Air Asia QZ8501 SUB To SIN Crash - Part 15

American 767 · Sun Feb 01, 2015 4:46 pm

Please continue here.

Air Asia QZ8501 SUB To SIN Crash - Part 14 (by EK413 Jan 29 2015 in Civil Aviation)

Ben Soriano

7BOEING7 · Sun Feb 01, 2015 6:04 pm

From Part 14:

Quoting rfields5421 (Reply 203):
Unlike 2009, we can be certain that pilots in these series of aircraft have received simulator training focusing on UAS and stall recovery.

Quoting Mandala499 (Reply 207):
Not stall recovery, only recovery from approach to stall ... coz the stall, isn't modelled in the simulator...
Some airlines did provide UAS sim sessions... but not on every sim check...

On my last several recurrency checks after AF447 they were starting to throw unusual attitudes at us and we always did approach to stall recoveries. To re-emphasize Mandala499's comment, simulators are not programmed/modeled to train for stalls and stalls are generally not done in non-instrumented (commercial) airplanes.

Independence76 · Sun Feb 01, 2015 7:44 pm

Quoting 7BOEING7 (Reply 1):
On my last several recurrency checks after AF447 they were starting to throw unusual attitudes at us and we always did approach to stall recoveries. To re-emphasize Mandala499's comment, simulators are not programmed/modeled to train for stalls and stalls are generally not done in non-instrumented (commercial) airplanes.

Even then, after AF447, weren't pilots given additional education in regards to recognizing a high-altitude stall and recovery? Simulator training is unlikely, but certainly airlines have implemented teachings post-final report?

flightless · Sun Feb 01, 2015 9:35 pm

If there is a posting here which concerns QZ8501 rather than AF447, will it be tagged in some way so that we can tell? Does there need to be a "QZ8501 SUB To SIN Crash - Not AF447" thread just in case?

hivue · Sun Feb 01, 2015 10:40 pm

Quoting flightless (Reply 3):
Does there need to be a "QZ8501 SUB To SIN Crash - Not AF447" thread just in case?

You could do that but people will just start bringing up AF447 there.

billreid · Sun Feb 01, 2015 11:24 pm

Alot of people are blogging on AF447. That should only occur if there is a direct correlation.
That said, I am waiting for the preliminary report, and hoping there are NO similarities.

LTC8K6 · Mon Feb 02, 2015 12:38 am

Is it possible that the FAC(s) were often troublesome with this plane such that an ECAM alert about them produced no comment from the pilots to ATC earlier in the flight? And no thought of returning to SUB?

Maybe the alert was "common" and was always successfully dealt with by resetting?

Only this time, that didn't work?

777Jet · Mon Feb 02, 2015 3:25 am

Quoting 7BOEING7 (Reply 1):
On my last several recurrency checks after AF447 they were starting to throw unusual attitudes at us and we always did approach to stall recoveries. To re-emphasize Mandala499's comment, simulators are not programmed/modeled to train for stalls and stalls are generally not done in non-instrumented (commercial) airplanes.

Thank you for that info regarding simulators and approach to stall recoveries

Quoting billreid (Reply 5):
Alot of people are blogging on AF447. That should only occur if there is a direct correlation.

Quoting billreid (Reply 5):
That said, I am waiting for the preliminary report, and hoping there are NO similarities.

I would not be surprised if those who keep blogging on about AF447 go silent all of a sudden if the preliminary report is released and basically rules out any similarities with AF447

hivue · Mon Feb 02, 2015 4:01 am

Quoting billreid (Reply 5):
I would not be surprised if those who keep blogging on about AF447 go silent all of a sudden if the preliminary report is released and basically rules out any similarities with AF447

The preliminary report has been produced and submitted. I don't believe the investigation plans to make it public.

RickNRoll · Mon Feb 02, 2015 4:07 am

Quoting hivue (Reply 8):
The preliminary report has been produced and submitted. I don't believe the investigation plans to make it public

Just a matter of paying someone enough to leak it, I think.

scarebus03 · Mon Feb 02, 2015 8:38 am

I believe there will be some similarities with AF447 but broadly will be more in line with XL888T which crashed of Perpignan in 2008 conducting a demonstration flight.

Cheers

Sb03

gzm · Mon Feb 02, 2015 9:16 am

I see some readers are trying to find similarities with other flights.That's how the human mind works: It has a need to simplify data so as to make it easier to categorize and draw conclusions...Two days ago I read in a similar Greek site that according to Reuters, "the aircraft had problems with a computer for more than a week.According to a source, the captain had already flown on the same aircraft when the problem had already appeared, a week before the accident. According to the news agency,the specific problem and the way the pilots dealt with it, is in the focus of the research. Bloomberg announced on Friday that the pilots tried at first to restart the computer and after they had failed, they unplugged it in order to disconnect it. It seems that the captain was not in the cockpit and when he returned it was too late to save the aircraft...". Well it is my turn to say that it reminds me of MH370 doesn't it? Anyway this time we do have the plane, we do have the black boxes which should give us some clues as to what really happened to that elusive flight. Do you agree?

flyingturtle · Mon Feb 02, 2015 9:21 am

Quoting scarebus03 (Reply 10):
I believe there will be some similarities with AF447 but broadly will be more in line with XL888T which crashed of Perpignan in 2008 conducting a demonstration flight.

What connections do you see to XL88T?

David

liquidair · Mon Feb 02, 2015 9:56 am

I really wish we could find out why the climb was initiated- that to me seems to be the pivotal, unexplained episode here.

I don't think they would climb knowing there was heavy traffic in the area. So why climb at all? ATC did eventually clear them, but by then they weren't able to get a response.

freakyrat · Mon Feb 02, 2015 10:44 am

The Reuters report said that the airplane had problems with the FAC and after the attempt to restart it was unsuccessful the Captain got up out of his seat to pull the breaker which is located behind the copilot. The question is why did the FAC fail? Why if the aircraft had problems for about a week with the FAC, why maintenance didn't fix it. Why couldn't the copilot fly the aircraft manually without the FAC? Did the airplane get caught in a thunderstorm updraft while all this was going on that overwhelmed the capabilities of the aircraft and crew? We will all have to wait till the report comes out listing the accident sequence.

Kaiarahi · Mon Feb 02, 2015 1:11 pm

Quoting scarebus03 (Reply 10):
I believe there will be some similarities with AF447 but broadly will be more in line with XL888T which crashed of Perpignan in 2008 conducting a demonstration flight.

Here's the Final Report on D-AXLA:
http://www.bea.aero/docspa/2008/d-la081127.en/pdf/d-la081127.en.pdf
What are the similarities?

garpd · Mon Feb 02, 2015 3:05 pm

Quoting flyingturtle (Reply 12):

What connections do you see to XL88T?

Quoting Kaiarahi (Reply 15):
What are the similarities?

I'm guessing the steep climb followed by a stall and crash into water.
I pointed out in thread 13 that I found the last known flight path of QZ8501 eerily similar to that of XL88T.

Rara · Mon Feb 02, 2015 3:15 pm

Quoting billreid (Reply 5):
That said, I am waiting for the preliminary report, and hoping there are NO similarities.

Since in both cases, a stall preceded a crash, in an aircraft that, by design, shouldn't be able to stall in the first place, a major similarity is already there.

Now, while with AF447 the most prominent cause was pilot error, you could at most "hope" (if that's the right word) that the cause of QZ8501 will be found to be technical.

hivue · Mon Feb 02, 2015 3:20 pm

Quoting garpd (Reply 16):
I found the last known flight path of QZ8501 eerily similar to that of XL88T.

By that logic the B25 that crashed into the Empire State Bldg. in 1945 and 9/11 are eerily similar.

garpd · Mon Feb 02, 2015 3:26 pm

Quoting hivue (Reply 18):

No, that is false logic.

[Edited 2015-02-02 07:26:59]

7BOEING7 · Mon Feb 02, 2015 3:54 pm

Quoting scarebus03 (Reply 10):
I believe there will be some similarities with AF447 but broadly will be more in line with XL888T which crashed of Perpignan in 2008 conducting a demonstration flight.

Quoting garpd (Reply 16):
I'm guessing the steep climb followed by a stall and crash into water.
I pointed out in thread 13 that I found the last known flight path of QZ8501 eerily similar to that of XL88T.

XL did not do a steep climb -- the only similarity with XL is the fact that they both ended up in a stall, probably. The dissimilarities being the QZ crew were flying a normal commercial flight at FL340+/- and they were qualified to do that. The XL crew were performing a test flight they were not technically skilled to accomplish doing a check that is normally accomplished above 10,000ft at 3,000ft (+/-).

Kaiarahi · Mon Feb 02, 2015 4:14 pm

Quoting 7BOEING7 (Reply 20):

And the aircraft had been washed without protecting the AOA vanes, resulting in water frozen inside them.

No (known) similarities with QZ8501.

hivue · Mon Feb 02, 2015 4:29 pm

Quoting garpd (Reply 19):
No, that is false logic.

That was my point.

kanban · Mon Feb 02, 2015 4:54 pm

Quoting hivue (Reply 8):
The preliminary report has been produced and submitted. I don't believe the investigation plans to make it public.

Frequently there are people who see any deviation or exclusion of their beliefs in the official report will blame it on cover up rather than accept they were wrong.

mandala499 · Mon Feb 02, 2015 6:32 pm

After putting out a story that the captain left his seat according to unnamed sources "close to the investigation", Reuters finally (after some pointers and persuasion) to ask the NTSC directly after a local media quoted the NTSC has denied such a story... And... (strangely extremely late in the day), Reuters finally put up the story that the NTSC finds no evidence so far that the captain left his seat... *phew... let's hope common sense remain in the media's heads)...
http://www.reuters.com/article/2015/...sia-airplane-idUSL4N0VC30D20150202

hivue · Mon Feb 02, 2015 6:40 pm

Quoting mandala499 (Reply 24):

All of this sort of grief could be avoided if the NTSC would just make public what facts they have in a timely manner à la the NTSB.

mandala499 · Mon Feb 02, 2015 6:46 pm

Quoting hivue (Reply 25):
All of this sort of grief could be avoided if the NTSC would just make public what facts they have in a timely manner à la the NTSB.

But they did make public the facts, albeit not in the form of a published preliminary report.
Leaks like this would have happened even with that. Even the NTSB as open as they are, were still criticized for not being open... There will always be criticism no matter what you do. Leaks, or claims of such, will always happen. It's just a matter of sifting through and determining what's reasonable and what isn't.

aklrno · Mon Feb 02, 2015 8:48 pm

Quoting mandala499 (Reply 26):
All of this sort of grief could be avoided if the NTSC would just make public what facts they have in a timely manner à la the NTSB.

Grief to whom? Airliners.net?

The reason there is no requirement to disclose the preliminary result is to prevent the spread of false information which will reverberate for decades. Until the final report is ready, anything disclosed early is subject to revision, and thus may contribute to a legacy of false information.

The only risk I see to not disclosing preliminary information is that there may be something that poses a continuing threat to safety that the aviation community may want to fix before the final report is out. I will presume that if such a thing is found that the relevant parties will be informed, and maybe that should be made public.

Requiring that the crash investigators fuel the rumor mill is not a good idea.

flyingturtle · Mon Feb 02, 2015 10:00 pm

Quoting aklrno (Reply 27):
The reason there is no requirement to disclose the preliminary result is to prevent the spread of false information which will reverberate for decades. Until the final report is ready, anything disclosed early is subject to revision, and thus may contribute to a legacy of false information.

But they can still put into the preliminary report what they surely *know*, or offer a public version of that prelim. It's open and proactive communication that stops the rumor mill.

David

kanban · Mon Feb 02, 2015 10:59 pm

Quoting flyingturtle (Reply 28):
But they can still put into the preliminary report what they surely *know*, or offer a public version of that prelim. It's open and proactive communication that stops the rumor mill.

My experience is that is only occasionally true, too often anything not answered or incomplete dives the conspiracy yo-yos, and on the other side anything that deviates from the final due to more information or analysis faces "But They said...."..

If the agencies want to communicate to survivors families for closure based on early results, that's one thing, but everybody else are just ambulance chasers with an "I'm entitled" agenda.

hivue · Mon Feb 02, 2015 11:27 pm

Quoting aklrno (Reply 27):
The reason there is no requirement to disclose the preliminary result is to prevent the spread of false information

And yet the false information that the captain left his seat to pull breakers was in fact spread.

Quoting aklrno (Reply 27):
Grief to whom? Airliners.net?

No:

Quoting mandala499 (Reply 24):
*phew... let's hope common sense remain in the media's heads)...

Kaiarahi · Tue Feb 03, 2015 12:13 am

Quoting aklrno (Reply 27):
The only risk I see to not disclosing preliminary information is that there may be something that poses a continuing threat to safety that the aviation community may want to fix before the final report is out. I will presume that if such a thing is found that the relevant parties will be informed, and maybe that should be made public.

Convention on International Civil Aviation, Annex 13

Article 6.8:
"At any stage of the investigation of an accident or incident, the accident or incident investigation authority of the State conducting the investigation shall recommend to the appropriate authorities, including those in other States, any preventive action that it considers necessary to be taken promptly to enhance aviation safety."

Article 6.10:
"A State that receives safety recommendations shall inform the proposing State of the preventive action taken or under consideration, or the reasons why no action will be taken

Article 7.1
"When the aircraft involved in an accident is of a maximum mass of over 2 250 kg, the State conducting the investigation shall send the Preliminary Report to:
a) the State of Registry or the State of Occurrence, as appropriate;
b) the State of the Operator;
c) the State of Design;
d) the State of Manufacture;
e) any State that provided relevant information, significant facilities or experts; and
f) the International Civil Aviation Organization".

777Jet · Tue Feb 03, 2015 12:50 am

Quoting gzm (Reply 11):
Bloomberg announced on Friday that the pilots tried at first to restart the computer and after they had failed, they unplugged it in order to disconnect it. It seems that the captain was not in the cockpit and when he returned it was too late to save the aircraft...". Well it is my turn to say that it reminds me of MH370 doesn't it?

And what about MH370 makes QZ8501 remind you of it?

To address the points you used to draw a similarity:

Did the MH370 pilots try but fail to restart a computer but that failed so they unpluged it? It is not known what happened in the cockpit of 9M-MRO let alone where the aircraft is.

Was the MH370 Captain not in the cockpit and when he returned it was too late to save the aircraft? Again, it is not known what happened in the cockpit of 9M-MRO - but it is known that the Captain was the last to speak to ATC just minutes before the plane almost went silent and turned around so IMHO it is most likely that the MH370 Captain was in the cockpit at the time something significant happened. BTW 9M-MRO apparently flew on for hours - the entire QZ8501 incident was over in a few minutes.

I just can't see how QZ8501 can remind somebody of MH370 so I am curious to hear your reasons...

md80fanatic · Tue Feb 03, 2015 1:37 am

Quoting kanban (Reply 23):

Quoting hivue (Reply 8):
The preliminary report has been produced and submitted. I don't believe the investigation plans to make it public.

Frequently there are people who see any deviation or exclusion of their beliefs in the official report will blame it on cover up rather than accept they were wrong.

Trust, but verify.

With only one source of data to go on (recorders), and those are in the hands of "not the public", all we can do is wait for someone to tell us what "happened". Naturally when there is an "appearance of impropriety" conspiracy theories are bound to fly. What is the inquiring mind to do when 80% of the wreckage is purposefully left beneath 30 meters of water?

toneale · Tue Feb 03, 2015 1:50 am

Fact is, the quicker they release facts/data, the less likely there is to be outside influence on the findings. Sunlight is the best disinfectant.

rfields5421 · Tue Feb 03, 2015 2:46 am

Quoting hivue (Reply 25):
All of this sort of grief could be avoided if the NTSC would just make public what facts they have in a timely manner à la the NTSB.

Quoting toneale (Reply 34):
Fact is, the quicker they release facts/data, the less likely there is to be outside influence on the findings. Sunlight is the best disinfectant.

There was a lot of criticism of the NTSB on this forum after the Asiana crash at SFO for releasing factual data from the FDR / CVR / etc during the first week's press briefings. While interesting, those also setup a blame game and ensured substantial attempts to influence the final investigation report.

Quoting mandala499 (Reply 24):
*phew... let's hope common sense remain in the media's heads)...

As much as we all would wish that to happen - Fat chance.

mandala499 · Tue Feb 03, 2015 4:18 am

Quoting aklrno (Reply 27):
Quoting mandala499 (Reply 26):
All of this sort of grief could be avoided if the NTSC would just make public what facts they have in a timely manner à la the NTSB.

Grief to whom? Airliners.net?

Errr... I didn't say that... I would appreciate it if you quote the correct person instead of me re. grief.

Quoting rfields5421 (Reply 35):
As much as we all would wish that to happen - Fat chance.

I know... but we can wish...

Quoting rfields5421 (Reply 35):
There was a lot of criticism of the NTSB on this forum after the Asiana crash at SFO for releasing factual data from the FDR / CVR / etc during the first week's press briefings.

Some people have short memories...
Some people have one rule for some, and another rule for others...

Quoting rfields5421 (Reply 35):
While interesting, those also setup a blame game and ensured substantial attempts to influence the final investigation report.

I wish people know the pressure for the blame game to continue over here. There are good reasons why the factual data isn't released (and yes, there are reasons for them to be released too). Without objective analysis of the facts, you're setting yourselves up for the blame game. One thing that is done here is that once the NTSC has embedded the data into the final report, it cannot be used for legal proceedings in Indonesia. This is why there's lots of pressure to release the data prior to the existence of final report, so that it can be used for other purposes.

The minister has already blamed LCCs as unsafe, blamed low promo prices of Air Asia as a cause of accident, and he wants to turn aviation back to the stone age... The minister himself, in order to achieve his objectives, already leaked some of the investigations' data... to everyone's horror... Why? Because it gets the media to question... and then, snoop around and see if they can find anything they can blame on...

People can scream conspiracy for a cover up all they want... they're just part of the black sheep conspiracy directly or indirectly, or, tragically, inadvertently.

The NTSC has put out the 18 points of factual information. How many of those who criticized "lack of openness" has actually looked at the 18 points? Beyond those 18 points, are stuff that require analysis before publishing the information, because it tends to end up in a witch hunt or blame game...

Mandala499

tailskid · Tue Feb 03, 2015 4:48 am

The 18 points.

The first point says that before taking off, QZ8501 was in a suitable condition for a safe flight and in balance on board.

Point two: Every crew member had the required licenses and medical certificates.

Three: The second in command pilot, or co-pilot, was flying the plane. He was on the right side while the pilot, or captain, was on the left side as monitoring pilot.

Four: The plane was flying at a height of 32 thousand feet on the M635 route.

"On the screen, the plane was seen turning to the left side," he added.

Five: the plane was identified by the Jakarta Air Traffic Controller (ATC) in the initial contact at 23:11 UTC/GMT; the time difference with Indonesia was around seven hours. The plane turned left on the M365 route.

Six: the pilot sought permission to fly at a height of 38 thousand feet, but the ATC in Jakarta ordered him to stay at 32 thousand feet (stand by).

Seven: At 23:16, the ATC cleared the pilot to climb to 34 thousand feet.

Eight: When the accident happened, satellite photos showed a formation of cumulus-nimbus with its cloud peak reaching a height of 44 thousand feet.

Nine: The latest position of the plane was captured by a radar at a coordinate of 3 34 48.6 degrees southern Latitude, and 109 41 50.47 degrees eastern Longitude.

"In this position, the plane was back at parallel position with the M635 route," he noted.

Ten: On December 30, 2014, the National Search and Rescue Agency (Basarnas) found a body and the planes debris floating in the Karimata Strait.

Eleven: On January 9, 2015, the planes tail was discovered at coordinates 03 37 40 degrees southern Latitude and 109 42 75 degrees eastern Longitude.

Twelve: The Flight Data Recorder (FDR) was recovered at coordinates 03 37 22.2 degrees southern Latitude and 109 42 42.1 degrees eastern Longitude.

"The FDR was taken to Jakarta in the evening. The next morning, or less than 24 hours, 1.200 recording parameters with 174 flying hours were downloaded," he remarked.

Thirteen: On January 13, 2015, the Cockpit Voice Recorder (CVR) was found at coordinates 3 37 18.1 degrees southern Latitude and 10 42 12.2 degrees eastern Longitude.

"The CVR recorded two hours and four minutes of the last flight and had conversations of the flights crew, those between the two pilots, and between the pilot and the ATC officers.

Fourteen: The black box was downloaded and studied at the KNKT laboratory and it took 11 hours to do it.

Fifteen: Based on the FDR and CVR data, before the crash happened, the plane was flying stable at a height of 32 thousand feet.

Sixteen: The black box recording stopped at 23:20 UTC/GMT.

Seventeen: Until January 27, 2015, 70 bodies were recovered by a joint search team headed by the Indonesian SAR Agency (Basarnas).

Eighteen: Evacuation and search efforts are still going on.

LTC8K6 · Tue Feb 03, 2015 6:25 am

PK-AXC ELT found? Interesting, but I guess not of much relevance to the crash.

Quote:
The AirAsia flight QZ8501’s emergency locator transmitter (ELT) has reportedly been found in waters near Mamuju, West Sulawesi, during search operations conducted in the area.

The head of the National Search and Rescue Agency (Basarnas) in Mamuju, Muhammad Rizal, said as of Monday, the joint SAR team had found seven bodies, all suspected to have been passengers on board the QZ8501 that crashed into the waters of the Karimata Strait, Central Kalimantan, on Dec. 28, 2014. All bodies have been recovered and sent to Bhayangkara Hospital in Surabaya, East Java, for identification.

Muhammad said that in addition to the bodies, locals had also found objects thought to be sections of the crashed AirAsia aircraft, including seats, aircraft cabin, fiber-made interiors, as well as a box with antennas emblazoned with the words, "emergency locator transmitter".

“On Sunday, a local fisherman found the ELT in waters near a beach in Mamuju regency. It seems the ELT can no longer function, however,” Muhammad said.

The Basarnas head added that during the search on Sunday, one body was found not far from the Tubo Sendana district beach in Majene regency, West Sulawesi.
...

http://www.thejakartapost.com/news/2...ator-transmitter-found-mamuju.html

aklrno · Tue Feb 03, 2015 8:27 am

Quoting mandala499 (Reply 36):
Errr... I didn't say that... I would appreciate it if you quote the correct person instead of me re. grief.

Sorry, I blame "quote selected text". I missed.

Kaiarahi · Tue Feb 03, 2015 10:33 am

Quoting aklrno (Reply 39):
Sorry, I blame "quote selected text". I missed.

It's one of the (many) bugs on this site.. Once you've selected text, you can click "quote" on any post.

Quoting LTC8K6 (Reply 38):
Sorry, I blame "quote selected text". I missed.

Quoting tailskid (Reply 37):
Sorry, I blame "quote selected text". I missed.

Quoting mandala499 (Reply 36):
Sorry, I blame "quote selected text". I missed.

gzm · Tue Feb 03, 2015 11:27 am

Quoting 777Jet (Reply 32):

I just can't see how QZ8501 can remind somebody of MH370 so I am curious to hear your reasons.

I just can't tell you how my sick mind works.I refuse to be convinced about MH370 and I am trying to analyze it in my own imaginative way.After all,everybody else has failed.

hivue · Tue Feb 03, 2015 5:08 pm

Quoting mandala499 (Reply 36):
The NTSC has put out the 18 points of factual information.

Quoting tailskid (Reply 37):
The 18 points.

I do not see the airspeeds or problems with the FACs among the 18. Are these not considered facts at this point? Or are they facts that the NTSC, for whatever (possibly very good) reason, elected not to publicly release? If the latter, why were FLs released but not airspeeds?

EDIT: CORRECTION, GROUND SPEEDS.

[Edited 2015-02-03 09:36:16]

ThirtyEcho · Tue Feb 03, 2015 5:36 pm

The problem with releasing partial information is what Scary Mary and Richard Quest then do with that information. They go on to extrude complete, entire hypothetical scenarios based on skeletal facts and posit what the FAA "ought" to do in response. Following rabbits down hypothesized tracks is what the nonprofessional media does best, leading to conjectures about UFOs and mini black holes.

brindabella · Tue Feb 03, 2015 5:55 pm

Quoting 7BOEING7 (Reply 1):
Quoting Mandala499 (Reply 207):
Not stall recovery, only recovery from approach to stall ... coz the stall, isn't modelled in the simulator...
Some airlines did provide UAS sim sessions... but not on every sim check...

On my last several recurrency checks after AF447 they were starting to throw unusual attitudes at us and we always did approach to stall recoveries. To re-emphasize Mandala499's comment, simulators are not programmed/modeled to train for stalls and stalls are generally not done in non-instrumented (commercial) airplanes.

The point being that the candidate/trainee should recognise the approach to the stall and react immediately, EG simultaneously nose below the horizon to unstall the wings & FULL POWER.

Which brings me to a question - there has been a great deal of ongoing discussion about "Unreliable airspeed indication".

Why were we not discussing the seeming failure of both crew to recognise the approach to the stall?

(An embarrassingly long time since I flew an A320, but I seem to recall a huge red flashing "STALL script on the PFD.
Or was that the 777? Ah, time passes!)

(But luckily my Thai g/f of half my age reminds me that I'm not that old.
Not yet, anyway!)

cheers Bill

dtw2hyd · Tue Feb 03, 2015 6:44 pm

Quoting tailskid (Reply 37):

So they officially leaked entire preliminary report without releasing. Crazy.

AIRWALK · Tue Feb 03, 2015 7:26 pm

Quoting brindabella (Reply 44):
The point being that the candidate/trainee should recognise the approach to the stall and react immediately, EG simultaneously nose below the horizon to unstall the wings & FULL POWER.

In regards to a developed stall, would the procedure be a reduction of thrust for aircraft with underwing-mounted engines to reduce AoA followed by a smooth application of power once airspeed recovers and wings unstall? Would the secondary effect of thrust increase be counter productive if in a developed stall and lead to a possibly higher AoA? Would the failure to recognise a developed vs incipient stall possibly result in the wrong recovery technique which would have a negative effect?

ubeema · Wed Feb 04, 2015 3:59 am

Quoting tailskid (Reply 37):
The 18 points.

Thanks for this. Looks like carefully hand-picked facts of the search and recovery efforts. One cannot fault them for trying to limit speculations to the best extent possible, or exposing the investigation to legal proceedings before a thorough investigation is complete.

Chaostheory · Wed Feb 04, 2015 4:50 am

Quoting brindabella (Reply 44):
The point being that the candidate/trainee should recognise the approach to the stall and react immediately, EG simultaneously nose below the horizon to unstall the wings & FULL POWER.

How can you unstall the wing when it isn't stalled?

Quoting AIRWALK (Reply 46):
In regards to a developed stall, would the procedure be a reduction of thrust for aircraft with underwing-mounted engines to reduce AoA followed by a smooth application of power once airspeed recovers and wings unstall?

Priority is to reduce angle of attack. Pitch nose down first. This may be followed by advancing throttles.

Quoting AIRWALK (Reply 46):
Would the secondary effect of thrust increase be counter productive if in a developed stall and lead to a possibly higher AoA?

That is a possibility and you have to be wary of it.

Some aircraft such as the A300/A310 and the 737 Classic to a lesser extent have nasty pitch power couples which have caught a number of flight crews out. An example we use in safety seminars at my airline involved a 737 getting into such an upset on approach to BOH. It is available on the UKAAIB website here:

The Boeing 737-300 was on approach to Bournemouth Airport following a routine passenger flight from Faro, Portugal. Early in the ILS approach the auto-throttle disengaged with the thrust levers in the idle thrust position. The disengagement was neither commanded nor recognised by the crew and the thrust levers remained at idle throughout the approach. Because the aircraft was fully configured for landing, the air speed decayed rapidly to a value below that appropriate for the approach. The commander took control and initiated a go-around. During the go-around the aircraft pitched up excessively; flight crew attempts to reduce the aircraft’s pitch were largely ineffective. The aircraft reached a maximum pitch of 44º nose-up and the indicated airspeed reduced to 82 kt. The flight crew, however, were able to recover control of the aircraft and complete a subsequent approach and landing at Bournemouth without further incident.

Although the commander reported the event to the operator the following morning, his initial Air Safety Report (ASR) contained limited information and the seriousness of the event was not appreciated until the Quick Access Recorder (QAR) data was inspected on 4 October 2007.

G-THOF was not subjected to an engineering examination to ensure its continued airworthiness and remained in service throughout this period.

The investigation identified the following causal factors:

1. The aircraft decelerated during an instrument approach, to an airspeed significantly below the commanded speed, with the engines at idle thrust. Despite the application of full thrust, the aircraft stalled, after which the appropriate recovery actions were not followed.

2. The trimmed position of the stabiliser, combined with the selection of maximum thrust, overwhelmed the available elevator authority.

http://www.aaib.gov.uk/publications/formal_reports/3_2009_g_thof.cfm

flyingturtle · Wed Feb 04, 2015 11:24 am

Quoting ChaosTheory (Reply 48):
2. The trimmed position of the stabiliser, combined with the selection of maximum thrust, overwhelmed the available elevator authority.

Not wanting to detract from this discussion, but the Perpignan crash (XL888T or whatever the flight was) also involved a horizontal stab, maximally trimmed for pitch up. During degradation from Normal Law to Direct Law, the amber USE MAN PITCH TRIM message was shown only for a very short time. So, the horizontal stab was in the full pitch up during the whole accident sequence.

How fast can pilots put the horizontal stab trim into the neutral position?

David

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