Air Asia Indonesia Lost Contact from Surabaya to Singapore
A common comment in this and the AF thread is: 'Why didn't they react to the STALL warnings?' The most likely answer is that the aural warnings were being sub-consciously filtered. When the brain is overloaded, the first sense our brains typically 'load-shed' is hearing. I can imagine that the pilots in both accidents would have have been very over-loaded trying to figure out what was happening and so their brains were not processing any aural information at all. This could also explain why the F/O didn't let go of his controller, rather than being a language problem, it might have been a 'I'm not hearing anything because my brain is over-loaded' problem.
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In the event of excessive pitch up (possible in direct law of the A320 ) I remember being taught forty years to immediately roll the aircraft beyond 90 degrees to give one a chance to sort the problem out.
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Re auto trim in Alternate Law; some confusion?
If Abnormal Attitude Law (*) is triggered by an upset, Pitch, Roll, etc, as defined on page 79 of the report (#3570) then auto trim is frozen at the value existing at change over.
* This is Pitch Alternate with load factor protection, but without auto trim (#3574).
However, if the aircraft ‘recovers’ from the upset condition (Abnormal Attitude no longer valid, but note overriding AoA range, and that the aircraft could still be in a stalled condition), then the auto trim might be available.
The description of system behaviour in #3574 indicates that auto trim is recovered after the ‘condition’ (presumed to be the upset condition) is exited, but is unclear (and probably irrelevant in this instance if Normal Law would be reinstated) which law, Alternate or Attitude is retained.
In this accident would a power interruption as suggested in the report trigger Alternate Law with auto trim?
Or alternatively, and /or during the event after power interrupt, would the Abnormal Attitude Law be triggered
and if so, which ‘law’ has priority, i.e. could a power interrupt inhibit a subsequent tigger point?
And could auto trim be reinstated later in the event, yet still in Alternate Law?
If Abnormal Attitude Law (*) is triggered by an upset, Pitch, Roll, etc, as defined on page 79 of the report (#3570) then auto trim is frozen at the value existing at change over.
* This is Pitch Alternate with load factor protection, but without auto trim (#3574).
However, if the aircraft ‘recovers’ from the upset condition (Abnormal Attitude no longer valid, but note overriding AoA range, and that the aircraft could still be in a stalled condition), then the auto trim might be available.
The description of system behaviour in #3574 indicates that auto trim is recovered after the ‘condition’ (presumed to be the upset condition) is exited, but is unclear (and probably irrelevant in this instance if Normal Law would be reinstated) which law, Alternate or Attitude is retained.
In this accident would a power interruption as suggested in the report trigger Alternate Law with auto trim?
Or alternatively, and /or during the event after power interrupt, would the Abnormal Attitude Law be triggered
and if so, which ‘law’ has priority, i.e. could a power interrupt inhibit a subsequent tigger point?
And could auto trim be reinstated later in the event, yet still in Alternate Law?
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Systemic (not necessarily systematic) issues
A0283 raises large issues, within a context of what I think it would be accurate to refer to as the overall system of international civil aviation (post w/title "Macro CRM"). While studiously avoiding any of the "flying" issues presented by the report's contents and also (if an understanding of some of the thread criticizing the report is correct) by the accident itself, my premise is that, it appears very nearly certain that efforts to address the underlying problems which caused this accident are not working, and have essentially no chance of working. By "working," I mean "solving the problems and preventing the same or essentially same thing from happening again."
But adding in the larger, "Macro CRM" issues A0283 identifies, is there an urgency brewing? - a need for mobilization of the overall system? Why would this be so? Here:
Indeed, ICAO's baseline projections are that overall global air traffic will double within something like the next 12-15 years.
The point I am hoping to make is, where does the learning curve go, next? After AF447, the learning curve seems not to have moved far enough (or, if it did move, it has not kept up with the scope of the problem). Where is the kick in the ar$e to the system going to come from? (And while observations about the profit motive, pin-headed management of some air carriers, wide variability of compliance with SARPs among various regions and countries, all are valid, they're kind of beside the point, is it not so? Those restraints on progress are well-known and not going away - the point is, how to improvise, adapt and overcome them? Unless you want to disbelieve that a winner never quits and a quitter never wins.)
But adding in the larger, "Macro CRM" issues A0283 identifies, is there an urgency brewing? - a need for mobilization of the overall system? Why would this be so? Here:
The point I am hoping to make is, where does the learning curve go, next? After AF447, the learning curve seems not to have moved far enough (or, if it did move, it has not kept up with the scope of the problem). Where is the kick in the ar$e to the system going to come from? (And while observations about the profit motive, pin-headed management of some air carriers, wide variability of compliance with SARPs among various regions and countries, all are valid, they're kind of beside the point, is it not so? Those restraints on progress are well-known and not going away - the point is, how to improvise, adapt and overcome them? Unless you want to disbelieve that a winner never quits and a quitter never wins.)
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To build in a mechanical connection between the two sidesticks would remove one dimension of complexity. And complexity is what get you by the balls if fear is in the air.
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New Gulfstream G500/600 aircraft will have linked Active Sidestick technology. Each pilot will be able to see and feel what the other pilot is doing (or even what the AP is commanding).
It's a no-brainer evolution.
It's a no-brainer evolution.
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Originally Posted by PT6Driver View Post
Cpn Bloggs
My question on yoke v sidestick was referring to the fact that inappropriate stall recovery is common to all.
Regarding actual handling time of the PF I quite agree with you.
b1lanc:
It wasn't just inappropriate stall recovery. It appears that neither PF recognized they were in a stall even with the stall warnings blaring. That screams for change and not just training or SOP.
The below 1 reduced Nz is accordingly asociated with the end of the stalled situation and the point where soon after the recovery to level flight starts. If we could check the Nz graph (i could not find it in the report, but forgive me if it is there and I just oferlooked it) we would see similar Nz value like in AF447, the Nz value below 1 ( I gestimate around .7-.9) for a prolonged period of the stalled descent. Such values can be felt very well. They may be even very uncomfortable if they have never been encountered before. Stalls on the other hand are thought to be accompanied by some violent maneuvering of the aircraft asociated with positive Nz. Reduced Nz could therefore be asociated with a unstalled situation.
What is my point? If the flight behaviour prior stall has been missed as being prone for an impending stall, the entry into stall and the following developped stall might be missed completely due to the unspectacular entry, and the felt Nz below 1 could be interpreted as the normalisation of the situation. We know that it is wrong to go after the body sensation, but in a stress situation it will happen anyway.
The most important point for the prevention of a stall and for a necessary stall recovery is the early recognition, that the flight before the stall entry is critical and a stall may occur. Then the crew is prepared for the flight dynamics which could developp during stall entry and also during a developped stall and how ro counter those. The importance lies in the avoidance of such situations.
It is a training issue, imho still not adressed thoroughly enough.
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So you're saying that the pilots who ignored a multitude of obvious indicators, would somehow magically look at the tiny AoA indicator in a high stress situation and all would be well? Especially considering the fact that 99.999 percent of the time they don't look at it (if it's available), hence, in a high load scenario, they would never do it anyway.
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Most people, and the industry, seem to be missing some fundamental safety systems issues here by focussing on the detail rather than the big picture. A key concept of safety systems is there are three types of factors: human, machine, and environment. In this case environmental factors are largely the inherently unsafe position of a flying aircraft at altitude.
With respect to human factors, human error is simply an unavoidable element. Human error can be minimised, but it will never be eliminated. So while better training and higher levels of competency should be constant goals, they will never prevent human error being a causal element. Focussing on human error as the root cause, or fixable cause, in these incidents is a mistake.
With over 35 years of experience in incident response and investigation, systems design, and high-risk hazard and risk analysis expertise, it is absolutely obvious to me that there are design flaws in the airbus operating environment. In no other high risk industry would some of the human-machine interface elements, (discussed enough here that they don't need repeating) be allowed to continue in place following the incidents that have occurred.
It really is that simple. But I imagine the financial cost of remedy is immense.
With respect to human factors, human error is simply an unavoidable element. Human error can be minimised, but it will never be eliminated. So while better training and higher levels of competency should be constant goals, they will never prevent human error being a causal element. Focussing on human error as the root cause, or fixable cause, in these incidents is a mistake.
With over 35 years of experience in incident response and investigation, systems design, and high-risk hazard and risk analysis expertise, it is absolutely obvious to me that there are design flaws in the airbus operating environment. In no other high risk industry would some of the human-machine interface elements, (discussed enough here that they don't need repeating) be allowed to continue in place following the incidents that have occurred.
It really is that simple. But I imagine the financial cost of remedy is immense.
Last edited by bud leon; 4th Dec 2015 at 01:55.
bud,
Very well put. I think that Airbus management are secretly wishing that they had linked the sticks and possibly added force-feedback, but of course they can never say that.
Very well put. I think that Airbus management are secretly wishing that they had linked the sticks and possibly added force-feedback, but of course they can never say that.
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New Gulfstream G500/600 aircraft will have linked Active Sidestick technology. Each pilot will be able to see and feel what the other pilot is doing (or even what the AP is commanding).
It's a no-brainer evolution.
It's a no-brainer evolution.
Sidestick characteristics—breakout forces, force displacement gradients and soft stops in each axis—are programmable and can be tailored by the aircraft manufacturer. “We offer an active stick with a feature toolbox that provides a wide range of parameters that can be tailored,” says Taylor. These include the breakout forces required to move the sidestick from its null position, “so the pilot has to pull, say, half a pound before it starts to move, to prevent inadvertent inputs and provide an obvious centering feel,” he says.
Soft stops are vertical sections of the force displacement gradient that provide tactile feedback on aircraft limits. “These are miniature walls that move back and forward and cue the pilot to impending limits. At 10 deg., the pilot may have to put in an extra 5 lb. of force to get over a mini wall,” says Taylor.
Soft stops are vertical sections of the force displacement gradient that provide tactile feedback on aircraft limits. “These are miniature walls that move back and forward and cue the pilot to impending limits. At 10 deg., the pilot may have to put in an extra 5 lb. of force to get over a mini wall,” says Taylor.
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Bud leon
Unfortunately you are missing the elephant in the room. The AIRCRAFT did not cause the accident incompetent pilots did.
One who could not fly straight and level and one who thought he knew better than Airbus and their test pilots. All they had to do was emergency cancel the warning and write it up on arrival!
If they had done that there would not be this ridiculous A vs B or stall recovery discussion.
The regulators and training are at fault, how many of the pilots in the cockpit these days have been scared and learnt from that experience? Flying is like being at sea the environment is rarely forgiving. Those that have completed training through a majority of simulator time certainly will not have.
Unfortunately you are missing the elephant in the room. The AIRCRAFT did not cause the accident incompetent pilots did.
One who could not fly straight and level and one who thought he knew better than Airbus and their test pilots. All they had to do was emergency cancel the warning and write it up on arrival!
If they had done that there would not be this ridiculous A vs B or stall recovery discussion.
The regulators and training are at fault, how many of the pilots in the cockpit these days have been scared and learnt from that experience? Flying is like being at sea the environment is rarely forgiving. Those that have completed training through a majority of simulator time certainly will not have.
Originally Posted by Iceman to Bud Leon
Unfortunately you are missing the elephant in the room.
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where were the safety champions
Others share the responsibility, but at significant times the captain must rise to the occasion by all means at his disposal. Exactly when is that?
The answer is, whenever it is obvious that others are not.
I'm not referring to compliance with regulations or getting a good night's sleep before a long flight duty. The captain is compelled to do that and it is generally reasonable to assume that these type of things are not normally a problem.
I am referring to responsibility during stressful or unusual circumstances. It is an extraordinary circumstance when repetitive flight control malfunctions cause multiple taxi back or unreasonably divert attention in flight. Exactly like the situation that existed for months on this aircraft.
Apparently no pilot sufficiently pressured the company to fix this problem when it became more obvious. If this is so, the question is, "can pilots in this airline ever confirm their authority and take an increasingly appropriate share of the responsibility?"
There are also other fatal hull losses that could have been prevented but for the absence of pilot fortitude before departure.
Another classic will be MH17, downed by a BUK missile. It was already known that an AN-26 had been downed by a BUK in that area. When I heard that 3 days later a B777 had been shot down, I was amazed that MH17 would plan over Ukraine, since a BUK has a capability in excess of B777 max altitude.
Korean, Asiana, BA and some others avoided the area.
Aeroflot, Singapore, Lufthansa, and others, continued planning via Ukraine. What were these airlines and their captains thinking?
Where were MH17 safety champions? Same place as QZ8501, nowhere.
The answer is, whenever it is obvious that others are not.
I'm not referring to compliance with regulations or getting a good night's sleep before a long flight duty. The captain is compelled to do that and it is generally reasonable to assume that these type of things are not normally a problem.
I am referring to responsibility during stressful or unusual circumstances. It is an extraordinary circumstance when repetitive flight control malfunctions cause multiple taxi back or unreasonably divert attention in flight. Exactly like the situation that existed for months on this aircraft.
Apparently no pilot sufficiently pressured the company to fix this problem when it became more obvious. If this is so, the question is, "can pilots in this airline ever confirm their authority and take an increasingly appropriate share of the responsibility?"
There are also other fatal hull losses that could have been prevented but for the absence of pilot fortitude before departure.
Another classic will be MH17, downed by a BUK missile. It was already known that an AN-26 had been downed by a BUK in that area. When I heard that 3 days later a B777 had been shot down, I was amazed that MH17 would plan over Ukraine, since a BUK has a capability in excess of B777 max altitude.
Korean, Asiana, BA and some others avoided the area.
Aeroflot, Singapore, Lufthansa, and others, continued planning via Ukraine. What were these airlines and their captains thinking?
Where were MH17 safety champions? Same place as QZ8501, nowhere.
