shown in the latest underwater pics, it would have been at a very high rate of descent – so I think both unlikely. However, I also agree that the damage to the airframe looks less extensive than the pictures I have seen for the AF447 wreckage, though a lot of bits and pieces can separate when a journey of 4k to the seabed is involved.

Like others on this forum, I am minded to believe that QZ8501 experienced a similar aerodynamic event to that which occurred to AF447, with the airframe basically intact and in a stalled attitude until impact with the ocean. The more important questions that need answering are how did the aircraft enter the uncontrolled state, and why was it not possible for the crew to regain control – was it a technical failure, or was crew incapacitation a cause. However, unlike AF447, we do not need to wait 2 years for the data recorders to be recovered. Hopefully this information should be revealed in the coming weeks or months.

The following link is instructive in providing an idea of how an airframe, a B737) in this instance, crumples when subject to a test 30-ft/s impact velocity, albeit that in this case the impact is on a hard surface.

http://www.cs.odu.edu/~mln/ltrs-pdfs/NASA-2001-3ikus-elf.pdf

[Belgianboy]

As already reminded on this thread, water is a hard surface in such circumstances.

Let's now wait for the outcome of the FDR and voice recorder.

[BG47]

PANGKALAN BUN (AFP) - Clinging desperately to underwater ropes, an Indonesian search leader said his divers appeared to be "flying like Superman" as they scoured the seabed in the gruelling quest to recover bodies and wreckage from crashed AirAsia flight QZ8501.

"The current is so strong that it could rip open our masks or drag us into a whirlpool," said Totok Subagio, in charge of a group that this week found the plane's two black box flight recorders, after a lengthy, difficult search. Trained to swim to depths of 45 metres, the Indonesian navy's finest frogmen were drafted in to scour the seabed for wreckage of the Airbus 320-200 that went down in a storm on Dec 28 en route to Singapore.

But in the Karimata Strait between Indonesia's Sumatra island and Borneo island, they have had to contend with rough seas, powerful underwater currents, and weather that changes from bright and sunny one moment to cloudy and rainy the next. Grainy images from specialist Singaporean search equipment Wednesday showed the plane body resting on the seabed, with part of the Malaysia-based airline's slogan "Now Everyone Can Fly" painted on the red-and-white exterior clearly visible.

Divers now face the grim task of examining the main body of the aircraft in the hope of finding more of the 162 victims who were on board the plane, believed trapped inside the fuselage. Almost three weeks into the search, just 50 bodies have so far been retrieved. - 'Two-metre-high wave is a blessing' -
Ferdy Hendarto, head of the navy's local underwater rescue division, described how divers would descend along ropes attached to buoys on the sea's surface marking the locations of the plane's wreckage.

The currents are so strong they can be dragged sideways and at times appear to be "flying like Superman", he said. The search has been tough even for veteran divers, with some suffering nosebleeds after spending too long at depths of 30 meters. Conditions on the surface have also been rough, with some vomiting on their way out to hunt for the wreckage as their tiny boats were hit by waves four metres high.

"In that search area, a two-metre-high wave is a blessing," Subagio said.

Most days divers have had only a four-hour window in the early morning when they can search, before clouds obscure the sun and reduce visibility underwater, rendering search efforts impossible. In the hunt for the plane's two black boxes, divers equipped with devices able to detect the "ping" signals emitted by the devices would inch along the seabed, dropping weighted markers in areas where they picked up the signals.

Digging at the sandy sea floor where the boxes were believed buried, diver Rajab Suwarno succeeded in locating both the recorders, which contain a wealth of data crucial for determining what caused the crash.

One of the boxes - which are actually orange in colour and designed to survive underwater - was trapped under the remains of the aircraft, making it more difficult to retrieve. He described finding one of the boxes: "That morning the sunlight was penetrating the water, it was very clear. We moved some small debris aside and dug in the white sand - and, thank God, we found it."

[Niner Lima Charlie]

From Pangkalan Bun (Indonesia) (AFP):

The boxes, which are actually orange in colour, have been flown to Jakarta, where Indonesia's National Transportation Safety Committee is leading a probe into the accident helped by experts from countries including France and the US.

Safety committee head Tatang Kurniadi said 174 hours of data had been downloaded from the flight data recorder, and two hours and four minutes from the cockpit voice recorder.

[nonprovisitor]

http://www.straitstimes.com/sites/straitstimes.com/files/20150115/underswterairsi1501e.jpg

From: AirAsia flight QZ8501: Divers hunt for victims in main body of plane - South-east Asia News & Top Stories - The Straits Times (http://www.straitstimes.com/news/asia/south-east-asia/story/airasia-flight-qz8501-divers-hunt-victims-main-body-plane-20150115)

[Ian W]

Wheelsright
I do not think that there is any example of a commercial aircraft being located other than by witness, ATC and/or conventional search.


This was my understanding too.
Perhaps someone knows if Sully's landing in the Hudson caused the aircraft ELT to work. I have not heard of any water landing/crash where the ELT worked.

I have only heard of military PLB's (SARBE) actually locating people. I was involved in the SAR for a P3 North of Malin head that nobody realized had crashed till we got a report from a small GA aircraft of hearing a PLB on 121.5.

I have only heard of one successful ELT alert that was the crash of a politician in the North US where apparently the ELT worked.

[Methersgate]

It seems reasonable to assume that the tail section may have downflooded more slowly than the fuselage. We know that there are strong currents in the area. Assume w current of 1.7 knots and assume an hour for the empennage to flood to sinking point and it will be 1.7 miles from the fuselage.

[Coagie]

The statistical chances of surviving ditching in the ocean are very small. Yet, every passenger aircraft has life jackets, rafts, passenger safety briefings and so on. Clearly, it is the intention of the air travel industry to give the passengers at least a reasonable chance of surviving a ditching event.


Although surviving an ocean ditching may be statistically low nowadays, the rafts, life jackets, etc are a bit of a throwback to when a survivable ocean ditching was quite possible. Back in the days when aircraft were much slower and had better glide ratios, in the pre-jet age, ocean ditching happened enough to justify rafts and life jackets. Piston engine aircraft were overall less reliable, so might have to ditch in the ocean, while still somewhat flyable. In today's reliable, but fast jet aircraft, the few times things go wrong, there's a good chance they go very wrong. A compromise in air worthiness often is either non-catastrophic or catastrophic. In the old days, there was an in between, where life jackets and rafts might come in handy. You might call it "Semi-catastrophic".
I personally feel good about the life rafts, etc still being in use, even if they are a throwback.

[Ian W]

It seems reasonable to assume that the tail section may have downflooded more slowly than the fuselage. We know that there are strong currents in the area. Assume w current of 1.7 knots and assume an hour for the empennage to flood to sinking point and it will be 1.7 miles from the fuselage.

From a previous post:

"The current is so strong that it could rip open our masks or drag us into a whirlpool," said Totok Subagio, in charge of a group that this week found the plane's two black box flight recorders, after a lengthy, difficult search. Trained to swim to depths of 45 metres, the Indonesian navy's finest frogmen were drafted in to scour the seabed for wreckage of the Airbus 320-200 that went down in a storm on Dec 28 en route to Singapore.

But in the Karimata Strait between Indonesia's Sumatra island and Borneo island, they have had to contend with rough seas, powerful underwater currents, and weather that changes from bright and sunny one moment to cloudy and rainy the next."

The underwater currents are put at more than 5 knots. Not only is that relatively fast it will exert a considerable force on light weight aircraft parts such as the empenage plus some fuselage. It may well drag the empenage further and faster once it has started to sink.

I am actually surprised how close these pieces are to each other considering the strength of the subsurface currents.

[Lost in Saigon]

Although surviving an ocean ditching may be statistically low nowadays, the rafts, life jackets, etc are a bit of a throwback to when a survivable ocean ditching was quite possible. Back in the days when aircraft were much slower and had better glide ratios, in the pre-jet age, ocean ditching happened enough to justify rafts and life jackets. Piston engine aircraft were overall less reliable, so might have to ditch in the ocean, while still somewhat flyable. In today's reliable, but fast jet aircraft, the few times things go wrong, there's a good chance they go very wrong. A compromise in air worthiness often is either non-catastrophic or catastrophic. In the old days, there was an in between, where life jackets and rafts might come in handy. You might call it "Semi-catastrophic".
I personally feel good about the life rafts, etc still being in use, even if they are a throwback.

I agree that is is probably easier to ditch a piston airliner, but.....

Modern jetliners should have better glide ratios than old piston airliners.

Just ask Captain Bob Pearson of the "Gimli Glider", or Captain Robert Piché of Air Transat Flight 236. :)

[broadreach]

For those still doubting what a 5-6 knot current can do, it's all in the buoyancy of the fin. The impact with the surface of the sea was obviously sufficient to buckle the aft pressure bulkhead, tear off the apu and elevators and dislodge the heavy recorders but leave the fin intact enough to float, gradually sinking as water filtered into its and the rudder's compartments and finally coming to rest when its anchor, the remains of the aft fuselage, snag on the ocean floor.

Did you read about the divers working downwards hand over hand on the buoy cables and being streamed out like flying Supermen? Imagine a semi-floating object, sinking only gradually. I'm surprised the tail was found only 1.7km from the impact point.

Regarding recorders being found "under the wing", at that depth, in murky water, wing or elevator would look the same. I'd assume elevator.

Finally, many divers are by nature consummate risk-takers. I'm not one but have butted heads with a few. it looks as though they've been lucky so far but I hope to hell they're careful over the coming days. Grim work.

[SysDude]

The "first" commercial jet to ditch in the open ocean: alm flight 980

ALM Flight 980 - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/ALM_Flight_980)

http://www.airdisaster.com/reports/ntsb/AAR71-08.pdf

[Coagie]

Just ask Captain Bob Pearson of the "Gimli Glider", or Captain Robert Piché of Air Transat Flight 236.

Captain Bob did a great recovery. Lucky he was at altitude. But, I'm sure if you give it a second thought, you'll remember that a jet's wings have to trade lift for less drag, so the slower aircraft of yesteryear were generally able to accomplish a slower, softer, unpowered landing than the faster jets of today.

[Dairyground]

Although surviving an ocean ditching may be statistically low nowadays, the rafts, life jackets, etc are a bit of a throwback to when a survivable ocean ditching was quite possible.


Aa ocean ditching many miles from land is not the only relevant scenario. We have had examples in recent years of landings in rivers at relatively low speeds, and runways with water at one or both ends are not unknown. Lifejackets and rafts may be very valuable in case of accidents in such locations.

[MrSnuggles]

Leightman957 (currently post 2062)

'more training' suggested by many seems to offer very few benefits.

IF it was weather related we may finally know in a few days, hopefully!

I, for one, would like to see more training in actual small planes, getting pilots to know the air and what it does, not just some pre-planned prepared sim button pushings. Of course bean counters will scoff at this, but I am thinking Logan Air, Braathens, Buffalo Air, Suzy Air etc. Excellent training for pilots to FEEL the element they are moving in.

Weatherwise, a CB in Indonesia is totally different from a CB in Sweden or over bigger parts of the US. In Sweden it is too cold to get any Godzilla CBs and in the US it gets big but it hasn't the ocean current beneath it to make it Godzilla. (Ok, except for the states close to the Mexican Gulf.)

[glendalegoon]

hey, how about making a rule that anyone flying for an airline actually has to have a good amount of experience PRIOR to getting hired.

mrsnuggles, somehow I really don't think your view about this is anywhere near correct.

let's find out what happened. though I think I know what did happen.

And if you learn to feel things in small planes, how does that relate to computer controlled wonder jets?

IN good old jets, it actually FELT different when you flew slowly vs flying fast.

[Australopithecus]

I don't know Glendale...how much general aviation goes on compared to the airlines? Worldwide, I mean.

When I first hired on to a turboprop regional the cover charge was 3,000 hrs twin. My 24 year old contemporaries all had at least that much time. Is that even achievable anymore?

Since the early 70's I think the airlines have quadrupled their fleets while GA has shrunk to almost nothing. My hometown, back in the day, had 13 piston twins, three PA-3Ts and two C-500, almost all crewed by eventual airline pilots. Now there are exactly two private twins.

I wonder how large most Air Forces are now compared to previous decades?

Also, Mr. Snuggles... I suggest you have not tried to pick a way through a North American cold front in the spring/summer. Anywhere in the prairies into Canada you get monster cells.

I find tropical thunderstorms much less daunting than their temperate zone cousins. For one thing the air is close to saturated in those latitudes, giving less change of state to amplify the vertical wind shear. Landing three miles away from a cell at the equator? No problem. In Kansas City? Not so much.

On the light aircraft training...it is a different animal to high altitude, high speed flight. Better would be theoretical training followed by mishandling into incipient stalls at altitude. I don't think that the average SOP monkey has an appreciation of just how fragile a 1.3 G buffet margin is.

[glendalegoon]

well, how about this


take an average airline pilot up with a test pilot in a wonder jet. go to FL350 and stall the plane, full stall.

recover

and VIDEO the whole thing from many viewpoints including the instruments, out the window

do it at night too

do it in clouds with nothing outside

show the nose down pitch attitude to recover and the altimeter winding down

show a G meter to show that the plane might go negative if the pitch down is abrupt.

record all the data that the FDR would get and feed it into the sims so we can all do it.

Quite frankly I wouldn't go up in a small plane for training unless I am being paid the full amount that I would get for flying a transport.

well, lets wait and HOPE that we hear soon what happened.

[Flagon]

"For example, if there had been a protection state in AFR447 that motored the THS to zero NU as soon as there was a stall indication" - a sensible idea, Ian, BUT now remember you have to build in protection against a false stall warning!

Far better to have homo sapiens trained to move the THS - and do it?

[Ian W]

The stall warning was real.

Yes Homo 'sapiens' could do this but then the same could be said of all the protections. However, in this case it just seems an easy thing to do and it puts the the aircraft into a recoverable position.

Out of interest do any of the stall recovery memory items include check trim neutral?

[Roseland]

Out of interest do any of the stall recovery memory items include check trim neutral?

The Airbus A330 stall recovery in place at the time of AF447 called for TOGA and 5° pitch (10° below FL200). Unless I'm mistaken, no mention was made of checking trim. See: http://www.smartcockpit.com/docs/A330-A340_Flight_Crew_Training_Manual.pdf page 204

BTW, I doubt when you're sinking at 10,000fpm (close on 100kts) any amount of power will unstall you without putting the nose down.

[Capn Bloggs]

"For example, if there had been a protection state in AFR447 that motored the THS to zero NU as soon as there was a stall indication" - a sensible idea, Ian, BUT now remember you have to build in protection against a false stall warning!

Far better to have homo sapiens trained to move the THS - and do it?
Far better that the stab trim does not move automatically when hand-flying!

[mcloaked]

Three to four years ago Airbus introduced new stall recovery procedures which I imagine all Airbus pilots would now be familiar with:

http://www.ukfsc.co.uk/files/Safety%20Briefings%20_%20Presentations/Flight%20Ops%20-%20Stall%20recovery%20Presentation%20Airbus%20June%202010.pd f

http://xa.yimg.com/kq/groups/10483604/2002517561/name/Updated%20Stall%20Procedure.pdf

[Sop_Monkey]

Glendalegoon

Your post is right on the money and well put.

[MrSnuggles]

glendalegoon:

And if you learn to feel things in small planes, how does that relate to computer controlled wonder jets?
Ok, I may have been vague here. I'm talking about "small" planes, turboprops, think SAAB 340 and the like, not tiny Cessnas with four seats. My favourite would be the DC-3 or DC-4... ;-D

The reasoning behind this is if you learn to feel how the winds and air affect the plane, those physics translate even to one of those big shiny ones albeit big and shiny has more resistance to weather events due to their size.

Austral...

Also, Mr. Snuggles... I suggest you have not tried to pick a way through a North American cold front in the spring/summer. Anywhere in the prairies into Canada you get monster cells.

I find tropical thunderstorms much less daunting than their temperate zone cousins. For one thing the air is close to saturated in those latitudes, giving less change of state to amplify the vertical wind shear. Landing three miles away from a cell at the equator? No problem. In Kansas City? Not so much.
You are correct. I have not flown in the US only in Europe. I extrapolated from what is known about storm cells and convective air over ocean currents. Sorry if I offended anyone, I realise I did make that clear before.

[Roseland]

Three to four years ago Airbus introduced new stall recovery procedures which I imagine all Airbus pilots would now be familiar with:


Only the second of the two links you included mentions trim, unless I've missed it.

[Volume]

The Airbus A330 stall recovery in place... The fundamental misunderstanding is, that this is not the stall recovery procedure, but the procedure to be applied when the stall warning starts to sound. It actually is a stall prevention procedure in case you get close to stall. And as such, it works perfect.
Large aeroplanes are not intended to be stalled, hence there is no procedure required to recover from a fully developed stall.

[Ian W]

Three to four years ago Airbus introduced new stall recovery procedures which I imagine all Airbus pilots would now be familiar with:

http://www.ukfsc.co.uk/files/Safety%20Briefings%20_%20Presentations/Flight%20Ops%20-%20Stall%20recovery%20Presentation%20Airbus%20June%202010.pd f

http://xa.yimg.com/kq/groups/10483604/2002517561/name/Updated%20Stall%20Procedure.pdf

As Volume points out these are stall avoidance procedures.
Has anyone recovered from a real full stall in these FBW aircraft at cruise level?

[barit1]

Roseland:...I doubt when you're sinking at 10,000fps (close on 100kts) any amount of power will unstall you without putting the nose down.

At altitude, doubly so, because of less dense air, in turn directly related to LESS ENGINE THRUST AVAILABLE, as well as slower engine windup rate. :ooh:

Reducing AOA does the job right now.

BTW, Roseland, do you mean 10,000 fpm, not fps?

[mcloaked]

There is interesting and relevant discussion on stalls at

Stop Stalling | Flight Safety Foundation (http://flightsafety.org/aerosafety-world-magazine/april-2011/stop-stalling)

[ironbutt57]

Glendalelagoon...add one more bit...bring up the bird, and let them see trajectory vs pitch, show them with full forward stick, but full THS up, how ineffective the elevator really is..

[Coagie]

Far better to have homo sapiens trained to move the THS - and do it?

Didn't need to train Homo Neanderthalis to move the THS. It came naturally to them, but you think it's hard to find pilots that have much general aviation or military aviation experience, try finding a Neanderthal pilot nowadays (Seems like I used to see them a lot in airport lounges back in the '70's).
You'll have to ask him, but I hear that even Australopithecus' dance card is full!
I have and others have brought up the trim issue in this thread more than once, but the "Authorities" cull the postings out for the most part. Not politically correct, I guess.
Considering what trim does on a particular aircraft, in what situation and when, needs emphasis in training, so pilots given sudden control of an aircraft, might realize why their elevator inputs may not have the level of effect they want. They can then adjust the trim in a timely manner if need be.

[A0283]

There are roughly 4 different groups of pictures associated with the Flight Recorders of AirAsia 8501 on the web at the moment:

1. Earlier pictures of FR's. We can often quickly eliminate these by the fact that the 'memory module cyclinders' are mounted horizontally. While the AirAsia recorder's 'cylinders' are mounted vertically and positioned at the extreme end of the 'sigar box'.

2. Earlier pictures of FR's submerged in a transparant casing, these can be eliminated because the latching/lid is much different from those on the photos with Gen.Moeldoko. So, his morale boosting visit gets a nice bonus.

3. FR's presented by the chief of the KNKT/NTSC during an earlier press conference. These have 'vertically mounted memory module cylinders. I do not have the exact date of the pictures yet. Low prio. These are undamaged indeed. And me be the exact same type of the actuals.

4. The actual recorders. Vertically mounted cylinders. Parts of supporting / mounting frame attached which are partially deformed. Corner of the CVR 'power cube' dented. I have not seen a picture of the 'outer box', would be interesting to see the damage on that.
During their trip the boxes have changed carrying/transport containers at least four times it seems. First an icebox (white and blue) on board Indonesian vessel Banda Aceh . Then a black box (like the divers use) from Indonesian vessel Banda Aceh to shore. And during the transfer from ship to shore at PB we first see the transparant box. Finally, in Surabaya, a black large box (probably containing the last transparant one), for transfer to Jakarta.
Early on there was one picture showing detailed configuration data of the CVR.

Hope this helps.

[BG47]

PANGKALAN BUN, Indonesia (AP) — An Indonesian search official said Friday that the crashed AirAsia jet's fuselage will be lifted to the surface after sea conditions again prevented divers from examining the large chunk of wreckage.

National Search and Rescue Agency chief Henry Bambang Soelistyo said that rescue teams discovered more wreckage despite the strong current and poor visibility.

"Apart from the fuselage, we found what we suspected as the aircraft's cockpit and also an engine," he said. "We also found what seems to be a passenger seat in which we thought there still bodies tied on it."

He did not specify whether or not the seat was inside the fuselage section that sits on the seabed at a depth of 28 meters (92 feet). The 30-meter-long (100-foot-long) part of the plane body with a wing attached was sighted Wednesday.

Rescuers believe that many of the bodies are still inside the main fuselage.

Soelistyo said the failure of the underwater examination of the wreckage left no option but to lift the fuselage, either by using floating balloons as the tail part was lifted early this week, or using cranes from tugboats. He did not say when the operation would start.

Earlier Friday, chief of operation of the agency, Suryadi Bambang Supriyadi said the wreckage that appears to be the cockpit was located by sonar imagery about 500 meters (yards) from the fuselage and partly embedded in the mud.

[MsCaptain]

not sure what to make of this
"Chief investigator" who seems to have knowledge of downloaded data from CVR/FDR says in interview that weather ("cloud") was not the only factor
(from twitter @nihonmama and Jeff Wise blog)
https://www.youtube.com/watch?v=usdnthtb7gY&feature=youtu.be

[FlexibleResponse]

mcloaked There is interesting and relevant discussion on stalls at

Stop Stalling | Flight Safety Foundation

After a lot of discussion, Claude Lelaie, special adviser to the Airbus president and chief operating officer, cut to the heart of the remedy for pilots finding themselves in a stall or near-stall condition: “If you push on the stick, you will fly!”

Perhaps it would be more accurate for Claude Lelaie to say,

“If you push on the stick (and trim forward as required), you will fly!”

[BG47]

Wall Street Journal
By ANDY PASZTOR

American and Indonesian air-crash investigators share a history of sometimes strained relations stretching back to the late 1990s, which U.S. officials say could impact the current AirAsia probe. That legacy also may partly explain why the two sides are still discussing potential U.S. participation in the probe of Flight 8501 nearly two weeks after the Airbus A320 with 162 people aboard dropped from radar while flying near storm cells en route to Singapore from Surabaya. In Washington, a spokeswoman for the National Transportation Safety Board has said officials are waiting for an invitation to join the multinational inquiry, which already includes French industry and government experts. In recent years, the U.S. agency increasingly has been reluctant to commit significant resources, or send investigators to foreign accident scenes, before wreckage or black box recorders are recovered.

By contrast, officials in Jakarta have said the U.S. is welcome to participate, all it has to do is ask, and that they expect the NTSB eventually will join the probe. But they added that is likely to happen only after remnants of the plane, sitting in the silt at the bottom of the Java Sea, are brought to the surface. A spokesman for General Electric Co., which helped build the jetliner’s engines, earlier this week said the company fully anticipates participating in the inquiry alongside the NTSB. But he didn’t indicate a possible timetable. Former NTSB officials said prior disagreements between the two countries—sparked by two earlier fatal crashes of Indonesian carriers—appear to be complicating the current situation.

Some of these officials, who were involved in the disputes, remember how tension between the two camps initially erupted. In the wake of the SilkAir flight that went down in a muddy Indonesian river delta in 1997, killing all 104 people on board, U.S. and Indonesian experts joined forces to dissect causes of the tragedy. But they had a falling out over the findings of the final report. In the end, Indonesian experts concluded there was no way to conclusively determine why certain flight-control panels on the tail were put into a dive configuration, or why both flight-data and cockpit-voice recorders stopped operating before the fatal dive. NTSB experts, however, felt the physical evidence and other data pointed to pilot suicide. By 2000, the NTSB’s chairman publicly indicated that no airplane-related failures could explain what occurred, and the only plausible explanation was intentional pilot action.

About 10 years later, there was similar friction after a jet operated by Adam Air, a now-defunct low-cost carrier, went down during a domestic flight, killing 102 people. Indonesian authorities, who said they needed various forms of outside help, persisted in asking the U.S. to foot the bill to try to bring the wreckage to the surface from some 6,000 feet under water. Mark Rosenker, who was NTSB chairman at the time, recalls that an Indonesian delegation came to Washington—and went to visit United Nations air-safety officials in Montreal—as part of a campaign to press for U.S. funding. But safety board officials kept saying no. “It became a point of principle,” Mr. Rosenker said this week, because the U.S. was convinced international law and precedent required Indonesia to underwrite retrieval costs. Eventually, the airline paid for the search to retrieve the recorders.

When it comes to AirAsia, Indonesian officials say data from the A320’s black-box recorders, once the devices are recovered, will be downloaded at a government laboratory in Jakarta, Indonesia’s capital. Government investigators from France, the country that certified the aircraft and where it was assembled, are expected to participate. Amid rough seas and poor visibility underwater in the search area southwest of the island of Borneo, Indonesia has accepted the help of military assets from many foreign nations, including the U.S., China, Malaysia, Australia and Russia.

Australia, which took the lead in the hunt for Malaysia Airlines Flight 370 last year, hasn’t taken such a prominent role this time. But Singapore, another commercial-aviation powerhouse that seeks to become the center of air-safety advocacy in the Pacific region, has provided some technical advice and search equipment. U.S. experts also have been involved in other recent Indonesian crash investigations. A number of NTSB experts traveled to Indonesia to participate in the probe of a Lion Air jet that crashed into the water short of a runway last April while trying to land in stormy weather in Bali. There were no fatalities, but the plane broke into pieces.

[GarageYears]

Does anyone know if the CVR has been received at the relevant lab? Recovery was what, 2 days ago now? It seems difficult to imagine that the basic cause of this incident isn't very obvious from what will be heard on that recorder. Certainly the FDR will reveal a lot more subtle aspects, but as in AF447, the "big picture" was very evident from the CVR transcript.

[training wheels]

From a previous post ..

Safety committee head Tatang Kurniadi said 174 hours of data had been downloaded from the flight data recorder, and two hours and four minutes from the cockpit voice recorder.

So, yes, it has been received and downloaded. Standby for the leaks on social media in the next couple of weeks. ;)

[training wheels]

Here's an interview with the chief of the KNKT (NTSC) after downloading data from the FDR. He's not revealing too much at this stage which is understandable. It's interesting that he has aircraft models of recent aircraft fatal accidents behind him in his office (Sukoi SJ 100 and Merpati's MA60).

usdnthtb7gY

[A0283]

As far as I know:

There is an unofficial piece of tape - claimed to be from 8501 - containing pre-takeoff comms with the control tower in Surabaya. I ve been listening to that and the quality is not that good. Tried to make a transcript ( because I could not find one ), but hard to confirm what has been claimed, based on that. Could just have been another flight.

Both recorders have been delivered to KNKT/NTSC HQ and Lab in Jakarta. The FDR on Jan.12th, and CVR on the night of Jan. 13th or in the early morning thereafter.

First reported results:

"Safety committee-head Tatang Kurniadi said that 174 hrs of data had been downloaded from the FDR, and 2 hrs and 4 min from the CVR. The data must be converted into a usable format before the lengthy analysis process can begin.- AFP".

Timeframes for download and first analysis given during the last few weeks by KNKT ran from 2 days to 2 weeks. It depends on the quality of what is retrieved. The recorders looked good, so most expect a quick retrieval. But you never know.

A prelim report is often set at 1 month after the accident. But with this open water search and the relatively later finds, it would not suprise me if they would set that at 1 month after the FDR find. So somewhere mid February. All parties involved will want to make sure that what will be reported does not have to be retracted later. Saves us all from all kinds of conspiracy theories.

Expect the worst, but (we all) hope for the best.

[A0283]

@ training wheels video

CCTV INTERVIEW WITH HEAD OF KNKT/NTSC

[ a quick and dirty transcript by A0283,which means it is not meant to be 100% correct, my additions are put between [ ] ...
[ Also, the Q's start the questions by the journalist, the A's start the answers by the Head of the NTSC ]
[And, I left the english as it was spoken]

Q ...[illegible]...[Tatang?]..

Q thank you so much for your time, You must be very busy,

Q how is your investigation going, were are you right now,

I think from the [find] of the flightrecorders...

Information has been download,

About 1200 parameters... and then frame hours download for 174 hrs...

Then from CVR... we download the length of 2hr and 4min...of the information [from] the CVR.

Q and did you find any red flags....like anything that caused for an alarm, that immediately stands out,

A ... there are around, just little more... when the accident happened to the aircraft,

A but the content is undisclose methodology...cannot be published,

Q so, to know cause of this crash, do you need all the wreckages, or is it...

A NO,

Q enough for the black boxes,

A [but] it is very good to lift it, makea mock up, and then to show it to the public, as lessons learned,

Q ...you will leave in your hands... you have the key to the cause of the crash,

A we have the key,

Q is it weather, is it because of the clouds,the weather,

A I cannot say like that, [clouds] that is only one aspect, [just] one factor, ...accident always happen because of too many factors ... clouds,

Q so we can you already found other factors,

A yes... also [found] other factors,[confirms and nods],

Q the Indonesian safety record is not very good, compared to other countries, what are some of the most pressing concern[s] that you have, as head of the NTSB [NTSC],

A I think our improvement started in2007, our rate of accident [was] dramatically reduced, from [then] 4.12 to 1.53[per ... ] in 2013, .. [dropped], assisted by the rate increase operational [flying]hrs...

A rate of

A to maintain [improve] our safetyculture, ... and then to enforce safety recommendations,...operators and also the regulators,

Q there is a lot of international attention on this crash, because of the two major crash that happened during[in] 2014, MH370 and MH17,

Q a lot of talks been going on, that [there] should be a better way for the black boxes to be found, for finding the black boxes ... to be found,

Q that this is something crucial for the aerospace industry

A sometimes we find difficulty to find the black box, where are they, especially when they happen at sea, and costly to find,

A I think in the future ... it should be new technology to transfer the FDR and CVR.. [data/information] to another system,

END OF INTERVIEW

[Capn Bloggs]

Large aeroplanes are not intended to be stalled, hence there is no procedure required to recover from a fully developed stall.
No, "required" should be "provided".

[klintE]

He's not revealing too much at this stage which is understandable.

Not revealing much but the message is that he clearly knows what happened.
Which is not specially surprising. They've heard recordings from the deck, they got radar data, they got large part of the wreck and (probably) autopsies.

And I suppose the moment when his knowledge will see the light of the day will be earlier then the publication of the preliminary report. Officially or not.

[albatross]

RE AO283's post
"Memory module cylinders" on the CVR , FDR boxes?
I always thought those were the "pingers" and that all data was contained within the CVR FDR boxes themselves.

[archae86]

I always thought those were the "pingers" and that all data was contained within the CVR FDR boxes themselves.

Nope.

Different brand, but with reference to this picture:
https://commerce.honeywell.com/wcsstore/B2BDirectMyAerospaceAssetStore/images/catalog/755x353_flight_rcdr.jpg
The small shiny cylinders are the pingers, which are attached to bigger red cylinders which contain the actual data memory--and some appreciable shock mounting and armoring. The main electronics are in the L-shaped rectangular boxes, which don't actually need to survive, as they are finished with their function by the time serious disruptive forces arrive.

Disclosure: I'm not a pilot. I am an electrical engineer, with a few degrees from MIT.

[p.j.m]

actual CVR blackbox from QZ8501

http://i.imgur.com/OBmj6wt.jpg


AirAsia flight QZ8501: Recovery crews suspect they have found crashed jet?s cockpit, engine (http://www.news.com.au/travel/travel-updates/airasia-flight-qz8501-recovery-crews-suspect-they-have-found-crashed-jets-cockpit-engine/story-fnizu68q-1227187788707)

[p.j.m]

Some of these officials, who were involved in the disputes, remember how tension between the two camps initially erupted. In the wake of the SilkAir flight that went down in a muddy Indonesian river delta in 1997, killing all 104 people on board, U.S. and Indonesian experts joined forces to dissect causes of the tragedy. But they had a falling out over the findings of the final report. In the end, Indonesian experts concluded there was no way to conclusively determine why certain flight-control panels on the tail were put into a dive configuration, or why both flight-data and cockpit-voice recorders stopped operating before the fatal dive. NTSB experts, however, felt the physical evidence and other data pointed to pilot suicide. By 2000, the NTSB’s chairman publicly indicated that no airplane-related failures could explain what occurred, and the only plausible explanation was intentional pilot action.

It's concerning if the Indonesian authorities have control of the recovered data, and they have a history of denying an issue if it is something they feel embarrassed about (like a suicide).

[training wheels]

There are reports coming through now that BASARNAS has now located the cockpit about 500 metres from the main fuselage. The pic below is just an artist graphic, but the news report is here (http://video.viva.co.id/read/37855-tim-sar-temukan-kokpit-pesawat-airasia-qz8501_1).

https://pbs.twimg.com/media/B7h8itYCIAAk_b-.jpg

[bud leon]

p.j.m (and others freaking out about Indonesia's capacity to respond)

It's concerning if the Indonesian authorities have control of the recovered data, and they have a history of denying an issue if it is something they feel embarrassed about (like a suicide).

So far there has been a very transparent and I think successful response (aside the issue about routes, which was not atypical of bureaucratic responses in more developed countries).

Interestingly when the NTSB gave early briefings on information during the Aseana investigation they were criticised on this forum for too much too soon.

So far the Indonesians have found the wreckage, located and recovered the FDR and CVR in very challenging and risky conditions, have recovered bodies with dignity and respect, are recovering the fuselage, and are providing clear updates on the state of the recovery and investigation. It's an error to use isolated past experiences as predictors of present and future events.

While the families of 9/11 victims still demand to see the redacted 28 pages, and Australia now has a range of new laws which substantially inhibit transparency, I'd say don't throw too many stones.

[glendalegoon]

these planes are sort of constructed in three big pieces...the front part, the middle part and the tail part


so, it seems we have found the big parts and they sort of break up that way.

[onetrack]

bud leon is correct - and the Indonesian divers merit special acknowledgment for their outstanding recovery efforts in conditions that are dangerous in the extreme.
Western divers would be looking for bravery awards under the conditions that the Indonesian divers are working in.

These divers have not only been battling strong and reversing currents - they have been travelling out to the wreckage sites in 2M to 4M waves and enduring violent seasickness as well.
They have been diving to extreme depths, at their diving limit. Then they have had to deal with low levels of visibility, as well as the potential finding of human remains staring back at them. It's not a job I'd volunteer for.

They have not had the luxury of ROV's or mini-subs or other exotic equipment, as many Western nations would produce and use.
They have done an admirable job of finding the wreckage and recovering some of it, in surface weather that has been less than favourable, more often than it has been favourable.

Cut the Indonesians some slack, I'm sure they are just as interested in improving their SAR skills, and finding the real reasons behind the crash, as any of us are.

The fact that a few of the middle-management Indonesians got a little excited and made pronouncements that were guesses, more than actual knowledge, is no reason to write off the whole exercise as one of total incompetence.

[A0283]

The actual recorders ... have vertically mounted memory-module cylinders ...

My intent was to give a general visual description. It would have been more complete if I had written: “The actual recorders have large diameter, orange coloured, vertically mounted, memory module containing cylinders. With the ‘pinger’ being the small diameter, silver coloured cylinder, mounted horizontally with two black brackets onto two orange brackets on the vertical cylinders.

Note - on quite a few recorders these two black brackets are connected directly to the memory module cylinders. Both actual 8501 recorders have a kind of ‘rather fat’ intermediate orange brackets on which these black brackets are mounted.

There is one ‘pinger’ each on the FDR and the CVR. ‘Pingers’ are better called Underwater Locator Beacon’s (ULB's), But in this case labelled “EMERGENCY LOCATING BEACON” by the manufacturer on the one mounted on the actual CVR. Not smart from the manufacturer to label it like this, as the ELB acronym might easily be confused with ELT. The (some are yellow) ELT is the Emergency Locator Transmitter, which should start its work on impact, and works above the water surface (ref its specific ELT higher frequencies). The ULB should start its work when it contacts(sea)water, and works under the water surface (ref its specific ULB lower frequencies). Seems like a small detail. But naming conventions are a sub-category of what is called “configuration management”. And the (most) advanced state of configuration management in aerospace, being both art and science, is (just) one of the reasons why the industry has become, and is, as safe as it is.

@Archae86 - agreed. Note that his image shows horizontally mounted memory module cylinders. So they are not from 8501. Thanks for the nice and shiny image. Better one than you usually find.

@p.j.m. - agreed. @albatross, note that the boss of the KNKT/NTSC pulls the CVR out of the black container by holding onto the ‘pinger’.

[A0283]

these planes are sort of constructed in three big pieces...the front part, the middle part and the tail part ...so, it seems we have found the big parts and they sort of break up that way.

Not always right and not exactly right. But certainly one of the things I look at, from the start of an investigation. In manufacturing they are often called "production breaks". Not always right and not exactly right - and rather simplified - but production break 'lines' are often 'stronger and stiffer' than the areas on either side. So the probability is high that the breaks are on one or either side of these 'lines', and the probability is low that 'through the line itself' is the break. The recovered tail section can be used as a case study. It shows technically important fracturing details.

Note that the production breaks that you mention are on the 'highest level'. Depending on the complexity and design date of the aircraft, there are a number of levels below that. A section break is not the same as the production break/interface of a fuselage panel for instance. This subject is a sub-part of the so-called "interface management". For all kinds of reasons there is a complex relationship between interface management and configuration management. I said something in my previous post about the latter subject.

Let's hope they find the missing passengers and crew in the recently discovered sections.

[sopwithnz]

PANGKALAN BUN, Indonesia (AP) " High waves and strong currents in the Java Sea again prevented Indonesian navy divers from accessing the fuselage and what is believed to be the cockpit from the AirAsia plane that crashed three weeks ago, officials said.

A team of 15 navy divers tried to get to the wreckage to examine it and calculate its weight, but failed to reach it due to the unfavorable conditions, said Suryadi Bambang Supriyadi, director of operations for Indonesia's National Search and Rescue Agency.

Indonesian survey ships have located at least nine big objects, including the jet's fuselage, what is believed to be the cockpit and an engine, Supriyadi said. The fuselage is sitting on the seabed at a depth of 28 meters (92 feet).

The 30-meter-long (100-foot-long) fuselage and an attached wing were sighted Wednesday. Divers attempted to reach the wreckage Thursday and Friday, but were turned back because of the rough sea conditions.

Authorities believe many of the bodies are still inside the fuselage. There were 162 people aboard Flight 8501 when it crashed into the sea Dec. 28 en route from Surabaya, Indonesia's second-largest city, to Singapore. Only 51 bodies have been recovered so far.

The head of the search and rescue agency, Henry Bambang Soelistyo, said Friday that the fuselage would have to be lifted because of the divers' inability to reach it. This will be done by either using floating balloons, as the tail section was lifted earlier in the week, or cranes from tugboats. Soelistyo did not say when the operation would start.

Divers, however, still need to reach the wreckage area. The wreckage that appears to be the cockpit was located by sonar imagery about 500 meters (yards) from the fuselage and was partly embedded in the mud.

"What we have so far is only a silhouette of the wreckage," Supriyadi said. "We need to deploy our divers to identify whether it's the jet's cockpit or something else."

He also said the divers have been told to retrieve the bodies of the pilot and the co-pilot if they are able to find them in the cockpit.

[Hyperveloce]

Hi there,
How long does it take to decode, visualize & analyse the DFR data ? (flight parameters, engine performance, structural modes,...). I mean to get the rought lines of the failure scenario ?
I have been working several years on tactical missile design and testing.
Knowing how a missile test had failed (in this case knowing whether it was a stall, a catastrophic descent due to a dual engine failure, or how these engine or other structural element failed, etc...) would have been a matter of several hours (if no data is missing/corrupted).

[Gysbreght]

How long does it take to decode, visualize & analyse the DFR data ? (flight parameters, engine performance, structural modes,...). I mean to get the rought lines of the failure scenario ?If there are no problems with the decoding and timing of the data, the first may take one or two days. The second will take longer. In terms of causes and effects I expect the accident scenario to be quite complex, and the investigators would be well advised not to publish any data before they have at least a rough idea of the causal chain of events.

[Megathron]

If they have a good idea of the cause but do not feel it urgent to release any information about it, can it be considered that the likely cause is something that does not pose an immediate risk to the operation of other aircraft of the type?

[Ian W]

I'm sure most posters will recall the Ethiopian Airways hijacking back in 1996 (Boeing 767) in which 125 of the 175 persons onboard perished. The pilot ditched the aircraft a couple of miles off the African coast, which was a large factor in the survival of 50. The ditching was recorded on video by a tourist from the beach and is easily found via Google.
As with the Airbus, the 767 has engines below the wing and, as the aircraft hits the water the first break-away is the empennage. I believe the cockpit also broke away (both pilots survived). One can only imagine the terrific forces involved when the engines hit the water, acting as massive water dams - hence the transference of stresses throughout the aircraft and its breaking up. The outcome of that incident bears some uncanny comparisons with this latest tragedy in the way that the hull has apparently seperated.

No doubt the true cause of this incident will be revealed during the next few days/weeks but I am of the opinion (for what it's worth) that the aircraft sustained complete/partial electrical & engine failure in the eye of the storm and the pilot(s) attempted a ditching as per the Ethiopian incident. I cannot see that an Airbus can fall from 32,000 feet and break into such large pieces upon contact with the water - at god knows what speed.

AFR447 fell from 38,000ft and the aircraft broke into similar parts as the Air Asia aircraft. The A330 was dropping at around 11,000fpm (125mph) with very little forward speed. The aircraft debris field was more compact as the underwater currents were not as strong, unlike the stormy sea and strong currents in the latest crash.

As A0283 posted earlier these breaks tend to occur close to the strengthened interfaces - production breaks - between major components. This explains the similarity in components of the debris after very different accidents.

[oldchina]

"If they have a good idea of the cause but do not feel it urgent to release any information about it, can it be considered that the likely cause is something that does not pose an immediate risk to the operation of other aircraft of the type?"

Yes it often can, because otherwise Airbus would issue an All Operators Telex (or whatever it's called these days) which without accepting blame (lawyers!) says "be careful about this".

[Shadoko]

ELT is the Emergency Locator Transmitter, which should start its work on impact, and works above the water surface (ref its specific ELT higher frequencies). The ULB should start its work when it contacts(sea)water, and works under the water surface (ref its specific ULB lower frequencies)
One more time: ULBs work with SONIC waves and ELTs with RADIO waves. Two different worlds...

[A0283]

Quote: ELT is the emergency Locator Transmitter, which should start its work on impact, and works above the water surface (ref its specific ELT higher frequencies). The ULB should start its work when it contacts (sea)water, and works under the water surface (ref its specific ULB lower frequencies)

Shadoko's comment:
One more time: ULBs work with SONIC waves and ELTs with RADIO waves. Two different worlds...


Yes I know. I tried to cover that with the word "specific". I should have written that explicitely as "specific to the use and medium". Your statement is clear and welcome.

[A0283]

As A0283 posted earlier these breaks tend to occur close to the
strengthened interfaces - production breaks - between major components. This
explains the similarity in components of the debris after very different
accidents.



As I mentioned in my post ... my statement is a simplification ... even with that in mind, I would personally like to adapt your lines a little to something like: “... A0283 post ... these breaks have a higher probability to occur close to the ‘stronger and stiffer’ interfaces, like the so-called production breaks between major components. This may explain similarities in aircraft break-up and components/debris distribution. Even after quite different accidents.” Or perhaps we should say “accidents with different causes”.

In that respect, depending on the type of accident, it could be well advisable to add a manufacturing engineer (which is a special job function, each Tier 1 aircraft manufacturer has a a few) to an investigation team. Their view can add to the views that people with a pilot, design engineer, and maintenance background may not immediately have. Would be interesting to know if anyone has any knowledge of, or experience with this in practice.

Your remark about AF447 made me think back to that accident. The main debris field was only 600x200m, and that at a depth of 3,900 m if I am not mistaken. That ‘compact’ distribution (its an ocean !, and it was in the ITCZ! at that time, and...) still amazes me ... for that depth. Compared to that, relatively speaking, the QZ8501 sections are (figuratively) ‘miles apart’. More knowledge about this might help (even if we do everything to prevent crashes from happening) future searches.

[MountainBear]

If they have a good idea of the cause but do not feel it urgent to release any information about it, can it be considered that the likely cause is something that does not pose an immediate risk to the operation of other aircraft of the type?

That is a reasonable inference.

[Boomtown]

Warning reference to QZ 8501 autopsies below.





It has been reported today that autopsies have QZ 8501 passengers revealed impact injuries such as broken legs, but no burns. Source:

Divers sent to investigate pings from crashed AirAsia flight QZ8501 (http://m.indiatoday.in/story/airasia-flight-qz8501-plane-crash-underwater-pings-java-sea/1/412507.html) (apologies for mobile link).

I recall that AF447 pax also suffered broken legs from the upward impact of their seats.

[LNIDA]

Unlike the AF crash i suspect this airbus hit the sea with some forward speed, cartwheeled and came apart.

I further suspect that this was a weather induced loss of control and at some stage an attempt at recovery was made, but the vertical rate of descent and space between cloud base and hard deck was insufficient

I very much doubt the weather was directly responsible the break up, but if they ended up in a viscous updraft and pitched down and cut the thrust it would be very easy to loose it and recovery in cloud with no visual reference, much turbulence and all manner of warnings going off......there but for the grace of god

[Schnowzer]

Vertical speed of about 10,000fpm is about 100kts straight down so coupled with 100kts forward it will not be pretty on hitting the ocean!

[A0283]

The majority of posters appear to 'vote' for most likely scenario(s) (and versions of those) going like: ‘... an event or upset, leading to a (low speed) stall, no recognition of that stall, or impossible or too late to recover from that stall, and finally the plane hitting the water at an almost even ‘keel’ ...’

I have read interesting comments on other scenario’s though. So I hope those interested in other scenario’s will share comments or suggestions on the following ‘theoretical scenario’.

What would the damage look like, if an almost intact A320 would dive almost straight in?

Keeping in mind the special circumstance in the 8501 case, being that the water is only 28-30m deep. If you take the fuselage length of 37.50 m and subtract the waterdepth of say 29.00 m you get 8.5 m. Now assume that the nose reaches the seafloor. The tail part that ‘sticks out’ is about 8 m. That would roughly be around frame 68-70. Ergo, around the aft strong frame of the aft passenger door?

The exact angle of entry into the water will then determine how the tail section breaks off. Following the earlier ‘production break’ discussion, that could be either just in front, or just behind the aft passenger door. It could also provide a (the section moving ...forward, backward or sideways) break-up scenario for the components of the tail section.

It is possible to think of a path now, that leaves the vertical tail rather undamaged( we can try to match that with the visible fractures – of course trying to exclude damage caused by pulling the tail on board Crest Onyx). And losing the APU and the THS. Where perhaps (see earlier posted scenario’s) the tail section with tail floated before it became water logged, anchored, and overturned. But now the THS also floated before becoming water logged. And therefore it is possible it will be found a bit further away.

I did some tower diving in the past from 10-12 m. When you get in under even a small angle with the vertical, your spine is bent, quite a force, so would fuselage show a kind of water dampened whip 'reflex'. Always very complex to make dynamic stress calculations ... but ...

Answers to these questions might be of some assistence in future searches. Till this accident it seemed most likely, if anything was found on the surface, find vertical tail or rudder first. Would it help to give SAR crews a description of most probably objects to look for. Also helping to separate ocean garbage from aircraft components and fragments.

[Jet Jockey A4]

Not an expert but if as you suggest the aircraft "went straight in" then one would have to assume it is not in a "stalled" condition, thus probably hitting/entering the water at a substantial speed.

In this case it would most likely break apart in many small pieces upon hitting the water almost like hitting solid ground.

[Ian W]

@A0283
Answers to these questions might be of some assistence in future searches. Till this accident it seemed most likely, if anything was found on the surface, find vertical tail or rudder first. Would it help to give SAR crews a description of most probably objects to look for. Also helping to separate ocean garbage from aircraft components and fragments.

A vertical or close to dive into water would cause considerable damage to the nose of the aircraft and stresses would show that the aircraft hit something nose first.
Passenger injuries would show severe seatbelt injuries and seats would be broken away from the floor and compressed toward the front of the fuselage. I am not sure that pax would show the same broken legs that appear to be apparent in this case. There would also be more detritus from inside the fuselage.

[Theoretical Scenario]

The concertinering of the fuselage seems to show that the aircraft hit the sea surface belly first perhaps with a slight nose down to provide the hydraulic disconnection of the empenage at the pressure bulkhead. As pointed out several times the break line of the tail is not consistent so there may have been a one wing low and turning vector.
So as a theoretical scenario, loss of control, stall into a relatively flat spin. This would also fit with the descent rate, a dive would have been considerably faster more than 30,000 fpm.
From Stall/Spin (http://www.aopa.org/asf/ntsb/stall_spin.html) " if the impact occurs nose down, at a high rate of descent which is typical of stall/spin scenarios, the G forces tend to be much higher, the aircraft does not slide much and there are resulting fatalities."

[/Theoretical Scenario]

[henra]

What would the damage look like, if an almost intact A320 would dive almost straight in?


Millions of tiny bits'n pieces....

Whatever remained would show orthogonal/circumferantial crumple lines instead of longitudinal.

This one here pretty surely hit flat (with maybe a touch of bank angle). If anything rather a tad Nose Up rather than Nose Down. Especially the seat structures showed signs of vertical and pratically no visible longitudinal bending. The same with the folds in the fuselage/tail skin

[mcloaked]

An interesting news article:

AirAsia flight QZ8501: Crash highlights perils of South-east Asia's crowded skies - South-east Asia News & Top Stories - The Straits Times (http://www.straitstimes.com/news/asia/south-east-asia/story/airasia-flight-qz8501-crash-highlights-perils-south-east-asias-crowd)

[Ian W]

An interesting news article:

AirAsia flight QZ8501: Crash highlights perils of South-east Asia's crowded skies - South-east Asia News & Top Stories - The Straits Times (http://www.straitstimes.com/news/asia/south-east-asia/story/airasia-flight-qz8501-crash-highlights-perils-south-east-asias-crowd)

Ask for a higher level on the Atlantic you will get a similar 'UNABLE DUE TRAFFIC' response. Then the article segways from that into apparently trying to blame ATC for the incident. Looking at the surveillance pictures showing the amount of traffic around 8501 - it takes a fair amount of hyperbole to call the airspace 'busy'.

As pointed out multiple times ATC has to meet separation standards that are enforced (often by automation 'snitch'ing to supervisors) Unless the flight crew states this is an urgent request to avoid weather, then the request will be treated as routine, so you will need to standby while the controller coordinates the level change with other sectors and the next air traffic unit. As I have said before 'communicate' in time can reduce pressure on 'aviate' later. If concerned take the weather avoidance then tell ATC what you are doing. Ideally do it into a space in the TCAS traffic picture :ok:. You have to balance the risk of the weather against the risk of loss of separation.

[Machinbird]

I've had the opportunity to investigate a military accident (dive into water @550 knots 50 degrees ND, and to see the wreckage first hand of a 250 knot fly into the water in (near) level flight. In addition, I had the opportunity to participate in almost the entire AF447 thread. QZ8501 was not a dive into the water. A high speed dive would shatter the aircraft into its component bits & pieces with the leading component pieces more highly fractured than the trailing components (due to deceleration).

From the damage observed so far, the aircraft entered the water at very low forward speed in a near level, slightly left wing down attitude. The major velocity component was downward. By comparing the damage observed with AF447 and with some of the events of the Perpignan A320 accident, there is one glaring difference. The vertical stabilizer remained attached to the fuselage structure until the tail was crushed from beneath. Instead, the skin forward of the VS shows a small section of fore and aft force induced compressive wrinkling in addition to the vertical compressive force induced folding along the stringers lower down. Below that, the structure was shattered and is missing with damage extending further up the port side than the starboard side.

In other words, it hit the water slightly left wing down, with minimal horizontal velocity, in a flat attitude with relatively high vertical velocity. I'm open to differing opinions, but there is only one way I know of to put an aircraft into the water in this way, and that is a flat spin (as differentiated from a nose down spin).

Transport aircraft are not intentionally deeply stalled during flight testing nor are they spin tested let alone training pilots how to recover from a full stall or a spin. For this reason, if a spin is entered at altitude, it is likely to continue. Often flat spins in jets are not recoverable events and are dependent on the specific aircraft characteristics (mass distribution-types of control surfaces, general planform etc.)

I know some of you fly aerobatics including spins however, flat spins in larger aircraft have an additional hazard in that the crew is located far from the center of rotation, and thus even a modest rate of rotation in a spin creates disabling eyeballs out g effects. For example, in the F-14 front seat, you had to lock your shoulder harness at the beginning of the event or you would be folded over in your seat and unable to eject. I don't think A320 pilots would be particularly effective in recovering from a spin if they found themselves involuntarily staring at their kneecaps:uhoh:.

Assuming that the foregoing analysis is in the ball park, it will be very interesting to learn how this departure from controlled flight developed.

[mcloaked]

@Machinbird: Your comments on flat spin are interesting, and it is possible to put some figures on the g load that a pilot would encounter using some basic physics. The acceleration during circular motion is 4 Pi squared times the radius for the motion times the square of the number of rotations per second. If the pilots are about 15 metres from the centre of rotation during a flat spin, and the aircraft was rotating about a vertical axis taking 3 seconds per rotation which is not unrealistic in this scenario then this gives a radial acceleration which after normalising to 10 m/s/s for 1G, leads to a g load in a direction facing the front of the aircraft (eyeballs out as you said), of over 6G. Any faster rotation than 3 seconds per turn would give even higher g loads which would likely render the pilot unable to react to the controls as you have detailed in your post. This calculation confirms your analysis if the aircraft did end up in a flat spin, despite this being a significant departure from the normal flight envelope. Nevertheless the FDR data should ultimately provide evidence as to whether the aircraft did end up in a spin following the event sequence at the time of loss of contact.

[macdo]

With a few minutes to spare after an LPC, the instructor demonstrated how easy it was to spin an a320. The spin was totally classic albeit with an astonomic RoD. Recovery was similarly straighforward. I think the loss of altitude was about 6000'.
I am in no way suggesting that in real life things would be so simple, but it was an interesting and reassuring experience.

[susier]

For those drawn to the fake CVR recording on Youtube that has been linked to at least once, please don't think it's genuine - it's very clearly not from an A320, and is probably a recording from a different incident.


There is no audible Bank Angle warning in an A320 afaik.

[Ian W]

With a few minutes to spare after an LPC, the instructor demonstrated how easy it was to spin an a320. The spin was totally classic albeit with an astonomic RoD. Recovery was similarly straighforward. I think the loss of altitude was about 6000'.
I am in no way suggesting that in real life things would be so simple, but it was an interesting and reassuring experience.

Of course that was without the out-of-spin g forces which may have made things a little more interesting. :eek:

[HeavyMetallist]

With a few minutes to spare after an LPC, the instructor demonstrated how easy it was to spin an a320. The spin was totally classic albeit with an astonomic RoD. Recovery was similarly straighforward. I think the loss of altitude was about 6000'.
I am in no way suggesting that in real life things would be so simple, but it was an interesting and reassuring experience.

As has been pointed out, there has been no spin testing of A320s (!) to provide data on which to base a simulation. The reason the simulation behaved in a "totally classic" manner will have been precisely because that was how it was programmed to behave, similarly the recovery. Any reassurance you gained was based on an educated guess, at best!

[Sailvi767]

There have been several references to the Ethiopean 767 crash. It appears some think this was a controlled ditching. It was a higher speed impact with the water while the crew was engaged in a ongoing struggle with the hijackers right up to the moment of impact. It was not a controlled ditching.

[md80fanatic]

What chance would engines have remaining attached in a 3 second period flat spin? Pylons don't appear to be made to tolerate many lateral g's.

[quackers]

Further to Ian W's comment:

Please excuse my ignorance, but do we have any evidence at this stage of any 'concertinering' of the fuselage or of any injuries (post mortem) other than broken limbs ?? Perhaps I've missed some latest photographs ??

[grizzled]

A couple of things...

First, it's so good to see some of the real professionals and experts back posting after so many have been quiet since the halcyon days of pprune (the AF447 threads come to mind of course). You -- and long time ppruners -- know who you are.

Second, whatever the cause(s) of this accident, the aircraft did not "explode" or come apart at altitude. A transport category jet aircraft without tail surfaces does not / cannot impact the surface in a near flat or near horizontal attitude. It would impact (whatever surface) nose first and at a vey high rate of descent. Very few large intact pieces would remain.

Lastly, as others have said in rebuttal to negative comments (including some slurs) against the Indonesians, their SAR, their ATC, and their investigative agency: Those of us Bules (Bahasa for foreigners) who have worked with them and for them recently agree that painting them as inept and/or corrupt is simplistic and inaccurate. The level of professionalism and commitment to improvement over the past few years is clear and obvious to other governments, ICAO, international corporations and individual aviation experts.

[PT6Driver]

A number of posts trying to find alternative explanations, many without due regard to the photographic evidence posted earlier in the thread, the basic laws of physics and how one should fly a modern jet aircraft.

Not in any particular order, no blame or insult is intended:

Vertical dive into sea.
A.Take an empty drink can and with the can on its base stamp on it.
B. Take another empty can lay it on its side and stamp on it.
Do the fusalage photos look like a or b?
Answer b. Therefore it can be infered that the plane hit the sea more or less horizontally.

Ditching.
You do not lose speed by banking the aircraft.
Ditching configuration varies acording to aircraft type but for all aircraft one should land parallel to the swell line with some degree of nose up attitude and wing level.
The time frame available is usually short enough that getting this right is very difficult.
C. Take yet another empty drinks can and scrape it horizontally along some rough concrete. (The sea will be as friendly to an aircraft).
Does the can look anything like the photos? Answer no. Inferance is therefore ditching very unlikely.
Please dispose of your cans in an environmentally friendly manner.

[BG47]

SINGAPORE: Singapore's search operation to locate the debris of the crashed AirAsia plane came to end today with its ship that found the jet's fuselage in the Java Sea returning back after days of rigorous scouring.

Singapore's Navy ship, MV Swift Rescue, with 70 men and women on board, arrived at Changi Naval Base here and was received by the country's Defence Minister Ng Eng Hen. He was accompanied by chief of Defence force Ng Chee Meng and navy chief Lai Chung Han.

The arrival of MV Swift Rescue marked the official end of Singapore's efforts in the multi-nation search operation, which started on December 28 when AirAsia plane carrying 162 people from Indonesian city of Saurabaya to Singapore crashed into the Java Sea within less than an hour after take off. Since then, the Singapore Armed Forces (SAF) have deployed more than 400 personnel, two RSAF C-130 aircraft, two Super Puma helicopters, five navy ships and a six-man Autonomous Underwater Vehicle team in the operation.

Many of those who had contributed to the search were also present for MV Swift Rescue's home-coming. As a mark of respect, they observed a minute of silence for those who died in the aviation tragedy. The Defence Minister thanked the servicemen and women for their efforts and for making a difference in the multi-nation search operations. The return of the vessel marks the end of the SAF's 22-day deployment for the search operations, he said.

[DrPhillipa]

Mindboggling stuff, as bad as advanced sailing theory. So presumably non of the boundary conditions for any of these swapover points are known for the A320, and so there is no way of knowing exactly when and how it will stall and or spin? especially if you include such things as changing CofG, weather etc.

If I recall the test regime for the 380 (I guess the 320 was similar) that consisted mostly of slowly going slower and slower as well as faster and faster until things got obviously dangerous, ceasing before you crashed and telling the computer not to let the AC go there. That with the background of fairly low g loading limts for the airframe which would make many escape strategies impossible anyway.

[RF4]

If it turns out to be a spin then Airbus should deeply think about an automated response by the flight control computer. The pilots have no realistic chance to break a full spin action. However the computer most likely can and has usually an easy and safe indication from the gyro instruments. If it takes 10000 feet so be it given the alternative of an assured crash.

In theory , perhaps a good idea, given that the flight crew would be effectively incapacitated. However, I must ask just what that programmed response would be. Airbus have no data, other that theoretical and computer simulated, concerning how the A320 would behave, and consequently what to tell HAL to do when all hell breaks loose.

Who is going to do the test flights to supply the necessary data to ensure that the programmed response is correct in all situations? That would be a very expensive and arguably fatal endeavour. If that data is not available, and HAL is programmed for a theoretical/simulated response who is going to do the testing necessary for certification ? I'm sure that Airbus has thought of such an 'adventure' during planning and totally rejected the thought for obvious reasons - similar thinking for a full stall.

Now you know why Airbus puts so much emphasis on avoidance.

[TyroPicard]

At least QZ 8501 had less kinetic energy in the vertical direction
Given the same water entry parameters, KE is proportional to mass..... and A320 is a lot lighter than A330...

[172driver]

I am quite sure this is true for any modern large transport certified after the 70s.

Apparently not so:

B787: https://www.youtube.com/watch?v=SvEMgmirldc
Includes interview with Boeing chief test pilot

MD11: 1990: MD-11 Memories | Things With Wings (http://aviationweek.com/blog/1990-md-11-memories)
The stall test comments come at the very end of the report

[Interflug]

If you believe (and told so) that your aircraft is protected from stall, you may not avoid it as actively as if you know it can kill you…
Bravo, the essence of the problem leading to these fatal accidents in a few words. (but let's wait for the data, to be sure)
You may not avoid it as actively and you may not know how to recover from it.
Bottomline it is difficult to say, if the computer protection has saved more lives than its presence has lured management and pilots into negligence regarding their skills of handling the aircraft at the borderlines of aerodynamics and costing lives in the process.

[FullWings]

If it turns out to be a spin then Airbus should deeply think about an automated response by the flight control computer. The pilots have no realistic chance to break a full spin action. However the computer most likely can and has usually an easy and safe indication from the gyro instruments. If it takes 10000 feet so be it given the alternative of an assured crash.
Problem with that is that from past evidence, unusual attitude / loss-of-control has occurred because the automated systems have given up due to conflicting/unverifiable data and dumped the whole lot back on the pilots to make something of it. If it is possible to get the aeroplane to “self recover” from spins, etc. then there is enough information to stop it happening in the first place, which I would suggest is the prime goal.

[Livesinafield]

Why is ther so much discussion about stall spin? Have a missed a statement ?

The aircraft looks fairly intact almost as if it was in a semi controlled state when it went in, the pictures of the af447 wreckage look a lot different

[Sikpilot]

AT what point in the crash do you think the tail separated from the fuselage?

The reason I ask I assume when the tail separated, the CVR and FDR went with it and and that will be the last data recorded.

[Boomtown]

Some information regarding the content of the CVR:

When asked if there was any evidence from the recording that terrorism was involved, Hananto said: “No. Because if there were terrorism, there would have been a threat of some kind.“

“In that critical situation, the recording indicates that the pilot was busy with the handling of the plane.”

Investigators said they had listened to the whole of the recording but transcribed only about half.

“We didn’t hear any voice of other persons other than the pilots,” said Nurcahyo Utomo, another investigator.

“We didn’t hear any sounds of gunfire or explosions. For the time being, based on that, we can eliminate the possibility of terrorism.”

Source: AirAsia crash investigators find no evidence of terrorism | World news | The Guardian (http://www.theguardian.com/world/2015/jan/19/airasia-crash-investigators-no-evidence-terrorism)

[AirScotia]

"...the pilot was busy.."

Perhaps only one pilot in the cockpit at the critical moment?

[Boomtown]

More info re CVR:

"From the (flight data recordings) so far, it's unlikely there was an explosion," Hananto said. "If there was, we would definitely know because certain parameters would show it. There are something like 1,200 parameters."

The final minutes of the AirAsia flight were full of "sounds of machines and sounds of warnings" that must be filtered out to get a complete transcript of what was said in the cockpit, said Hananto, who has been an air safety investigator since 2009.

The first half of the two-hour long cockpit voice recording has been transcribed. That includes audio from the previous flight and the beginning of Flight QZ8501, which crashed around 40 minutes after takeoff.

The team, which is working with French, Singaporean and Chinese air safety investigators, hopes to finish transcribing the recording this week, Hananto said.

With seven computers and various audio equipment, the small NTSC laboratory dedicated to the AirAsia investigation is split into two rooms; one for the cockpit voice recorder and the other for the flight data recorder.

Analysis of the flight data recorder would take longer, Hananto said, because investigators were examining all 72 previous flights flown by the aircraft.

Investigators hope to finish a preliminary report on the crash early next week. The full report could take up to a year, but will not include the entire cockpit voice transcript.

"In Indonesia it remains undisclosed," said Tatang Kurniadi, chief of the NTSC. "Just some important highlights will be included in the report."

Source: Indonesia says no evidence so far of terrorism in AirAsia crash | Reuters (http://uk.reuters.com/article/2015/01/19/uk-indonesia-airplane-investigation-idUKKBN0KS0SM20150119)

Nurcahyo Utomo, another investigator from Indonesia’s Transportation Safety Committee, said nothing heard on the audio recording so far suggested pilot suicide played a role in the crash.

“So far we’ve managed to transcribe only half of it because there are so many noises,” he said. “We hope to complete it in a week.”

Source: http://www.wsj.com/articles/airasia-crash-investigators-no-sign-so-far-of-terrorism-pilot-suicide-1421667736?tesla=y

[DouglasFlyer]

Perhaps only one pilot in the cockpit at the critical moment?

Perhaps not:

“We didn’t hear any voice of other persons other than the pilots,”

[Ian W]

Problem with that is that from past evidence, unusual attitude / loss-of-control has occurred because the automated systems have given up due to conflicting/unverifiable data and dumped the whole lot back on the pilots to make something of it. If it is possible to get the aeroplane to “self recover” from spins, etc. then there is enough information to stop it happening in the first place, which I would suggest is the prime goal.

I am not sure that is true.

The spin self-recovery could be a basic protection that is not lost. As it can use GPS Alt, and Inertial Nav to identify the aircraft is dropping fast and rotating in a particular direction. Then the system takes over and carries out the recovery.

Entry into a stalled/spin condition could be extremely fast in severe turbulence at cruise level with sudden wind reversals and OAT changes and yes even pilot mishandling. In some cases there may be no gentle and considered 'approach to stall'.

[HeavyMetallist]

I think the continuous references to "HAL" have misled some people into thinking that the Airbus flight control system is far more capable, in the sense of intelligent, than it is. It's actually fundamentally very conservative in design, only flies the aeroplane itself in quite benign parts of the flight envelope, and uses simple rules (albeit perhaps in too many combinations for some peoples' tastes) for its protections. It would be a massive change to give it the capability to reliably identify spins, quite possibly in the presence of sensor failures or anomalies, and then somehow act like the autopilot to end all autopilots in recovering from that spin, without the benefit of prior data on spin characteristics and best recovery methods. It's not going to happen, at least anytime soon.

[Sailvi767]

As posted above the Airbus has a very basic FBW system. Spins have so many modes and types that it can be very difficult to identify if the aircraft is spinning and what mode. Even more advanced FBW systems incorporating rate motion feedback can't recover from a spin. In fact the most important step in spin recovery for the F18A was to disconnect the FBW computers and go to direct electrical link. The Airbus does not allow pilot selection of that option.
You would also have to do extensive spin testing on the aircraft in order to determine the proper recovery inputs for each spin mode and CG situation.

[Volume]

Analysis of the flight data recorder would take longer, Hananto said, because investigators were examining all 72 previous flights flown by the aircraft.So they are not only examining the famous "what does it do now", but also "did it do that before"? Interesting that they look at all the previous flights, is there some pre-existing malfunction suspected? Do they need to calibrate some models?

That includes audio from the previous flight and the beginning of Flight QZ8501, which crashed around 40 minutes after takeoff.
100% Audio coverage is a very positive thing. That may help a lot.

Overall it looks like some more professional people are now on the job. The Statements given do make much more sense than previous ones...

[Australopithecus]

Heavy Metallist: bravo.

There are problems with protections and envelope constraints: they rely on fallible sensors for their information. So, back to "Data Processing 101" : Garbage In= Garbage Out. True in 1971, doubly so now.

For the uninitiated- the aeroplane relies on its flight control software to implement the control laws complete with protections to address the needs of 99.99X% of all flights. On a very very few flights the sensors get compromised, all of the laws, protections and load relief goes away and the now betrayed crew is left with a lightweight, flexible, undamped aeroelastic, auto trimming nut case with a one-eyed determination to save the day by diving or stalling the aeroplane into the ground.

Bad sensors. Like bad rumours, mixed up lab results and WMD intelligence, they lead to grave misjudgements and irrevocable error. The problem of an uncrashable aeroplane is the same as an unsinkable ship: The crew has to politely smile at the marketing, understand its limitations and, if called, be able and willing to step up and act like an old fashioned master, not someone who is just along for the ride. (EMPHATICALLY NOT SUGGESTING THIS IS THE CASE WITH THE ACCIDENT FLIGHT, by the way. But I suspect that it is an industry problem. )

The flight guidance system at this stage is too rudimentary to provide guidance out of unusual attitudes. That's the stuff that we are supposed to be experts at after 15 or 20 minutes of training every couple of years. Oh...and the mythical aerobatic experience as a teenager followed by the fighter training and pylon racing, I guess.

Since recovery from inappropriate energy states and attitudes is actually pretty binary it might be possible to quickly develop a recovery guidance mode to facilitate the lowest common denominator crew** to follow prompts or director cues to the correct attitude to regain normal flight paths and loads. That would be the missing half of the promise that fly-by-wire makes: (This aeroplane is not stallable. If, however, you do stall it, it will tell you how to undo your error)

**: this is relative, obviously. Any one of us could be the lowest common denominator depending on skill, experience, fatigue and other intangibles on the day.

To recap:
1:FBW is a huge improvement on the pieces of sh1t that I used to fly when I was a zygote. So is almost everything else
2:FBW has probably reduced the incidence of serious incident by at least an order of magnitude. (And hence the accident rate is equally reduced)
3: Auto flight, at least on the approach, is not as smooth as the hypothetical experienced, well rested crew.
4:Like all numerically controlled machines, modern aeroplanes rely on sensors. Lots of them. They are lightweight, built to a price, and they fail from time to time.
5:Spurious warnings, cautions and whatnots are far more common that real ones.
6:Spurious alarming data is not immediately distinguishable from actual alarming data.
7:Active protections can save passengers from random dumb crew mistakes.
8:Spurious protection triggers can expose passengers to random dumb designer mistakes. (Too trusting of sensors without appreciating the "what if" hypothetical scenarios. Which happen from time to time)
9:"Golden Rule" instructions are all predicated on the presence of a very experienced, jaded yet competent crew to fly manually like a conventional aircraft when any unexpected or sub-optimum performance is demonstrated by the automatics, however subtle.

On edit, added: 10: the altitude capture mode, called "Alt star" presents peril when it engages during a high rate of climb manoeuvre. It locks in the current rate of climb, in this case, if it engaged, at over 1000 ft below the target altitude. If the wind shear dissipates and or the updraft fails, the aircraft will be left with a rapidly decaying airspeed and an autopilot disconnect at high alpha.

(At my peak I used to manually fly 1000+ hours every year. On raw data. While doing star shots and smoking black coffee and drinking unfiltered Luckies. And listening to disco music on the ADF receiver. While keeping an eye on that pesky number 13 cylinder on number two.

Today I get about three minutes of manual flying per week. I am considered a thrill-seeker for doing that much. Incredibly, an entire industry has grown on the convenient lie that the old skills, if ever attained, remain honed after decades of neglect.

[formationdriver]

One of the most educated and intelligent posts read on this forum. But what of the folks who were /are NEVER even taught the "old skills...?"

[rideforever]

In this world, the whole point of flight control software is to make planes cheaper by making pilots cheaper, giving manufacturers something to contrast them with the competition.

Training pilots properly AND having sophisticated flight control software makes no financial sense.

[FullWings]

9:"Golden Rule" instructions are all predicated on the presence of a very experienced, jaded yet competent crew to fly manually like a conventional aircraft when any unexpected or sub-optimum performance is demonstrated by the automatics, however subtle.
Yup, I couldn’t agree with you more on that.

As others are saying, FBW and envelope protection has likely saved many more lives than ended them but we are getting to the point that experience levels (that is experience in directly controlling an aircraft in all flight phases) have deteriorated such that: a) realising something’s not right takes some time, b) working out what might be done about it takes yet more time and c) actually taking the aircraft by the scruff of the neck and putting it roughly where it should be has become a HUGE decision accompanied by much trepidation.

I was in the sim yesterday and did a couple of unreliable airspeed scenarios. Taking out the FBW after the initial diagnosis made it so much easier, as the aeroplane was no longer actively trying to kill you.

[Una Due Tfc]

They'll be going all the way back in the FDR to check for previous malfunctions of systems as well as to see if anything else may have played a role I.E. unreported heavy landing etc that may have weakened the structure

[A0283]

Australopithecus nice post :-)


...to address the needs of 99.99X% of all flights. On a very, very few flights the sensors get compromised,...




In your post you do not specifically mention one of the 'major automation and FBW sales items', which might be called "continuous trip optimalization" (from the economics point of view) (which might contain quite a lot of boring 'continuous' fuel/alt/cost/eta calculation)."

Could we say that 'trip optimalization' is for the 99.99X%. And that for the other (100-99.99X%) we sincerely need to revisit, redefine and retrain pilots 'flying skills optimalization'.

Is there an open source publication that compares the actual trip optimalization performance of low, medium and highly experienced pilots?

Would be interesting to hear your views on these two questions.

[A0283]

AirAsia crash not the result of terrorist attack | Video | Reuters.com (http://uk.reuters.com/video/2015/01/19/airasia-crash-not-the-result-of-terroris?videoId=361818664)


FYI the Reuters article has a short video in the lefthand corner showing the KNKT lab and a very short interview with one of the investigators.

[jcjeant]

The final minutes of the AirAsia flight were full of "sounds of machines and sounds of warnings" that must be filtered out to get a complete transcript of what was said in the cockpit

"sounds of machines and sounds of warnings"

That's a old story .....
Now investigators thanks to the analysis of the FDR will be able to sort these warnings and know which ones were appropriate and which were inappropriate
Will the pilots have the means or knowledge to do this sorting in fews minutes ?

[susier]

I do wonder if the situation with ECAM can sometimes be likened to having a padlock in front of you, ie the actual problem that's occurring, and you're handed a bunch of keys and have to try each in turn before you get to the correct one.

[DrPhillipa]

5:Spurious warnings, cautions and whatnots are far more common that real ones.If we are talking about stall warnings, this does not seem to be the case, not in AB anyway. The 767 and 737 had their problems it seems. ATSB, at least mandates reporting of All stall warnings. http://www.atsb.gov.au/publications/2012/ar-2012-172.aspx (https://duckduckgo.com/l/?kh=-1&uddg=http%3A%2F%2Fwww.atsb.gov.au%2Fpublications%2F2012%2Far-2012-172.aspx)

6:Spurious alarming data is not immediately distinguishable from actual alarming data.
It can by definition not be distinguishable, otherwise it would not be alarming. Unfortunately non useful reactions are 1) panic or 2) ignore it 3) decide it is "spurious" - in any order.

Useful reactions one assumes are part of the type training of pilots. c) actually taking the aircraft by the scruff of the neck and putting it roughly where it should be has become a HUGE decision accompanied by much trepidation. should this not be AAA* priority 1 rather than c? - though possibly inserting a "gently" or "carefully" somewhere? The Quantas A380 exploding engine crew seem to have done it right, others less so.

8:Spurious protection triggers can expose passengers to random dumb designer mistakes. (Too trusting of sensors without appreciating the "what if" hypothetical scenarios. Which happen from time to time)I am far from convinced that there are many "spurious protection triggers" or "dumb designer mistakes". No, I am not a pilot, but I have been intimately involved in real time safety critical software design, realisation and testing. The overwhelming majority of the work is actually involved in the "what ifs". Unfortunately in some situations there is just not enough information for the software to continue reliably. Why the Bus can not default to sensible neutral values of thrust and pitch (and trim maybe) before dumping it on the pilots I do not know, I have only worked on environmental software for AC not FBW.

[TyroPicard]

DrPhillipa
Why the Bus can not default to sensible neutral values of thrust and pitch (and trim maybe) before dumping it on the pilots I do not know
So many posters know diddly-squat about A320 FCS.... if you don't know why post?
It does not "dump" on the pilots... In alternate law thrust is locked at current value until PF takes over manually, pitch law remains (with auto-trim) the same (1g stick free so no pitch change if you leave it alone), except you lose protections in the event of high speed, high alpha, and big pitch excursions, roll law degrades to direct control of ailerons and spoilers.
If it goes to direct law then you have direct control of elevators as well, and must use manual pitch trim.
In all laws the a/c remains completely controllable by flying attitude.

[RatherBeFlying]

An A330 driver was telling me of the new sim exercise at high altitude with sensors gone u/s.

As per current drill, he switched off the automatics and set pitch and thrust manually.

The instructor then had him restore autothrust. A/T decided there was an overspeed, reduced thrust and things went downhill from there.

During the AF447 discussion, I was wondering when AB would flight test a high altitude stall as it could provide important information to the investigation.

With drone technology, the tests could be flown from the ground.

[Ancient-Mariner]

Quote/...

Post AF447
During the AF447 discussion, I was wondering when AB would flight test a high altitude stall as it could provide important information to the investigation.

With drone technology, the tests could be flown from the ground.

.../unquote.


The Concorde prototypes had a crew escape hatch CONCORDE SST : Duxford Internal Pictures (http://www.concordesst.com/duxford/duxford2.html)


Possibilities....

[calypso]

I am far from convinced that there are many "spurious protection triggers" or "dumb designer mistakes". No, I am not a pilot, but I have been intimately involved in real time safety critical software design, realisation and testing.

And yet, out in the real world, physics and reality stubbornly come up with scenarios and combinations that you had not though about.

I am a pilot and I can testify to the thousands of spurious faults and messages an A320 comes up with. Most of the time Ctrl/Alt/Delete does the job. Sometimes sadly there is no time for that sort of thing. A humble attitude and a very heavy dose of realism is an essential attribute of any engineer dealing with safety critical systems

[Organfreak]

TyroPicard:
So many posters know diddly-squat about A320 FCS.... if you don't know why post?

In order to ask questions and learn. And your answer was quite informative, thanks.

[FullWings]

c) actually taking the aircraft by the scruff of the neck and putting it roughly where it should be has become a HUGE decision accompanied by much trepidation.
should this not be AAA* priority 1 rather than c? - though possibly inserting a "gently" or "carefully" somewhere? The Quantas A380 exploding engine crew seem to have done it right, others less so.
We are discussing the problems associated with automation not behaving as intended. You need to realise that all is not well, then what you might do to rectify it and after that take action, otherwise you’re just doing random stuff.

On two recent flights I’ve observed otherwise competent pilots watching the speed rapidly bleed off due to a high-rate altitude capture. At that point, no FMC or MCP skills are going to help, you’re in a pre-programmed trajectory. It’s AP out and I had to hint several times as many people are reluctant/uncomfortable/unhappy doing this at altitude.

If nasty things start happening up near the top of the flight envelope, e.g. you are rapidly approaching the definition of a “jet upset”, gently and carefully could be your undoing as it may take pitch/roll attitudes and control deflections that you’ve never used before outside the simulator (and maybe not even in there) in order to recover. See AF447. The QF A380 was a fine example of CRM and technical skills saving the day but they were not fighting the aeroplane for control.

(In the above quote “roughly” was meant as “approximately” rather than crudely or violently.)

[Coagie]

" In fact the most important step in spin recovery for the F18A was to disconnect the FBW computers and go to direct electrical link. "

Of course, the point was, that the pilots of most airliners are far enough from the center of gravity, where, in a spin, it is more like the infamous "G machine" centrifuge, astronauts trained in, than an F18A. The pilots of the larger airliner, can not take control because the G's keep their hands pinned. Although I think it's a good idea worth looking into, maybe an automation cure is worse than the disease. Instead of automation to get out of flat spin, maybe more training, to not get there in the first place, is a better use of resources. Maybe some resources to both. Doesn't always need to be either/or.

[tdracer]

Ian and Machinbird
I don't know how applicable would be to the AF A330 scenario, but back during the original 777 flight testing, there was a story going around (from normally reputable sources) that an FAA pilot had inadvertently gotten a 777 into a deep stall at high altitude. The Boeing pilot promptly took over and was able to recover the airplane but the resultant altitude loss was "well over 10k". I can't personally vouch for the accuracy of the story (friend of a friend type stuff) - and assuming it did indeed happen it was kept pretty quiet (no news reports that I'm aware of).

BTW, again, not sure how applicable to how Brand A does things, but Boeing routinely does stall testing of its new aircraft, although not extreme deep stall scenario. Back in the late 1980's I was onboard for many hours of stall testing on a 767. Granted, fairly benign stalls (hold altitude, let the speed drop until the wing stalls and let it fall out of the stall and recover). Also, "windup turns" - used to test inlets at high airflow/high AOA (perform a constant altitude turn with engines set to the desired power, then keep pulling the turn tighter until the aircraft stalls and falls out of the turn). Such testing was always done in daylight in clear air - and during one preflight I recall a request that the flight test pilot "avoid" using the rudder when recovering from the stall, as large rudder swings could slice off the trailing cone which would end the test day. The pilot rather roughly responded that he was going to do whatever he felt necessary to recover the airplane :ok:

[Bergerie1]

May I ask two questions:-
1. Why are we discussing spins when no one knows whether the Air Asia aircraft ever got into a spin?
2. How many large commercial jet aircraft have ever got into a spin?
It seems to me that the discussion is taking a wrong turn.

[peekay4]

The closest analogue might be a Russian airliner (Tu-154M) that got caught in a massive thunderstorm over Ukraine in 2006.

After large pitch oscillations due to the severe turbulence, the aircraft climbed beyond its service ceiling before entering a flat spin -- plunging 37,000ft into the ground. All 170 aboard perished.

[thcrozier]

I was always under the impression that entering a deep stall, where elevator authority is lost because airflow over the HS is in a "shadow" created by the wings, occurred mostly in high tail designs. Am I wrong?

[mcloaked]

Since the discussion on stall/spin is continuing, it would be useful to know if there is an answer to the following question. For the A320 is it known if there have been any tests, including wind tunnel tests during the design phase, that might indicate if the aircraft can be put into a deep stall condition, which in this case would be due to the THS itself stalled so that there is no longer elevator control effectiveness (since with a non-T-tail the mainplane would be unlikely to be able to shield the THS from normal airflow). In this case would this likely be unrecoverable even with significant height loss, or might there be unusual recovery techniques such as using thrust to provide airflow over the THS or possibly attempt to bank using residual aileron action, and then apply rudder to push the nose down enough to regain airflow across the mainplane?

This will likely stretch the limits of knowledge in an area beyond the normal flight envelope but it would be interesting to know if there is any knowledge of this extreme flight condition.

There is video of stall tests in flight for the 737 such as at https://www.youtube.com/watch?v=a4V8W31YwTQ, and presumably analogous tests for the regime as the stall begins were also conducted by Airbus for each of the type it designed and built? There is also a nice lecture given jointly by Boeing and Airbus about stall testing at:

https://www.youtube.com/watch?v=HVt6LiDbLos

[Machinbird]

May I ask two questions:-
1. Why are we discussing spins when no one knows whether the Air Asia aircraft ever got into a spin?
2. How many large commercial jet aircraft have ever got into a spin?
It seems to me that the discussion is taking a wrong turn.
1 The answer to #1 is that it appears to fit the impact conditions very well. See http://www.pprune.org/rumours-news/553569-air-asia-indonesia-lost-contact-surabaya-singapore-109.html#post8830502 (http://www.pprune.org/rumours-news/553569-air-asia-indonesia-lost-contact-surabaya-singapore-109.html#post8830502) At this point, it is just a theory until confirmed or denied by the accident investigation.
2. If it has wings, it can depart into a spin. Ask yourself what would happen to your twin underwing engine jet if it pitched up for some inappropriate reason and then compressor stalled one engine at an inopportune time due to the high transient AOA.

[Clandestino]

I know what will happen to at least 95% of posts on this thread when FDR readout is available.

[khorton]

The Concorde prototypes had a crew escape hatch
I'm not sure what your point is, but all the Airbus prototypes I've been on have had crew escape hatches. They would be used in case something went very badly during any of the many stall tests that were done.

[tdracer]

Thcrozier, while this definition is not universal, this is the way I think of stalls:
Stall - When the airflow separates causing the wing to loose lift. Most stalls can be readily recovered with a simple nose-down command, although the details can be tricky since one wing will often stall first resulting a sudden roll.
Deep stall - extreme stall where the nose is not allowed to drop and most forward speed is lost - forward speed is similar to the descent speed (e.g. Air France A330). Deep stalls take a long time to recover from since there is initially little airflow over the tail to provide a nose down command.
Unrecoverable stall - stall where the spoiled flow from the stalled wing effectively blanks the tail, completely preventing the necessary nose down command to recover - quite common in 'T' tail aircraft.


OK465 - I don't know how the FAA pilot would have done that, but my suspicion is that he was trying something that he wasn't supposed to and/or hadn't been briefed (that's happened before, where I do have first hand knowledge, when the FAA pilot performed a maneuver he'd been specifically told not to perform - tends to result in rather strained relations between Boeing and the Feds - and would also be consistent with it being kept 'quiet').

[JSmithDTV]

@Volume

Interesting that they look at all the previous flights, is there some pre-existing malfunction suspected? Do they need to calibrate some models?

Why would one think that the investigators would not analyse previous flight data? For the purpose of a full investigation this must be done... simple as that. They're not "expecting" anything per se...

[glendalegoon]

all this talk of stalls...

just remember for those of you who haven't heard of the many types of stall...if you can't get the nose down...

you might try rolling into a steep bank and this may cause the nose to come down eventually. this was taught many years ago when concepts like deep stall came out.


I would like to think that most planes certified will likely NOT get into the hairiest of stalls without some coaxing from either a very good test pilot or an odd sort of computer scenario.

I imagine , right now, that at least a dozen people in indonesia have a really good idea of what happened ...and what didn't happen...we might hear something in 10 days or so...just a guess

[Ian W]

@A0283

Having had the misfortune to have done some transcripts of fatal air accidents, I can assure you that it takes longer than you would think and is more draining than you would think - especially when you know the people involved. Add in chaotic ECAM and cavalry charges and alarms etc etc and I am surprised that they have done as much as they have.
All the time you are aware that someone will challenge your transcripts so you go over and over. Each alarm has to be identified, each sound identified. Not a pleasant task at all.

[bigjames]

in a number of these accidents we hear of the mayhem of alarms going off on the flight deck. no doubt making it even more difficult for pilots to try to think clearly. while audible alerts are obviously helpful if one goes off, they rapidly achieve the opposite of the desired effect in a full on crisis.

just thinking out loud, but does it makes sense at some point to have them shut off when they system senses the pilots are trying to respond? they obviously know they need to recover but being screamed at by hal non stop is not delivering any kind of useful infromation at that point.

[Boomtown]

We have reason to believe that the stall alarm cutting in and out on AF447 may have led to it being disregarded as spurious (and may have induced the PF to pull back again when airspeeds became valid and the alarm restarted). Certainly there is much more work to be done in providing prioritising relevant information to pilots in an audio saturated environment. I am anticipating a near impossible workload in the QZ8501 cockpit.

[ZFT]

audio saturated environment That's a new one

[Australopithecus]

A recent sim exercise had an alarm repeat every couple of minutes during a busy procedure which rightly required the crews to formally acknowledge and evaluate the damned alarm each time it triggered. You don't want to get into the habit of blithely waving off repeat alarms without at least assuring yourself that it isn't something new, or worse, something new dressed in the previously used alert.

Cognitive overload under stress is a huge problem which the designers address by adding more unthinking and contextually ignorant alarms. Kind of like fixing a language problem by shouting.

[Vinnie Boombatz]

A March 2013 lecture by an test piloe and a flight test engineer from Boeing and Airbus on stall testing:

Royal Aeronautical Society | Event | Jet Transport Stalls (http://www.aerosociety.com/Events/Event-List/740/Jet-Transport-Stalls)

Royal Aeronautical Society | Podcast | Jet Transport Stalls (http://aerosociety.com/news/Podcast/1522/Jet-Transport-Stalls)

Video of the lecture, about an hour and 40 minutes long:

https://www.youtube.com/watch?v=HVt6LiDbLos

The individual speakers (times approximate):

Paul Bolds-Moorehead, Boeing flight test engineer, 0:00:00 to 0:02:30; 0:27:00 to 0:37:00; 1:31:00 to 1:37:00

Stephane Vaux, Airbus flight test engineer, 0:02:30 to 0:27:00; 0:37:00 to 0:49:00

Van Chaney, Boeing test pilot, 0:49:00 to 0:59:00

Terry Lutz, Airbus Test Pilot, 0:59:00 to 1:31:00

A similar set of briefing slides from 6 months later at a Society of Flight Test Engineers meeting:

http://sfte2013.com/files/78988645.pdf

A search engine turned up this description of the briefing, with a few web links that have since changed:

http://theairlinewebsite.com/topic/398198-joint-boeing-airbus-lecture-on-jet-transport-stalls/

The same Airbus and Boeing people published a journal paper later, but it's subscription only:

Royal Aeronautical Society | Aeronautical Journal | Stalling transport aircraft (http://aerosociety.com/News/Publications/Aero-Journal/Online/1051/Stalling-transport-aircraft)

Bootleg source:

http://www.sfte2013.com/files/75234188.pdf

[Belgianboy]

In modern Electrical Power stations, in case of serious problem for the security of the plant, the system sounds the alarm requiring immediate action from the operator. Afterwards, lesser urgent requests for action appears on the screen and so on...

It had been found that too much alarm sounding at the same time stress the operator which might not take the corrective actions as requested.

[gcal]

@ZFT


'audio saturated environment'
That's a new one

Not at all really and a lot of people, males in particular, have problems assimilating several noise sources.
It is something which happens at puberty to about 30 percent of males.
For myself it made learning morse code (in the Grey Funnel Line) the devils own job; all I heard was a stream of noise.
The same may happen if several people are talking at the same time; perhaps in somewhere like a pub where music may also be playing.
I wonder if this surprisingly common condition has been sufficiently thought about.

[fly strong]

I am far from convinced that there are many "spurious protection triggers" or "dumb designer mistakes". No, I am not a pilot

Yes it is quite clear to see that! I have seen guys & girls cancel genuine warnings because they are so used to cancelling a nuisance warning at a particular phase of flight....

All the talk on this thread of stalling may or may not be related to the accident in question, we will soon find out, but let me give the non pilots some practical info.

Is it possible to get a stall warning and a high speed warning go off at once without it being spurious?
Yes! Coffins corner.
All it would take is an updraft, especially when in bad weather and in turbulance. Descending to a lower altitude with increased margins between low speed and high speed is the only thing that will save your neck.

Put yourself in this situation. In moderate / severe turbulence at high level naturally only a few knots from low speed stall due to the G. Static tubes /smart probes ice up due to super cooled water droplets, first indication is that you are over speeding. If either you or the automatics reduce the power you are in a whole world of trouble.
To save your neck, recognition of the situation must be instant which is most likely not a practical stance.

You realise within a few seconds 'oh we must have unreliable airspeed' you decide to fly a sensible attitude and power as per the book, but guess what? it's already too late as you've already stalled the wing due to the initial reduction of power and / or severe turbulence.
So you now need to initiate a stall recovery but by this stage you don't trust any of your instruments so continue to fly that sensible attitude and power which you have been trained to do. It's very likely the instruments will be telling you that you are flying straight and level due to frozen ports. You are actually stalled and descending at 7000 + ft/min and you or the plane can't make sense of all the conflicting information before your eyes and that unfortunately is game over.

A good crew will recover from the above situation but the best solution is avoidance. Avoid the weather ahead, don't attempt to climb over and if you must go through or if you hit nasty turbulence, descend to a lower altitude immediately where your margins are increased and you buy yourself time to recognise the problem and carry out the sensible actions before it's already too late.

This is why a human brain will always be required in a flight deck to analyse and pre empt future problems.
Pilotless airliners? No thanks :ok:

[fireflybob]

Also worth a reminder that when humans become "maxed out" the brain "deletes" hearing.

[Piltdown Man]

CVR transcription is a very difficult task. There are typically four channels: LHS, RHS, Intercom & Cockpit ambient. Within these channels are multiple inputs such as Com 1, Com 2, Nav., Ramp, Inter-phone, PA, warnings etc. The comm. and nav. channels are easy to decode. The difficult ones are voice, ambient noises and warnings. These will have to be cross-checked against each other, FDR data, software versions, aircraft manuals etc. to determine exactly what warning sounded when, who heard and it and what was said. Only when combined with SOPs, cultural norms, company standards etc. can a complete audio picture be given. So maybe the 50% refers to first hour. If the complete CVR transcript takes less than two months, that will be rapid progress.

[marchino61]

Not at all really and a lot of people, males in particular, have problems assimilating several noise sources.
It is something which happens at puberty to about 30 percent of males.

I find this quite intriguing. What is the source of this information?

[gcal]

I cannot remember the condition being given a name by the doctor I was sent to.
He asked me a series of questions one of which was 'Before puberty did you need to hold your nose when you swam underwater or jumped into water'
My answer was no.
He then asked me if I needed to do so now and I answered yes which was correct.
That was only part of the examination but he did not seem to think it was that unusual a condition.

I do not believe the condition can be picked up by normal hearing tests.

[catterwell]

gcal: I think it's called "Sensorineural deafness".

[AmericanFlyer]

AirAsia crash investigators rule out terrorism, consider human error (http://www.smh.com.au/world/airasia-crash-investigators-rule-out-terrorism-consider-human-error-20150120-12uh8t.html)

[training wheels]

Apparently, the radome of PK-AXC has been found washed up near Sembilan Island 550 KM away from the rest of the wreckage.

http://images.detik.com/content/2015/01/20/10/134226_hidungc.jpg

Source: Detik.com (http://news.detik.com/read/2015/01/20/133923/2808368/10/basarnas-hidung-pesawat-yang-ditemukan-merupakan-tutup-radar)

Approximate location of where the radome was found (https://www.google.com/maps/place/Sembilan+Island,+Baru+City,+South+Kalimantan,+Indonesia/@-2.7647096,113.529495,7z/data=!4m2!3m1!1s0x2de8019f3cbd1047:0xba140c6d211c1388).

[Ian W]

I find this quite intriguing. What is the source of this information?

The name given is low levels of discrimination. The ability to make out a particular sound or voice in amongst other sounds, or even just the ability to understand speech.

In the extreme people can hear a voice but not actually discriminate the sounds into meaningful words. This is common in the deaf/hard of hearing and audiologists will carry out speech discrimination tests. This is usually done by playing voices of different people at different sound levels with or without background noise. They may talk in snippets or single words so there is no contextual clue to what the word is, or give a sentence that provides some contextual clues to what is being said.

The count the bleeps type hearing test is just for that hearing it does not identify people who cannot understand voices or sounds well against background noise.

I am surprised that this is not tested for. The person suffering a loss of speech or sound discrimination may not be aware of it, but will find talking/listening in noisy surroundings difficult and tiring.

This is totally different to the 'attentional' or 'cognitive' tunneling effect, where under pressure humans will focus on one particular part of their environment and exclude all others. If that is the wrong thing then that will lead to problems in a cockpit environment.
Sounds are one of the first stimuli to be filtered out, the last to be filtered out are haptics (touch and feeling) hence the reason for stick shakers.

[A0283]

IAN W -- having had the misfortune to have done some transcripts of fatal air
accidents, i can assure you that it takes longer than you would think and is
more draining than you would think

A0283 notes -- was my impression, and confirms other people talking about their experience with this hard work,

- especially when you know the people involved.

the captain involved taught one of the present investigators to fly, this investigator fully confirms your statements,

add in chaotic ecam and cavalry charges and alarms etc etc and i am surprised
that they have done as much as they have.

like i said in my post ... 'no professional would hold that 50% against them' ... And i was indeed impressed by the 50%

all the time you are aware that someone will challenge your transcripts so you
go over and over. Each alarm has to be identified, each sound identified. Not a
pleasant task at all.

fully agree with that,

Note:

Once i took a number of tapes, listened to them, made a transcript, and compared that with what was published in appendices of the final reports. The easy part was that the report left out the private and human side ... In spite of that, you could feel the strain. The hard part was making a good transcript, my impression based on that is, that i would never leave it to a single person to make a transcription. And for more reasons than one, including sharing the tremendous emotional stress.

In the past you could find pretty complete tapes and texts. Today it appears that less and less is published. I wonder if that is wise. If you really want to understand an accident, then ... The negative side is of course people using the information with an uninformed or wrong intent.

[Sailvi767]

There is no hail damage on that radome. It's in remarkably good condition. In fact it does not even show the type of erosion you normally see when a aircraft is flown through extreme rain.

[RifRaf3]

So far there have been a lot of good suggestions re training for high altitude turbulence, stalling, and even spin recovery. However, as many have pointed out, the first priority is to avoid the extreme weather. There is a long history of jet fighters being lost in large CBs because they lacked any weather radar and yet they were stressed well above airliners' G limits and had much higher control response.

We can't properly simulate really severe turbulence, so the training - as for ditching - has to be rather arbitrary. There is a lot more we can do in regard to weather avoidance at reasonable cost/risk benefit by integrating weather data sources and I hope at least that this tragedy will spur greater efforts in that direction.

It has also become obvious that current automatics in extreme turbulence and icing may not cope adequately and that pilots are easily overstressed by violent movement and temporary or spurious warnings. Hopefully, this accident will provoke better algorithms in preference to relying more on manual takeovers. It's very hard in severe turbulence, blinded by lightning, to take over efficiently with your head and arms flailing around.

Having said that, each pilot must still know the limitations of their auto systems and be prepared for manual takeover. I'll bet on the technology in the long run. Self driving cars have, to my knowledge, not had an accident yet and had completed over 3 million miles last time I checked.

[A0283]

Ian W --

The name given is low levels of discrimination. The ability to make out a particular sound or voice in amongst other sounds, or even just the ability to understand speech. In the extreme people can hear a voice but not actually discriminate the sounds into meaningful words. This is common in the deaf/hard of hearing and audiologists will carry out speech discrimination tests. This is usually done by playing voices of different people at different sound levels with or without background noise. They may talk in snippets or single words so there is no contextual clue to what the word is, or give a sentence that provides some contextual clues to what is being said. The count the bleeps type hearing test is just for that hearing it does not identify people who cannot hear voices or sounds well against background noise. I am surprised that this is not tested for. The person suffering a loss of speech or sound discrimination may not be aware of it, but will find talking/listening in noisy surroundings difficult and tiring.

This is totally different to the 'attentional' or 'cognitive' tunneling effect, where under pressure humans will focus on one particular part of their environment and exclude all others. If that is the wrong thing then that will lead to problems in a cockpit environment. Sounds are one of the first stimuli to be filtered out, the last to be filtered out are haptics (touch and feeling) hence the reason for stick shakers.


Great post Ian W. It would not suprise me, based on the status by today, if these aspects will return in discussions following the investigation, and will even find their way into the final report.

When you go from relaxed to stressful situations, and end up at the most extreme stress levels on human beings - then you go through something that I call "roll back" (using my own words - I am sorry, but I do not know if there is a scientific label for the whole 'movement'). Which means that the brain's main processing moves from the frontal lobe, to the 'centre of the brain', and finally down to the 'brain stem'. One of the effects is for instance that you cannot lift as much weight in an extremely stressful environment as in a relaxed one. The reduction can be up to 50%. I do not know any numbers for the degradation of pull strength ( ref old fashioned sticks).

[RifRaf3]

Under severe stress according to my psychiatric contacts you 'regress' towards primitive fight or flight (escape) mode. Both are problematic in high technology situations, which are not quite our evolutionary scenarios. One sub mode of 'flight' is to go catatonic or 'play possum'. I know of one incident where an inexperienced F/O got overwhelmed going into LHR and went to sleep and could not be woken until after landing.

[MrSnuggles]

On the topic of stress, there is an interesting Dutch investigation into military personnel. I believe though that the report might be of interest for anyone working in a high stress environment.

http://tinyurl.com/m9kwpga

Short summary of the above PDF: The "scientifical" words for what others call easy things like "roll-back" (I like that expression) is perceptual narrowing and indeed it messes up your perception. One of the first senses to be disregarded is hearing unless it is short, distinctive and preferrably in your mother tongue. Motor skills deteriorate because smaller muscles aren't provided with enough oxygen due to the fight-or-flight state that adrenaline dictates where it is most useful to have a good flow in your large muscles to be able to do either. Loss of near vision is also among the things that hampers your performance.

EDIT: Another one, more directly related to stress in aviation:

http://tinyurl.com/pflgb95

If the radome found belongs to the missing plane, it looks very clean and I see no visible hail marks or scorching as by lightning.

[Boomtown]

There is no hail damage on that radome. It's in remarkably good condition. In fact it does not even show the type of erosion you normally see when a aircraft is flown through extreme rain.

It doesn't look like it has hit the ocean at 100 knots either.

[RifRaf3]

At that distance it's looking like it has detached before the crash, but whether it's turbulence or mechanical/latching failure remains to be determined.

[FiveGirlKit]

Assuming the radome was attached to the aircraft when it hit the sea, the radome has drifted on average 24km per day (550/23).

[RifRaf3]

Yes it could have drifted that distance and also no radome was reported lost when they requested climb only minutes before the crash position. It's possible also that it was detached in the uncontrolled descent if spinning, for example, with lateral airloads.

[JCviggen]

6000 fpm climb and subsequent stall reported BBC News - AirAsia flight QZ8501 'climbed too fast' (http://www.bbc.com/news/world-asia-30902237)

Indonesia's transport minister has said AirAsia flight QZ8501 climbed too fast just before it stalled, crashing into the sea with the loss of 162 lives. Ignasius Jonan told a parliamentary hearing in Jakarta the jet had climbed at a speed of 6,000 ft (1,828 m).
"It is unlikely a fighter jet would increase its flight level at a speed of 6,000 ft per minute," he said.
There were no survivors when the jet crashed in the Java sea on 28 December, en route from Surabaya to Singapore.
The Airbus A320-200 is thought to have encountered difficulties from an approaching storm.
Bodies are still being retrieved from the crash area where debris was scattered across the sea.
The cockpit voice recorder and flight data recorder were found last week.
The fuselage of the plane, believed to hold most of the bodies, has also been located and search teams are now working out how to retrieve it.
The authorities are expected to issue a preliminary report on the crash on 28 January.

[RifRaf3]

It's not a controlled rate of climb. 6000'/min is impossible at that altitude and type. It's a pitchup zoom climb possibly aided by updraft with reducing IAS into a stall; then we are guessing.

[Niner Lima Charlie]

That report of the 6000 fpm climb is based on old radar data, not FDR data.

[RifRaf3]

It was the Indonesian transport minister not a journalist that claimed that it climbed "too fast", so the assumption is that the "old radar data" has been confirmed somewhat by data already gleaned from the recorders. It's also stated that it stalled which they would probably know by now. Also updrafts do not necessarily bleed airspeed but zoom (speed for height) climbs always do. The pitchup into a stall scenario during the climb to FL 340 now seems most likely for whatever reason.

[Vasco dePilot]

"Audio saturated environment" is a very appropriate expression for the cascade warning sounds bombarding the pilots during an abnormal occurance on a modern airliner. Add it to the lexicon!

[timpara]

6000'/min is quite believable for an updraft. Even paragliders have been known to climb at 4000'/min in quite modest Cb.

[RifRaf3]

Of course 6000'/min is possible for an updraft, but gliders do not stall when they enter thermals. They gain total energy, The ROC mentioned is adequately explained by trading speed for height. There equally could have been a slight downdraft.

[Ian W]

Of course 6000'/min is possible for an updraft, but gliders do not stall when they enter thermals. They gain total energy, The ROC mentioned is adequately explained by trading speed for height. There equally could have been a slight downdraft.


6000 fpm unexpected in an Airbus with a change of Outside Air Temperature? Not at all impossible indeed its happened before.

For 18 seconds after the autopilot disengaged the aircraft remained within 200 feet altitude of FL
360 but once AoA law was invoked at 14:21:50 hrs, the aircraft's attitude began to pitch nose-up.
The pitch-up trend continued for 17 seconds reaching a peak of 15° nose-up shortly before the first
nose-down sidestick command was applied. Throughout this phase the aircraft climbed rapidly
(reaching a peak rate of about 6,000 ft/min) due to the increase in lift created by the flight control
system's capture of alpha prot. The aircraft reached its apogee at FL 384 at 14:22:28 hrs where the
airspeed had decayed to 205 KIAS and 0.67 Mach even though full thrust had been applied.
Throughout the turbulence encounter, the normal g fluctuations were between 0.5g and 1.5g. The
recorded wind direction remained within 20° of the mean of 240° but the wind speed varied
between 67 kt and 108 kt and the static air temperature fluctuated between -42° C and -52°C. There
were 7 cycles of temperature change, the second cycle being the most severe. The mean air
temperature before the AIRPROX event was -46.5° C and afterwards it was -44.5°C. The crew
subsequently descended back to FL 360 and successfully re-engaged the autopilot and autothrust
systems.

http://www.rvs.uni-bielefeld.de/publications/compendium/incidents_and_accidents/ACAS-AAIB-dft_avsafety_pdf_501275.pdf

[SAMPUBLIUS]

Geeze ...

AirAsia Jet Climbed at Rate Beyond Design of Commercial Planes
Plane Climbed at Rate of More Than 8,000 Feet a Minute, Transport Minister Says

The Airbus Group NV. A320 jet turned left away from its assigned flight path en route from Surabaya to Singapore, climbed at more than 8,000 feet a minute—six to eight times the normal rate—descended and finally disappeared within three minutes, Mr. Jonan said, citing data from the plane’s automatic dependent surveillance-broadcast, or ADS—B, system.


Note it is not from the FDR!

Pitot problems ??

[RifRaf3]

That's one credible scenario to account for the 2000' odd overshoot of assigned altitude and the eventual stall. You often get temp changes in CBs, however it could also be sensor icing and autopilot pitchup or pilot error. There's not enough data yet to factor out all the possibilities.

[Ian W]

That's one credible scenario to account for the 2000' odd overshoot of assigned altitude and the eventual stall. You often get temp changes in CBs, however it could also be sensor icing and autopilot pitchup or pilot error. There's not enough data yet to factor out all the possibilities.

Enter an updraft which by definition has higher temperature than the surroundings and is already carrying you up fast and then the aircraft does an 'assist' by climbing at 6000fpm inside the updraft. All IMC.

[RifRaf3]

It seems that we are back to square one if he's just quoting the ADS-B figures because all these variables like temps and extreme gusts may adversely affect the accuracy of the sensors supplying that ADS system.

[Longtimer]

Crashed AirAsia A320 undertook rapid climb: minister
By: DAVID KAMINSKI-MORROW Source: in 5 hours
Indonesia’s parliament has been told that the Indonesia AirAsia Airbus A320 which crashed into the Java Sea last month climbed rapidly before its fatal descent.

The aircraft climbed at 6,000ft/min and then descended 7,900ft in the space of 45s, transport minister Ignasius Jonan stated.

He was briefing the parliament on the latest findings in the flight QZ8501 investigation on 20 January.

There is no immediate indication as to the reason behind the rapid climb or the subsequent descent, nor any details on the flight-control law under which the A320 was operating at the time.

The aircraft’s crew had requested a climb to 38,000ft from its assigned altitude of 32,000ft, while in the vicinity of poor weather, during the service to Singapore on 28 December.

Investigators have previously stated that the aircraft had been cleared to climb only to 34,000ft

[RifRaf3]

So where did SAMPUBLIUS get his info from re 8000'/min and the ADS-B?

[Coagie]

How used to the local weather we're these pilots? On AF447, Bonin was spooked by St Elmo's Fire and the "Electrical Smell" from lightening. It was new to him. He'd never even heard of either phenomenon before. These two things, along with his leader, Captain Dubois, leaving the cockpit, made him so uncomfortable and nervous, that he was using his reptilian brain and was in fight or flight mode, even before the pitot tubes iced up. To put it in medical terms, he was already "freaked out".
These Air Asia pilots may have already been familiar with the weather and it's associated sights, sounds, and smells they encountered. They may have done all the right things. Investigators may find that there is nothing they could have done to save the aircraft. The storm may have affected the flight with specific combinations (up/downdrafts, ice, etc), that were beyond the capacity of the aircraft, crew, and flight computer to handle, even if everything was handled correctly. Could have been a combination that almost never happens, and didn't happen to the flights ahead of them or the flights behind them. It might just be, "The storm got 'em".
I think the Indonesians will find out soon enough, and I think they're doing a good job with the investigation. They may have learned from the missteps of their neighbors on the MH370 issue, on getting their ducks in a row, before they issue statements. I join those who laud the Indonesian divers. They have put their lives at risk, pushing the envelope on getting the Bends, and fighting strong currents, in order to move the investigation and recovery along.

[rgbrock1]

Non-pilot here but just a question. (Which hopefully doesn't come across as blatantly ignorant.)

Is it possible, or even likely, for a severe updraft to carry a commercial airliner to that rate of ascent? Just curious.

[fireflybob]

Assuming the data comes from the pressure instruments (IAS/VSI/ALT) these would be indicated values.

Within an active CB there are big pressure variations which will affect these instrument indications.

The a/c may actually have been doing something different.

Personally I don't like this drip feed of information. Better to wait and hear all the facts.