Air Asia Indonesia Lost Contact from Surabaya to Singapore
Quite simply, the investigators KNOW what happened by now. The fact that there has been exactly ZERO airworthiness directives sent our to Airbus Operators would suggest that we can almost rule out Structural / Equipment failures and are more likely looking at a mishandled event. Investigators probably just trying to figure out what to pin on airbus to shift some of the blame much like the ASIANA investigation which concluded that the pilots were duped into crashing by a 'hard to understand' autothrottle.
SAMPUBLIUS, auraflyer and Gretchenfrage.
Your concerns about load protections on Airbus have been repeatedly raised ever since features of Airbus FBW have become known, about a year or two before first A320 entered service. They have being pointedly ignored by aeronautical powers that be ever since. There are at least two possible explanations for this:
1) there is a worldwide conspiracy started by Airbus and involving all of the aviation authorities that accept the Airbi to be of airworthy design (that means all of them!). This conspiracy is very stealthy, no one has ever managed to prove its existence yet it is so powerful it suppresses data on every incident where overstressing the aeroplane saved the day so perception is there was none and whistelblowers are sidelined to anonymous fora.
2) whoever proposes that 2.5G with 50% reserve is too low for transport category aeroplanes combined with FCS actively maintaining the limit has no clue about certification criteria, structural design of the transport category aeroplane or operations of them - provided they really believe what they write - and everybody who is somebody in aviation is right to ignore that contributions as their notions represent acts of spectacular ignorance. There really is not any accident where transport aeroplane could be realistically saved by being built stronger instead of not getting it her into mess in the first place.
Your pick.
Transport category aeroplanes have to withstand 3.75 G at MTOW, clean, without damage or plastic deformation. For the time being, I'll leave it at this to solicit some entertaining responses.
Dynasty 6 accident happened near the end of cruise. They were lucky to be light yet with enough fuel in wings.
Loss of engine on FBW Airbi does not degrade control laws. Alpha protection would prevent the stall and bank protection would prevent the spiral dive.
Speaking of devil.
Your concerns about load protections on Airbus have been repeatedly raised ever since features of Airbus FBW have become known, about a year or two before first A320 entered service. They have being pointedly ignored by aeronautical powers that be ever since. There are at least two possible explanations for this:
1) there is a worldwide conspiracy started by Airbus and involving all of the aviation authorities that accept the Airbi to be of airworthy design (that means all of them!). This conspiracy is very stealthy, no one has ever managed to prove its existence yet it is so powerful it suppresses data on every incident where overstressing the aeroplane saved the day so perception is there was none and whistelblowers are sidelined to anonymous fora.
2) whoever proposes that 2.5G with 50% reserve is too low for transport category aeroplanes combined with FCS actively maintaining the limit has no clue about certification criteria, structural design of the transport category aeroplane or operations of them - provided they really believe what they write - and everybody who is somebody in aviation is right to ignore that contributions as their notions represent acts of spectacular ignorance. There really is not any accident where transport aeroplane could be realistically saved by being built stronger instead of not getting it her into mess in the first place.
Your pick.
Originally Posted by SAMPUBLIUS
IMO that is a logic flaw. I posted earlier about a China 747 in 1985 that had an engine failure, went into a major spiral dive, and was recovered- and still flew - but it was severly bent with estimated 5G loads during pullout. Wings were bent up permanently sever inches at tips, who knows how much during flight. Part of horiz stabilizer was torn away.. plane landed safely, and was repaired and put back into service. Structural limit load test the wings on a 747 go several feet above top of fuselage at 2.5 to 3 G equivalent ..
Dynasty 6 accident happened near the end of cruise. They were lucky to be light yet with enough fuel in wings.
Loss of engine on FBW Airbi does not degrade control laws. Alpha protection would prevent the stall and bank protection would prevent the spiral dive.
Originally Posted by Gretchenfrage
Did you notice the absence of the usual Airbus lobby-suspects' trivial contributions on here?
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A preliminary report into last month’s crash of an AirAsia passenger jet that killed 162 people will not include an analysis of the black box flight recorders, an Indonesian investigator said today.
The preliminary report, which the ICAO requires within 30 days of the date of the accident, will include “information on the plane, the number of passengers and other information like that”, NTSC investigator Suryanto told Reuters.
It will not include analysis from the cockpit voice recorder and flight data recorder, both of which were recovered by divers from the bottom of the Java Sea.
Data from radar and the aircraft’s two “black box” flight recorders is providing investigators with a clearer picture of what occurred during the final minutes of Flight QZ8501.
The preliminary report, which the ICAO requires within 30 days of the date of the accident, will include “information on the plane, the number of passengers and other information like that”, NTSC investigator Suryanto told Reuters.
It will not include analysis from the cockpit voice recorder and flight data recorder, both of which were recovered by divers from the bottom of the Java Sea.
Data from radar and the aircraft’s two “black box” flight recorders is providing investigators with a clearer picture of what occurred during the final minutes of Flight QZ8501.
So it doesn't look like there will be an official explanation anytime soon as to what happened.
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3 attempt abandoned
Latest I hear is they may not raise the fuselage and the ships involved may be recalled. No additional bodies have been recovered.
edit: ships were recalled.
edit: ships were recalled.
Last edited by FlyerBabe; 27th Jan 2015 at 07:11. Reason: added update
Sorry, engineer here!
The GPS speed question that keeps on getting asked ad nauseam usually only gets half the answer it deserves.
With many apologies to those who know this well, IAS is INDICATED Air Speed. If a plane climbs at constant IAS then, due to the decreasing air density, its actual air speed will increase progressively. This is good, because if the speed didn't increase then the lift would decrease.
IAS is an exceptionally useful parameter, GPS speed in itself is doubly useless because it is:- 1) not airspeed, and, 2) requires desnity information and calculation to be of any use.
But GPS height data could be useful, in this engineer's opinion.
With many apologies to those who know this well, IAS is INDICATED Air Speed. If a plane climbs at constant IAS then, due to the decreasing air density, its actual air speed will increase progressively. This is good, because if the speed didn't increase then the lift would decrease.
IAS is an exceptionally useful parameter, GPS speed in itself is doubly useless because it is:- 1) not airspeed, and, 2) requires desnity information and calculation to be of any use.
But GPS height data could be useful, in this engineer's opinion.
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Recovery Called Off
27Jan15 1700 hk
QZ8501 recovery operation called off: Indonesian military - Channel NewsAsia
JAKARTA: The Indonesian military on Tuesday (Jan 27) called off efforts to recover the wreckage of an AirAsia plane that crashed into the Java Sea last month after failing for several days to lift the fuselage.
"All of our forces are being pulled out," said Rear Admiral Widodo, a navy official overseeing the search and rescue operation. "The operation has been ongoing for 30 days so the joint team has pulled out," he said. "We apologise to the families of the victims. We tried our best to look for the missing victims."
QZ8501 recovery operation called off: Indonesian military - Channel NewsAsia
JAKARTA: The Indonesian military on Tuesday (Jan 27) called off efforts to recover the wreckage of an AirAsia plane that crashed into the Java Sea last month after failing for several days to lift the fuselage.
"All of our forces are being pulled out," said Rear Admiral Widodo, a navy official overseeing the search and rescue operation. "The operation has been ongoing for 30 days so the joint team has pulled out," he said. "We apologise to the families of the victims. We tried our best to look for the missing victims."
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The 787 supplies a back up IAS derived from AOA and inertial system should you lose all pitot's. The GPS takes over altitude. A very nice feature.
p.s the GPS/FMC ground speed indicator is always a vital tool for handling unreliable airspeed especially if you still have wind data.
The vital difference with Boeing is that there are no control FBW inputs to overspeed/underspeed. (Only trim inhibit) This means any failure is passive and Boeing want the pilot to have control over the aircraft not the other way around.
I am losing count of the number of airbus incidents of altitude climb/bust due to transitory overspeeds.
Throttles that don't move/ sidesticks cancelling each other out with inputs not visible to the other pilot/ FBW system that commands pitch manoeuvres without the autopilot..........The airbus design philosophy counters not helps piloting ability and awareness especially when its needed most with out of the ordinary occurrences.
p.s the GPS/FMC ground speed indicator is always a vital tool for handling unreliable airspeed especially if you still have wind data.
The vital difference with Boeing is that there are no control FBW inputs to overspeed/underspeed. (Only trim inhibit) This means any failure is passive and Boeing want the pilot to have control over the aircraft not the other way around.
I am losing count of the number of airbus incidents of altitude climb/bust due to transitory overspeeds.
Throttles that don't move/ sidesticks cancelling each other out with inputs not visible to the other pilot/ FBW system that commands pitch manoeuvres without the autopilot..........The airbus design philosophy counters not helps piloting ability and awareness especially when its needed most with out of the ordinary occurrences.
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Rudder Problems?
I'm surprised that no-one has commented on the report above by 757SP5 at http://www.pprune.org/rumours-news/5...ml#post8841170 about rudder problems with this aircraft.
Apparently
Could 'auto rudder trim limiter flight control' problems be the key to this crash?
Sorry to see the wreckage is now to be abandoned, but I guess there is a trade off between the risk to recovery team members and any benefit that might result from their efforts.
Apparently
Former Garuda Indonesia pilot Capt. Shadrach M. Nababan, said -based on its logbook data - that the Airbus A320-200 serving AirAsia flight QZ8501 had experienced problems as much as nine times on its auto rudder trim limiter flight control in 2014.
Three days before crashing on December 25, 2014, flight QZ8501 experienced a 'return to apron' twice, according to Shadrach.
Three days before crashing on December 25, 2014, flight QZ8501 experienced a 'return to apron' twice, according to Shadrach.
Sorry to see the wreckage is now to be abandoned, but I guess there is a trade off between the risk to recovery team members and any benefit that might result from their efforts.
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Airspeed determination
Failures in airspeed measurements seem to be increasingly implicated in aircraft upsets.
Rather than relying on pitot-based airspeed measurement, a number of contributors have suggested GPS-based approaches (which are unsuitable, as discussed).
As a back-up, could a fuselage-embedded mini-RAT type system work - an air-driven impeller (probably rather smaller than the cooling fan in your PC)?
Or perhaps even an acoustic system: a simple hull-mounted microphone which detects airspeed-derived noise? Frequency tuning or filtering could avoid interference from engine-derived noise.
Rather than relying on pitot-based airspeed measurement, a number of contributors have suggested GPS-based approaches (which are unsuitable, as discussed).
As a back-up, could a fuselage-embedded mini-RAT type system work - an air-driven impeller (probably rather smaller than the cooling fan in your PC)?
Or perhaps even an acoustic system: a simple hull-mounted microphone which detects airspeed-derived noise? Frequency tuning or filtering could avoid interference from engine-derived noise.
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Deanm - good observation.
Building on that, why not incorporate GPS data as a fall back, in the event of a pitot head icing up, the FMS advises that there is a mismatch between GPS/Pitot speeds and does nothing pending pilot acknowledgement.
Descent to a lower level at this stage gives more speed margin whilst reducing a stall scenario, the secondary effect of pitot head icing is loss of awareness and subsequent loss of control (in some cases).
Just thinking about being in heavy turbulence/wind shear at night with no speed awareness and close to speed margins gives me the sweats.
Prevention is better than cure.
Building on that, why not incorporate GPS data as a fall back, in the event of a pitot head icing up, the FMS advises that there is a mismatch between GPS/Pitot speeds and does nothing pending pilot acknowledgement.
Descent to a lower level at this stage gives more speed margin whilst reducing a stall scenario, the secondary effect of pitot head icing is loss of awareness and subsequent loss of control (in some cases).
Just thinking about being in heavy turbulence/wind shear at night with no speed awareness and close to speed margins gives me the sweats.
Prevention is better than cure.
Each of those is still subject to icing. You need sensing from something that does not involve air that's moisture laden. A combination of inertial reference and GPS can compute a probable wind until you get out of icing conditions. There is no simple solution.
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Deanm - good observation.
Building on that, why not incorporate GPS data as a fall back, in the event of a pitot head icing up, the FMS advises that there is a mismatch between GPS/Pitot speeds and does nothing pending pilot acknowledgement.
Descent to a lower level at this stage gives more speed margin whilst reducing a stall scenario, the secondary effect of pitot head icing is loss of awareness and subsequent loss of control (in some cases).
Just thinking about being in heavy turbulence/wind shear at night with no speed awareness and close to speed margins gives me the sweats.
Prevention is better than cure.
Building on that, why not incorporate GPS data as a fall back, in the event of a pitot head icing up, the FMS advises that there is a mismatch between GPS/Pitot speeds and does nothing pending pilot acknowledgement.
Descent to a lower level at this stage gives more speed margin whilst reducing a stall scenario, the secondary effect of pitot head icing is loss of awareness and subsequent loss of control (in some cases).
Just thinking about being in heavy turbulence/wind shear at night with no speed awareness and close to speed margins gives me the sweats.
Prevention is better than cure.
The 787 supplies a back up IAS derived from AOA and inertial system should you lose all pitot's. The GPS takes over altitude. A very nice feature.
p.s the GPS/FMC ground speed indicator is always a vital tool for handling unreliable airspeed especially if you still have wind data.
p.s the GPS/FMC ground speed indicator is always a vital tool for handling unreliable airspeed especially if you still have wind data.
Didn't Airbus family aircraft have a recent Airworthiness Directive release having to do with pitch control in certain circumstances? (The answer is yes). If you look at the longer view of the A320 and its successors, in terms of the concept of the control architecture, this is a mature system. That they are still "discovering" certain issues with it (albeit having to do with rarely encountered variables lining up) speaks to the complexity of the system and its software suite.
With the complexity of the system in mind, it speaks for a need for more training and education on the system, not less, for those who operate it. What is curious is that this seems to be counter-intuitive to the suit wearing sorts who design and who buy these systems to be put into place to deliver people from here to there for a fee.
Maybe it's a paradox: if one is to build an airplane that "a concierge can fly" you have to build a complicated plane, which means that this concierge actually needs to have more invested in him on an ongoing basis in training and education in order to operate this complex machine.
No Free Lunch?
Analogue: you need deeper training and education of flying a swept wing transport aircraft than you do a Piper Cub.
With the complexity of the system in mind, it speaks for a need for more training and education on the system, not less, for those who operate it. What is curious is that this seems to be counter-intuitive to the suit wearing sorts who design and who buy these systems to be put into place to deliver people from here to there for a fee.
Maybe it's a paradox: if one is to build an airplane that "a concierge can fly" you have to build a complicated plane, which means that this concierge actually needs to have more invested in him on an ongoing basis in training and education in order to operate this complex machine.
No Free Lunch?
Analogue: you need deeper training and education of flying a swept wing transport aircraft than you do a Piper Cub.
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Air Asia Indonesia's update tonight states that today's operation was called off due to strong currents. The decision to abandon recovery was made in part because observations of the fuselage have led investigators to believe there are no further bodies to be recovered from this part of the wreckage. (I suppose the cynical part of me observes that two failed attempts to haul the wreckage aboard a recovery vessel, the second of which resulted in the fuselage breaking into two pieces, is not likely to have helped that situation.)
I'm disappointed there has not been confirmation of the location of the cockpit or recovery of occupants. Whilst it may not be of material benefit after recovery of the FDR and CVR, it would have been fitting to lay them to rest, having gone down fighting it seems.
I'm disappointed there has not been confirmation of the location of the cockpit or recovery of occupants. Whilst it may not be of material benefit after recovery of the FDR and CVR, it would have been fitting to lay them to rest, having gone down fighting it seems.
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Airbus design philosophy "keep the pilot in the dark".
Disclaimer, I fly Airbus so don't call me a Boeing troll.
How does a whole family of aircraft (Airbus FBW) get certified when through Air Asia, Air France, Lufthansa and the many other reports of, at the least UAS show a major design flaw still not corrected.
Ie where a simple disagreement between similar sensors (AOA, Pitots/ADRs), followed by computer rejection of perhaps the one accurate sensor, may then cause the computers to initiate drastic action on the flight controls requiring IMMEDIATE and correct response by the pilot whilst assessing what is valid and what isn't, with spurious ECAMS, Aural Alerts and displays, be allowed to be certified safe.
All, without letting the pilot know in the first instance of a disagreement between sensors and then the decision by the computer to reject a specific sensor, giving the pilot no indication anything is abnormal until all hell breaks loose?
To me this borders on the criminal, at the very least an immediate ECAM advising a specific sensor has been rejected, or even better is approaching the limits of rejections similar to "IRS excessive drift etc", would at least advise the pilot that something is amiss and the computers maybe about to take drastic action..
How does a whole family of aircraft (Airbus FBW) get certified when through Air Asia, Air France, Lufthansa and the many other reports of, at the least UAS show a major design flaw still not corrected.
Ie where a simple disagreement between similar sensors (AOA, Pitots/ADRs), followed by computer rejection of perhaps the one accurate sensor, may then cause the computers to initiate drastic action on the flight controls requiring IMMEDIATE and correct response by the pilot whilst assessing what is valid and what isn't, with spurious ECAMS, Aural Alerts and displays, be allowed to be certified safe.
All, without letting the pilot know in the first instance of a disagreement between sensors and then the decision by the computer to reject a specific sensor, giving the pilot no indication anything is abnormal until all hell breaks loose?
To me this borders on the criminal, at the very least an immediate ECAM advising a specific sensor has been rejected, or even better is approaching the limits of rejections similar to "IRS excessive drift etc", would at least advise the pilot that something is amiss and the computers maybe about to take drastic action..
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The recovery process of lifting a fuselage-full of water (wings too) is the subject of a tech memo from Boeing. And it was proof-tested in March 2002 when the precious, sole survivor B-307 was ditched in Puget Sound.
The essential limitation is the rate at which the aircraft is lifted as it surfaces; the water must be allowed to drain slowly, and the hoisting reduced to a rate of inches per hour, to insure the aircraft structure and lift cables/straps are not overloaded.
Granted, the 307 was in sheltered and shallow water of Eliott Bay (in fact, still awash, not submerged). This made the job easier, and the place was probably swarming with engineers from Boeing's nearby offices, and the hoist was successful. The 307 was restored to airworthy, and was ferried one last time to the NASM facility at IAD. History, Travel, Arts, Science, People, Places | Air & Space Magazine
The precautions from the Boeing 307 experience were probably impossible to execute in the choppy Java sea, leading to the inevitable breakup of the AirAsia ship.
The essential limitation is the rate at which the aircraft is lifted as it surfaces; the water must be allowed to drain slowly, and the hoisting reduced to a rate of inches per hour, to insure the aircraft structure and lift cables/straps are not overloaded.
Granted, the 307 was in sheltered and shallow water of Eliott Bay (in fact, still awash, not submerged). This made the job easier, and the place was probably swarming with engineers from Boeing's nearby offices, and the hoist was successful. The 307 was restored to airworthy, and was ferried one last time to the NASM facility at IAD. History, Travel, Arts, Science, People, Places | Air & Space Magazine
The precautions from the Boeing 307 experience were probably impossible to execute in the choppy Java sea, leading to the inevitable breakup of the AirAsia ship.
What a/c parts could be secured? Now what do we do if we end up in need of -for example- certain electronics boxes and maybe rudder actuators to find out what really happened? Go back into the mud with another campaign again? If we end it here we might lose all traces.
Or is this case considered solved already behind the scenes?
Or is this case considered solved already behind the scenes?
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Originally Posted by Clandestino
Loss of engine on FBW Airbi does not degrade control laws. Alpha protection would prevent the stall and bank protection would prevent the spiral dive.
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NO EXPLANATION ANYTIME SOON?
Doubtless Airbus and AirAsia know by now EXACTLY what happened and the lawyers are gearing up for the fight.
If it was a rudder hardover, as allegedly previously reported, then the maintenance is in the frame.
If it is an Airbus peculiarity about which few if any of the crew were/are aware, then manufacturer is in the frame.
If it was mishandling of a recoverable situation, then the airline and xAAs are in the frame for inadequate training.
Meanwhile the amateur accident investigators in this forum will continue to speculate about spins, stalls, aerobatics, impact angles, aircraft flight paths, configurations and so on ad nauseam.
Perhaps if those in the industry might take some time out, particularly the designers of the kit which is confusing the operators so regularly (no particular type specific) to try reading "The Organized Mind" by Neuroscientist Daniel Levitin (as soon as it is published 2 days from now,if you want it Kindled).
If that task can be achieved, either before their next flight or before their next design, then we might be part-way down the road to reducing the rates of such tragic mishaps.
Listening to the author on BBC Radio 4 Monday 26th January at 0900Z (try pod-casting it?) it appeared that someone with knowledge of the brains of the species of advanced-level Bonobo Chimps, who design and operate the current airliner fleets, has cast light on the supreme arrogance of said Chimps and their (possibly) false confidence in their ability to multi-task and handle multiple information threads.
If I may quote: "The brain worked well enough for our Stone Age ancestors and has barely changed since then, during which it has been forced to absorb vastly more knowledge than ever before in human history. "
I await the incoming fire, yours truly, a retired Bonobo!
If it was a rudder hardover, as allegedly previously reported, then the maintenance is in the frame.
If it is an Airbus peculiarity about which few if any of the crew were/are aware, then manufacturer is in the frame.
If it was mishandling of a recoverable situation, then the airline and xAAs are in the frame for inadequate training.
Meanwhile the amateur accident investigators in this forum will continue to speculate about spins, stalls, aerobatics, impact angles, aircraft flight paths, configurations and so on ad nauseam.
Perhaps if those in the industry might take some time out, particularly the designers of the kit which is confusing the operators so regularly (no particular type specific) to try reading "The Organized Mind" by Neuroscientist Daniel Levitin (as soon as it is published 2 days from now,if you want it Kindled).
If that task can be achieved, either before their next flight or before their next design, then we might be part-way down the road to reducing the rates of such tragic mishaps.
Listening to the author on BBC Radio 4 Monday 26th January at 0900Z (try pod-casting it?) it appeared that someone with knowledge of the brains of the species of advanced-level Bonobo Chimps, who design and operate the current airliner fleets, has cast light on the supreme arrogance of said Chimps and their (possibly) false confidence in their ability to multi-task and handle multiple information threads.
If I may quote: "The brain worked well enough for our Stone Age ancestors and has barely changed since then, during which it has been forced to absorb vastly more knowledge than ever before in human history. "
I await the incoming fire, yours truly, a retired Bonobo!
Last edited by BARKINGMAD; 27th Jan 2015 at 15:41. Reason: Clarify publish date.