airtechy
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 4:32 pm

Actually...if I understand the operation correctly...it would be easier on an Airbus to crash the plane. If you hold the priority button down, the other person cannot override. At least with a yoke you have a fighting chance.

From the report...

"A pilot can deactivate the other stick and take full control by pressing and keeping pressed his priority takeover pushbutton."
 
awthompson
Posts: 517
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 4:34 pm

Accidents where pilots (may have) pulled the stick or yoke back all or most of the way to the ground (in date order):

Pulkovo flight 612 Tupolev Tu-154
Colgan Air flight 3407 Dash-8-400Q
West Caribbean Airlines flight 708 MD82
Air France flight 447 Airbus A332
Air Asia flight 8501 Airbus A320

These account for 770 fatalities.

There are likely many more in the archives if I could remember them.

The Pulkovo Tu-154 and the West Caribbean Airlines MD82 accidents prove that the phenomenon under discussion is not exclusive to side stick controlled aircraft.
 
DUSdude
Posts: 103
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 4:34 pm

Quoting WesternDC6B (Reply 98):
I have to wonder if this was a "cracked" solder joint, or the result of solder "whiskering". This problem was brought about when lead was banned from solder used in electronic components for "the good of the environment".

Lead hasn't been banned in solder for electronics, onnly in soldering plumbing, and not because of the environment but because of your health with respect to drinking water quality. And in any case, I doubt these North American regulations apply to Air Asia's maintenance in Indonesia.
 
hivue
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 4:35 pm

Quoting zeke (Reply 99):
Quoting kurtverbose (Reply 96):Here the pilot was not trying to recover from a stall. He didn't know he was in a stall.

This isn't the first time. It seems to happen with depressing regularity.

Why?

That is a very valid question, and which has not been answered.

Once again I would suggest this thread in Tech/Ops;

Stall Recovery (by BravoOne Nov 30 2015 in Tech Ops)

It contains a link to the FAA Advisory Circular.
"You're sitting. In a chair. In the SKY!!" ~ Louis C.K.
 
hivue
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 4:39 pm

Quoting airtechy (Reply 100):
"A pilot can deactivate the other stick and take full control by pressing and keeping pressed his priority takeover pushbutton."

Both sticks have a priority button. It just boils down to two guys trying to control one airplane at the same time. Same thing happens on Boeings.
"You're sitting. In a chair. In the SKY!!" ~ Louis C.K.
 
Kaiarahi
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 4:43 pm

Quoting D L X (Reply 78):
the other pilot was not able to see and consequently fix

Not in this case. The PIC was applying nose down on the stick. What he didn't do (SOP) was announce that he had control and push the priority button on the side stick giving him control.

Quoting airtechy (Reply 92):
Wow! You win.

You're missing the point - sidestick position does not indicate flight path. That's what instruments are for.

Quoting kurtverbose (Reply 96):
Here the pilot was not trying to recover from a stall. He didn't know he was in a stall.

The PIC apparently knew. But he didn't take control (SOP).

Quoting D L X (Reply 91):
On top of that, before the A320 series, all planes had the two control columns operating in tandem. So the question of why Airbus would deviate is germane.

Linked sticks were extensively tested during the design phase. Pilots preferred the priority button.

[Edited 2015-12-01 08:45:54]
Empty vessels make the most noise.
 
airtechy
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 4:45 pm

Quoting hivue (Reply 104):

Both sticks have a priority button. It just boils down to two guys trying to control one airplane at the same time. Same thing happens on Boeings.

I was addressing that answer to a deliberate crash situation...not a confused pilot situation.
 
Kaiarahi
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 4:48 pm

Quoting airtechy (Reply 100):
If you hold the priority button down, the other person cannot override.

It's a little more sophisticated than that. You should do some reading - it's easy enough to find.
Empty vessels make the most noise.
 
airtechy
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 4:53 pm

Quoting Kaiarahi (Reply 105):
Linked sticks were extensively tested during the design phase. Pilots preferred the priority button.

For whatever reason, I don't doubt that they did. However, that testing did not have the knowledge gained from analyzing two crashes to influence the result.

Edit: ...and as I remember reading on here, at least one new aircraft manufacturer has stated that their sidestick controllers with be synced.

[Edited 2015-12-01 08:56:23]
 
Amiga500
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 4:59 pm

Quoting zeke (Reply 99):
Ask me again in 20 years when we understand what they have found. It does not matter what techniques you use, you cannot predict aerodynamics with 100% precision, there are always assumptions.

Yes you can. Unless your going to be pedantic and argue about the irrelevant 0.01% error...


Ever heard of the Navier-Stokes equations?

They precisely describe turbulent airflow of a fluid.


Or heard of the Boltzmann equations?

They describe the statistical behaviour of single particles.


The latter allows us to know that (at the altitudes airliners fly at) air can be treated as a homogeneous fluid for non-thermal problems (such as aerodynamic lift) with a negligible error.

The former allows us to determine that approximations of turbulence can be applied to calculating turbulence over a full aircraft and do so accurately enough to fulfil the end goal. i.e. cruise aircraft flight lift and drag.... or stability.
 
Kaiarahi
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 5:00 pm

Quoting airtechy (Reply 108):
However, that testing did not have the knowledge gained from analyzing two crashes to influence the result.

Differential input was fully tested. Bottom line is that these two accidents had nothing to do with sidestick design and function and everything to do with CRM and training.
Empty vessels make the most noise.
 
Amiga500
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 5:00 pm

Quoting zeke (Reply 99):
Mine is to do none of your answers, clarify what the issue is first before acting.

and that is why you fail.
 
mmo
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 5:00 pm

Quoting Amiga500 (Reply 58):
f your in a sliding bank, one or both (dep. if masked) of your ailerons may be seeing significant lateral airflow - which means it can have some authority - which you may lose upon attempting to use it - particularly aggressively.


Go back to your books.

What an arrogant response. First of all, I suggest you do some research on two items. First, you need to review the characteristics of swept wings and how they stall. Secondly you need to understand what an aft stick stall is.

Please explain to me where "relative wind" is during this "skidding bank" you refer to is. Secondly, the problem with an aft stick stall is the horizontal stabilizer is blanked out because of the stall characteristics of the swept wing. Normal stall recovery will not work.

For someone who isn't a pilot, you sure do think you know an awful lot. That's dangerous!!

Quoting goosebayguy (Reply 86):

I don't get it. A stall warning means push the stick forwards. How difficult is that? Yet time after time pilots are pulling back. Its a very very basic manoevre.

Again, an aft stick stall is very insidious and the recovery, if you have never done it before, is very different. The problem with airline training is stalls are not allowed to fully develop in the simulator for a number of reasons. The biggest reason is the flight characteristics are only provided for the normal flight envelope and once out of the envelope the simulator will not respond in a way that would replicate the aircraft.

Quoting Amiga500 (Reply 94):
Two questions for MMO - you don't have to answer of course.

(1) When is the last time you flew an aircraft (or glider or simulator) around the sky exploring the limits of the flight envelope?
(2) When presented with an alarm, what is your first thought - pigeon-hole the problem, start checklisting, or primary instruments?

1) I have done several aircraft acceptances where the stick shaker CB is pulled so stall speed can be verified with the charted value. I have done several overspeed tests. But if you think I'm going to do something out of the envelope with a $150 million aircraft, you're even more stupid than I thought. The limits are there to be respected not broken.

2) When presented with Master Caution, I fall back to habits. Aviate, navigate, communicate. Wind my watch and then see what I have. Nothing gets done quickly. Again, I am happy to answer your question but I will not justify what I do or don't do to you.

AMF!!
If we weren't all crazy we'd all go insane!
 
airtechy
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 5:06 pm

Quoting Kaiarahi (Reply 110):
Differential input was fully tested. Bottom line is that these two accidents had nothing to do with sidestick design and function and everything to do with CRM and training.

You said essentially the same thing after the AF447 crash. Will you parrot the same excuses after a third crash?
 
Amiga500
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 5:08 pm

Quoting MMO (Reply 112):
Please explain to me where "relative wind" is during this "skidding bank" you refer to is.

If your aircraft is moving laterally, due to wing sweep you have a vector component of airflow over the wing.

Quoting MMO (Reply 112):

Secondly, the problem with an aft stick stall is the horizontal stabilizer is blanked out because of the stall characteristics of the swept wing. Normal stall recovery will not work.

You are describing a deep stall. Which is not applicable to the events here as the aircraft was in a steep bank and thus retained some control authority.


Aft stick stall is one where the pilot has to maintain full elevator deflection to hold the aircraft in stall condition.

Quoting MMO (Reply 112):

But if you think I'm going to do something out of the envelope with a $150 million aircraft, you're even more stupid than I thought.

If you think I was ever talking about using your airline's aircraft in such a fashion you must be incapable of reading.... worrying considering the checklist nature of some pilots these days - they might not even read the checklists right.

Quoting MMO (Reply 112):

2) When presented with Master Caution, I fall back to habits. Aviate, navigate, communicate.

Good! If only they weren't all like you.

[Edited 2015-12-01 09:09:40]

[Edited 2015-12-01 09:16:53]
 
FlyHossD
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 5:15 pm

Quoting KarelXWB (Reply 11):
Colgan Air Flight 3407 has proven the opposite of your theory.

How so? In the Colgan accident, was there any evidence that the first officer was even attempting to counteract the captain's actions on the controls? As I recall, there was not.

IIRC, the Dash 8s have a physical connection between the controls, though they may be disconnected by deliberate action.
My statements do not represent my former employer or my current employer and are my opinions only.
 
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seahawk
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 5:15 pm

Another crash where the side sticks are to blame for the crash. It is becoming obvious that the not linked sidesticks are not suitable for safe operation, as there is no feedback on what the other pilot is doing and feeling is better than seeing or commanding. They might be no problem for a well trained crew working in a simulator, but those crews are becoming rare.
 
airtechy
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 5:15 pm

Quoting MMO (Reply 112):
I have done several aircraft acceptances where the stick shaker CB is pulled so stall speed can be verified

Interesting that you mention this. The reason you had to pull the CB is obviously because the actual stall speed is less than the stick shaker is set for....or in the Airbus case the "hard stall protection". Every time I see that Airbus fly into the trees, I wonder if an additional .1 or .2 degrees of pitch up would allowed him to clear the trees. Alas, the hard protection didn't allow him to take advantage of the predicted "hard limit stall speed" vs. the actual stall speed.
 
roseflyer
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 5:18 pm

Quoting Kaiarahi (Reply 110):
Bottom line is that these two accidents had nothing to do with sidestick design and function and everything to do with CRM and training.

I don't think you can say nothing, with regards to sidestick design and function. It may have been a contributing factor. Also, I don't think you can say that everything was caused by CRM and training. Everything started with a intermittent wiring fault. Maintenance not correcting this started the chain of events. Flight crew then did not appear to follow procedures when the fault happened in flight. Then the crew did not react correctly when the autopilot disconnected.

There was not a single failure here that caused everything. You can't say sidestick design and function had nothing to do with it. It isn't the cause, but a contributing factor likely was that the crew were inputting opposing inputs into the sidesticks. A control column and control wheels that are mechanically connected to each other may have resulted in a different outcome. I agree that CRM and training are likely more significant issues, but there were problems with the airplane, maintenance and pilots. All three were contributing factors. I don't think there is anything inherently wrong with the concept of the sidestick and the design. However, when combined with the series of other problems, in this specific incident it is one of many contributing factors. I am not saying that a yoke would have prevented the accident. I am saying that there are inherent benefits and weaknesses to every design.
If you have never designed an airplane part before, let the real designers do the work!
 
Amiga500
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 5:22 pm

Quoting Kaiarahi (Reply 110):
Bottom line is that these two accidents had nothing to do with sidestick design and function and everything to do with CRM and training.

If the cockpit operation is adding to pilot's workload and decreasing their situational awareness in times of stress; then that is something we need to look at.


For instance, potentially sacrificing a hand to hold in an over-ride button is a no-no. Having to continually look to see what the other pilot is doing r.e. stick inputs is also a no-no.


If the crew don't establish a clear chain of command, thats a bad failure on their part. But they can be helped resolve this mistake before it becomes a fatal one by a more tacit control system.
 
WIederling
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 5:22 pm

Quoting D L X (Reply 91):
I mean, the force feedback on my Audi A4 steering is electrical (there is no direct connection between the Audi steering wheel and the car's wheels).

Afaik there currently are no regular cars ( or other legally roadable vehicles that go faster than ~25km/h ) around with "steer by wire". Obviously on the horizon ... but not yet. Currently there is a mechanical path from steering wheel to front wheels. The electric motor is assisting. ( servo function but can also turn the steering on its own or assist in other ways like introducing a force to keep you in lane, compensate side winds ... )
http://en.wikipedia.org/wiki/Power_steering#Electric_systems
Murphy is an optimist
 
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AirPacific747
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 5:26 pm

Quoting hilram (Reply 21):
An airline should be forced to give real employment status to the pilots flying, and make sure they are properly trained, rested and monitored health-wise.
Quoting hilram (Reply 21):
If a lack of training indeed is the cause of this accindent (possibly coupled with some shortcuts in maintenance) I hope for a gigantic class-action lawsuit against the airline, that burns them so hard that going forward they will see to that their pilots get proper training.

Completely agree. The state of this industry is very sad indeed, and it's very hard to comprehend how this can continue, especially in Europe. Even 'legacy' airlines along with low cost airlines use this kind of employment now where the pilots are self employed through an agency. That means airlines like Brussels airlines, Turkish airlines, Ryanair, Easyjet, Wizzair, Aer Lingus, etc.

If the pilot is sick, in best case means losing a lot of money each day being abscent, and in the worst case means losing his or her job. Completely unacceptable.

[Edited 2015-12-01 09:29:31]
 
WIederling
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 5:28 pm

Quoting airtechy (Reply 108):
For whatever reason, I don't doubt that they did. However, that testing did not have the knowledge gained from analyzing two crashes to influence the result.

No. I don't think so. They lack your faith so they have to work with factual observations / rational arguments  
Murphy is an optimist
 
rbavfan
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 5:32 pm

Quoting Chaostheory (Reply 40):

Remember the inappropriate use of the rudder on the AA A300-600R crash in New York. They over stressed the rudder and ripped it off the aircraft for total loss of control. If you have to much force on the rudder it will snap. Thats why you do not do that.
 
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seahawk
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Tue Dec 01, 2015 5:32 pm

You do not have to link them, it would be enough to have large warning lights that go on, when both sticks are giving different inputs.
 
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Polot
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 5:39 pm

Quoting WIederling (Reply 120):
Afaik there currently are no regular cars ( or other legally roadable vehicles that go faster than ~25km/h ) around with "steer by wire". Obviously on the horizon ... but not yet

Not to go completely off topic but the Infiniti Q50 has steer-by-wire. It was the first, and I believe currently only, car to feature it on all wheels. GM use to have a optional system where the back wheels on their large pickups/SUVs had a steer by wire system (to improve turning radius) but it was dropped after a few model years due to poor uptake mostly as a result of high option cost coupled with poor advertising.
 
Amiga500
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 5:41 pm

Quoting rbavfan (Reply 123):

Remember the inappropriate use of the rudder on the AA A300-600R crash in New York. They over stressed the rudder and ripped it off the aircraft for total loss of control.

If I recall correctly (big if!!!) they inputted alternating full rudder deflection several times before the rudder failed - and it failed far beyond the design structural envelope!
 
747megatop
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 5:51 pm

Quoting B747400ERF (Reply 10):
Often you are not thinking logically.

Isn't that what separates trained "professional" pilots from the ordinary folks? Isn't that why they are paid a salary and undergo stall scenario training in a simulator multiple times? That's probably why sierrakilo44 emphasised that the crew weren't really pilots.
 
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CALTECH
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 5:54 pm

Quoting KarelXWB (Reply 11):
Colgan Air Flight 3407 has proven the opposite of your theory.

Since we will never know, what if it happened at flight level altitudes ? Might have not changed a thing, but maybe the co-pilot might have said 'push the nose down, we are in a stall ' ?

Quoting KarelXWB (Reply 17):
Lack of proper stall training?

Why he pulled back ? Instinct, stall and stall warning, if I'm not mistaken, in a part of a pilot's mind does mean the aircraft has stopped flying and could be falling towards the ground. Even with the training, can see how in a panic and not following training would result in some pilots pulling back on the stick, especially at low altitude. Instinct versus training, and in some panic situations, instinct wins out.

Quoting Buyantukhaa (Reply 25):
Still, pulling CBs in flight wasn't by the book either. The soldering crack was faulty maintenance, but most of the accident was pilot training and CRM...

Not really faulty maintenance, the Airbus Fault Verification Guide allows circuit breaker resets. Have to check the AMM for the Airbus, but in the FVG, if the fault goes away after a reset, the problem is considered cured. Unless there is tracking or looking at history, if it fixes the fault and the plane gets over the fence, perfectly legal.

Quoting lutfi (Reply 43):
Hmm. Sounds like they were doing the equivalent of ctrl alt del (pulling the CBs) to reset, rather than fixing the damn part...

Except with these C/Bs being pulled in air mode, which is actually power being interrupted, the computers would fault and not reset.

Quoting MMO (Reply 52):
Both Airbus and Boeing are very explicit about having flight crews resetting C/Bs inflight. It's a big NO NO!

Special Circuit Breaker Procedures are in place, but not doubting what you state, but I believe it is more about resetting circuit breakers that have popped, rather than resetting them, even though resetting some circuit breakers to .

Quoting TheRedBaron (Reply 62):
Crappy maintenance >

Not tracking or verifying history, but as above, if a circuit breaker reset removes the fault, it is okay to go, according to Airbus documentation.

Quoting loalq (Reply 67):
I am worried about the fact that the rudder issue was notified 23 times BEFORE the final occurrence. That is shocking. I have never ever seen anything being reported and probably somehow improperly dealt with 23 times in any type of equipment, that's really excessive and brings questions about AirAsia's maintenance standards.

Probably not doing tracking and checking history. As stated above, the Airbus Fault Verification Guide says to reset circuit breakers and if the problem goes away, it was a interrmitent fault and good to continue. I'll check the preamble of the Airbus FVG, probably has some extra instructions there. Usually, if it is seen to be a repetitive issue, the mechanic or maintenance control stops the aircraft until it can be fixed at some airlines in the US.

Quoting KarelXWB (Reply 75):
The Airbus side stick has been in use for almost 30 years now. If there was something wrong with the design, the EASA would long ago have ordered a design change.

Nothing wrong with the design, but wouldn't it be a added redundancy ? AF447 sounded like both pilots in the seats had the sticks in their hands and priority buttons kept getting pushed. A little force feedback might have helped, might not have, but for the chance it could have saved AF447, maybe it should be looked into.

Quoting D L X (Reply 78):
Let me ask at it this way: what is the design reason to not have the two sidesticks tied to each other?

Can't see any reason why not, other than the cost of certifying the system.

Quoting AIRWALK (Reply 82):
Weight + lack of purpose. You want to see what the other guy is doing? Turn your head

But what if all your attention is devoted to looking at the instruments as you try to figure out what has happened ? With one hand of the stick and devoting your eyes to the instruments, might be a good redundacy and one worth the added cost.

Quoting hivue (Reply 83):
Plus (a) there are not supposed to be two pilots controlling the airplane at the same time and (b) flight controls are not flight instrumentation so why engineer them to pretend like they are.

But they were trying to on AF447, and priority buttons were being pushed. Right seater had his stick back, and when the left seater pushed his priority button, he probably had his stick in neutral when he took priority, not knowing without coupled sidesticks that the right seater had his stick aft. Might have given the left seater a warning soon enough to push the nose down, maybe ?

Quoting Polot (Reply 87):
It is the aircraft manufacturer's and certifying agencies job to maximize passenger and crew safety in the event that the pilot does do something wrong (among other scenarios) to the fullest extent that is technically and feasibly possible.

Coupled sidesticks, even though 99.99999999% of the time not needed, if it could possibly save another aircraft, might be something good to look into.

Quoting roseflyer (Reply 89):
The type of fault where there is intermittent wiring faults with loose or dirty connectors and/or chaffed wires is just about the hardest type of fault for a mechanic to fix. Intermittent wiring faults affect all airplanes. It looks like Air Asia maintenance did not solve the problem and let the issue to continue going on with circuit breaker resets. Again since it was intermittent and likely not happening on the ground they could get away with this.

Not getting away with it, I'll have to look into more maintenance documents, especially the Fault Verification Guide, but legal to do. If this would have been happening at my outfit, the aircraft MX history more than likely would have been looked into and hopefully fixed or at least get a documentation trail started. In my opinion, there are too many Airbus circuit breaker resets happening, which many times are a glitch, but sometimes are masking a true issue with the aircraft. And not just Airbus, but Boeing too.

Quoting roseflyer (Reply 89):
Most regulatory authorities require airlines to have a chronic or repetitive defect list to catch problems like this. Air Asia may or may not have been addressing this. I would hope they get better maintenance oversight because this could easily happen again.

  History of the fault on the aircraft in question is always a good thing to do.

Quoting D L X (Reply 91):
A couple ounces?

The cost of re-certiying the system might be too steep. But if it could save one aircraft, might be worth it.

Quoting airtechy (Reply 92):
Wow! You win. That has to be the best spin to justify non-synced controls I have ever read. Boeing should obviously cut the linkage between the yokes as it only ads confusion.

Coupled sidesticks might have, or might not have saved these crashes, AF447 and AirAsiaQZ8501. Would rather err on saving a aircraft with this type of fix, relatively simple would imagine. Though there have been countless crash free incidents, two is too much.
You are here.
 
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litz
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 5:55 pm

Quoting warren84 (Reply 9):
the PIC had had this problem on this specific aircraft before on a previous flight and returned to the gate where he observed a line engineer do the same thing to resolve the issue)

Wait a sec... he saw a mechanic do this on the ground, and thought it would be a good idea to repeat the remedy in the air?

That's mind boggling ....

Quoting airtechy (Reply 22):
"The Upset Recovery training was included in the aircraft operators training manual.he aircraft operator advised the KNKT that the flight crew had not been trained for the upset recovery training on Airbus A320, and this referred to FCTM Operational Philosophy: “The effectiveness of fly-by-wire architecture, and the existence of control laws, eliminates the need for upset recovery maneuvers to be trained on protected Airbus”.

There was no evidence of DGCA findings for this incompliance of training"

Except for the fact that when your airplane gets itself into a state where these protections no longer exist, you're no longer a 'protected airbus' and you lose control because you haven't had the exact training required to keep the shiny side of the airplane pointing up.

That quote is just .... wow.

This is a viewpoint that has to be immediately remedied.
 
WIederling
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 5:57 pm

Quoting Polot (Reply 125):
Infiniti Q50

interesting. Wonder how they got it certified?
Murphy is an optimist
 
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scbriml
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 6:00 pm

Quoting seahawk (Reply 116):
Another crash where the side sticks are to blame for the crash.

Case solved. Thanks, Sherlock.

Quoting seahawk (Reply 116):
It is becoming obvious that the not linked sidesticks are not suitable for safe operation

Yet thousands of Airbus planes fly passengers safely every single day without issue and planes with linked yolks also crash.
Time flies like an arrow. Fruit flies like a banana!
There are 10 types of people in the World - those that understand binary and those that don't.
 
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Polot
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Tue Dec 01, 2015 6:00 pm

Quoting WIederling (Reply 130):
interesting. Wonder how they got it certified?

Here is an article about the system, you can find more online:
http://www.caranddriver.com/features...ring-but-the-wheel-remains-feature

The car basically has a clutch that is always open, but if an electrical fault is detected the clutch closes giving a direct mechanically link between the steering wheels and driving wheels and the steering behaving like a typical car's electric steering system.
 
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Moose135
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 6:01 pm

Quoting WIederling (Reply 130):
interesting. Wonder how they got it certified?

It has a mechanical backup if the electrical system fails.
KC-135 - Passing gas and taking names!
 
hivue
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 6:01 pm

Quoting seahawk (Reply 124):
You do not have to link them, it would be enough to have large warning lights that go on, when both sticks are giving different inputs.

You should read the report:

"Note: In the event of simultaneous input on both sidesticks (2° deflection off the neutral position in any direction) the two green SIDE STICK PRIORITY lights on the glare shield come on and “DUAL INPUT” voice message is activated."
"You're sitting. In a chair. In the SKY!!" ~ Louis C.K.
 
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Classa64
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 6:04 pm

As per the report ....

Maintenance
41. The maintenance records showed that there were 23 Rudder Travel Limiter problems starting from January 2014 to 27 December 2014.

42. The Reliability Report November 2014 recorded 4 pilot reports regarding the RTLU problem.

43. On 19 December 2014, the repetitive RTLU problem was inserted to MR2. After completing the scheduled flight, the maintenance personnel performed Auto Flight System (AFS) and the MR2 was considered closed.

44. On 21 December to 27 December 2014, the MR1 recorded 2 pilot reports on 25 December 2014 and on 27 December 2014 related to RTLU while the FDR recorded at least 9 problems


... So twice a month there was a problem and it was not looked into further !? This part baffles me, I would think as critical as the rudder and controls are that after a few times they would have started digging more into this. I mean I work in automotive and people loose there mind sometimes if there check engine light comes on more than once BUT as a tech it bugs the hell out of me if it does and I want to fix it and find the cause. i would think ( I realize the two are different but as an example)
"Freedom is the miles i'm rolling on"
 
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TheRedBaron
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 6:12 pm

Quoting airtechy (Reply 69):
Ah yes....more training...that is the answer to every accident caused by the pilots. Training to improve what? After AF447 the answer was to train for "high altitude stall recovery". Well.....here we are again....an entry into a high altitude stall and a non-existant recovery in an Airbus with the same flight control system.

I would never lecture a pilot since I am not one, but since I work in systems and human behavior/procedures I can tell you right away that if CRM and procedures were followed the accident would not had happen ( pulling the breakers mid flight, and not taking the control by the captain and make sure that the inputs for safe flying are done.

Quoting KarelXWB (Reply 75):
The Airbus side stick has been in use for almost 30 years now. If there was something wrong with the design, the EASA would long ago have ordered a design change.

Its imposible to design something foolproof because time and time again fools have proven resourceful to break things.

Quoting seahawk (Reply 124):

I agree.

Airbus and Boeing should put an acelerometer and a gps interlinked that checks the parameters of pitch, speed and altitude to assess if a stall or dangerous condition is going on. Time and Time again pilots have become disoriented or don't know they are stalled (even with the shaker and the warning going on) only to crash.

The system detects an abnormal flight parameters, stall, drop in altitude while in a flight configuration that should not be, and promptly changes all displays to put STALL warning and a readout on altitude with big letters and a big arrow stating with pilot has inputs. That way instead of trying to analyze the data the screen tells the pilot he is in a bad situation, the main parameters of the situation and who is in control.
I wonder why a lot of aircraft doesn't use the computers and software to ALLOW pilot to FLY not to manage emergencies with confusing results from interpretation.

I can't believe this aircraft flew so many times with a bad FAC... that is the main cause of this tragedy.

TRB
The best seat in a Plane is the Jumpseat.
 
UALWN
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 6:25 pm

Quoting zeke (Reply 85):
If you want to see a clear example of that have a look at the research coming out of the Large Hadron Collider to see that what you would have learned at school and university about matter and atoms does not explain the new particles and dark matter they have discovered.

With all due respect, let me assure you that we at the LHC have not (yet) discovered any dark matter particles. If we had, you would all know: think the media coverage of the Higgs particle's discovery in 2012 times 10.
AT7/111/146/Avro/CRJ/CR9/EMB/ERJ/E75/F50/100/L15/DC9/D10/M8X/717/727/737/747/757/767/777/787/AB6/310/32X/330/340/350/380
 
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caoimhin
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 6:38 pm

Quoting Kaiarahi (Reply 110):
Differential input was fully tested. Bottom line is that these two accidents had nothing to do with sidestick design and function and everything to do with CRM and training.

I hope that the engineers who design future aircraft don't have this attitude toward failure points that have been shown more than once to be contributing factors in aviation disasters. Denying the involvement of this design trait this point would be negligent.

No aircraft design is perfect. We should all be open to the possibility that the way things are done is not necessarily the best approach.
 
ltbewr
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 6:40 pm

Quoting loalq (Reply 67):
More than crew training, which is indeed a very important aspect of this accident, I am worried about the fact that the rudder issue was notified 23 times BEFORE the final occurrence. That is shocking. I have never ever seen anything being reported and probably somehow improperly dealt with 23 times in any type of equipment, that's really excessive and brings questions about AirAsia's maintenance standards. This should've been taken more seriously by the airline.

As others have noted, such intermittent problems are very difficult to diagnose, but there should be no excuse to ground the plane to fix such a potentially serious problem. AirAsia, like too many LLC's especially in South Asia, run on such thin financial margins, have corrupt management, hate to have to withdraw a plane from service and tick off customers or local governments, put pressure on pilots to fly with problems and just hope they don't crash. That is something that needs to change for all such airlines in the region.

As to the battle over stick/Airbus vs 'wheel'/Boeing, um, Sully did a pretty good job of landing an A320 in the Hudson River.
 
PlanesNTrains
Posts: 9526
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 6:44 pm

Quoting 777Jet (Reply 46):
Whilst I don't have time right now to read the full report, if the above summary is correct, then it sounds like AF447 style attempted flying in a faulty plane... I don't think I'll be flying this airline in the future.

Which one? AirAsia or AF?

Quoting N766UA (Reply 72):
You can lecture all you want, but don't be surprised when the surgeons stop contributing to your board.

"Your board" or "Their board"?

Quoting airtechy (Reply 113):
You said essentially the same thing after the AF447 crash. Will you parrot the same excuses after a third crash?

If it's the same circumstances, probably. Why wouldn't he? Should he make something up?

Quoting airtechy (Reply 117):
Every time I see that Airbus fly into the trees

Ya, I remember the 80's too.

Quoting 747megatop (Reply 127):

Quoting B747400ERF (Reply 10):
Often you are not thinking logically.

Isn't that what separates trained "professional" pilots from the ordinary folks?

Or so I've been told by a pilot in this very thread.

Quoting CALTECH (Reply 128):
in a panic

That's the crux of it right there. We are all human, and some of us will "freak out", so to speak, when faced with the sudden realization that we may be falling out of the sky. I'm not sure how you fix that, particularly in the Colgan case where it sounded like the captain was not the best recruit.

Quoting litz (Reply 129):
Wait a sec... he saw a mechanic do this on the ground, and thought it would be a good idea to repeat the remedy in the air?

That's mind boggling ....

Yep.

Quoting scbriml (Reply 131):
Quoting seahawk (Reply 116):
It is becoming obvious that the not linked sidesticks are not suitable for safe operation

Yet thousands of Airbus planes fly passengers safely every single day without issue and planes with linked yolks also crash.

Like a lot of these topics, it seems to become an all-in for a lot of posters. We sort of want to close our mind to one set of facts or another, or see it through A or B colored glasses. I guess in my mind there have been plenty of accidents which exposed a previously unrealized fault (mechanical, training, etc) and I don't think the fact that many tens of thousands of flights had previously been flown successfully should detract us from considering how things might be even safer with just a subtle alteration to something.

-Dave
-Dave


MAX’d out on MAX threads. If you are starting a thread, and it’s about the MAX - stop. There’s already a thread that covers it.
 
D L X
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 6:51 pm

Quoting zeke (Reply 99):

Quoting D L X (Reply 91):
That is indeed very interesting stuff they're doing over there, but what does the Higgs boson have to do with aerodynamics? Or any subatomic particle?

Ask me again in 20 years when we understand what they have found. It does not matter what techniques you use, you cannot predict aerodynamics with 100% precision, there are always assumptions.

In 20 years, I'll ask this question that I can ask now: what unexplained aeronautical events have now been explained by subatomic particles? (Or even theorized?)

Quoting zeke (Reply 99):
Quoting D L X (Reply 91):
And the physics remained the same. It was our understanding of the physics that changed. There aren't "exceptions" to physics.

When you get to the subatomic or quantum level everything changes. Since hitting 22 nm computer chips we have had a very significant slow down on building faster computer chips.

Now you're entering an area of my expertise.  
The reason we haven't gotten much faster since hitting 22nm is because of physics that have been known since probably the 60s. Computer chips rely on electrons moving around. Physics says nothing can move faster than the speed of light through a medium. Generally speaking, the clock speed is tied to how far we're asking the electrical signals to go, which is directly affected by the size of the pathways.

But what's also affecting things is that it is now cheaper to add an additional core than it is to squeeze a little more speed out of an individual core. The shrink down to 22nm has allowed us to put more cores on the same amount of silicon AND increase the yield at the same time.

This is all without learning new laws of physics -- it's physics as we have understood in theory for decades, finally able to put it to use.

I'll let you have the last word on this, but I think you may have overreached with your earlier statement.

Quoting Kaiarahi (Reply 105):

Linked sticks were extensively tested during the design phase. Pilots preferred the priority button.

Interesting! Thanks.

Do you believe that is still the correct choice?

Quoting WIederling (Reply 120):
Afaik there currently are no regular cars ( or other legally roadable vehicles that go faster than ~25km/h ) around with "steer by wire".

Hmm.... I could have sworn I read that as a feature, but now I can't find it. I may have to retract that Audi does it, but I know Infiniti does.

Quoting CALTECH (Reply 128):
Quoting D L X (Reply 91):
A couple ounces?

The cost of re-certiying the system might be too steep. But if it could save one aircraft, might be worth it.

Yeah, I'm not advocating changing it now. I'm just trying to reach an understanding of why they did it this way in the first place.
 
mmo
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 7:12 pm

Quoting Amiga500 (Reply 114):
Aft stick stall is one where the pilot has to maintain full elevator deflection to hold the aircraft in stall condition.

BINGO!!! We have a winner!!! What was the FO doing with his sidestick the whole way down? He was applying full aft stick and it was in a right bank. The aircraft did exactly what it was supposed to do. Look at the airspeed indications from the DFDR, it was what you would see in an full aft stick stall.

If the aircraft was wings level when they entered the stall, they would have maintained wings level unless the wingtips were bent. There was lateral control input when they entered the stall. That's where the bank came from. The only control that was effective was the rudder which was due to the airflow being blanked out by the wings

Quoting Amiga500 (Reply 114):
If your aircraft is moving laterally, due to wing sweep you have a vector component of airflow over the wing.

Really? How can you have any control authority when the ailerons are stalled. There is NO RELATIVE WIND.

Quoting CALTECH (Reply 128):
Special Circuit Breaker Procedures are in place, but not doubting what you state, but I believe it is more about resetting circuit breakers that have popped, rather than resetting them, even though resetting some circuit breakers to .

IIRC, in the supplemental procedures, there is a matrix of C/Bs that can be pulled and reset if you really have to have the affected system restored. That's not one of them. The days of troubleshooting is long over for pilots.
If we weren't all crazy we'd all go insane!
 
hivue
Posts: 2000
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 7:14 pm

Quoting caoimhin (Reply 138):
I hope that the engineers who design future aircraft don't have this attitude toward failure points that have been shown more than once to be contributing factors in aviation disasters.

The Airbus side stick architecture and functionality was not listed in the report as a contributing factor in this accident. I don't recall it being listed for AF447 either.

Please cite an example where it was.
"You're sitting. In a chair. In the SKY!!" ~ Louis C.K.
 
Kaiarahi
Posts: 1807
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 7:14 pm

Quoting seahawk (Reply 124):
You do not have to link them, it would be enough to have large warning lights that go on, when both sticks are giving different inputs.

Better yet, an aural warning "Dual Input". Which is exactly what the A320 has.
Empty vessels make the most noise.
 
PanAm1971
Posts: 444
Joined: Wed Aug 29, 2007 4:28 am

Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 7:16 pm

Quoting PlaneInsomniac (Reply 70):
So apparently it has transpired that many surgeons these days, when faced with any sort of deviation from plan such as suddenly spiking blood pressure, completely panic and blindly start stabbing the patient with their surgical knife until the patient dies. Although their training - aside from common sense - has taught them time and again that if you stab a person for a long time again and again with a surgical knife, they die. Exhaustive independent expert reports conclude that these surgeons are 100% to blame for the patients' deaths.

Surgeons get to stop during the operation and consider their next move. Pilots don't have that luxury traveling hundreds of miles an hour miles above the earth. That's why only qualified and mentally suited folks are meant to be pilots. However, the rapid growth of the industry-and lets say it-the LCC's in particular, is bringing in mentally unsuited people into a profession that punishes even small errors with death.
 
spartanmjf
Posts: 511
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 7:17 pm

Did I read the report (correctly) that the pilot in command had recent experience with this specific airframe and that there were issues with the Rudder limiter? If so, would not (and I am just asking) there seem to be some responsibility there for checking the maintenance records before this flight to see if any maintenance action (beyond resetting by pulling the power) had been taken?
"Nuts to the man in 21D!"
 
PlanesNTrains
Posts: 9526
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Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 7:30 pm

Quoting Kaiarahi (Reply 144):
Better yet, an aural warning "Dual Input". Which is exactly what the A320 has.

I don't have any idea, but is there a difference in how we process physical inputs versus aural inputs? In other words, does the "Dual Input" warning tax our mental processing differently than a physical input through a sidestick/yoke?

Quoting PanAm1971 (Reply 145):
Surgeons get to stop during the operation and consider their next move.

Not trying to be argumentative at all, but just thinking that a surgeon and a pilot BOTH will usually have time to respond to things, but sometimes it can go south for BOTH, requiring quick action and leadership. I am sure plenty of people have died over the years because things suddenly became life-threatening on the table and the surgeon simply didn't get ahead of it in time or otherwise responded poorly.

-Dave
-Dave


MAX’d out on MAX threads. If you are starting a thread, and it’s about the MAX - stop. There’s already a thread that covers it.
 
Bongodog1964
Posts: 3542
Joined: Wed Oct 18, 2006 6:29 am

Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 7:30 pm

Quoting MMO (Reply 19):
The root cause of this accident was lack of training on the part of both pilots

[quote=lutfi,reply=43]"The plane's flight control computer had a cracked solder joint that malfunctioned repeatedly, including four times during the flight, and 23 times the previous year"

The root cause to me seems to be the fault with the rudder limiter, that despite occurring more on and more frequently was not fixed. When it occurred 4 times in a few minutes, it is no wonder that the crew failed to cope with the situation
 
Amiga500
Posts: 2518
Joined: Tue Mar 03, 2015 8:22 am

Air Asia Crash: Final Report Released - Part 1

Tue Dec 01, 2015 7:53 pm

Quoting MMO (Reply 142):
BINGO!!! We have a winner!!!

Not the same as a deep stall... where all controls are ineffective, which is what you alluded to earlier.

In this instance, if the pilot had released the stick, the aircraft would likely have recovered itself from stall.

Quote:
The only control that was effective was the rudder which was due to the airflow being blanked out by the wings

You've a fundamental misunderstanding of what deep stall is. Its impossible to mask the elevators of an A320 due to the wings stalling.

A T-tail is much more susceptible to deep stall, even then, AoA has to be fairly silly but unfortunately not ridiculous enough to stop it from happening to a few poor unfortunates.


Quoting MMO (Reply 142):
Really? How can you have any control authority when the ailerons are stalled.

You have incorrectly assumed that once stalled, an aircraft in a sliding bank will always reattach from root to tip. In a 50deg uncoordinated bank, that will almost certainly not be the case.

Go doodle an aircraft, with rear-swept wings, then put on the vector from lateral airspeed. Does it have a component over the aerofoil section of the wing? Yes it does. Is that component greater at the tip than the root? Yes it is, because the wing chord line changes (for the worse in this case) as you move to the zero sweep trailing edge.

So, if you are in a coordinated 55 deg bank, descending at, say, 6000 fpm, then you've approx 25 knots airspeed over the wing aerofoil section. If its uncoordinated, then that number will rise further.

Even in stall, L/D is >>1, just taking 1 for handiness, at 100 kts forward speed you generate a further 30 kts over the wing aerofoil section. [A finite wing will have an L/D of about 2.5 in 'stall', but that doesn't include fuselage drag.]

So thats 100+25+30 = 155 kts over the outer wing on the inboard side.

[Edited 2015-12-01 11:58:39]

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