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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.
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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 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. |
gcal: I think it's called "Sensorineural deafness".
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January 28th date set to release preliminary report
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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...26_hidungc.jpg Source: Detik.com Approximate location of where the radome was found. |
Originally Posted by marchino61
(Post 8832552)
I find this quite intriguing. What is the source of this information?
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. |
@ Ian W - on transcripting
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 - 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. 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. |
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.
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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. |
@ Ian W On sound and sound processing - under stress
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. 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). |
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.
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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. |
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. |
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.
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Assuming the radome was attached to the aircraft when it hit the sea, the radome has drifted on average 24km per day (550/23).
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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.
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6000 fpm climb and subsequent stall reported BBC News - AirAsia flight QZ8501 'climbed too fast'
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. |
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.
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