Air Asia Indonesia Lost Contact from Surabaya to Singapore

[latetonite]

All what if's, regulations, circuit breakers left on the side, how about a glance at the artificial horizon?

[Volume]

Why would flight crew fail to professionally communicate for several minutes during these incidents?They are struggling to find the right words / phrases for situations they do not even fully understand? We also had incidents/accidents where the communication with ATC did not work at all, because they were unable to cover an exceptional situation with standard phrases.
Some of the standard terms (e.g. Stall) are just to simple to cover all the real situations that could occur. Also the up/down discussions (meaning nose up/down or climb/descend?) are sometimes dirsturbing...
To understand "push the nose down" if your colleage screams "we are going down" is beyond typical human brain capacity (your brain would think "up" not "down" in that case). The same is with negation, never scream "don´t pull" at somebody, scream "push". Our brain is poor with the opposite of words heard, our brain is designed to identify, not to exclude something.

Unfortunately human factors is not yet an independent science, it is covered by a lot of different disciplines these days (ergonomy, neurology, psychatry...), they do not produce a lot of output useful for aircraft designers or training programme providers yet.

It is almost impossible to fix that issue, as long as there are different mother tongues on this planet and crews are international.

[ExV238]

Whereas everyone else provides both seat of pants + stick shaker.

The question of stall warning is interesting indeed. Remember that the Airbus AoA protection should prevent stall in Normal Law. The probability of being in Alternate or Direct Law AND the crew allowing the aircraft to get into the stall regime is minute, regardless of how often we discuss the tiny number of cases in which his has happened. Nonetheless, these accidents demand a response.

The question is then; in the cases under discussion, did the crew fail to recognise the stall condition, or recognise it but fail to react effectively? There is some evidence that at least one pilot in both the AF and Air Asia recognised a need to push forward on the stick.

Should Airbus provide tactile artificial stall warning in reversionary flight control laws? Historically, aircraft were designed to give natural stall warning through buffet. Where this was inadequate, or the consequences of a full stall were intolerable (deep stall, for example), artificial stall warning was added in the form of stick shakers or even AoA protection in the form of stick pushers. Another important certification requirement is that the pilot be able to clearly identify the stall itself. The following is the relevant part of CS25:

d) The aeroplane is considered stalled
when the behaviour of the aeroplane gives the
pilot a clear and distinctive indication of an
acceptable nature that the aeroplane is stalled.
(See AMC 25.201 (d).) Acceptable indications of
a stall, occurring either individually or in
combination, are –

(1) A nose-down pitch that cannot be
readily arrested;

(2) Buffeting, of a magnitude and
severity that is a strong and effective
deterrent to further speed reduction; or

(3) The pitch control reaches the aft
stop and no further increase in pitch attitude
occurs when the control is held full aft for a
short time before recovery is initiated.

If the above cannot be satisfied through the natural characteristics of the aeroplane, then the manufacturer must fit artificial devices. In the case of the Airbus types under discussion, deterrent buffet is always reached before the point of stall, and the stall itself is naturally benign. The deterrent buffet is of such a magnitude that I doubt a pilot would reliably feel a stick shaker. Aerodynamic buffet has always been the classic natural indication of stall, from the most basic light aircraft upwards. The Airbus doesn't have a stick shaker because it doesn't need one! Whether we as an industry are training pilots to correctly respond to a stall is another question...

[Volume]

The probability of being in Alternate or Direct Law AND the crew allowing the aircraft to get into the stall regime is minuteThis might be a typical misconception, similar to what we see for system safety assessments sometimes.
The same reason why the aircraft has to revert to a different law might also cause the crew to do strange things. These events are not necessarily independent. So in the end the probability of being in alternate Law might be exacly the same as the one one that a crew is confused. And it may both happen at the same time because of the same reason.

It needs to be very carefully evaluated, which failures are really independent (and their combination therefore highly remote), and which are resulting from a common cause or from each other, and hence are not so remote.
It is clear that we can not design aircraft for the combination of all possible events and conditions, but it should also be clear that we can not claim all events to be unrelated.

(1) A nose-down pitch that cannot be readily arrested
This is exactly the same misconception as the pilots had: when your aircraft drops its nose it wants to tell you something, and you should not try to arrest this nose-down by pulling the stick all the way back, just to find that this does not arrest the movement.

Should Airbus provide tactile artificial stall warning in reversionary flight control laws?Airbus reverts to other control laws, because the computers do no longer have all the data they need to identify that you leave your safe envelope. So by the nature of this, you may not be able to provide a stall warning in that situation. If the computer still would be able to fully understand the situation, it would still run in normal law.

[ExV238]

Volume,


It is clear that we can not design aircraft for the combination of all possible events and conditions, but it should also be clear that we can not claim all events to be unrelated.


I agree with you completely. However, it remains true that the aircraft remains flyable without stalling in Alternate and Direct Laws, as other crews have demonstrated. So there remains an additive element to this.

Re your other points; the quote I made is from the certification requirements, not advice to pilots! The aim is indeed that the aircraft should 'tell you something'. Likewise, your point about artificial stall warning is correct; natural buffet is independent of air data and can be relied upon regardless of the state of the aircraft's systems. That's the beauty of it.

On a technicality, loss of data is not the only reason why an Airbus might revert from Normal Law. Loss of Normal Law doesn't necessarily mean that your air data is bad.

[Peter H]

(Retired s/w engineer interested in human factors.)

Do we know what the flight director was doing in these loss of SA cases?
Did it help? Did it hinder?

[safetypee]

Clandestino, re “pulling full aft stick …” - normal.
To clarify the point in my post, which had previously considered the hypothesis that the crew followed the FD, then following the commanded roll and pitch could be normal behaviour.
The pilot might not appreciate the magnitude of the stick input, particularly if the FD control laws are not optimised for such a situation; also, if the FD computation and/or normal use assumes that the commands are continually nulled, i.e. a director vice a recovery indicator for a gross deviation. Thus a large roll angle and subsequent loss of altitude could result in a significant FD demand, where its magnitude could be interpreted as requiring a large stick input.
Furthermore, consider how the FD is used; is it normal to follow a combined path, pitch and roll together, or alternatively separate the axis, nulling roll independently of pitch, (which FD format did this aircraft have - single or split cue?).
If a sequential axis response was made then a FD roll demand at a high bank angle could be interpreted as having a significant pitch component; obviously this is speculative.
Another view might also conclude that the stall was induced by the FD and SOP.

Thus there may be greater safety value in considering how crews fly the FD in normal operation and how SOPs are interpreted – always follow the FD ??! .

Another ‘SOP mantra’ is ‘fly the aircraft’, but what does ‘fly’ mean.
A better approach is Aviate, Navigate, Communicate, … which should be more likely to generate the question ‘what does ‘Aviate’ mean'. Many posts focus on stick and rudder skills (fly) overlooking the preceding need to understand the situation – 90% of human thought involves understanding; when and where are the skills of understanding taught.
Some recent views of awareness suggest that we should be teaching the identification of situations where SOPs should not be followed (how to identify them), opposed to always follow SOPs.

ExV238, re ‘fail to recognise …’, see Errors in Aviation Decision Making: Bad Decisions or Bad Luck? (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20020063485_2002103814.pdf)
The decison to pull CBs?

Peter H, for info, http://xstar.ihmc.us/research/projects/EssaysOnHCC/
See Sensemaking (2), Janus principle (training), boiled frog (procedural drift)

[A0283]

@Volume Unfortunately human factors is not yet an independent science, it is covered by a lot of different disciplines these days (ergonomy, neurology, psychatry...), they do not produce a lot of output useful for aircraft designers or training programme providers yet.

My impression is that human factors is not a science as such, and wonder if it should be. It is an umbrella label that covers a lot of different subjects (just like 'structures engineering' could cover loads, stress, stiffness, fatigue, etc).

When you dig deep into specific aspects of accidents you run into multiple factors. So you have to study them all and use the published knowledge.

Human factors indeed do not tell you what and how to design, or who to listen to. But you can and shall certainly make use of knowledge of all these aspects under that label while working on designs in design teams. Design teams consisting of people with a lot of different specialisms. I would expect that multiple people in these teams have knowledge of multiple human factors aspects.

A good designer tries to read as much as possible on as many aspects as possible. And uses and applies that while designing. I would say that modern aircraft are not and can not be designed without serious knowledge of a range of especially these human factors aspects. I have certainly seen a lot of that knowledge being applied to designs that happily fly around today.

To further improve on that you would need a lot of detailed information. And that may well be the real challenge.

What could be very useful to engineers to go beyond what they can do now, is information that is not directly available today. In such cases the engineer would not be interested in the specific airline or pilot as such. He just would like to see if pilots (new, bad, average, expert) act and react in the way the design (by lack of deeper knowledge) assumes. What he can use is information based on pilots interviews, and he of course uses test pilot inputs. The engineer would also like to have data that supports pilots statements and is accurate enough for design input (see Volume's post). In quite a few cases you have data that is available to airlines but not to design engineers. In this AirAsia case we see that KNKT investigators withhold CVR information that would certainly have been studied under human factors for years to come. Which is shocking.

There are multiple reasons why the ideal flow and type (think about video of instruments or even pilots) of information is not directly available. Every party that delivers information would wants to be sure that the information is only used for the intended purpose, and cannot be misused or even used against them. Which is hard nut to crack indeed.

[Bergerie1]

Clandestino,
Perhaps my one liner posts are a little too cryptic! First, I will come clean - I have never been qualified on Airbus types, though I have on several occasions flown some of their simulators. All my experience of jet types was on VC10s, 707s and 747s, on each of which I did CofA testing which included lots of stalling.
Having watched the video you mentioned it seems clear that, in what I would call a 'normal stall environment' as done in flight testing and training, there is a considerable degree of natural pre-stall buffet. Thus there is no certification requirement for artificial protections such as stick shaker and/or stick pusher as in the T-tail VC10.
However, as others have mentioned, and I know to be the case, when under high stress the first cognitive sense to 'fail' is hearing. The person under extreme stress just does not hear what is being said to him/her. This is one of the main reasons why, on aircraft requiring artificial protections, a stick shaker was used.
It would appear, in both the Air France and the Air Asia accidents, for most of the time the pilots did not recognise they were in a stall despite the aural alarms and voice shouting 'Stall, Stall, Stall'. Thus, it seems to me, a stick shaker, even though it may not be required under current certification rules, might have provided an additional warning stimulus when the pilot's hearing channel was blotted out by stress.

[CONSO]

A wee bit off topic- but the ability to recover from unexpected aircraft attitudes when everything turns to worms comes from skill, practice, and bucu luck

For a stunning example of EXTREME upsets and recovery- the following is classic

Chuck Yeager Interview -- page 2 / 8 -- Academy of Achievement (http://www.achievement.org/autodoc/page/yea0int-2)

scroll down to the section that starts

And on the fourth flight, I think it was on December 12, everything went beautiful. The drop was right on speed, and the chambers ignited when you flick the switch. The profile was beautiful. The only thing that happened, on the climb out, on all four chambers running and you're really accelerating - you fly off of a little eight ball flight indicator for attitude reference.

there is a short video that follows - film taken from a cockpit camera.:cool:

My explanation is that he recovered one axis at a time.

[xcitation]

Many posts focus on stick and rudder skills (fly) overlooking the preceding need to understand the situation – 90% of human thought involves understanding; when and where are the skills of understanding taught.
Some recent views of awareness suggest that we should be teaching the identification of situations where SOPs should not be followed (how to identify them), opposed to always follow SOPs.
TY safetypee for one of the best posts I have read in a long time. This identifies the root issue. All of these pilots knew how to fly, however they failed to understand their situation, their awareness was behind what their a/c was doing. This caused them to apply the wrong/opposite solution to their situation. Being aware of what the other pilots inputs to flight controls is a part situational awareness!

For this reason I suggest a modification of the flying maxim:

Situate, Aviate, Navigate, Communicate

(where situate means situational awareness).

In my first flying lesson around 12 yrs old I vividly recall trying to move the stick and finding it stuck, then looking at my instructor and seeing he had limited the sticks travel. Ever since then I always communicate who has control without exception. This is not a side stick vs shared control column issue. It is about knowing your plane and having strict discipline. Current flying practice has been honed in blood over the decades, are we to learn from the lessons of others or blaze our own trail?

[Bergerie1]

xcitation,
I believe you are correct. When things go horribly wrong you first have to diagnose the problem, then you have to recover the situation and/or carry out the correct procedure. It is not unlike the pilot shutting down the wrong engine. He misperceives the situation, therefore misdiagnoses the problem and then carries out a perfectly correct action on the wrong engine. Finally, when under extreme stress the human being has great difficulty in changing his perception - he tends to cling to his original view.
Thus, in an unexpected stall (which may or may not have all the characteristics of what I called in a previous post a 'normal stall') the startle factor causes confusion and a consequential misperception. the pilot fails to realise he is in a stall and carries out the wrong procedure - he pulls back when he should have pushed forward to unstall the wing.
And in all the mayhem that is going on around him he cannot bring himself to change his mind.

[deadheader]

It appears that some very important questions are either being politicised or deliberately ignored so I'd like to ask if anyone is willing to simply apply robust airmanship without prejudice or agenda to any of the following?

***

The commonalities between aspects of this accident and AF447 raise some questions which, however obvious, ridiculous or otherwise they may appear, simply cannot be dismissed IMHO:


1. Was the PF of either accident aware they were operating the aircraft in a degraded FBW condition (e.g. alternate law)?

2. With what degree of certainty can we know the answer to question 1, above?

3. Did anyone in the flight deck verbalise or otherwise communicate the change from normal to alternate law, regardless of the obvious cues/indicators etc?

4. Given the PF's action of moving the sidestick fully aft is [I]arguably more rational in Normal law, how can we be certain that all bus drivers are proficient and/or confident operating in degraded FBW conditions, in all phases of flight, irrespective of the answer to question 1, above?

5. Assuming each PF commanded a stall unintentionally, and maintained the stalled condition unintentionally, is there a possibility, however remote one may wish that to be, that operating in a degraded FBW condition is one layer of complexity too many when faced with the deteriorating situation each found himself in (i.e. swiftly decreasing altitude with nose up attitude, unreliable or decreasing airspeed, stall warnings etc), especially considering the same action of full aft sidestick does not have entirely the same effect in each law?


***

We have to assume that neither PF intended to mush into the drink from cruise and are therefore faced with a reality in which two pilots applied full aft sidestick in the belief that doing so would command a climb/arrest his rapid descent/recover the situation. The only logical explanation for such an action is that the PF either:


A> was unaware he was operating in a degraded FBW condition

B> was aware he was operating in a degraded FBW condition but did not understand that applying full aft would not have the same effect as doing so in Normal law

C> was unaware he was applying full aft sidestick or was gripped by fear/other human factor


I can think of no other logical explanations for applying full aft sidestick and therefore, as we have 2 instances of this occurring, I believe we are able to derive some conclusions and make some recommendations in order to help prevent further recurrence. Explanations A> and B> above can be mitigated by:


I> Removing any element of doubt about which FBW condition/law one is operating in at any given time

II> Removing any element of doubt about what the correct course of action is during an upset in the law/FBW condition one is operating in at the time

III> Training crews to operate the aircraft in all FBW conditions/laws in all phases of flight


I'll leave mitigating C> above for the interesting 'human factors' discussion ongoing on these and other pages, but the point is that action can be taken, in numerous/varied guises, to address some of the concerns arising from some of the similarities between this and the AF accident.


And even if one takes the view all of this is too simplistic, or not necessarily relevant, there is little harm in doing all possible to ensure one more PF doesn't hold full aft sidestick all the way to his, his colleagues and his passengers' premature doom.

IMHO.

[ChrisJ800]

There have been several incidents of Airbus A330's degrading to alternate law and the crews successfully riding through the procedures and ECAMS. In 2009 alone a Northwest 330 and 2 Jetstar A330's had unreliable airspeed incidents in severe weather in the Asia region that degraded to alternate law. Crews in each case got through the 5 minutes or so of uncertainties without major pitch changes. And a couple of Qantas 330's suffered ADIRU faults causing uncontrolled pitching, resolved by experienced and trained crew. If you pull full up in most aircraft (canards excepted?) you will stall, Airbus being the exception when in Normal law.

[IcePack]

This may not go down too well & I expect the post to be removed:

Back in the day I was once told:

You can teach a monkey to fly:

BUT a very big BUT

Only 5% of the population could actually be trained to be a Pilot. (This means that only a small number of people have the ability to assimilate information whilst under stress & such things as coping with responsibility etc etc)

Again a BUT

Only 2 to 3% will actually make it & become a PILOT. (Sorry for shouting)

Maybe aviation is now starting to see the results of every tom dick & harry getting their flying licences. (Monkeys)

Trouble is that with the lack of available training aids (Sims for upper Air Work) the Monkeys can not be trained, so you have to rely on pilots which now appear to be very few & far between. (Would the likes of Chuck Yager "lost" the aeroplane )


IMHO Airbus particularly tried to design an aeroplane for the monkeys but have obviously failed in that respect.

[CONF iture]

Is it the third time in 7 years an Airbus ends up stalled in the water with full trim up ... ?
THS grah ... anyone ?

[mm43]

Is it the third time in 7 years an Airbus ends up stalled in the water with full trim up ... ?

Yes, and its the third time that a SS has been held full back and the Trim Wheel has been calmly spinning with no-one realizing the implications; the aircraft is no longer in Normal Law.

[_Phoenix]

SS has been held back because of the overspeed mindset, also the overspeed is accompanied with buffet and awful aerodynamic noise. The FO PFD was not recorded in the FDR. The only reasonable explanation is an amazing speed shown on FO side. FO relaxed SS at the same time with selection of CAPT 3. That`s not a coincidence...
What would you do, in the second part of this video?
https://youtu.be/MbiVuPWX5K8

[vilas]

What are the situations in the air where you require full back stick or yoke? I can't visualize any other than EGPWS activation which is basically a lower level phenomenon unless you were flying over the Himalayas or Alps. Even at lower levels in a non protected aircraft it can cause structural damage. I am not sure this basic information is understood in that manner. A pilot doing that in any aircraft at cruising levels will stall the aircraft. In speed stable aircraft it may not auto trim but if the stick is held back disregarding the stall warning will the aircraft unstall itself without the yoke being released? In airbus FBW which is flight path stable once the stick is held out of neutral it is g demand reverting to AOA demand at lower end with the trim following it up unless the stick is neutralised. In both AF and QZ the pilot pulling and holding full back stick is extremely bizarre handling of the aircraft at those Flight levels. Any full application of flight control at cruise will end up in disaster. Full rudder will cause separation of tail, full bank can roll you on your back a 747 has done that.

[Volume]

1. Was the PF of either accident aware they were operating the aircraft in a degraded FBW condition (e.g. alternate law)?
The question probably is, was the PF fully aware what it means to fly a FBW aircraft in degraded condition?
Was he aware, which FBW functions were still operative (e.g. Autotrim, Stall Warning) and which were not (e.g. artificial roll damping, Stall Protection).
Are humans designed to fly half-automatic? I feel fine to program and monitor automatics fly the aircraft, I feel fine to hand fly. But I find it strange to share the job between the automatics and me. I find it strange if a system is still able to warn, but no longer to protect me.

[cats_five]

All what if's, regulations, circuit breakers left on the side, how about a glance at the artificial horizon?

I keep wondering about the VSI...

[gums]

For those not familiar with the FBW systems, once outta neutral you are commanding a "change"

So as Vila points out for the 'bus, pulling back on the stick in NORMAL you have a blend of AoA and gee when slow, but mainly gee when not slow. This means you can increase pitch to steep angles with only a slight amount of back stick as you are not commanding elevator position - the computer is!. In DIRECT, you do command position, but in either of the ALTERNATE laws you do not.

We discovered this aspect of FBW in the Viper after the first deep stalls. Just a tiny amount of back stick kept increasing pitch and we got too slow too quicky for the AoA protection to take effect. AF447 did the same thing but at a much lower pitch attitude, and the elevator/THS had little to no command authority for getting the nose down, although some sim tests showed it was possible using manual THS trim and nose down command.

[PT6Driver]

Deadheader and others,

Q1 and 2
We will never ever know what they knew for certain. However the post by safetypee an xcitation are excellent possible answers, they knew not where they were.

All these pilots and I can include colgan in this reacted in a way they thought was correct.
None of them realised the situation they were in and reacted using gut instinct.

No amount of legidlation or "protection" can protect against this.

Air france thought overspeed.
Colgen thought .... well we don't know but he fought to maintain height overriding stike push etc.
This one? Well we cannot know, and there is no cvr transcription worth a damn to analyse.

I was always tought

FIRST SIT ON HANDS

[Ian W]

Volume and Deadheader
I was thinking along the same lines but with a rather different direction.

Pavlov ringing a bell and his dogs salivated as a conditioned reaction. For some pilots a lot of flying is conditioned reaction when there is a sudden workload increase with failures and alarms - it is the conditioned reaction that will win as the tunnel vision increases and the hearing fades to nothing.

In both AFR 447 and this flight the PF relatively inexperienced was suddenly dropped into alternate law. The roll becomes really squirelly and both PF fought to get wings level (tunnel vision) but their conditioned reaction from all their flying on the aircraft was that to go up pull back and the aircraft will go up. This is of course not the case in Alternate law. Pull hard back and the aircraft will stall.
So what cues are there to a PF with tunnel vision fighting for wings level that the aircraft is now in Alternate law and requires different handling. Almost none.
I would suggest not a stick shaker but perhaps some kind of 'stiffener' so the stick is less easy to move a haptic clue that you are now in Alternate Law respect the stick as there are less protections. This could also reduce PIO by slowing the rate of movement (less mayonnaise more thought).
Of course there will be those who had and have no problem with dropping into Alternate Law but there will always be some out at the end of the probability tail that don't notice and revert to type expecting protections that are no longer there. There will also be those that are perfect in the Sim but lose it in the real aircraft.
So a brake on the sidestick making it a little more difficult to move might be sufficient to remind them that they are in Alternate.

[HundredPercentPlease]

Ian W,

Your implication is that they didn't know that they were in Alternate Law, and that if they knew then they wouldn't have zoom climbed.

May I suggest that even in Normal Law, it's a really bad idea to fly into protections anyway? And that therefore your suggestion is targeting the wrong area?

What pilots need is adequate training such that when bad stuff happens they don't start madly flailing with the controls, but they engage in a discipline which promotes diagnosis and then considered actions.

Adequate training will not happen until we can break away from the cycle of greedy airlines looking to sap the last penny from the operation, customers who will choose one airline over another to save a penny, and regulators who simply want a quick V1 cut, circuit, NPA to G/A and S/E landing.

Ironically, with the advent of safer, more "protected", complex aircraft - never has there been more need to ramp up the training. Old boys in crap aircraft were exposed to situations like this every day. Newbies now "fly" FBW+A/P from ILS to ILS day in, day out.

[FlightDetent]

IW: Sorry, I need to ask in hope of understanding your point. Are you aware of the differences in pitch control between normal and alternate law of 320?

100pp: "Old boys in crap aircraft were exposed to situations like this every day" 35+ degrees AOA with ,75 mach at FL350 under heavy leans/vetigo? Really?

[wiggy]

Personally I think 100pp has got a bit of a point.

I wouldn't claim to be that much of a man but even a callow youth such as myself remembers hand flying a heavy in the cruise at high level (even if you were not doing it for the heck of it it was part of our cruise trimming procedure on the 747) and a lot of the "old boys" I knew hand flew the 747 from just before top of drop all the way through to the landing when circumstances permitted, something that these days would ring alarm bells in the office and a telephone call when you got home.

I'm not saying doing the above is a panacea to all handling ills but it sure as heck sharpened up the scan and above all reminded you how gentle you had to be and how small some of your margins could be at high level. Above all you sure as hell knew that applying full back yolk at high level was never appropriate and was never going to end well.

Oh carp, does that mean I'm an "old boy..".........

[HundredPercentPlease]

I exaggerate slightly. ;)

My first transport aircraft had no autopilot, so hand flying in the cruise was second nature. The 737 has left me with no autopilot in some pretty odd attitudes, and we hand flew it a lot because we were better than the rough old autopilot fitted.

This aircraft did NOT give them 35 degrees AoA. It simply rolled to the left as a result of rudder deflection. Nothing else. It was the PF who did nothing for 9 seconds and then yanked in the back stick which caused a pitch of +9 (while rolling it right).

[vilas]

Ian W and deadheader
Simply emphasizing on the pilots that at higher levels applying full back stick is bizarre, irrational and suicidal and never to be done in any law is good enough. There are enough indications on the PFD to indicate change in flight control law for anyone who cares to look. Applying back stick and not checking attitude is simply poor instrument flying technique. It is as bad as SFO accident where visual approach was flown without ever looking at speed. In all these accidents there were professional deficiencies in pilots who were at controls and those were exposed, that's it. As I said before all one has to do is to routinely notice the bank, pitch and thrust the automation uses at higher levels and when you loose the automation just do the same yourself.

[RAT 5]

As I said before all one has to do is to routinely notice the bank, pitch and thrust the automation uses at higher levels and when you loose the automation just do the same yourself.

100%: oh that todays training emphasised such basics and allowed pilots to practice, attain & maintain these basic skills. It really is KISS, but there are too many higher influences that are acting against this basic principle. Those of us at the sharp end of TQ training, and those at the sharp end of Line Training are screaming for changes, but deaf ears abound. In many other instances on here there has been the cry that "until a smoking hole occurs nothing will happen". In recent years there have been too many smoking holes caused by serviceable a/c. What has been the reaction? Sadly too little. It is not yet too late. Who is holding their breath?

[aguadalte]

What would you do, in the second part of this video?
https://youtu.be/MbiVuPWX5K8

First of all: AP off, FD Off;
Move the thrust levers to idle and disconnect the A/T. (A/C is over speed);
Then aliviate the angle of attack (zero G, if needed);
Bring the nose to the horizon and wings to level;
Adjust Thrust as necessary;
Confirm speed brakes in;
Return to the desired flight path.

[RAT 5]

aguadalte:
Given all the performance parameters displayed your summation seems reasonable. Can someone explain why there was the 'stall' audio warning going off? I wonder if that seemingly conflicting warning was behind the question? Would your ears override your eyes and make you do something different?

[FlightDetent]

I'd assume because it stalled in overspeed condition. Caution advised, it is a SIM not a plane, still it looks controllable, but without seeing the pilot's commands dangerous to draw conclusions.

Proffesional observation at 1:33 Samolot uratuje sie sam, beleby mu pilot nie przeskadzal The aircraft will guard/safely take care of itself, if it was not for the pilot standing in the way.

[_Phoenix]

What would you do?
..Move the thrust levers to idle and disconnect the A/T. (A/C is over speed);
Then alleviate the angle of attack (zero G, if needed);
Bring the nose to the horizon and wings to level;....
Can someone explain why there was the 'stall' audio warning going off? I wonder if that seemingly conflicting warning was behind the question? Would your ears override your eyes and make you do something different?
I'd assume because it stalled in overspeed condition.


WOW! Bingo! So the stall warning goes off and we all would say(including me) Nah! The PFD picture shows overspeed (then AOA ~0deg), so the appropriate response is: PULL UP! :ok::ok: ->from both french FOs

What are the similarities between overspeed and stall?
- Buffet, impressive aerodynamic noise, bells and whistle sounds, pitch down, high descent rate, altimeter indication, FD (pull up!).
What is different:
- Airspeed indication
But from report (page 185, comments 39):
...the airspeed from ADRIU was unavailable... (showed unreasonable values)
See Figure 28: stall warning on! airspeed - red SPD! - This upset would initiate overspeed scenario.
The red SPD indication remained until switch to CAPT 3 when FO released SS after 2.5 min of pulling... At that time everything was too late, with AOA over 40 deg
So we all would be dead... by watching again the video at 1:10, substitute the speed indication with red - SPD

[Clandestino]

Can someone explain why there was the 'stall' audio warning going off?

Because video is forgery and quite a bad one.

I'd assume because it stalled in overspeed condition.No practical flying fixed wing can reach stall angle in overspeed without severely busting structural limit and transport machines limited to ultimate 3.75G can even less so. It's vee squared thing (or envelope, for visual types)
The report does.Would you be so kind to provide page reference, sır?

[_Phoenix]

Clandestino,

Stall and overspeed warnings together happen in real life too:
Incident: LOT B763 near Toronto on Jun 19th 2009, unreliable airspeed, simultaneous overspeed and stall warning (http://www.avherald.com/h?article=41b7477b&opt=0)

Just imagine the AOA of a bird while flapping the wings.

[Clandestino]

...which doesn't change the fact that video posted has nothing to do with either QZ8501/AF447 and was probably made by overdubbing stall warning or that 767s don't flap their wings to fly.

[1201alarm]

This is another lack-of-knowledge-discussion, the possibility that the crew was thinking to be overspeeding. If they really were thinking that and reacted like that it would be again meaning not being up to the task to hold a seat upfront.

Although overspeed is not desirable in a modern transport jet, it is much less harmful than stalling it.

Talk to test pilots and certifying engineers. Modern transport jets are deliberately flown into heavy overspeed situations, and they are just fine compared to being in a fully developed stall with 40° AOA and falling like a stone.

If I could pick 50kt overspeed or 40° AOA I would always choose overspeed.

As vilas rightly said, fully pulling the stick / yoke is never ever a wise thing except when you are low and approaching cumulus granitus. If you think you are too fast, gently fly your plane out of it, may be by help of the speedbrake. For sure you are not supposed to violently react.

[gums]

Thank you, Cland

Many here should wade thru the thoudands of posts we had concerning AF447. Points/counterpoints and many volumes of 'bus manuals and procedures.

I feel most of us from those discussions thot we had enuf new training as a result of that tragedy to prevent another duplicate. Sheesh.

I must remind all that when you see the FDR numbers from AF447 and the "airshow demo" crash by a "test pilot", that the 'bus seems to have very benign stall buffet/burble and such. So you can fly into the stall regime and not realize it. Then there's the problem of control law reversion that still seems to be a problem that the crews do not understand.

"You can't stall this plane", huh? YES YOU CAN!!!

Besides the crew coordination and the "I got it", "You got it" and such, I still see a lack of understanding about how the 'bus works when not in the NORMAL law. I also see a need for some warning that clearly lets the crew know they are in ALTERNATE or DIRECT.

Lastly, I go with the philosophy expressed by a few here, which says, "Don't do something, just sit there". There are a very few problems that require a reaction within a second or so ( however, the 9 second reaction by the PF in this tragedy puzzles me). If the warning lights come on and the jet is not pitching or rolling violently, than don't screw the pooch.

[WillowRun 6-3]

First, no comments whatsoever (or even questions) will be found in this post about comparisons of control yokes and sidesticks, and also nothing about control inputs or piloting techniques.

But what I do want to comment on, or ask about, is: what is the next level of authority, above the level of a given country's air accident investigatory outfit? I know already that there is nothing actually above the particular country's investigation board - that's just the point. It's up to "the industry" or some rudely conceptual agglomeration of constituents such as pilots (professional or otherwise), manufacturers, regulators, and so on.

What can happen and where?; specifically, where can the multiplicity of factors about avoiding or preventing the "next AF447" incident get sorted out? Maybe the answer is, there is no such thing. Which means, the sorting out of what to do to fix the problem or problems, preceded by the analysis of the cause or causes, defaults to . . . legal processes and the less-than-binding methods of the status quo. The efficacy of which speaks for itself, in this occurrence (and others).

[tdracer]

WillowRun, the investigation board typically has no rule making authority - however it can issue 'recommendations'. The regulatory authority then reviews those recommendations and determines what (if any) action to be taken based on those recommendations.
So, in the US, the NTSB makes recommendations and the FAA determines what action to take as a result. This has sometimes resulted in considerable friction between the NTSB and FAA when the FAA determined the NTSB recommended action was not justified.

[CONF iture]

The SIC was pulling more that the PIC was pushing but the PIC could not see it so was not able to understand the situation.
Initially the SIC responded correctly to the first STALL warning but not to the second one ... Was he preoccupied by the bank angle, was he trying to follow that "pull down" ambiguous directive from the PIC or was he chasing unrealistic FD Indications ... ?
How was doing the THS ?

Similitudes with AF447 are all over the place.

This time at least the STALL warning never quit ... The conditions were not met or the program was modified ... ?

[WillowRun 6-3]

@tdracer: I appreciate your reiteration of the relationship, in terms of authority, between the FAA and NTSB. And I regret if my prior post lacked clarity.
The point I was reaching for is: when a given investigatory authority in a single country reaches conclusions (whether in the form of just recommendations or any other form presently in use by the various investigatory authorities around the world), and those conclusions relate to a problem or a set of problems which cut across national boundaries and implicate major components of the worldwide civil aviation system as a whole, what is the mechanism, the forum (no irony intended), for progress on solutions? There isn't, in the realm of civil aviation accident investigation boards or agencies, any umbrella group, or something akin to a "court of appeals", so, where can the multi-national problem-solving take place? Even if ICAO SARPs and other programming were implicated in how the AF447 and this incident unfolded (and no one is claiming they were implicated, as far as I recall), there isn't such a process in place at the Organization, as far as I know.
What I am trying to stir up, in terms of discussion, is the idea that in order to attack and redress problems like low-hours aviators who may be too reliant on automation generally, or too unfamiliar with recognition of imminent stall and recovery from stall, or the problem of airline management too cheapskate to allow for hand-flying to be experienced more extensively, the first action seems to be to create a forum (again, no irony intended) where the major constituents of, and participants in, what I will dare to call "the safety community" can conduct a broader problem-solving process than the country-by-country process as reflected in the interactions of FAA with NTSB, as noted by tdracer's post.

[safetypee]

xcitation, #3771, thanks.

Situate, Aviate, Navigate, Communicate. :ok:
These concepts offer the potential for the most significant change in Human Factors / Airmanship training and operation in recent years.

The problem (not as a naysayer) is how to achieve this change. As much as we have difficulty in teaching the wide ranging aspects of ‘Aviate’ (flying as an art and skill), then ‘Situate’ appears even more obscure.
Many people are taught Situation Awareness by definition or level (text book), but without assurance of achievement; neither are we encouraged to practice what is a skill – that of thinking; the process of how to think, not what to think.
This problem could be the difference between implicit knowledge and tacit knowledge, e.g. we can be told how to ride a bike, but we learn how to ride a bike by doing it, … and once done never forgot, and with continual practice improved.

A view of training which might help. http://high-reliability.org/vanstralen-implementation.pdf

[safetypee]

@WillowRun, as you may be aware that the investigative process is overseen by ICAO; in this instance via the internationally agreed Annex 13 (not every State, and some have opt out clauses). There are also associated safety processes (forums) which include continued airworthiness (aircraft) and flight operations. Generally ICAO recommends, States implement, Authorities and Operators act.

In today’s complex operations the ICAO guidelines (even more so State / National interpretations) may hinder accident investigation, e.g. difficulties arising from the need to identify ‘probable cause’ and with the consideration of human factors.
Many, most accidents do not fit the old model of ‘cause and effect’; they are better represented with a systems view where outcomes emerge from ‘the seemingly random conjunction of many factors, each necessary, but in isolation not sufficient’ (James Reason, et al).

Therefore to improve safety it is necessary to encourage a systematic view, which currently is not at the forefront of safety activity, and international changes are slow. Fortunately several national investigators do venture into supposition and conjecture to provide more relevant understandings of the accident, but according to international agreements insufficient to recommend change.

An investigator can make recommendations to another State for action by a National Authority (more often operational issues); also recommend changes via the State of aircraft certification to a Manufacturer (technical issues). (ICAO Annex 13. 6.8 - 6.10)

Fortunately many National Authorities, Manufactures, and Operators will consider safety enhancements based on the subjective discussion, but this requires a ‘good’ report. IMHO this report is ‘fair to good’ given the circumstances.
Thus because more ‘worldly’ safety activity still requires factual arguments (evidence), the complexity and incredibility of modern accidents leads to frustration in judging how to manage the different points of view of safety actions, particularly where influenced by inherent human bias.
Even your examples reflect bias, suggesting that these points are known ‘causes’ (fact), whereas from a systems view they may only be contributions in a process applicable to a particular situation (probably never to be encountered again).

From the theories of high reliability organisations (the current level of safety qualifies aviation as such); it is difficult if not impossible to identify the mechanism of the next accident. It’s equally difficult to make effective recommendations from past accidents unless there is a change in safety views and processes.
Such changes take time, willingness, and understanding.

A lesson from quantum mechanics, first accept that nothing is certain.
We live and operate in an uncertain world, thus our safety activity must involve managing uncertainty, particularly where changes could be applied to aspects which were previously assumed to be satisfactory.
What was uncertain in this accident?

From a systems view, the industry’s problem is that we may not know what the problem is.
In ‘problem situations’ the human can be an asset in resolving the issue, but with ‘messy situations’ the problem is often the human.

How complex systems fail. (http://web.mit.edu/2.75/resources/random/How%20Complex%20Systems%20Fail.pdf)

Systems Thinking. (www.demos.co.uk/files/systemfailure2.pdf)

[roulishollandais]

We are not flying in quantum mechanics ! That is for very small scale.:=
We are not flying in general relativity ! That is for very high speeds:=.
We are not flying in the neuroscience bigdata and complexity.
:=
We are flying in the Newton world, and are able to be aware quickly of simple situations with KISS design, maintenance, teaching, training.:ok:

[_Phoenix]

We are flying in the Newton world, and are able to be aware quickly of simple situations with KISS design, maintenance, teaching, training

I subscribe to this.
Moreover, regarding KISS design, in my previous posts my intention is to show the necessity to clearly distinguish between overspeed vs stall, at high altitude, then the importance of having the AOA indicator or the bird (FPV) on PFD.
Another point is to clearly identify who does what, PIC, SIC or automation.
A more philosophical issue is the complexity of LAWs, especially the Alternate in combination with incipient stall condition when g is below 1.0 then a pitch input close to neural, i.e. 0.9g to 1.1g > 0.5g, for computers that is a Pull Up command that will bring THS at max NU. I think a simpler design would imply two laws Normal(all protections) and Direct(conventional), similar to Bombardier philosophy. All these changes should not imply a huge amount of money and it can be done quietly just by a simple software update, by bring the bird on PFD and revise the FCOM

[FDMII]

roulis, I think most can agree that Quantum Mechanics may not apply directly but, if I may, that is not what is being suggested.

I interpret Safetypee's remarks as the recognition and acknowledgement of both complexity and uncertainty that requires a change in approach concerning the question, Why do "accidents" still occur?

Safetypee is seeking a model for understanding why accidents occur which may be more successful than the present Newtonian (Cartesian) model of classical physics.

Rather than wagging a finger, shouldn't we take our lessons from where we find them when confronted with aviation's Gordian Knot, human factors?

We must examine experience in other, perhaps-unfamiliar ways because, as SP has pointed out, the old interpretations of how accidents happen are showing themselves as no longer able to carry the potential for strong change and improvement. What imagination as much as we need knowledge.

Cartesian approach has largely resolved, (we cannot quite say eliminated) the old problems of mechanical failure, weather, navigation, communication, CFIT and mid-air collision. That is, aviation has resolved these direct causes through changes in technology.

Despite coming to terms with direct causes, accidents continue to occur is a result of human frailties - errors in perception, comprehension, or other "normal", human incapacities in complex, rapidly-changing systems and environments in which accidents presently seem to unfold.

[gums]

We are moving back to the discussions several of us here had at length concerning AF447 on the Tech Log.

I disagree about going directly from "you can't stall or over-gee this plane" to "a pure stick displacement equals corresponding control surface movement". Several considerations regarding that implementation.

The whine I have is two ALTERNATE laws and a lack of training as to how the plane flies in either or both. Secondly, some things may be lost from the primary NORMAL law, but seems a few simple things could still be in play such as over-gee, as that can be derived from within the flight control computers themselves. Ditto for some of rates and pitch/roll limits. Finally, loss of air data should be no biggie, as several 'bus crews have demonstrated before and since AF447 - "standby gains" for many functions and basic "keep doing what you were doing" training.

[_Phoenix]

I disagree about going directly from "you can't stall or over-gee this plane" to "a pure stick displacement equals corresponding control surface movement".
Yes, the pilot is aware of pushing the envelope limits (tactile soft stops), so let him go through it in order to clear a cumulus granitus or the tree tops or allow to flare the plane over Hudson.
Details about soft stop in video below at 0:54
https://m.youtube.com/watch?v=QN0qQrMaLYw
The direct law should not be spooky, but just a reversion to conventional flying. Many of Cseries tests were performed in direct:
https://m.youtube.com/watch?v=OghtdzFXFoo

[WillowRun 6-3]

Many thanks, Safetypee and RDMII, for enlightening discussion. SP: "unless there is a change in safety views and processes"; RMDII: "change in approach concerning the question, Why do "accidents" still occur?" What would such a change - or changes (plural) - look like? (and if that question seems impertinently stated, then, is it even a useful question to ask, "is the present system moving in the right direction for such change or changes to occur?")

The "How Complex Systems Fail" article (the link to which SP provided) is at least 15 years old - can't help but wonder, how have any more current analyses looked at the overall complexity construct?... any differently, or differently in ways relevant to the general subject matter of the thread?

Also couldn't help but note a slight, not objection, but "reservation" about seeing ICAO Annex 13 as an "oversight" process or method relative to nationally-authorized safety boards or agencies (but it's not too important to discuss further right now).

Reading comments by RDMII & Safetypee over again, was reminded of the not-too-long ago ICAO Loss of Control In-Flight Symposium (May 20-22, 2014). Exclusively in the interest of contributing, possibly, to the discussion of safety improvements (however difficult those may be to identify, enunciate and make happen), much info apparently very relevant to observations by prior posters is listed in the Symposium program and Key Outcomes (presentation powerpoints also can be accessed - though lacking the intensity of videos of flight parameters - slides only).
The program for the Symposium:
http://www.icao.int/Meetings/LOCI/Documents/LOCI%20Formatted%20Agenda_FINAL.pdf

and Key Outcomes:
http://www.icao.int/Meetings/LOCI/Documentation/Key%20Outcomes.pdf

[gums]

@ Phoenix.......

Good video links.

The point about "direct" is that the computers still bias your control stick deflection or pressure using some math function.

Is one degree of stick deflection equal one degree of elevator deflection? If not, what is the ratio?

Is ten pounds of stick force about like we used to feel with the fully hydraulic systems ( no mechanical linkages, just hydraulic pressure to move an actuator) that used pneumatic and spring doofers to provide a bit of feel. And BTW, are the stick movements at the same pressure regardless of how many degrees they move?

I have no problem with the test pilots using some DIRECT implentation initially, then going to the NORMAL mode. But I have no idea of the gains or control input ratios to control surface movement or even how fast they move ( rate of surface movement).

Hooray for Bombardier. I like their approach.

But I still wannna see some charts and graphs.

[_Phoenix]

Thanks Gums! Soon CS100 will get the type certificate, then more data will be available publicly (in Canada or Tech Log )

[dlen]

If it's not possible to link sticks mechanically, disallow for dual input mode altogether. Too much complexity. One stick has control, the other is blocked, in order to make it clear for the respective pilot, that he has no control.

In case of takeover-button conflict, the captain gets priority.

[safetypee]

@WillowRun, even with some heartening views expressed at the symposium there are few indications that the industry is changing, excepting perhaps some aspects of SMS.
The reluctance to change could represent the difficulty in changing culture, which conventionally might take a generation. In that respect 15 yr old thoughts could still be valid, more likely they represent exceptional forward thinking. For more recent views see Cook and Hollnagel, refs.

Ah, Annex 13 ‘Oversight’ – perhaps ‘Overarching Standards and Practices’ is better.

One ‘change’ initiative, amongst others is the awkwardly termed ‘Resilient Engineering’ - to build resilience (and how to spring forward, not back to an original positon).
The fundamental concept seeks a different way of thinking about safety – safety is not something to have, but that which is done. Furthermore, safety thinking should be against the backdrop of what happens in every-day situations – the successes, and most importantly to view humans as an asset, not as a hazard. Also, by comparing ‘work as done’ against ‘work as imagined’, any gaps in safety assumptions could be understood.
With understanding and improving the ‘successes’ there should be less opportunity for the failures. Unfortunately this assumes that the industry does not demand more activity, in more complex operational system, and the need to work near to the edge of established safety boundaries.
Distantly this can reflect the gap between researches seeking to better understand human behaviour (know-what) vs the industry’s need for the ‘know-how’ to enable current academic views to be implemented, an aspect which is reflected in some symposium presentations (inconsistent HF, CRM, TEM, training).

The change of view above is often defined as ‘Safety 2’, unfortunately with the potential for misinterpretation as a replacement for what we do now – Safety 1. I subscribe to the concept of “Safety 1 and Safety 2”. S1 has enabled today’s successes and should not be totally rejected, but in order to progress – high reliability organisation, complex operations, etc, S1 and S2 could provide the means for managing the uncertain nature of modern operations and reducing the potential for major accidents. Additionally, S2 thinking in areas of S1 may add unseen safety advantage, particularly in the ‘safety – commerce’ balance which could be overly subjected to S1 type commercial thinking.

A practical aspect RE starts with Learning, and then cycling though Responding, Monitoring, and Anticipating. The cycle can be entered at any point, i.e. Learn from accidents, Monitor the Responses made based on what has been learnt, which could provide the Anticipation to avoid or minimise the effect of future events, even to the point in not being exposed to situations which could not have been foreseen – we never know - uncertainty.
The points of learning should not require massed evidence or deep understanding; they could be questions about what is done ‘normally’, individually or collectively. Thus relating to this accident ‘what is the normal cruise seat positon’, ‘can full control be achieved from this position’, ‘is the SOP to follow the FD overstated’, ‘how is the FD interpreted’, ‘should we leave our seat to switch systems’, trim, etc.
With answers to these then the responses the required safety activity should be clearer, quicker, and pertinent to operations opposed to time-delaying regulation and training.

Resilience Engineering. (www.msb.se/Upload/Kunskapsbank/Forskningsrapporter/Slutrapporter/2009%20Resilience%20Engineering%20New%20directions%20for%20m easuring%20and%20maintaining%20safety%20in%20complex%20syste ms.pdf)

Introduction to S-I and S-II. (http://safetysynthesis.com/onewebmedia/Introduction%20to%20S-I%20and%20S-II.pdf)

Resilience Analysis Grid. (www.resilience-innovationlab.org/community/sharingKnowledge/documents/RAG---Resilience-Analysis-Grid-Eric-Hollnagel-20100510.pdf)

The Resilient Organisation. (www.scribd.com/doc/293278326/The-Resilient-Organisation)

From Safety 1 to Safety 2 (www.skybrary.aero/bookshelf/books/2437.pdf)

and for roulishollandais, et al; Non-Newtonian View of Accidents. (www.scribd.com/doc/78438533/Non-Newtonian-View-of-Accidents)

[ExV238]

Although overspeed is not desirable in a modern transport jet, it is much less harmful than stalling it.

Talk to test pilots and certifying engineers. Modern transport jets are deliberately flown into heavy overspeed situations, and they are just fine compared to being in a fully developed stall with 40° AOA and falling like a stone.

If I could pick 50kt overspeed or 40° AOA I would always choose overspeed.

As I'm sure the poster of the above knows, Part 25 certificated aircraft are tested for structural behaviour (flutter) up to VD/MD, but not above. Above VD/MD all bets are off and the designer has no more data for you. Flutter can develop in seconds and can be catastrophic in only a few more. To take the A320 as an example, MD is approximately MMO+20 knots at FL390. If you allow your aircraft a '50 knot overspeed', then you are not only conducting experimental flight test, you're doing a research programme that's unlikely to end well.

In contrast, all Part 25 aircraft have to demonstrate safe stall characteristics, and there's no reason why AoA should develop to 40° unless you hold the aircraft into the stall. Even then it should be recoverable with the published technique for your type.

Let's all be REALLY careful what we post on this professional forum, and REALLY careful what we read and believe. Let's base ourselves on the facts. Seriously.

[formulaben]

Let's all be REALLY careful what we post on this professional [rumor] forum, and REALLY careful what we read and believe.

Careful of WHAT? Seriously.

Better advice of immediate use for those pontificating to those reading would be to be "REALLY careful" when flying with fully aft stick. :hmm:

[phylosocopter]

Can someone who actually flies a bus tell me

Are you trained /practiced in flying in alternate law at cruise altitude?

Is there any policy that says pilots should / should not recieve this training?

Why/ Why not ?

[xcitation]

Overspeed vs Crazy AoA.
Surely there are too many variables to say which is preferable:
how much energy a/c has, are the engines at idle and how long until they can be safely spooled up without providing a pitch moment due to under slung turbines, is pilot 2 whisking mayo, how much altitude above and below, traffic, terrain, wx, aircraft hot high and heavy, are we in a war zone. :confused:

[piratepete]

There are only two realistic solutions to the problems we are having in aviation with perfectly flyable planes crashing and killing the pour souls on board.

1.The PIC must be highly experienced and well-trained in all scenerios.By this I mean at least 7-10000 hours in general, and a comprehensive simulator syllabus.

2.The F/O might be low hours meaning only 200-300, that is okay but must have a significant simulator training syllabus as well, not the cheapskate rubbish now being accepted.

In order for these things to happen a lot of money needs to be allocated.What we have now is just crap.The airlines know it and the regulators are just going along with it, both have a lot blood already on their filthy hands.

[vilas]

In my opinion the problem is not that mystical or of serious systemic deficiency requiring drastic modifications but of insufficient knowledge of effects of flight controls in alternate law. With all protection removed applying and holding full back stick is very dangerous and totally unwarranted. In alternate law at lower levels even with EGPWS warning you don't do it. If this is done with sufficient speed the aircraft will do a loop. With rate of roll doubling pilots action on roll should be very gentle. At higher cruise levels to do all this is sheer madness. In alternate law you never, ever pull and hold back stick. If this simple thing was instilled during training and flying these accidents would never have happened. Following are my inputs to some of the suggestions by members:
At cruise levels let alone alternate law but it is simply not possible to even fly manually due to RVSM.
Having only experienced PIC is ridiculous because one has to start as inexperienced to get experience.
In AB FBW in direct law computers do not modify pilot inputs, it is a linear direct relationship between stick and elevators. Except max elevator deflection is function of C of G.
About shiny red button, fear of pilots using it is not unreal. If they can reset forbidden CBs then nothing prevents them practicing in direct law by using the button and erroneous activation of a protection can be handled in alternate law. Why is it so difficult to understand that in alternate law you never use the side stick to any extreme, leave alone pulling the stick back and holding it there? which is what started it all.
In Airbus FBW there is only one way to take over controls and that is by pressing the take over button. One needs to develop the habit.

[alf5071h]

phylosocopter #3818, an interesting thought, where it would be logical to assume that pilots would have some exposure to alternate law. Yet the law is only an ‘alternate’ and does not, as AFAIU, pose any great difficulty in control; more so with protections in place.
A different question could ask if crews have been exposed to the situations where their apparent inability to fly in alternate law was noticed, but these are very rare and often unforeseeable. Why attempt to train every 1 in 10-9 event, which represents impossible reactive safety, we never catch up. Why not ‘ask’ (determine) how many pilots inappropriately (foreseeably) pull CBs in flight.

A different approach is to consider the problem at a higher level. The informative presentation Managing Startle (http://www.icao.int/Meetings/LOCI/Presentations/Managing%20Startle%20Individual%20Crew%20and%20Organizationa l%20Strategies.pdf) gives some well-constructed views of the human issues, but even then solutions to the ‘how to’ problems of imparting and refreshing knowledge, teaching and practicing SA, and need to plan ahead, are not outlined.

The underlying problem appears in both teaching relevant knowledge – ‘know what’ (but who decides on what is relevant), and the much more difficult acquisition of ‘know-how’ skills, when and where to use the knowledge.
From a previous post, you can provide knowledge of how to ride a bike, but you have to do ‘it’ to be skilful. What is the ‘it’ in flying (not the hands on bit) that is so elusive, perhaps we have to get on our metaphorical bikes to find out.

[CONF iture]

In alternate law at lower levels even with EGPWS warning you don't do it.
Of course you do it, unless you don't mind ground contact ...
Apply full back stick, just don't hold it when approaching the stall speed or buffet is coming.

In alternate law you never, ever pull and hold back stick.
...
Why is it so difficult to understand that in alternate law you never use the side stick to any extreme, leave alone pulling the stick back and holding it there?
You demonstrate "insufficient knowledge of effects of flight controls in alternate law."
Or are they too many laws in the Airbus world ... ?

[vilas]

CONF iture
You don't apply full back stick in alternate law but steadily pull up to stall warning, by stalling you won't avoid ground contact. In alternate law You pull full back stick if you want to do a loop which in absence of pitch attitude protection is possible. I have made points very clear and you haven't added anything. In any case your opinions about airbus are more visceral than technical. You seem to be supporting the unnecessary rapid full pitch inputs in these accidents and suggesting revolutionary changes in aircraft design which are not going to happen.

[1201alarm]

As I'm sure the poster of the above knows, Part 25 certificated aircraft are tested for structural behaviour (flutter) up to VD/MD, but not above. Above VD/MD all bets are off and the designer has no more data for you. Flutter can develop in seconds and can be catastrophic in only a few more. To take the A320 as an example, MD is approximately MMO+20 knots at FL390. If you allow your aircraft a '50 knot overspeed', then you are not only conducting experimental flight test, you're doing a research programme that's unlikely to end well.May be I formulated my point in an unclear way. So I try to rephrase, since I consider it important.

VD/MD of the A320 is 381kt / M0.89. As we usually don't fly over 340kt / M0.80, and we were talking the high level case, '50kt overspeed' is a rough ballpark just to show that you can go very far on this side of the performance.

In reality you will have an extremely hard time to bring your aircraft to such an overspeed in high level. It needs considerable pitch down plus engines at full steam to accelerate that fast (if I remember correctly we talk about a pitch down of 7.5° compared to the pitch before plus full thrust but certification pilots will sure correct me on that).

If you cruise happily along with AP/FD/ATHR on and suddenly the alarm bells go on or your plane is throwing ECAM failures at you, there is ZERO need to be ****-scared about overspeed. If you are overspeed, it won't be in any lethal way, just gently fly your plane out of it. No need to pull the stick fully backwards.

In such a situation, while you pull GENTLY out of the overspeed, AOA should be your concern, because it doesn't take a lot of degree pitch up to stall at such levels.

Once you are in the fully developed stall (high AOA due to low forward speed due to huge drag due high pitch), it takes a lot of pitch down to make your wing fly again (you basically have to pitch down nearly to your flight path vector), then a lot of time to accelerate again to a speed that supports level flight, and again a lot of time to gently change your flight path from rapid dive to level flight. I don't want to image how many thousands of feet that takes.

[gums]

@ conf and vila

If the DIRECT law has a completely linear plot from zero stick/elevator to full deflection, then how does cee gee come into play? Show me the plot of deflection/stick pressure versus control deflection. 45 degree line? Is a degree of stick equal to a degree of elevator movement? Maybe it's 1:2 or 2:1 or whatever.


I have to agree that full stick deflections are not always the way to go even in NORMAL laws. I also point out that the two 'bus crashes we have dissected appear to indicate very little buffet or shaking or such that many of us here were used to in other jets.

TNX 1201, you sound like the crowd that thinks "don't just do something, sit there"

[_Phoenix]

Hey Gums, see the graph in reference below at page 112.
http://www.bea.aero/docspa/2008/d-la081127.en/pdf/d-la081127.en.pdf

At the bottom of page, the flight law switched from normal to direct = "intuitively" alternate law + landing gear extended, between 15:45:15 to 15:45:40. See the purple and green curves are proportional, however the elevator is at 75% (12.5 deg out of of 17 deg) for stick at full ND.
Note: Interesting for pitch in alternate law, the stick to elevator relationship, is opposite ?!
As per FCOM, the pitch in direct law is a direct stick-to-elevator relationship (elevator deflection is proportional to stick deflection). However, maximum elevator deflection varies as a function of CG. No protections are available.

[CONF iture]

You don't apply full back stick in alternate law but steadily pull up to stall warning
Negative - GPWS requires to apply full back stick - Alternate law is still a load factor demand law as Normal law is - Load factor protected - Apply full back stick, let the law working, just don't hold it when approaching the stall speed or buffet is coming.
As instructor you pretend to be, that you disseminate false information is a bit disturbing.

I have to agree that full stick deflections are not always the way to go even in NORMAL laws.
For GPWS warning, Airbus gives no other choice. Alternate laws work the same except the responsibility to avoid stalling will be yours so full back stick you cannot hold for ever.
And of course Direct law is something else totally ...
I know ... many laws !

[joema]

Re decoupled sidesticks and possible involvement on AF447 and AirAsia, it was already mentioned in this thread the new G500 and G600 will have "active sidesticks" which are electronically coupled.

I just saw this brief video that explains it:
https://www.youtube.com/watch?v=vXhCJYWvwd0

The system is made by BAE. I wonder what the cost/risk/complexity would be to retrofit this to an Airbus?

Commercial Active Sticks - An Active Role | BAE Systems | United States (http://www.baesystems.com/en-us/feature/an-active-role#)

However this FlightGlobal article says BAE has no plans to offer it as a retrofit option:
https://www.flightglobal.com/news/articles/mc-21-ushers-active-sidesticks-into-commercial-aircr-411455/

[ExV238]

1201,

Thanks for that clarification. I certainly agree with you that a heavy pull on the stick at high altitude to avoid an overspeed is inadvisable. But let's not underplay the risks of exceeding VD/MD. And I'm talking about a real overspeed here, not a falsely indicated one in the unreliable airspeed case.

The Part 25 VD/MD tests require the dive to be held for 20 seconds, which isn't that long really, and at less than full power. The testing is one aspect of determining VD/MD, but be clear that the aircraft won't have been flown above that speed.

The extreme AoAs reached in the Air Asia and AF cases were the result of pulling and holding the aircraft into the stall. A correct recovery flown at the point of stall warning, or even at the stall itself, will not lead to such AoA, or to huge altitude losses.

What I'm saying is that the stall case is recoverable, but that the result of flutter probably won't be.

You're not Buzz Aldrin, by any chance?!

[Sorry Dog]

However this FlightGlobal article says BAE has no plans to offer it as a retrofit option:

It sorta stretches the imagination to see AB endorsing such an item that they don't offer "in house"....

...maybe one day after it is offered as a nextgen option to a neoneo model 350 then maybe the wheels might start turning for such a retrofit

[vilas]

https://www.faa.gov/training_testing/training/media/cfit/volume1/4d3.pdf


TERRAIN AVOIDANCE PROCEDURE


Applicable to FBW aircraft: A319, A320, A321, A330, A340 in NORMAL LAW


Immediately:


- THRUST LEVERS TOGA


I- A/P DISCONNECT
- SIDE-STICK* PULL UP, WINGS LEVEL


- SPD BRK Check retracted


[f necessary, use full back stick and maintain a max speed until terrain clearance is assured,


(GPWS warning ceased and radio altitude increasing).


When flight path is safe, decrease pitch and accelerate.

When speed above VLs and V/S positNe, retract flap and gear as required.




*In pitch alternate or direct law, pull up aggressively, wings level. if necessary, maintain speed at stall warning until terrain clearance assured.

[PDR1]

It sorta stretches the imagination to see AB endorsing such an item that they don't offer "in house"....

...maybe one day after it is offered as a nextgen option to a neoneo model 350 then maybe the wheels might start turning for such a retrofit

Not sure what you mean by "in house", but BAES hasn't been part of the AB consortium for many years. I'm sure that if approached by AB as a potential customer for this sidestick they'd be delighted to negotiate a sale of sidesticks for AB to integrate and certify on their aircraft.

PDR

[1201alarm]

You're not Buzz Aldrin, by any chance?!

:ok: Not at all, just a strong admirer of what these guys managed to pull of in the Apollo program. It seems I am not alone with that.

[gums]

C'mon CONF, as Vilas has posted, you only use full stick if you have to and you still have some "protections" ( tho I call them "limits").

Problem is we have ALT1 and then ALT2 and then DIRECT. Good grief!!!

I do not like DIRECT unless in a high-performance jet fighter that pilots can handle or a modified DIRECT that has given relations of stick displacement to control surface displacement, and then there's the rates/gains to consider.

Sheesh.

I do not see a lotta engineers here or pilots that went thru the birth of FBW and all the "laws". Many things to incorporate and many inputs to the computers. Human factors played a large role back in the 70's. The current discussion about not having sticks connected is a good example. Ditto for "pressure" versus "displacement" of the controls, be they yokes/wheels/sticks or touchpads.

[phylosocopter]

I still dont get this.

If the aircraft is not carrying persons who can fly it in alternate or direct law at cruise altitude how can it be certified to be there ?

Thats regulatory failure.

If it is not certified to fly at cruise except in normal law then how can it be certified whithout an agreed process for getting from cruise to some other altitude in event of law degredation.

[CONF iture]

So vilas, where does it say "Do not apply full back stick" ... ?
Make your own procedures as you like, but they're not from Airbus.

C'mon CONF, as Vilas has posted, you only use full stick if you have to and you still have some "protections" ( tho I call them "limits").
Not too sure why vilas choose to post a paper old of 20 years, but just opening the actual FCOM in the emergency procedures and GPWS ALERTS will put things straight :
"PULL UP"
Pull to full backstick and maintain in that position

No choice really - Maintain if you're fully protected in Normal law, but don't if you're only partially protected to respect the stall warning.
Alternate law in pitch is still a load factor demand with maneuver protection included, why wouldn't you take advantage of it if it can save you from hitting the ground ?

Vilas makes rules that are not in the books.

[QDMQDMQDM]

I've been a private pilot for years and I'm an emergency doctor with an interest in human factors.

Surely, there is a basic design flaw in a system which hands the aircraft back to the pilot in an emergency in one of a number of different control modes, all of which have different levels of protection and response to control inputs. The pilot, already stressed and faced with an emergency situation, cannot fly the aircraft automatically, but has to devote much of his higher cognitive function to trying to remember what he should and shouldn't be doing in this particular mode and what happens with different control deflections. For responses to be automatic and instinctive in this kind of situation, where there are so many different variables, seems to me like it would require a frequency of recurrent training and a level of basic handling skill which may be untenable.

Aircraft need to be designed to be flown by idiots, because some day one will.

[vilas]

Conf
What you are repeatedly saying is true only in normal law. You never pull full back stick in alternate. If you can quote any document stating you pull full back stick even in alternate law I will accept it. I don't make procedures but only keep quoting airbus documents unless there is a discussion where opinions are expressed. Even quoting airbus has irritated some people.

[_Phoenix]

Aircraft need to be designed to be flown by idiots, because some day one will.
"Manual flying" is just an illusion. Basically, pilot sends impulses to computer: up/down, left/right, the rudder is a footrest. So the aircraft is already designed to transform a pilot in idiot, but you need superman to fly the alternate laws.

[FDMII]

_Phoenix;

I'm sure what is said below will be familiar to you - just reiterating some of the characteristics of the Airbus system for the discussion. I don't intend here to be pedantic or instructive.

With that in mind..., "manual flying" has been an illusion for over fifty years.

The DC8 ailerons and rudder were hydraulically-powered with spring-tab backup while the elevator was cable-pulley & tab. Boeing had introduced hydraulic flight controls on the B707 in the late-50's.

Back then, it was fluid that sent the impulses - today it's electrons. Springs on control column/control wheel circuits & mechanisms provided feedback to the pilot.

The AB SS provides such feedback by the same method, (springs), so doing steep turns, for example, in either Normal, Alternate or Direct laws, the stick has to be held back more firmly when the bank angle is exceeds 33°.

What may be confusing to some, particularly when discussing the Airbus, is the difference between C* laws in FBW systems, and the various protections that may be built into EFCS systems. FBW in and of itself, offers no "protections"; FBW is just another way of moving flight control surfaces. "Protections" are possible because the system is digital and as we all know, anything that can be imagined can also be done with digital signals.

The rudder pedals have been, and should absolutely continue to be a footrest except in the usual circumstances with which pilots are familiar - crosswind landings and engine-out yaw control.

You do not need, "superman to fly the alternate laws", (an exaggeration I'm sure). What you actually need is a thorough understanding of the airplane and that comes, as always, with training, experience and continuous learning through staying in the books, (which is something I really wonder about in today's pilots, who seem to be discouraged by managements, (who are focussed entirely on slavishly following SOPs rather than encouraging airmanship and thinking), from deepening their knowledge of systems, high-altitude, high-speed, swept-wing flight by study, and reading accident reports.

Alternate Law circumstances are regularly-trained in the sim as a result of system failures which are in the script. Alternate law is a non-event; the airplane is conventional in the sense that one just flies the airplane normally, including respecting the stall warning. When actually flying the airplane, the change in laws is essentially transparent to the pilot. The cautions (and therefore the responsibility for knowledge of one's airplane), are related to loss of protections, not to any "special handling" requirements due to FBW.

I don't think you can say that computers have transformed pilots into "idiots" any more than hydraulics have.

Even as technology is never neutral or innocent, it is, in my view, the abuse of the tools that has done so because airline managements began assuming that "these airplanes fly themselves", and so require/mandate that the autoflight systems be engaged as soon as possible after takeoff and remain engaged until the landing rollout is completed. Asian carriers monitor this with FDM, a wholly inappropriate abuse of a safety technology, so disconnecting and doing something with the airplane is both an institutionalized fear as well as a safety problem. A more irresponsible mandate on the part of an air carrier could not perhaps be conceived/implemented, but there it is - a growing generation of "pilots" who can't fly and who are increasingly afraid to try.

[ExV238]

Not at all, just a strong admirer of what these guys managed to pull of in the Apollo program. It seems I am not alone with that.

Correct! :ok:

[ExV238]

FDMII,

An excellent summary.

:D:D:D

We also can trace flight envelope protection back to technology such as Q-feel systems, cracking struts and stick pushers; all features of pre-FBW flight control systems that limited a pilot's 'authority' to break an aircraft. Some were controversial when introduced, but are old hat now...

[_Phoenix]

@FDMII, neither me intend to be instructive or to initiate a polemic.
Back then, it was fluid that sent the impulses - today it's electrons. The hydraulic fluid does not interpret the pilot inputs as flight computers determine the actuators movement

Springs on control column/control wheel circuits & mechanisms provided feedback to the pilot. The AB SS provides such feedback by the same method, (springs) ... Maybe the active sidestick
What may be confusing to some.... FBW is just another way of moving flight control surfaces
If the pilot releases the stick, the aircraft keeps the pitch until the stick is moved again, then the flight computer moves the actuators without pilot input whatsoever. Also pitch control provides automatic elevator to compensate in turns "You just roll the aircraft and leave it alone"
Airbus said long time ago: "Flying the fly-by wire is similar to driving a stagecoach. Where the coach driver gives a command and the horses take care of the road, the A320 pilot makes a control input and the aircraft takes care of the flight-path. Having been educated in all the permissible speeds, attitudes, and manoeuvres, the A320 will never overspeed, overload, or stall"

[CONF iture]

I don't make procedures but only keep quoting airbus documents
Unfortunately you have not been able to quote a single document to state :
"Never pull full back stick in alternate"

Why applying full back stick in Alternate law which has the same pitch control than Normal law ?
Because flight experience has revealed that an immediate 2.5 g reaction provides larger obstacle clearance, than a hesitant and delayed high G Load maneuver.

[FDMII]

_Phoenix;

Yes, agree - for FBW systems the computers determine actuator movement through both FBW & Airbus protections.

The action/result of the flight controls is transparent to flight crews in the sense that, (hopefully without conflating the description!), something like CWS, control-wheel-steering in Boeings and the Lockheed, the airplane stays in the last set position, albeit, for the Airbus, without the control surface movement to maintain 1g. Minor corrections to pitch & roll attitudes during manoeuvering are natural pilot inputs.

The feedback/feel of the SS would be the same for both sticks as a function of the design of the SS mechanism itself, which provides the required amount of pull to maintain altitude when bank-angle is > 33°.

To your third, again agreed, (same reasons as your first). But I would hasten to observe that informal, (marketing) remarks made by Airbus a "long time ago" are not in, or part of the AOM and FCTM, nor are they part of formal training curriculae. I would emphasize that understanding the EFCS of the airplane through the usual training & checking regimes is key, just as it is with any type and design.

The AOM and FCTM cautions when in Alternate or Direct law are abundant and clear: protections are degraded or lost: in all ways, fly the airplane as one would a conventional transport aircraft, respecting all airframe limitations, cautions and warnings.

[xcitation]

Surely the argument of computers being between pilot and control surfaces has long vanished from relevance. Many modern aircraft cannot be directly hand flown as they are aerodynically unstable by design e.g. f117. The days of real direct control are gone, transport pilots no longer require bulging biceps to execute emergency flight control inputs.

[FDMII]

@xcitation;

In my view the discussion regarding computers-flying-airplanes was over decades ago.

However, the subject keeps re-surfacing perhaps from those who don't fly transports or who do but haven't been trained on and haven't flown the Airbus.

Understanding is important and a collegial discussion on this forum may provide a way for all to gain an insight into FBW/automation issues.

Equally important is the reading and study of accidents, beginning with the reports. I think that makes a well-rounded airline pilot at a time when such well-roundedness, including airmanship is, in my perception, actively discouraged in favour of a box-ticking-for-audit-purposes culture and jammed-full simulator scripting.

[gums]

From excite:

Many modern aircraft cannot be directly hand flown as they are aerodynically unstable by design e.g. f117.I must take exception, as I flew the first operational jet intentionally designed to have negative static stability belore 0.95M, and was fully FBW with zero mechanical anything connected to the control surfaces. You can see my bio on the info for we posters, unlike 99% of those who post here.

The Concorde prolly led us, but still had a few cables or whatever, maybe tabs controlled by cables.

Even the 'bus is not unstable, tho it does allow a cee gee back further than would be approved 40 years ago.

I cannot find a single commercial jet or more than one ot two military designs that cannot be flown with out cosmic computers, protections and such.

Although the computers or "boxes" shape the signals to the control surfaces, being hydraulic pressure or electronic waveforms, most jets fly today exactly as they did 60 years ago. So my jets 50 years ago used hydraulics, but the valves had shapes that did not provide a 1:1 pressure change for each pound/degree of displacement. Those early jets also had neat dampers that used gyros and/or rate sensors to dampen things. So dutch roll was not a biggie for we clueless jocks.

We even had "protections"!! No kidding. My Voodoo back in the 60's had an AoA limiter and then a 28 pound pusher on the stick if we exceeded 'X" Aoa or a certain pitch rate closse to the AoA limit. Sucker worked like a charm, although that beast provided awesome warning before the stall/pitchup - wing rock, hard buffet, etc. No roll protections, but what the hell. On other jets we had stick shakers or duddr vibrators or......

So the "manual" advocvate folks here have it close, but I am not convinced many of the nuggets have their basic skills burned-in by hours of practice and exposure to the dark side of things in their planes.

The practice of "engage otto" at 300 feet with gear up and the reverse when landing bugs me beyond anything. I don't feel all should be Chuck Yeager, but if we can't fly the profile without using otto, then we should not be flying at all. I used and expounded otto for a few thousand hours in single-seaters to reduce workload when wx or other problems arose. But I never flew a profile that I had to use otto versus my own skills/eperience, and remember that otto has ZERO experience.

out

[ExV238]

The hydraulic fluid does not interpret the pilot inputs as flight computers determine the actuators movement

If the pilot releases the stick, the aircraft keeps the pitch until the stick is moved again, then the flight computer moves the actuators without pilot input whatsoever.

Indeed!

Designers have used the best available means to make aircraft as easy as possible to handle, ever since the earliest days, whilst also allowing progressively higher performance. That's led successively to refinements in reversible (purely manual) control system with spring tabs, balance tabs, bob weights and the like; servo controls; and then the introduction of powered flight controls and associated artificial feel.

The nirvana is surely something such as described in the second quote above (although it's typically the flight path that's kept, not the pitch attitude as such), in which the pilot directs the flight path with the stick and the flight control system removes external and unwanted disturbances such as turbulence. This is what modern FBW seeks to achieve, but clearly it has to move the waggly bits on the wings and tail to do so, without a direct input from the pilot. This is nothing new; we've had yaw dampers moving the rudder without pilot command for over half a century!

FBW gives the opportunity to remove secondary effects such as (for example) roll due to sideslip, thus making tasks such as crosswind landings easier. Designers can now get much closer to providing pilots with handling qualities that they should have had decades ago, had the ability to provide them existed.

Turning to degraded modes; well, yes... If a Comet or 707 lost yaw damping, then the pilot had a very significantly greater problem on his/her hands than being in Alternate Law in an Airbus. And you'd better be careful not to reach the stall AoA in a VC-10, 1-11 or the like with a failed stick pusher.

FBW is still relatively new technology in the big scheme of things. There are rough edges still, to be sure, and it's being refined just as previous generations of flight control systems were. But the fundamental principles are right.

P.S. Sorry - some duplication with Gums' post, with which I agree completely.

[galaxy flyer]

With three Airbii in the water after something resembling a "full aft stick stall" (T-38 stuff) and a Colgan Q400 crashing after a similar stunt; I am bugles by the pilot reaction to yank BACK. Where are they learning this?

GF

[peekay4]

Where are they learning this?

It's called "normal human reaction".

[Machinbird]

With three Airbii in the water after something resembling a "full aft stick stall" (T-38 stuff) and a Colgan Q400 crashing after a similar stunt; I am bugles by the pilot reaction to yank BACK. Where are they learning this?Well, the first (XL) crash was more of a mouse trap where defective AOA data allowed the aircraft to slow to a stall (trimming as it went) and then at the stall, dropped into a mode that required manual trim (probably without adequate warning to the crew) so that as the aircraft accelerated under TOGA thrust, the nose climbed uncontrollably, stalled, recovered only to fly into the water due to inadequate recovery altitude. The crew was actually pushing as hard as they could. I wouldn't count that one.

AF447 was the first piloting failure where the guy flying lost control of pitch and spent a lot of time with too much aft stick.

QZ8501 is now the second of these strange aft stick events where the pilot flying lost the bubble and ended up holding in aft stick where it wasn't needed.

In both of these accidents, they started with a roll PIO which is an extremely concerning situation to the pilot. I cannot state that I know a reason that this would cause a pilot to pull full back stick, but we now have two Airbus instances of unexplained inappropriate aft stick plus the Colgan accident.

It could be something as simple as an inadvertent reaction by a pilot who's scan has broken completely and who is trying to hold his posterior in the seat in a manner to which he is accustomed.

Somebody had better be doing some basic research PDQ on human response to better understand the reasons for this "Pull the Stick" phenomena. Then we can actually fix the problem.

I have no gripe with Airbus Normal Law. What I have real problems with is the transition to Roll Direct as part of Alternate Law.

Letting an unsuspecting pilot start flying in Alternate law with Roll Direct before he understands fully the implications of that configuration, is asking for trouble. If a pilot is startled into making a large initial correction or if he naturally pilots with large stick motions, he is very likely to set up a roll PIO. Roll Direct requires gentle control motions for success, particularly at cruise altitude where damping is low. Roll PIO destroys the trust that a pilot has in his flight control system and (empirically) can fully saturate a weak pilot's scan in seconds.

There is a lot that can be done to make the transition to Alternate Law easier. I would hope that Airbus will give that area some study.

[Machinbird]

It's called "normal human reaction". peekay4, reaction to what?
Break it down to its elements.
What is the pilot reacting to that causes the "pull back" reflex?

[peekay4]

In normal flight, pull back stick == plane climbs up.

When plane plunges down, instinctive reaction == pull back stick (to make plane go back up).

All pilots do this almost sub-consciously. Feel plane sink a little? Pull back the stick a little to compensate. In 99.99999% of the cases this works out for the pilot, i.e., in normal flight with sufficient power and nominal AoA. (And especially with a working autothrottle).

Of course we all "know" that this "doesn't work" during a stall -- or even near a stall (area of reverse command).

Thus the problem with surprise stalls is that the pilot must overcome his/her instinctive reaction (which until this point has worked 100% of the time) and do the complete opposite: push the stick down when the plane is already going down.

To summarize:


Pushing the stick down is an "intellectual" reaction. It requires knowledge that the plane is in a stall, and recall of the correct stall recovery procedure.
Pulling the stick back is a "instinctive" reaction. It is based on "muscle memory" from thousands of hours of normal operations.


There is a human-factor safety theory that says that if you have to "remember" to do something different (opposite) during an emergency vs. normal ops, then you will always have a high risk of failures.

Training does help, but only to a certain extent. Training happens at most a few times a year. Yet pilots "pull the stick back to climb" on every single flight. That's "training" as well (from a neuroscience perspective).

I'm sure every single pilot familiar with AF447 and QZ8501 has concluded that "this can NEVER happen to me!" but the truth is, when you are startled and confused, it's hard to fight instinct.

Imagine it's year 2100. AirBoeingBus 78320-ER somehow gets into a stall and starts losing altitude. The Pilot, last of her kind, pulls back the stick, to go back up. Autopilot-G (for George) recognizes the stall, automatically lowers the nose to reduce AoA, recovers from the stall, and then pitches up until the plane climbs -- as commanded. In this case, the pilot does nothing different between normal and stall condition. From a pure human-factors perspective, this is the preferable system behavior.

Edit: to add, even in the non-stall case, when a plane is rolled with nose down attitude, the instinctive (and incorrect) upset recovery action is for the pilot to simultaneously apply opposite roll and pull back on the stick. This is in part why UPRT training is being mandated.

[RAT 5]

From Gums:... but I am not convinced many of the nuggets have their basic skills burned-in by hours of practice and exposure to the dark side of things in their planes.
The practice of "engage otto" at 300 feet with gear up and the reverse when landing bugs me beyond anything. I don't feel all should be Chuck Yeager, but if we can't fly the profile without using otto, then we should not be flying at all. But I never flew a profile that I had to use otto versus my own skills/eperience, and remember that otto has ZERO experience.

I find it amusing that many interviews still include a sim check where it is common to fly a basic IR profile without FD or A/T. Then, in that same airline you are, near as damn it, forbidden do such such a dangerous thing again. Same goes for base training: a manually flown circuit with only Mk1 eyeball guidance, but don't let them catch you doing such a heinous thing on line. If you can't fly a procedural ILS raw data, including a hold and reversal turn to finals ILS and GA, you should not be there. Computers fail and must be able to maintain SA and cope with achieving a safe arrival.

Peekay4: some interesting observations and comments about human reactions. It is an old chestnut that to fly an a/c you "push on stick = houses get bigger: pull back on stick = houses get smaller: keep pulling back = houses get bigger again."
We all know that, but you went on to say that to do the opposite of what is instinctive you need to know e.g. you are in a stall. There has been much discussion about this on this thread and Tech Log (FD in a stall) thread. Is the stall warning on AB, or any a/c, sufficient to make your training kick in and combat the panic? I know nothing of AB warnings, but the Boeing Stick Shaker is unmissable.
In old tech a/c, at a stall there was often a stick shaker and a pusher/nudger. If you/A.P hadn't trimmed too much you could even just let go and the a/c would possibly lower the nose slightly by itself. What happens with FBW at the stall if you let go? Does it hold the attitude à la CWS?
From the human factors point of view what I think needs considering: in AF & QZ they had an enormous amount of air beneath them; perhaps time to let go and start analysing, but they didn't. (in my world of paragliders it is often the pilot, in a panic, who makes UAR worse. Often letting go allows the aerodynamics to start the recovery process.) In 'close to the ground stalls' the training has a much greater difficulty combating the panic of rapidly rising ground. Similarly it would be difficult, without extreme training and practice, to know when in a car incident it is better to use power rather than brakes.
However, one would hope, that an unmissable STALL visual AND audible warning + stick shaker (tactile) would not be ignored and training would kick in. That training involves use of stick, thrust levers, attention to instruments. We know that under stress your ears shut down, hence the addition of a powerful visual warning. Designers could also include that the a/c will attempt to recover if you just let go.
Those with more knowledge of current FBW actions and future designs could share it with us.

[alf5071h]

… ‘zero experience autopilots’.
One view of the problems being discussed is that the level of human experience is decreasing and the opportunities for gaining experience have significantly reduced.
Many accidents suggest ‘zero experience pilots’ in the specific conditions.
More manual flight might aid the physical skills, but without encountering demanding, rare situations, little or no cognitive experience is gained – that which helps understand a situation before acting.
A more beneficial approach to safety might be to consider the precursor situations to ‘those which have never been experienced’, where appropriate awareness and action might avoid the upsets.
Are the recent accidents also an indication that pilots’ experience levels of the precursor situations are also weak?


“What is the pilot reacting to that causes the "pull back" reflex?”
‘It’ would be based on whatever the pilot perceives, which with the experiences from memory, provide an awareness of the situation. Thus the actions would be ‘normal’ for what was perceived – doing what is always done or what is believed to be required in a situation which has never been encountered before

Many people present arguments for changing 'the aircraft', but these are based on probable and inconclusive evidence; the result is a weak argument particularly as it is impossible to determine what the pilots perceived.
The alternative argument – no change – based on what happens in every day operations, might be similarly hampered by not knowing. However, it is strengthened by the overwhelming numerical success of safe operation and some ability to enquire what pilots perceive. This should not be seen as a winning argument – complacency, but an opportunity to consider what is not known in both normal and accident scenarios.

We should not conclude that if every flight ends safely we are safe, but equally we should not label all accidents as being ‘unsafe’ because of … , because we just don’t know.
‘Unsafe’ is our judgement of the outcome; for the accident crews it’s quite possible that they believed what they were doing was ‘safe’, but … we don’t know.
The various arguments are presented on the basis of not knowing which is immensely frustrating both for debaters and audience.

[FDMII]

RAT 5;
Link: http://www.pprune.org/rumours-news/553569-air-asia-indonesia-lost-contact-surabaya-singapore-193.html#post9216057 "Those with more knowledge of current FBW actions and future designs could share it with us." It would take the knowledge of an aerodynamicist who knows C* laws to discuss the "letting go" scenario.

My thoughts as a former transport pilot are that in a fully-developed stall, (35°+ AoA, vertical speed > 10,000fpm), just releasing the controls to neutral would not recover the aircraft, FBW or no.

Bear in mind that all aircraft would have different responses; whether such differences make a difference in handling during a full-stall is one of many unanswered questions.

A full nose-down stick command, wings level, thrust at idle is almost certainly a recover strategy, but no one's done it in flight tests and the sim data, post-stall, is extrapolation from best-knowledge as there is no basis in testing - yet.

The flight control computers for the Airbus attempt to maintain 1g, (Nz, in relation to the longitudinal axis in Normal and Alternate I Laws) and the trim horizontal stabilizer, (THS) autotrim function attempts to unload the elevator, but the follow-up is not instantaneous.

In AF447, the THS was driven full NU and remained there because of full-up stick inputs. If the stick had been placed full-forward, the THS would follow-up and return close to a neutral setting.

From discussions with others here and elsewhere, it is likely the elevator retained sufficient effectiveness to get the nose down, unload the wing and recover.

[galaxy flyer]

Peekay,

The absolute last thought I'd have with a stall warning is to pull back! Unload the wing FIRST. This is pretty basic flying. Also, basic training is not panicking.

Then again, I have a couple of thousand hours of fast jet time.

GF

[Machinbird]

In normal flight, pull back stick == plane climbs up.Peekay, If we have pilots flying who when stressed, revert to that simplistic mode of thinking, then we have unqualified pilots flying aircraft! Period.

I graduated from the USN fast jet school of training where I learned to overcome the sensation of sitting in a waste basket while I flew instruments and to fly intellectually-because your physical sensations were not to be trusted. Later, as an instructor, I would have washed out any pilot that could not measure up to this basic standard. (They would only have gone on to kill themselves and others.)

If we cannot properly qualify pilots to actually take direct control of an aircraft, then we had darned well better not be putting those guys occupying the seats with the best view into that position. The airframe folks are going to have to ensure that their aircraft never gives up to the point where it has to pass highly degraded control to the "pilots". There is a body of evidence building to suggest that an improper transition to Airbus Alternate Law-Roll Direct can become a highly degraded condition. Do we need more accidents to prove the thesis?

[FDMII]

Do we need more accidents to prove the thesis? The thesis requires proving, not that way of course but through the usual examination, data, studies then statements, etc., and, as part of the process, needs challenging by those who have the knowledge and experience to contribute to the thesis.

At present there is almost no research available regarding human factors and the actual transition from 'normal', (which is a protected airplane), to Alternate I/II, and possibly to Direct Law depending upon system losses, (a conventional airplane in theory and, I have discovered, in practise).

Such absence in and of itself may speak to the question - it doesn't appear to constitute a primary problem, particularly for those experienced in manual flight. I've flown the aircraft at cruise altitudes many times - the A320, A330 & A340 fly just like any other transport, and as you'd know, you must absolutely be gentle with the controls.

However, inexperience, need-to-know knowledge levels, and low or absence of exposure (the case in both these accidents) to abnormal attitudes does not leave much 'resourcefulness-in-reserve' when faced with such circumstances, especially for those entering the profession now. I think there may be something to the apparent sensitivity of the controls which speaks to training issues regarding handling the stick.

Nor is there anything informal regarding the transition. Those who have trained-on / flown the Airbus do not seem to find the transition (from Normal to Alternate I/II / Direct) problematic, nor are two samples in millions of flights, statistically significant.

I think what alf5071h has to say under "zero-experience autopilots", above, would be a more rewarding area of examination.

[RAT 5]

I graduated from the USN fast jet school of training where I learned to overcome the sensation of sitting in a waste basket while I flew instruments and to fly intellectually-because your physical sensations were not to be trusted

Did you earn to fly limited panel IMC? Do students still at CPL still learn that skill? It certainly gave one an appreciation of what was going on and how to control it. It also taught you not to panic when you lost what had previously been perceived as a vital parameter. You calmly used other information to maintain control. If it has been removed from basic flying school IMC training then IMHO it should be re-introduced.
Has anyone attempted this in a modern jet? The worst I was ever given in recent recurrency was an FMC failure or flight on SBY (EFIS) display. Neither a big deal. An ILS with total unreliable airspeed is a good one, but rarely trained. As a trainer my dictated syllabus was very basic when displaying unreliable airspeed scenarios. A nice tick in the box for 3.4 system failures, but as a training exercise to 'save the day' when it happened for real, not so useful.
One of the best I had in a B757 sim was to fly an ILS on full old fashioned SBY displays. It became even better when the RMI went awol and we had to use the old fashioned compass. Again no big deal if you used the basics.

The absolute last thought I'd have with a stall warning is to pull back! Unload the wing FIRST. This is pretty basic flying.

I have to confess that when teaching stick shaker stall recovery I questioned the FCTM. It said "apply power & reduce attitude." It didn't say anything about minimum height loss. That was an exercise 'if ground contact was a factor'. I stressed to reverse the wording might be better, especially in underslung engines, to 'reduce attitude and increase thrust.' Split second, even both at the same time, but elevator leads the way. To me aerodynamics had not changed so why pretend it had. Beforehand I saw guys apply the thrust and then go closer to a full stall than they were. i.e. they made it worse before they made it better. After THY at AMS guess what happened. Aerodynamics and common sense won the day and FCTM was changed to UNSTALL the wing first.

One view of the problems being discussed is that the level of human experience is decreasing and the opportunities for gaining experience have significantly reduced.

Great comment, and then ask why & how? Let's get to the root cause of this demise and start to solve the problem there, not massage it and put a few sticking plasters on a gaping wound. It may need an operation or stitches, but there needs to be a serious reasoned debate from all parties. There appears to be a lack of leadership on that. Many interested parties are spouting words of wisdom, and some even showing disinterest. Will it be EASA, an XAA, ECA, IALPA, Boeing, AB, a government, an airline group, anybody, but it needs somebody to lead. There is a real problem and we are perhaps seeing the tip of an iceberg. A/C will evolve into more computerised sophisticated beasts; MPL cadets will be less experienced and thrust into RHS of said jets; companies will expand and give commands with less experience to meet that expansion; cadets will pay for their training and grab any job with any T's & C's they can find; rigid SOP's will evolve to reduce piloting skills. So how can the industry protect itself from a declining spiral of skills that could hurt it? We already know that there are airlines from certain regions that certain pax avoid due to suspicion of standards. We want to reverse that trend not allow it expand.

[Machinbird]

I graduated from the USN fast jet school of training where I learned to overcome the sensation of sitting in a waste basket while I flew instruments and to fly intellectually-because your physical sensations were not to be trusted Did you earn to fly limited panel IMC?
One of my instrument instructor's favorite tricks was to tell you to look down at your lap while he roughly maneuvered the aircraft, freezing the attitude indicator in a near upright position, then rolling nose high or nose low inverted and saying, "You have the aircraft." We did not have a standby attitude indicator. We had to recover to level flight by needle-ball-altimeter-airspeed techniques. It was an immense confidence builder.:ok:

[wanabee777]

One of the instruments I missed the most on the triple 7 was the ball sideslip indicator.

[F-16GUY]

The practice of "engage otto" at 300 feet with gear up and the reverse when landing bugs me beyond anything. I don't feel all should be Chuck Yeager, but if we can't fly the profile without using otto, then we should not be flying at all. I used and expounded otto for a few thousand hours in single-seaters to reduce workload when wx or other problems arose. But I never flew a profile that I had to use otto versus my own skills/eperience, and remember that otto has ZERO experience.


Gums has it right. When are the beancounters gonna wake up and figure out that the fuel savings from flying otto all day long, are gonna bite you the day otto decides to quit?

And that is the route cause of those disasters. It does not matter if your flying a Boeing with jokes that move in unison or an Airbus with sidesticks. What you practice is what you get good at, and if you never practice manual flying skills (by that I mean Stick (yoke), rudder and throttle, and not just dialing a heading and VVI rate on the panel upfront while using auto-throttle), you are gonna suck at it the one time you really need it.

Practice as you fly - fly as you practice, and not only once a year in the sim.

[Machinbird]

Nor is there anything informal regarding the transition [to Alternate Law-Roll Direct] Those who have trained-on / flown the Airbus do not seem to find the transition (from Normal to Alternate I/II / Direct) problematic, nor are two samples in millions of flights, statistically significant.

First let me make clear that Alternate Law-Roll Direct is a specific type of Alternate Law where pitch is a C* law with reduced or no protections and roll is a direct law where aileron deflection is proportional to stick deflection.

As long as one knows he is dealing with Alternate Law and approaches with careful control inputs, I have no doubt that control is like any other aircraft.

Now take that same alternate law aircraft and start with near full deflection roll inputs in cruise and tell me what happens. That is what happened with AF447 and QZ8501. In both cases, it not clear that either PF knew from the outset he was in Alternate Law. That is a setup for roll PIO. Do you understand the hazard that roll PIO presents?

[wiggy]

First let me make clear that Alternate Law-Roll Direct is a specific type of Alternate Law where pitch is a C* law with reduced or no protections and roll is a direct law where aileron deflection is proportional to stick deflection.

As long as one knows he is dealing with Alternate Law and approaches with careful control inputs, I have no doubt that control is like any other aircraft.



machinbird, I'm sure you are right but boy are we or Airbus insisting on making things difficult or at the very least overly technical.....

Back in the day ( a long time back) I got a Physics degree with a handful of Fortran 4 thrown in. .......yet when I moved on to greater things and learnt to fly I never ever recall my QFI's mentioning C laws , algorithms and the like.....just that regardless of what you're in at high level it's an aircraft so be gentle with ( then again my basic was on jet provost and hawk with a suitable system of levers, etc). Now I thought the idea was that even on a bad day a 'bus or even 777/787 should not be any more difficult to handle than a 70's steam driven type. . Make it any more difficult than that and on a bad night you're going to loose people ...did I miss something,?

[peekay4]

The absolute last thought I'd have with a stall warning is to pull back! Unload the wing FIRST. This is pretty basic flying. Also, basic training is not panicking.

Then again, I have a couple of thousand hours of fast jet time.

Peekay, If we have pilots flying who when stressed, revert to that simplistic mode of thinking, then we have unqualified pilots flying aircraft! Period.

It's not easy (but possible) to beat thousands of years of evolution wiring certain behaviors into our brains.

Each of us like to think that we are above average and will not make the same mistakes, but in reality few of us have experienced real-life startle + upset + disorientation situations, outside of training environments.

Being a basic human reaction, this "hold the stick back until crash" phenomenon is not limited to the civilian world, but affect highly-trained military pilots as well.

E.g., the C-17 Globemaster crash at Elmendorf in 2010 during practice for an airshow. The commander-pilot, contrary to SOP, aggressively maneuvered the C-17 in a low-energy state and subsequently entered an accelerated stall.

With the stall warning blaring, the Angle of Attack Limiter System (ALS) activated. During the stall, the co-pilot and an onboard Safety Officer warned the pilot four separate times. The stick shaker was also activated.

The pilot attempted stall recovery by rolling the plane level and holding aft stick pressure. (Sound familiar?)

Aft stick pressure was maintained throughout the stall until the C-17 struck the ground, fully 12 seconds since the stall warning + stick-shaker activated.

Even without the startle factor (or even a stall), experienced pilots have failed to recover from spatial disorientation, and even when they recognize the condition.

A recent example is the fatal USAF F-16CM crash into the Adriatic sea two years ago.

During a night training mission out of Aviano, wearing NVG, the F-16 pilot became disorientated at over 20,000ft (which was plenty for recovery). He was confused and did not apply any control input for 8 seconds. By that time the F-16 was in a high speed dive.

The pilot attempted to level the wings but ended up inverted. He then rolled right-side up, and pulled the nose towards the horizon to successfully recover.

With the F-16 no longer in danger of crashing, the pilot -- still spatially disoriented -- decided to eject at 7,000ft and nearly 600 kts, and was killed instantly.

This pilot was rated top 10% of his squadron officers, had received many commendations and had well over 2,000 fast jet hrs including over 400 combat hours. He was just selected to be a Flight Commander and slated to receive promotion to Major.

Yet he decided to eject out of a perfectly flyable plane at Mach 0.96, with lots of altitude to spare and in no danger of crashing.

It's a reminder that no matter how well trained a pilot may be, when he/she is spatially disoriented (as the AirAsia FO apparently was), anything can happen.

[Machinbird]

Back in the day ( a long time back) I got a Physics degree with a handful of Fortran 4 thrown in. .......yet when I moved on to greater things and learnt to fly I never ever recall my QFI's mentioning C laws , algorithms and the like.
Wiggy, funny you should mention the Physics and the Fortran 4. I did the same thing, except being older, I did the Physics first and went back for the Fortran 4 ten years later. Anyhow, are you going to tell me it will blow your mind to tell you that your Boeings are now C*U aircraft. :}

on a bad day a 'bus or even 777/787 should not be any more difficult to handle than a 70's steam driven type. . Make it any more difficult than that and on a bad night you're going to loose people ...did I miss something,? No, you did just fine.:ok:

[Machinbird]

It's a reminder that no matter how well trained a pilot may be, when he/she is spatially disoriented (as the AirAsia FO apparently was), anything can happen.So what disoriented the AirAsia FO? It appears to have been the high roll rates he encountered and the unnoticed entry into the initial bank. If those had not happened and he had started flying using the controls gently, then in all likelihood, nothing untoward would have happened. Those are all things that can be fixed in the transition to Alternate Law.

[wanabee777]

"I’ve sampled the capabilities of BAE’s active side sticks in Gulfstream’s G500 engineering mockup in Savannah. I’m sold. If it were up to me, I’d mandate that all new FBW airplanes with side sticks be upgraded to active inceptors as a condition of type certification."


Fred George, Aviation Week senior editor for business and commercial aviation.

[ExV238]

Machinbird,

Now take that same alternate law aircraft and start with near full deflection roll inputs in cruise and tell me what happens. That is what happened with AF447 and QZ8501. In both cases, it not clear that either PF knew from the outset he was in Alternate Law. That is a setup for roll PIO. Do you understand the hazard that roll PIO presents?

With great respect, have you flown an Airbus in Alternate Law? At high altitude?

The transition is seamless, and roll control is not so different to Normal Law. with regard to your first sentence above, I wonder how many pilots have actually manoeuvred their aircraft in Normal Law at cruise alts? Not many, I bet. And even fewer would have used full deflection roll inputs under those conditions, which gives 15 degrees per second in Normal Law in the Airbus. I believe that the issue is general unfamiliarity with high altitude/high Mach manual flying and reations to upsets than it is about 'degraded' flight controls.

You have it right when you suggest that pilots should be cautious with control inputs in Alternate Law at high altitude, but so they should even in Normal Law. The aircraft will ultimately protect you, but shouldn't be asked to!

Finally, do you actually mean PIO, which has a very specific meaning? I don't believe that either of the accidents in question showed signs of PIO. Maybe some over-controlling in the case of AirAsia.

[RAT 5]

All this talk about various Laws gives me a headache, because I'm a Boeing oldie. What do other FBW a/c have? e.g. B777 and even military a/c. Is this the common FBW family of in-laws & out-laws or just an AB thing?
What is certain is FBW is here to stay and will most likely become the standard control system in future a/c. Should there not be a common specification for all the 'laws' and how they do things? With FBW & EFIS & EICAS and and .......etc.. in mind I suggest there should be a total review/overhaul of how the pilots for these new a/c are trained. I also suggest that every operator follows the same syllabus designed but the manufacturer, who, after lengthy discussions with the authorities have an approved course. (designers are not always the best at deciding how an a/c should be 'operated' on a line basis. They know how to fly it.) This would emphasise how the a/c was designed to be flown, operated basically, and would then go into all the non-normals and especially all the traps that can catch you out. THEN, and only then would company SOP's be introduced. I've had to teach a real variety of TR syllabi on same/similar Boeing a/c. It is astonishing how some people try to reinvent the wheel and emphasise the SOP over how the a/c was designed to fly/be operated, and how different those SOP's can be to achieve the same task.
Redesigning the basic CPL might be more difficult. At that stage you don't know where or what the pilot us going to fly. They could be single crew air taxi guys, biz-jet pilots or airliners. Each has their own skills. It is easier to oversee airlines with their in-house training depts; less so with the fringe operators. It is not a one size fits all answer; not after the basic PPL and early CPL training.

[gums]

With all respect ExV:

The transition is seamless, and roll control is not so different to Normal Law.

What if otto ( read A/P) had cranked in aileron or rudder trim before it disconnected? With direct control of the ailerons/spoilers, looks like even small stick displacement can result in fairly high roll rates. I could not see the report's graphics clearly, but maybe some have or can.

We saw the system crank in THS trim in AF447, and that was in an alternate law. So one thing to emphasize is the need to manually trim if not in NORMAL, ya think? Also, the difference in control surface displacement required at 300 knots is prolly vastly different that with gear down and flaps extended, huh?

So I would guess a perfectly normal system with a perfectly rigged jet would move to ALTERNATE with no seat of the pants cues and we could go from there 'cause the warning light and tones would advise us to be gentle.

However, that's not what happened in either crash.

Secondly, 'bird means real PIO - pilot-induced-oscillation. He and I and many here have seen it, and not just those who flew lites. The AF FDR traces show a "twitchy" jet and many of us felt the PF was so concerned with roll that much of the initial aft stick was unintended. Problem was holding it back once roll was under control. I was impressed by the PF in the other crash for getting wings back to level, but the troop made same mistake as AF troop.

@RAT

You prolly had more "laws" than you realized in the 777. Even in the older planes there were reversion "laws" for yaw and pitch dampers, aileron-rudder-interconnect and such. Even 707 and its heirs depended on a good yaw damper, and we lost a KC-135 due to dutch roll when its damper went AWOL.

In the Viper we did not use the term "laws". As with the 'bus we had fixed gains if we lost air data - STBY GAINS lite came on and we had gains for about 300 knots and another set for gear down and maybe 150 knots or so, I can't nail it down. We also had our leading edge flaps "lock" if we had to use alternate flaps or we turned the suckers off, as I did when one of mine failed and folded up ( see my interview)

All of us knew the "real" laws, but called them limiters, and we did not have a plethora of backups, being a simple system and requiring a vastly expanded maneuver envelope.

In any case, RAT, I feel your pain, heh heh.
.

[ZeBedie]

Basic flying training:

Push=Down, Pull=Up.

But this is a stall - Pull = Down even faster, Push = Survival.

The second piece of information is to be put aside and not to be used at any time, until one dark and dirty night in ten years time, when something awful is happening and you're already disorientated...

[RAT 5]

The second piece of information is to be put aside and not to be used at any time, until one dark and dirty night in ten years time, when something awful is happening and you're already disorientated...

Zebedie: spot on. What has been asked; and will someone please explain unequivocally for us non-AB guys, is what warnings does the AB, and other FBW a/c give you? In an old stick shaker a/c it can not be missed. It is audible & tactile. One hopes it would break through any level of panic you had and training would kick in. That, in part, is the philosophy of repetitive training. It can become an automatic response when all else fails. So, does the AB stall warning achieve this? Some spoke of a visual unmissable flashing red light. I wonder. We know that stress cancels out the ears first, and can be eyes 2nd. I'v seen guys in B737 sims fly around with the yellow MC attention getter burning holes in their foreheads for minutes endnote re-set it. They cancelled it out. Same for the flashing red A/T disconnect light. After 15 secs or so they filtered it out. I can imagine that, when is deep horrific WTF is happening scenario the audible "STALL STALL" is filtered out as you stir the pot. The visual flashing red light shortly afterwards, but would anyone mistake the muscle shuddering stick shaker? Would you really be able to filter out all there training and keep pulling?
Do FBW, side sticks or yokes, have stick shakers?

[joema]

One of my instrument instructor's favorite tricks was to tell you to look down at your lap while he roughly maneuvered the aircraft, freezing the attitude indicator in a near upright position, then rolling nose high or nose low inverted and saying, "You have the aircraft." We did not have a standby attitude indicator. We had to recover to level flight by needle-ball-altimeter-airspeed techniques.

Interesting, yet isn't it true in both AF447 and AirAsia cases the EADI horizon on the PFD was fully functional throughout each event? I just re-read both reports and I don't see any indication they were malfunctioning.

If so it wasn't a case of the pilots having to decode the attitude from other instruments. Rather the EADI was accurately showing pitch attitude.

How could the EADI show a big blue sky, extreme pitch angles, yet either PF or PNF be confused about why the aircraft was buffeting and acting funny? Even the original Sperry artificial horizon from 1929 was painted blue and black to immediately convey an instinctive grasp of aircraft attitude.

There is a picture of the 1929 Sperry horizon here, and some discussion of how pilots can nonetheless get spatially confused even with newer designs. However most of these involve a tumbling horizon:

THE SOLUTION (http://pdp-technologies.com/solution.htm)

Has there been any discussion or human factors research on why the AF447 and AirAsia pilots did not take action based on the indicated EADI pitch attitude?

[ZeBedie]

Do FBW, side sticks or yokes, have stick shakers?

Airbus ones don't. I agree that a tactile stick shaker is a far better warning than an audio "STALL-STALL", which will be be filtered out by an overloaded brain.

joema - I thought the same thing - if you'd just zoom climbed into a stall, you ought to know you're stalled because you more or less deliberately stalled it yourself!

[Uplinker]

Has there been any discussion or human factors research on why the AF447 and AirAsia pilots did not take action based on the indicated EADI pitch attitude?

It seems to me that the PF of AF 447 and the Colgan crash thought that to avoid a stall, one should pull up ???!!!!! What the hell had their TRIs and training managers been teaching them?



On Airbus sidesticks, there is a small oval panel at the top secured by two screws. It appears to have no function, except as a place to rest one's thumb.

It seems to me that this panel could be replaced by a vibrating element, like that found in mobile phone batteries - to give tactile feedback to a pilot that his plane is stalling. The logic to identify the stall already exists - to give the "stall stall" warning, so one only needs to use that to energise a vibrating element in the side stick to create a haptic attention getter - like that of a stick shaker.

[Machinbird]

With great respect, have you flown an Airbus in Alternate Law? At high altitude?

The transition is seamless, and roll control is not so different to Normal Law. with regard to your first sentence above, I wonder how many pilots have actually manoeuvred their aircraft in Normal Law at cruise alts? Not many, I bet. And even fewer would have used full deflection roll inputs under those conditions, which gives 15 degrees per second in Normal Law in the Airbus. I believe that the issue is general unfamiliarity with high altitude/high Mach manual flying and reations to upsets than it is about 'degraded' flight controls.
ExV238, I'm just one of the guys, and I don't take offense easily so do not worry about an adverse reaction. Just speak your piece and don't hold back.

First, to be absolutely clear, I am a tactical jet pilot by experience and at heart. The closest I came to multi-pilot transport operations was flying the Navy C-1A transport on logistic runs and cross countries at a couple of duty stations. But before you think, "just another keyboard commando," you might wish to take into account my experiences and historical perspective on aviation.

Unlike most of those here who are flying the line, I have had some experience with roll PIO and those few seconds of PIO were so gut-wrenching that I remember them clearly to this day. This was in a visual simulator no less! Can you perhaps imagine the sensation of the poor souls flying AF447/QZ8501 who understood that "This is for real and it is all on me to save the day?"

. One of the things about AF447 that stands out was the initial roll oscillation that lasted for 30 seconds or so. Everyone looking at the data was saying it wasn't that bad of an oscillation and he got it under control in 30 seconds. But if your were looking at the data from the inside view, I could see clear signs that the pilot had to develop a strategy to attempt to control the roll oscillation and that this strategy had actually prolonged the oscillation. (He was attempting to get ahead of the oscillation by accelerating his roll inputs.)
This fits the definition of a PIO. If it had not been a PIO, he should have been able to stop the oscillation immediately.

On QZ8501, the aircraft got to 54 degrees bank angle before the roll correction was applied. In addition, the FAC system is responsible for re-configuring the PFD airspeed display for Alternate Law but the FACs were disabled. I expect the only place he might have quickly seen that he was in Alternate Law was on the ECAM display.

A strong roll input was applied and the aircraft reached 6 degrees of bank in less than 2 seconds before it reversed and reached almost the same initial bank. FCOM states that in roll direct in a clean configuration, the maximum roll rate is about 30 degrees per second. When you consider that the roll rate had to be decelerated to reverse, it is clear that peak roll rates were easily in the maximum range. In hands of an inexperienced pilot in cruise flight, this type behavior should be looked at as roll PIO until proven otherwise.

With regard to the concept of a seamless transition from Normal to Alternate, think back to your initial training on Alternate Law. Weren't you first briefed on it and told to be gentle with the controls? Then you had a clear transition to Alternate Law, and after about 15 seconds, you had the feel for it and afterwards it was no big deal. Contrast that introduction with what the pilots flying AF447 and QZ8501 received. No warning, no briefing, no previous experience, a confusing transition to Alternate Law with other factors in play, and then a hurry up and try to catch up with an aircraft that is rolling. No wonder they over-controlled.!

Now for the Boeing guys here, this is primarily an Airbus training and probably a design problem as well. Something that Airbus would rather not be addressing under time constraints. But don't let your guard down. I can post a video of a triple 7 doing a roll PIO on short final and into the touchdown if you need motivation.:}

Gums, thank you for your recent input.

The gents suggesting a stick shaker for the Airbus have it right. The sooner the better.

But there is a lot that can be done to make the transition to Alternate Law uneventful. :8

[CONSO]

uplinker said On Airbus sidesticks, there is a small oval panel at the top secured by two screws. It appears to have no function, except as a place to rest one's thumb.

It seems to me that this panel could be replaced by a vibrating element, like that found in mobile phone batteries - to give tactile feedback to a pilot that his plane is stalling. The logic to identify the stall already exists - to give the "stall stall" warning, so one only needs to use that to energise a vibrating element in the side stick to create a haptic attention getter - like that of a stick shaker.

From this mere SLF- what a great idea. :ok::ok: Why doesn't everyone join in and send letter or petition to Airbus re this elegant solution- perhaps it could be patented. I use the vibrate on my cell phone in my pocket and it does get my attention. IMHO a heavy duty version set at a freq which would NOT interfere with electronics tied to stick, etc would be ' relatively' simple to check and perhaps incorporate or retrofit.

But it wont happen until enough pros jump up and down and SHAKE THE BCRATS INTO ACTION :ok::ok::ok:

[EMIT]

An MD82 stalled at high altitude over Venezuela and with stick shaker rattling all the way, the interconnected yoke was pulled fully back until the ground was hit.

A Q400 near Buffalo indicated an imminent stall by shaking the interconnected yoke and the startle reaction was a pull that did induce the stall, which led to a wing flip from which recovery was not anymore accomplished.

An MD83 stalled over Mali, flipped over its left wing and with stick shaker rattling all the way, the interconnected yoke was pulled fully back with full right aileron all the way until the Sahara was hit.

Yeah, surely, interconnecting side sticks and providing stick shakers or haptic buzzers on them is gonna save Airbusses from pilots stalling them.

[EternalNY1]

Serious question here ... with all the automation, couldn't the system be designed so that it rolls wings level at an appropriate pitch + power setting?

If I was flying AF447 or any of these other flights with odd indications, I'd level myself and set the power manually to approximately where it "should" be, bypassing the autopilot.

I am beyond confused on why other pilots are pulling BACK on the stick when they are getting a stall warning. If stall warning, overspeed, anything ... level the plane and set an appropriate power setting. Then you at least know the alarms are incorrect and can go from there. No?

[Machinbird]

DREAM ON
An MD82 stalled at high altitude over Venezuela and with stick shaker rattling all the way, the interconnected yoke was pulled fully back until the ground was hit..........................
Yeah, surely, interconnecting side sticks and providing stick shakers or haptic buzzers on them is gonna save Airbusses from pilots stalling them. EMIT,
This old Phantom Phlyer used his rudder shaker to good advantage in the busy traffic pattern around his aircraft carrier. It was one of two signals telling him to add power after pulling power to dirty up in the break over the ship. (The other signal was the GIB with his sarcastic, "Don't you think you need to power up?") Haptic signals like that rudder shaker are good triggers for a properly trained conditioned response. The real problem is that we have a lot of poorly trained pilots out there, and some of them have a lot of flight time. How to fix that training problem is going to take a big investment and a lot of study. In the meantime, the best we can do will be to avoid rattling their heads too badly.

I can tell you that I am here, still making trouble, because when the chips were down, I did not snatch the stick back as the ground was rushing up. It is all in the training. Flying properly is an intellectual enterprise, not a rote response task. The thinking, calculating mind must be in control.

[Olive61]

The appropriate pitch and power for just about any modern aircraft at cruise altitudes, and not stalled, is a Body Angle of approx +2.5 deg and 80% N1. This will stabilize the aircraft safely and allow troubleshooting/descent to follow. Stabilized descent will be achieved with Body Angle Zero and Thrust Idle. The problem is - many pilots don't have this fundamental knowledge, and many airlines do not require their pilots to regularly practice loss of air data/loss of airspeed at altitude. If a stall is imminent at cruise altitude the manufacturers immediate recovery actions are required - the first of which is always immediate and significant reduction of Body Angle (A of A). Excessive A of A is the ONLY reason that a wing will suffer aerodynamic stall.There are numerous cyclic training programs out there with numerous carriers. The unfortunate truth is that some of them are simply bogus box ticking exercises, and we will continue to have hull losses of the kind recently experienced until professional training to professional standards becomes universal.

[PrivtPilotRadarTech]

I think more and better training is a great idea, I'm totally in favor, but automation is only going one way: more. These accidents are unacceptable. The aircraft is telling the "pilots" it is stalled, but they are ignoring the warning. One of the sim videos posted has the AirBus softly bleating "Stall. Stall." How about "Stall. Stall. Stall m-----------r! What part of "STALL" is it you don't understand? Push the friggin' nose down or DIE!" If that doesn't work, the computer should say "My aircraft." And take control, wings level, AOA and thrust to a standard level.

Same with CFIT. With a GPS, digital terrain map, and computer calculating close rate there is no reason that should ever happen again. Hal should say "Sorry Dave, I can't let you fly this aircraft into the ground. My aircraft."

[ve7pnl]

Reminds me of a talking depth sounder I designed many years ago for fishermen in the shallow regions of the Bering Sea. It would call out the depth on a speaker out on deck every 15 seconds - faster and with a tone when below the alarm depth.

An initial software error cause the voice to stutter on the first syllable of each depth call out when within the alarm range. That stutter got their attention!

Now, back to flying talk.

[CONSO]

Yeah, surely, interconnecting side sticks and providing stick shakers or haptic buzzers on them is gonna save Airbusses from pilots stalling them.

Lets ASSUME the combination of interconnect and sidesticks prevents ONE 100 plus passenger aircraft going splat in say 10 years.

Please compute the cost- benefit ratio OF NOT doing it and provide it to the few survivors or families of those who did not survive along with your message of condolence. :rolleyes:

Why would anyone NOT want to use or have available ALL three senses ( light- sound- physical ) when the fit hits the shan ?

Granted adding such is not a cure all- and never will be absolute, but it would add a few nines to the human error probibility equation.

[_Phoenix]

Maybe both, more situational awareness training combined with design improvements are needed. At high altitude, it is crucial to distinguish between overspeed and stall. For stall condition, how about to show on PFD Red/Brown colors (instead Blue/Brown). Separation line to be at FPV (flight path vector) location, the red above with big text STALL on it.
However, stall recognition is only half of the puzzle, the second one is THS position awareness.
Off the top of my head: West Caribbean 708, Air Algerie 5017, Birgenair 301, XL888, AF447, ROT381 have two things in common
- THS NU
- pilot error (stalled the airplane)

...and a good candidate for Guinness book :
https://www.youtube.com/watch?v=FJViilcDTyw
(sadly pilot error again)

[CONF iture]

If that doesn't work, the computer should say "My aircraft." And take control, wings level, AOA and thrust to a standard level.
Then what happen next time there is a false stall warning on take off due to a damaged AoA probe ...
More automation is certainly not the solution, I prefer your suggestion for more training.

Yeah, surely, interconnecting side sticks and providing stick shakers or haptic buzzers on them is gonna save Airbusses from pilots stalling them.
If both guys agree to pull the yokes or one guy is lost enough to let the other one to pull his yoke, there's not much we can do, but in both cases for AF and AIrAsia the PM had no idea what the PF was doing with his sidestick and knowing how that sidestick was commanded could have been a tremendous piece of information to help him to understand the situation.
Yokes or at least coupled sidekicks provide information that independent side sticks do not.

In AF447, the THS was driven full NU and remained there because of full-up stick inputs. If the stick had been placed full-forward, the THS would follow-up and return close to a neutral setting.
My question is why Airbus made an automatic operation on that THS to help the guys to set the airplane in a pronounced and comfortable stall ... ?

[IcePack]

Lorma
Did you notice in the Air France report the statement "we have no indications" I have wondered why more was not made of that statement. (Not disputing the report, but what was meant by that statement from the F/O)(so is the pfd blank in both these accidents? Or mentally blanked, funny on air Asia request of capt to 3)

[FDMII]

CONF iture, re the THS and connected sidesticks questions, I sense a hamster wheel on the horizon... These have all been done over and over again on the AF447 thread.

Machinbird, I do understand what you mean by PIO, thanks. I've seen a small version of it when hand "flying" the simulator at cruise altitudes in Alternate Law. Certainly, few if any would be able to fly the early transports without the yaw damper! In this, I believe you would be correct regarding PIO!

However, for experienced, well-trained pilots who are accustomed to manual flying transports at high altitudes, it is a non-event in Alternate Law, as I suspect the triple would be. The airplane, (Airbus, but other types are also sensitive), does rock a bit and settles down; there's no lag in flight control response - one freezes the stick, as per Davies' statements, instead of applying inputs and it stops; QED. I'm not military so I haven't experienced what you talk about but I'm very experienced in transports of all types including the narrow-body & widebody Airbus.

I find it difficult to accept that such oscillations in an of themselves, lead to a continued NU pitch command without asking further questions regarding experience, training, background and so on, and the counterexamples (that control columns don't make a difference) are abundant. I'm not saying it can't occur, but CC or SS, stick-shaker or no, the data shows that all types had the control CC or SS buried, NU. I don't think the solution lies in connected sticks or stick shakers so while I remain open to an extended study and the data in the thesis showing PIO as a signficant, primary factor for all crews and not just inexperienced pilots we'll have to agree to disagree.

[Clandestino]

First I would like to express my gratitude to all the usual sciolistic reaction eliciters, who unfazed by repeated warnings their pet theories suffer from disconnection from reality, keep on providing some comic relief in this sombre thread. Then there are some pretty well-meant suggestions that, alas, are founded in misunderstanding of aerodynamics, flight controls, airliner operation and aviation psychology. All in all, I'd estimate that less than third of the posts around here contain anything that can be useful in understanding the QZ8501 crash - which is pretty normal for PPRuNe.

Regarding the issue of FBW Airbi not having stickshaker, estimate whether the aeroplane possesses sufficient natural pre-stall buffet and therefore require artificial stall warning system is left to development and certification test pilot and is somewhat subjective, yet the tests on 330s and 340s in the wake of AF447 have shown them to shake wildly before stall and it can be also seen on recently posted A320 video. Anyway, fact that aeroplanes were stalled with shakers & pushers operating was repeatedly stated on this thread. On the subject of automatic stall recovery, CONFiture has rightly pointed out it could present danger in itself if warning is unwarranted and that's why stick pushers have to be overridable (read the HTBJ, folks). Even for human pilot, stall warning isn't call to push mindlessly but to gather one's wits, realize aircraft energy state and do appropriate actions - which more often than not will be (approach to) stall recovery. Two widebodies were lost to overreaction to false stall alarm but it is easy for Joe PPRuNer to gloss over them; TWA 843 (http://aviation-safety.net/database/record.php?id=19920730-0) resulted in no casualties while Kenya Airways 430 (http://aviation-safety.net/database/record.php?id=20000130-1) happened in Africa.

"Protections" are possible because the system is digital and as we all know, anything that can be imagined can also be done with digital signals.
True, up to a point. Hard protections were indeed made technically and commercially feasible by the introduction of digital FBW but soft envelope limiting, similar to ones on B777 and called "Flight Augmentation", was available on early Airbus widebodies and Fokkers 100. As none of these were selling exceptionally well, there was no commercial pressure to defame such a system as "unnatural", "taking control from pilot" and "potentially unsafe".

How many serviceable large jet a/c stalled & crashed before FBW, and how many since? Seemingly "classical" jets keep stalling & crashing even after FBW was introduced (Amsterdam, Comoros, Mali..) but the metric of how many is just plain wrong. Somewhat better would be how many per number of flights or how many per flight hour and with aviation expansion we have, statistical conclusion is overwhelmingly in favor of:

We are doing very good job of teaching pilots how not to stall the aeroplane.

IMHO, Peekay4 (thanks for the comments on Elmendorf catastrophe, I wasn't aware it was another stick-back-until-impact crash) and Unworry's nephew are on the right track. We are dealing here with pilots rejecting skills they were supposed to learn before first solo and some of them were extremely experienced so no amount of training or experience we provide today can change this. Of interest to me is dynamics of spatial disorientation in multicrew cockpits. We are not dealing with the amounts of G and angle rates of tactical jets so it's harder for us to get to get disoriented yet again facts of the accident fly in the face of the notion that if one pilot gets his vertical gyro between the ears toppled, the other will come to rescue. It seems almost as if disorientation is contagious. In most of the similar accidents so far, captain was PF so we could take some solace in notion it was about command authority gradient yet here very experienced captain failed to perform recovery (or any decisive action at all) so it's back to square one for HF research.

[Uplinker]

Agree with most of that, except I don't agree that "we're doing a good job of training stall recovery" - it's just that SOPs usually keep us out of trouble. I think that perhaps (note to self) rather than inventing all sorts of extra attention getters that will probably also be ignored by an undertrained, under experienced and panicking mind; the fundamental point here is that :

PILOTS SHOULD NOT PULL UP WHEN THEIR AIRCRAFT STALLS


When stalling is "trained" in the SIM, the trainee is typically told 'Right, we are going to do some stalls now. This is what you will see, this is how you get out of it. Ready? OK, here we go'. 'Hmm, yes, not too bad, let's try it again. That's better, good. {Tick}. Right, on to the next item.............'

So this is one for the TRIs, TREs and Training Managers: Do your pupils really, truly understand what they have just done? You are in the SIM and you have just told them they are going to stall. There is nothing else going on to distract them. You have explained what to look for, how to recover, and......they do it! Brilliant, they are now fully trained to recognise and escape from any stall {Tick}.

BUT, Will that cadet pilot be able to instinctively do the right thing six months later, on a dark and dirty night when they are not expecting to stall and have not been primed to react correctly? Over to you, Training Captains.



I remember when a very experienced training Captain did an absolutely textbook incipient stall recovery, (hello Rolf!). He had got slightly slow in the base turn, and neither of us had noticed owing to distractions (another note to self!) The stick shaker started and he instantly dipped the nose and gently applied power - perfect. Mind you, he did a lot of stunt flying at airshows and competitions, so he was well practised.

[alf5071h]

“… the opportunities for gaining experience have significantly reduced ... in rare situations”. “… then ask why & how?” (#3857 & #3862)

A backward looking ‘why’ often focuses on what went wrong, etc, ‘blame and train’, and thence ‘back to the old ways’. One difficulty is in understanding exactly what has changed (and why) and that this and/or the implementation of change might contribute to recent events. Thus there could be new hazards as well as impracticability in turning the clock back.

When looking forward, ‘how’ often focus on issues which we are familiar with – pilots’ training – and flight deck interfaces - automation. Whilst past operational implementation of automation may not have been ideal, the resultant level of safety is something to be valued, thus any change to automation will require a cautious approach. Furthermore, the timescale for change is relatively long; cf the A330 mandated pitot change, yet the holes all lined up; AF447.

Generally it is impossible to create experience of rare events. There is more opportunity for precursor events, but the rate of occurrence may not warrant further change and most outcomes are 'saves', but it should be possible to improve the process of 'experience' in normal operations.
This is not a call for more hand flying; the vast majority of precursor situations involved automated flight. The industry should consider improvement in the manner of learning, memory recall, and assessment of situations; these are generic thinking skills applicable to all situations – normal, the ‘seeable but improbable’, and the ‘unforeseeable’.

As an alternative or supplement to retrospective aircraft changes and oft ineffectual human training it should also be possible to reduce the frequency of encountering demanding situations. See BEA ASAGA (www.bea.aero/etudes/asaga/asaga.summary.pdf ) study – need to simplify GA procedures, charts, ATC calls, radio and nav management, crew callouts, and SOPs.
Complex situations demand a combination of small, relatively easy, and quick changes, which can be managed both at middle management level and on the front line, independently of tedious regulatory change.

Experience is a quality which is held individually; individuals and operators can improve their level of experience with continual evaluation and understanding of normal operations, but this requires a willingness to do this, unfortunately this appears to be a quality lacking in the modern social climate.


Thinking critically (www.au.af.mil/au/awc/awcgate/army-usawc/crit_thkg_gerras.pdf), civil operators can put aside the military aspects; for replacement examples choose amongst the range of posts in this thread.

[wanabee777]

Before trying to rise to any dangerous height a man ought to know that in an emergency his mind and muscles will work by instinct rather than by conscious effort. There is no time to think.Wilber Wright address to the Western Society of Engineers, Chicago, June 24th, 1903.

[RAT 5]

You have explained what to look for, how to recover, and......they do it! Brilliant, they are now fully trained to recognise and escape from any stall {Tick}.

BUT, Will that cadet pilot be able to instinctively do the right thing six months later, on a dark and dirty night when they are not expecting to stall and have not been primed to react correctly? Over to you, Training Captains.

Excellently out. 100%. And it's not just stall training = tick. But there have not been too many occasions, recently, where the same fault in piloting skill has crashed an a/c. It really does need a fundamental review; as does the basic AB design of anything to do with the stalled condition. That includes how the a/c became stalled in the first place; what the pilot saw and felt, and what they did about it. Somewhere everything is not quite right. Improvements need to be made, but where and to what?
In the past if it was possible to connect a hydraulic unit the wrong way round and it caused a crash the root cause was researched and the threads or diameter of connectors changed. "it must not happen again." was the cry. A simple fix saved many lives, and this philosophy has carried forward. Is that way of thinking still prevalent with this repeated fault?

[joema]

Air France report the statement "we have no indications"....what was meant by that statement from the F/O....so is the pfd blank in both these accidents?
I think the AF447 "no indications" statement meant no airspeed indications or possibly no flight director indications.

I have never read any information that either AF447 or AirAsia had blanked out or malfunctioning EADIs. In both cases the big blue/brown horizon on the PFD was accurately showing the extreme pitch angle the PF had commanded.

It appears the pilot's cognition had degraded so they could not mentally process that "blue is up and brown is down" and take the obvious action.

If so that is a more profound and basic issue than automation dependency. It involves human factors and psychology under stress. If they could not mentally process and act on the simple blue/brown PFD, it is possible they might not have reacted to stick shakers either.

It is possible that more research is needed on human behavior under stress. However it is difficult and expensive to obtain this, since authentically reproducing the environment is difficult and only a small % of the population will behave that way.

[vilas]

In alternate law, within the flight envelope aircraft behaviour in pitch is exactly same as in normal law, the complications are outside the envelope. In roll the max application of side stick the rate of roll is 30°/sec which is double of normal law. The pilots had no experience of high altitude handling in roll in alternate law and yet they did not lose control in roll. AF and QZ were the results of irrational, bizarre, extreme and sustained elevator application. This could have been out of total unawareness of the fact that at altitude full elevator application is totally unwarranted and extremely dangerous. This knowledge can be instilled even without or a little hands on training. In my opinion lack of raw data skill is also not the reason but lack of even theoretical knowledge of cruise attitude could be. Even the ATHR fails at the last N1 and holds the status quo. Another reason may be it was a response of an individual frightened out of his wits by the entree into the unknown so it is not possible to seek any logic in their actions. No drastic changes in design are likely to be come due these two accidents. Some training to give high level handling is already initiated by airbus.

[CONF iture]

CONF iture, re the THS and connected sidesticks questions, I sense a hamster wheel on the horizon... These have all been done over and over again on the AF447 thread.
And for good reasons. On many aspects, AirAsia is a copy paste from AF447, and so only 5 years later.

Sidestick - Interesting how coupled sidesticks are lately appearing in the industry.
THS - Not a single data or comment on the THS in the AirAsia report - Shame !

One more thing : If the AirAsia crew had spent time to read the AF447 report and most part of our literature here on this site, I truly think they would be still with us.

[FDMII]

CONF iture;


Sidestick - Interesting how coupled sidesticks are lately appearing in the industry.

That's as much marketing as it is lawyers talking. Like stick buzzers (as suggested above (http://www.pprune.org/rumours-news/553569-air-asia-indonesia-lost-contact-surabaya-singapore-195.html#post9217339)), it won't make difference. This isn't where the problem is.
One more thing : If the AirAsia crew had spent time to read the AF447 report and most part of our literature here on this site, I truly think they would be still with us. You may "truly think" this but what you or anyone else thinks does not and cannot explain the accident and so cannot prevent a recurrence.

This already has the earmarks of the hamster-wheel. Standing down until something new comes along.

[RAT 5]

It appears the pilot's cognition had degraded so they could not mentally process that "blue is up and brown is down" and take the obvious action.
If so that is a more profound and basic issue than automation dependency. It involves human factors and psychology under stress. If they could not mentally process and act on the simple blue/brown PFD,

I wonder; is it really "human factors & psychology under stress"?

The better the basic training, and the more the recurrent practice, the less the stress when you are out of your comfort zone. If you have a strong inbuilt data base to call upon the more you can relax, analyse and react correctly when in an unexpected situation. I've been in aerobatic a/c & paragliders when it's all gone wobbly. The first thing was pause, then analyse then react. It was easy when you have oodles of air underneath you and knowledge to call upon. We've seen the airshow crashes where they did not have this luxury, but in the case of AF & QZ they did have such a luxury, and also most of the other stall crashes.

Sit on your hands was a basic theme drummed into me in my early days. It is also true on airliners & I drummed it into my students as well.

I still think that most SOP's emphasis is on keeping pilots well away from the edges of the envelope where these skills are required. In many ways I can agree with that idea. You do not train a taxi driver to handle a car like a rally driver, but you'd hope a professional limousine driver could handle a skid or drift without burying it in the hedge.
IMHO this lack of skill is not a fault of the new automatic FBW a/c, it is about not having a full understanding of how those automatics work and not having a full understanding of the true handling characteristics of the a/c, and not having consistent practice and recurrency training of both.

[A0283]

@Clandestino: Of interest to me is dynamics of spatial disorientation in multicrew cockpits. We are not dealing with the amounts of G and angle rates of tactical jets, so it's harder for us to get to get disoriented yet again facts of the accident fly in the face of the notion that if one pilot gets his vertical gyro between the ears toppled, the other will come to rescue. It seems almost as if disorientation is contagious. In most of the similar accidents so far, captain was PF so we could take some solace in notion it was about command authority gradient yet here very experienced captain failed to perform recovery (or any decisive action at all) so it's back to square one for HF <human factors> research.

An interesting point that you put forward here.

Some rough first impressions...

When i think about the books on the subject of SD, it seems like they often, if not always, focussed on single pilots in one way or another. Part of that is probably because a lot of research has been focussed on single seat fighters. But even in multicrew situations, i get the feeling (have to start rereading stuff with your observation in mind) they translate lessons learned back to an individual pilot and/or primairily his set of displays.

First book that i picked from the shelf here and quickly checked, titled "Spatial disorientation in aviation" (500+ pages), appears to confirm this.

A question that immediately popped up was - what would (a statistical group of) PNF's INSTINCTIVELY do when their respective airplane experiences an upset:
a. do they first try to understand what the PF is doing, or,
b. do they independently assess the situation first,

Followed by the question:
If they start with either a. or b., how likely is it that they stay either in a., or in b., or move from a. to b., or move from b. to a. And how likely is it that a PNF switches more than once (like a. to b. and then back to a.), And within what timeframe and situation can they do what.

When you take the mentioned book as an example, you can immediately say that the answer will be in statistical terms. Even 'simple' disorientations are unevenly spread over pilots. Even if they have had the same selection process and exactly the same type of high quality training.

If i try to recall the AF447 CVR Captain statements, it appears that he started with point a. And i wonder if he really ever got to b. Would have to reread that too.

This again shows the importance of a full (AirAsia) CVR transcript by the way.

More questions than answers i am afraid.

[gums]

Dunno about the 'bird or Rat, but this is the attitude indicator I had to use in the T-33 and later in the first A-37 jets over in 'nam.


http://i120.photobucket.com/albums/o196/gatlingums/j8_zpsru0u7w7z.jpg

No horizon shades for up or down , just the roll arrow and the two legs on roll line.

Our IP's taught us to use "bar widths" for piitch when doing an ILS or PAR. After that, they taught us to use the small black line that surrounded the yellow main one, heh heh. Then they covered up most of our stuff and we were needle, ball and IAS. Gotta love it.

As many here have opined, we are losing basic airmanship skills and experience. Dunno what we can do about it except for we slf's to stop flying behind these nuggets, but I am getting more and more nervous.

Some here have opined that stall onset should be easy to recognize. I take issue with that opinion, as many of the new designs have subltle warning signs. The FBW types may even have more subtle warning signs due their super compensation for all kindsa stuff when the primary mode/law. The 'bus seems to be very gentle, and my Viper was so smooth that first deep stall was a surprise to a highly experienced test pilot. Testimony on request, but was posted on the AF447 thread. .... out!

[galaxy flyer]

Gums,

When my ANG unit transitioned from the "Hun" to the "Hawg", many were concerned we'd loose the instrument edge we had flying 170 knot finals on an MM-3 (at least it was white on top, black on the bottom). I'm beginning to think that level of proficiency in basics has gone. I'd hate to go from "glass" (Collins Fusion) back to the FD system I had in the C-5 and I flew a 2 NDB aporoach into Yerevan with threatening terrain, no map display, no FMS, no EGPWS.

The pilots grown up in glass cockpits can't transition back to something they never knew. The two cases (C-17 at Elmendorf and F-16) show it's possible to have out of control with even well-trained pilots, BUT neither of those accidents were in cruise with miles of airspace to work out the problem.

GF

[joema]

"...As many here have opined, we are losing basic airmanship skills and experience..."

In the AirAsia case the PIC had F5 experience, upset recovery training in the 737, 4,678 hrs on type and 20,573 total hrs. He had received Alternate Law stall recovery training, and high altitude stall recovery training.

Unlike the old black/white horizon, the A320 PFD has a large blue/brown display right in front of each pilot. The EADI does not require mental interpretation of numeric values -- it graphically and colorfully reflects the aircraft pitch attitude:
http://cdn-www.airliners.net/aviation-photos/photos/4/7/8/1887874.jpg

There is no indication of dissimilar attitude readings between the PFDs or the backup display, hence no rational reason for the pilots to doubt the attitude indication. They were all showing blue, which means the aircraft was pitched way up. Why the pilots would not take the obvious action is a mystery. You would expect even a student private pilot to know and act better. This issue is apparently beyond basic airmanship, and involves psychology and human behavior under stress.

Of course the SIC was flying. But if this level of experience by the PIC is not sufficient to maintain CRM and intervene, then what is?

[Uplinker]

Whatever the reasons, I think pilots are losing their basic instrument scanning and flying skills - if they ever had them in the first place. I think three things need to happen:

1. The authorities need to look at the training regime in force when the pilots in control of the crashed aircraft were trained on that type. Had it changed and if so how? I personally think that something vital had probably been removed from the syllabus. It might not be something obvious, it might be something very subtle and seemingly unconnected, but something seems to be missing from some pilot's abilities and skills if their actions - which caused these crashes - are anything to go by. We need to work out what was missing from the training syllabus they did and put it back in - quick.

2. We need to introduce upset recovery practice to every SIM - like my training on piston engined aircraft for my ATPL - we had to close our eyes while the instructor would put the (real aircraft - we were actually flying) into an unusual attitude, for example nose high, turning left. On the command, we had to open eyes, and purely by reference to our instruments, had to take control and smoothly recover, rolling wings level, pitching back to a sensible angle and adjusting throttle to control speed. We should do this today in our jet SIMs. Eyes closed, and an unusual attitude selected with flight freeze on. At the command, open eyes (a split second after flight freeze is removed), and pilot has to recover. This would only add a couple of minutes to the SIM detail but would be very valuable.

3. All pilots, but particularly experienced captains need to be properly tested and their flying skills properly assessed - it is too often assumed that they know what they're doing and that their skills are still sharp. In my company I have witnessed a seasoned captain making a horlicks of something, but I am the one who gets the bollocking because I didn't call out or take control. Once, a senior training captain in the SIM made the wrong calls, wrong actions etc, during an EFATO, but the response from our TRE was 'yes ahem, OK then, right, now onto the next item.....' WTF ???? Had I performed as badly as that I would have been lucky to escape with my licence intact. There is a distinct element of the old boy network going on, where senior pilots rubber stamp each other's efforts in the SIM. The XAAs should run SIM tests, not TREs from the same airline as the pilots being tested.

[dlen]

Pilots need to train not only situational awareness concerning their plane, but also about their own state of mind, and an extra routine to learn: what to do first when they recognize "Gee, I am disoriented."

[PashaF]

I guess this is another really close case.

A Boeing 737-53A passenger plane, operated by Tatarstan Airlines, was destroyed in an accident at Kazan Airport (KZN), Russia. All 44 passengers and six crew members were killed.
Flight U9-363 departed from Moscow's Domodedovo Airport (DME) at 18:20 local time on a scheduled service to Kazan (KZN).
During the approach to Kazan's runway 11/29 the airplane was 'not in a position to land', according to an initial statement by the Interstate Aviation Committee. TOGA (Take Off/Go Around) mode was selected and the autopilot switched off. The engines spooled up to takeoff power and the crew raised the flaps from 30° to 15°. The airplane began to climb and the pitch angle increased to 25°. Consequently, the indicated airspeed began to decrease. When the airspeed reached 125 knots, the crew reacted by pushing to control column forward. Up until that moment, from the execution of the go around, the crew had not used the flight controls.
From a height of 700 m the airplane entered a nose down attitude, reaching a -75° pitch.
The airplane impacted the ground at a speed of 450 km/h.
Time from the start of the go-around to the impact with the ground was 45 seconds.

[EternalNY1]

At least some pilots appear to be lowering the nose, and hence the AoA, in an indicated stall ...

Incident: Cobham B712 at Brisbane on May 27th 2015, stick shaker activation in initial climb

Incident: Cobham B712 at Brisbane on May 27th 2015, stick shaker activation in initial climb (http://avherald.com/h?article=486ff90e&opt=0)

[CONSO]

Nov 17, 2013 - A Boeing
737-53A passenger plane, operated by Tatarstan Airlines, was destroyed in an accident at
Kazan Airport (KZN), Russia. :(


Please put dates on such incidents when reported-posted in thread :=

PashaF on 23 dec 2015 posted . . .

I guess this is another really close case.

A Boeing 737-53A passenger plane, operated by Tatarstan Airlines, was destroyed in an accident at Kazan Airport (KZN), Russia. All 44 passengers and six crew members were killed.

[PashaF]

Nov 17, 2013 - A Boeing
737-53A passenger plane, operated by Tatarstan Airlines, was destroyed in an accident at
Kazan Airport (KZN), Russia. :(


Please put dates on such incidents when reported-posted in thread :=


My bad - 17.11.2013

IAC have issued the final report just yet. However, Russian officials are strongly disagree, implying that elevator malfunction occurred. I can translate something from Russian document if it unavailable in English. In general - the same issues as "hard-over" situation.

[FDMII]

PashaF, your offer to translate is very kind, thank you. The letter from the MAK/IAC can be seen on the AvHerald website at News: Russia suspends airworthiness certification for Boeing 737s, but does not prohibit operation of 737s (http://avherald.com/h?article=48ee3567). Would it be possible to translate this letter?

Amidst the disagreements between agencies, I think it would be helpful to know the exactly how the elevators or the pitch control system malfunctioned. (to be clear, I don't expect the MAK/IAC letter will explain the malfunction - for those not reading Russian it would be interesting to know what it states).

[PashaF]

PashaF, your offer to translate is very kind, thank you. The letter from the MAK/IAC can be seen on the AvHerald website at News: Russia suspends airworthiness certification for Boeing 737s, but does not prohibit operation of 737s (http://avherald.com/h?article=48ee3567). Would it be possible to translate this letter?

Amidst the disagreements between agencies, I think it would be helpful to know the exactly how the elevators or the pitch control system malfunctioned. (to be clear, I don't expect the MAK/IAC letter will explain the malfunction - for those not reading Russian it would be interesting to know what it states).The letter you linked is just formal notification. I was talking about 14 pages document - "special opinion of rosaviation investigation member" at Mak-iac.org. It published with final report.

It is a lot there, mostly focused around hydraulic piston conditions.

Hmm. I have an idea. You can read official Boeing response to technical part here http://mak-iac.org/upload/iblock/8dc/%D0%9A%D0%BE%D0%BC%D0%BC%D0%B5%D0%BD%D1%82%D0%B0%D1%80%D0%B8 %D0%B8.pdf


If you interested in pilot behavior analysis it focus on the monotonous force applied to the column according to the official report. Practically, pilots have to put 80 pounds efforts in -1g situation to do provide such input.

[Centaurus]

and not having a full understanding of the true handling characteristics of the a/c, and not having consistent practice and recurrency training of both.

Agree whole-heartedly. Part of the problem is new pilots get automatics drummed into their brains from their first type rating in the simulator. No longer is the policy of learning the basics of jet instrument flying on manual raw data taught anymore. This leads to the inevitable situation when forced to switch off the automatics for some technical reason, they have a fear of flying. The fear of flying is exacerbated by company policy where switching off a FD is a mortal sin picked up by the QAR and the hapless pilot is pulled in for a stern talking to by managers who themselves suffer from the same fear of flying syndrome.

I recall reading of one very well known major airline boasting how they have managed the "threat" of automation dependency by adding two raw data hand flown ILS in their cyclic training every six months. That would not add one iota of basic handling skills to already nervous Nelly's.

[roulishollandais]

The very bad maintenance of the aircraft is a major factor of that crash. Both airline and owner didn't do their job.Did I miss the owner's identity in the official report ?

[Machinbird]

I think have found some potentially useful psychological information that relates to the human response to danger. How, Why We React To Danger As We Do - tribunedigital-sunsentinel (http://articles.sun-sentinel.com/1987-03-26/features/8701190673_1_staten-island-ferry-emergencies-researchers)
How, Why We React To Danger As We Do
March 26, 1987|By GAYLE YOUNG, United Press International
When a Pennsylvania official drew a gun from his briefcase during a news conference earlier this year, it took reporters precious seconds to realize he was about to kill himself. By that time, they said afterwards, it was too late.
Last July, a retired police officer quickly drew his gun and subdued a deranged killer who had pulled a sword on a crowded Staten Island ferry before some witnesses even realized what was happening.
A recent study of 500 fire victims showed - that when confronted with a blaze - men invariably stepped forward to fight it while women raced away to alert potential victims and save lives.
When seconds count, why do people react the way they do?
Psychologists say how people react in emergencies depends on a variety of factors, most of them tied to human instinct.
But they dispute the idea that the world is divided into cowards and heroes.
``Most heroes later say privately they wouldn`t have done what they did if they knew the risks they were taking with their own lives,`` said John Dovidio, chairman of psychology at Colgate University. ``What makes a person focus on the gun and another focus on the victim during an emergency is simply a quirk.``
Researchers say when emergencies strike, most people become extremely tense and agitated. Their attention focuses exclusively on the danger and their thoughts become simple and methodical.
``Accident victims sometimes say the few seconds before the crash was like slow motion,`` Dovidio said. ``That`s because all their attention is focused on the upcoming danger and they process it richly.``
The ability humans have to create a sort of mental tunnel vision during emergencies is seen by psychologists as a survival technique developed over evolution.
``You want to process danger very well, not a lot of information that is no use to the situation,`` Dovidio said.
Once danger is perceived, how people react varies, researchers said. When they have only seconds to react, some risk their lives for strangers, others may try to escape and still others freeze in panic.
But researchers have seen patterns of behavior in their studies of human response. For instance, it is clear that some split-second reactions can be learned.
Police and emergency personnel who are drilled in how to respond in emergencies often perform deeds within moments that are later deemed heroic, like the retired police officer who captured the Staten Island ferry swordsman by firing a gunshot into the air.
``People have a tendency to think simply, so they act best if they have had a drill,`` said John Keating, professor of psychology at the University of Washington in Seattle.
Researchers also said studies have indicated that witnesses to violence usually focus on the weapon and not on the victim. As a result, the first reaction of most people at the scene of violent crime is to cower.
But there are exceptions to this rule.
``If the victim is known by the witness, then the victim, not the weapon, becomes a primary focus,`` Dovidio said. ``That`s why we have people running back into burning houses to save relatives or friends.``
But people who get easily excited appear to have a natural tendency to ignore the weapon and focus in on the victim, Dovidio said.
These are the heroes who later say they would not have risked their lives if they had realized the danger, but who at the moment of crisis plunge forward to yank a victim from the path of an oncoming train or dive into an icy river to save a drowning person.
Gender also may be a factor in how people react in emergencies. Keating said his fire studies indicate men are much more likely to react aggressively and women intuitively.
``The men see the fire and want to eliminate the danger while the women tend to think about others first,`` he said.Of particular interest to me is the "mental tunnel vision" response to danger. I've seen that at least twice in my life, where time seems to move in slow motion. In both cases, I was evaluating a question that was a critical constraint and my mind rapidly processed the question numerous times sequentially in an extremely short period. Questions like: "Can I pull any more AOA?" or "Where will I stop?"
I discussed this discovery with my daughter who then relayed her experiences in interviewing people for a job opening (she can be intimidating). She asked a simple logical question that had a correct answer that required good logical reasoning. She stated that she was amazed that people who started out with an incorrect initial logical analysis of the problem were often unable to restructure their thoughts to find the correct answer even when she attempted to coach them into the correct chain of thought!

It appears (to me) that these observations may provide tools for understanding the otherwise inexplicable pilot behaviors observed at the fundamental level in the AF447 and QZ8501 accidents.

[galaxy flyer]

From the article:

[QUOTE][Once danger is perceived, how people react varies, researchers said. When they have only seconds to react, some risk their lives for strangers, others may try to escape and still others freeze in panic.

But researchers have seen patterns of behavior in their studies of human response. For instance, it is clear that some split-second reactions can be learned.

Police and emergency personnel who are drilled in how to respond in emergencies often perform deeds within moments that are later deemed heroic, like the retired police officer who captured the Staten Island ferry swordsman by firing a gunshot into the air.

``People have a tendency to think simply, so they act best if they have had a drill,`` said John Keating, professor of psychology at the University of Washington in Seattle./QUOTE]

This is SUPPOSED to be drilled into pilots in training, but maybe it isn't being done thoroughly enough. I always said USAF pilot training was about learning to be comfortable in very uncomfortable situations--something PC training may have given up on.

GF

[formulaben]

This is SUPPOSED to be drilled into pilots in training, but...

Truly makes me wonder how much dual given this co-pilot and the SIC from AF447 had logged...I'm willing to be bet it isn't much.

[roulishollandais]

Machinbird,
Logic and intuition are concepts of thought not of behaviour.
In any case any theory used in flight must be validated in flight
Logic seems easy, clear, mandatory, but paradoxes and errors exist I.e.:

That equation :
x²+x+1=0
x(x+1)=0 and. x+1=-x²
x(-x²)=0
-x³=0
x=0

Verification :
0²+0+1=0
1=0
..:mad:

...correct the errors and find the paradox !

[BoyFly]

Hi Joema


You hit the nail on the head! The article below has probably been posted previously but is so well researched and written it deserves another look. So many factors in todays aviation exist as described.


All pilots should know what can hurt them on the type they are current on and specifically know basic pitch and power settings for each phase of flight.




Should Airplanes Be Flying Themselves? | Vanity Fair (http://www.vanityfair.com/news/business/2014/10/air-france-flight-447-crash)

[formulaben]

1+1=1.

But if you point out that it's wrong, your post will get deleted. :rolleyes:

[avionimc]

Not sure if this was already mentioned here:
Torqued: Air Asia Crash Highlights Risks of In-flight Troubleshooting | Business Aviation: Aviation International News (http://www.ainonline.com/aviation-news/blogs/torqued-air-asia-crash-highlights-risks-flight-troubleshooting)

[Machinbird]

avionimc
I am concerned that the long term understanding of the QZ8501 accident will be, "They were just conducting unauthorized inflight troubleshooting."
That was definitely a factor in the accident of course, but we should never lose sight of the fact the loss was directly caused by a gross piloting failure.

The aircraft was actually capable of being controlled, but the improper crew reaction to the new configuration caused them to lose control. In this regard, the accident very closely resembles the AF447 accident.

Perhaps we need to be tracking an accident causal factor called, "Loss of Control-Unrecognized or Not Understood Control Configuration Change."

[ElitePilot]

All comes down to the regulators.
Over reliance in automation and companies restricting pilots hand flying day to day on line ops combined with not providing recurrent sims for handling due to commercial and budget.
Initial type ratings give you the skills but how are you supposed to maintain them.

[piratepete]

Over several years, both here on PPRUNE and in several other forums this issue of "losing handling skills" keeps coming up.Certainly it is real, I even notice it affecting me even though I have 20,000 plus hours and have been an instructor on big jets for 25 years.

One answer, which is a method I use, during the initial line training/IOE period, is about once every 4-5 legs, just prior to flap extension, I turn off AUTOPILOT, FLIGHT DIRECTOR and AUTOTHROTTLE, providing conditions are suitable, and let them "feel" the machine.Many seem to take this practice into their flying lives, its very satisfying to see and the results show up in the SIM training as well.Pete.

[ElitePilot]

Totally agree Pete however not all operators allow to reduce the level of automation to that level.
Then on the other hand some pilots/pic are too afraid to reduce the level of automation to that level in case they mess it up or can't get it stable again resulting in a go around and consequential fdap.
Sad times (i'll put a period there on the automation topic).

[phylosocopter]

Automation did not remove the need for an engineer, there needs to be a systems engineer in the cockpit. Pilots cannot be expected to understand failure modes of automation , thats a specialist discipline and modern aircraft should carry a systems engineer.

[avionimc]

Or, is it possible that airbuses are not really meant for human full understanding?

Notable accidents, and yes, easy to blame them on pilots:


Habsheim airshow, 1988, seasoned crew. Still fresh in my memory, seeing that unbelievable crash on the French evening news that same day; it would not have happened with any other aircraft make.
Air New Zealand Airbus crash in the Mediterranean (Perpignan) 2008, seasoned German & NZ crew, including engineers, no one understood, until too late.
Qantas and Lufthansa substantial loss of altitude due to sudden uncommanded pitch-down descent, 2014, causing, at least in one occurrence, serious injuries. Remedy to that was to pull a CB, wasn't it? There too, seasoned Australian and German crews.
Etc., etc.

[The Ancient Geek]

You really are talking rubbish. Do you have even the slightest clue about how to fly an aircraft ?

Habsheim airshow, 1988, seasoned crew. Still fresh in my memory, seeing that unbelievable crash on the French evening news that same day; it would not have happened with any other aircraft make.Too low, too slow, nose high, back side of the curve.
The result was inevitable in ANY aircraft including Boeing or even a Piper Cub.

Air New Zealand Airbus crash in the Mediterranean (Perpignan) 2008, seasoned German & NZ crew, including engineers, no one understood, until too late.This one goes beyond pilot error into the realm of utter stupidity.
Functional test of alpha protection. The test instructions are very clear that the test MUST be conducted at 14000 ft and not less that 10000 feet AGL. Deliberately stall the aircraft to confirm that the alpha protection prevents the stall. Anyone who tries this at low level is way beyond stupid and certifiably insane. They did it at low level. DUH.

[RAT 5]

If the 'Air Crash investigation' reconstruction of these 2 accidents are to be believed I think you will find that they were contributed to, significantly, by the automatic systems doing what they thought was correct, but due to a few swiss cheese holes proved to be in error of what was required.

[Machinbird]

Quote:
Air New Zealand Airbus crash in the Mediterranean (Perpignan) 2008, seasoned German & NZ crew, including engineers, no one understood, until too late.
This one goes beyond pilot error into the realm of utter stupidity.
Functional test of alpha protection. The test instructions are very clear that the test MUST be conducted at 14000 ft and not less that 10000 feet AGL. Deliberately stall the aircraft to confirm that the alpha protection prevents the stall. Anyone who tries this at low level is way beyond stupid and certifiably insane. They did it at low level. DUH. With all due respect Mr. Geek.
If it had been a Boeing non FBW, even with the frozen AOA vanes, it would have just recovered and flown away. The crash occurred because the computers got in the way and changed the control laws 2 or 3 times (Sorry, I last read the accident report a few years years ago so I don't remember the exact sequence.)
A clear case of "Loss of Control-Unrecognized or Not Understood Control Configuration Change."

[The Ancient Geek]

Do you honestly believe that a Boeing can recover reliably from a low level stall ?

[Machinbird]

Do you honestly believe that a Boeing can recover reliably from a low level stall ? Heck YES, given the same initial conditions as the XL Airways A320.
They are aircraft that have been designed and tested to recover.

Even the XL airways recovered from the stall nicely only to be sabotaged by a change from Normal Law to Direct Law, then to Abnormal Attitude Law. Problem was, the trim was already cranked full nose up by the system as they approached the initial stall. It was the excessive nose up trim that caused the loss of the aircraft. (Maybe a warning system is required as you approach full nose up?)

Your question should really be do I really think every ATPL rated pilot can recover from a stall? On that count, we have seen too many failures.:(

[A320FOX]

Somebody is forgetting about Turquish B737 approaching Schiphol or Asiana B777 approaching SFO.

[Machinbird]

Somebody is forgetting about Turquish B737 approaching Schiphol or Asiana B777 approaching SFO. Not really.
On the Turkish B737:
What do you expect to happen when the autothrottles pull the throttles to idle on an above the glideslope approach-but not for the reason you would expect.

By the time the crew finally realized they had a problem and forced the throttles up, it was almost too late. When the autothrottles then snatched the throttles back again, it was too late.
You have to watch your airspeed on approach. You really cannot delegate all the responsibility for watching your airspeed to the systems. You must monitor and control airspeed. Insufficient power on approach means you are going to be landing short. Same goes for Asiana's 777. Different reasons for insufficient power, but same short landing result.
These were not primary stall accidents, even if the crews got to some high AOA in attempt to buy air time.

[_Phoenix]

In XL 888 crash, the FBW changed law from normal to direct, because landing gear was down. The THS was at max. nose up position in manual mode. The elevator moved accordingly to sidestick input, mostly full ND, but couldn't counter-react the pitch up moment. The FBW switched to alternate for landing gear up. Intersting is the alternate law behaviour with elevator movement in opposition to sidestick input - reference Final report, FDR graph in page 113.
In conclusion, good luck with improving the "manual flying skills" in alternate law.

[Jwscud]

Do you honestly believe that a Boeing can recover reliably from a low level stall ?

Both Ryanair and Thomson line crews managed it from self-inflicted positions at low level and unfavourable conditions (night, IMC) with a massive startle factor and quite impressive pitch attitudes. I believe both managed to recover from IAS less than 100!!!

One NG, one classic.

[AtomKraft]

The trouble with using very advanced systems to make flying easier, is that they degrade the very skills that you desperately need for when those same advanced systems fail.

[Teddy Robinson]

The point that strikes me from reading the report a few times is that having seen the reset on ground procedure it was "felt appropriate" to try it airborne .. now thats a no-no for line flying.

That and the failure to bring the units online again by pushing the reset buttons to regain dark cockpit, then add the stick back stall recovery !!

And where was the crew brief before the cb pulling started ?

It's very simple to blame the architecture and turn this into a A vs B slanging match, but really ... the aircraft and it's occupants should have survived, and it would appear that human intervention prevented that.

[MrSnuggles]

Please enough with the AvB slagging contest!

Sometimes things go awfully bad. In some planes they go bad because they lose a prop blade. Does this mean we should start beating on turboprops because "jets don't have props"?

Nah, come on peeps. Meddling with the CBs in the middle of the flight was never, has never been and will never be a good idea, something pilots MUST have learned at least since that bad bad crash in the US many moons ago. The one where they pulled a CB to prevent unwanted noise, but that also meant they tried to take off with no flaps or anything. One single survivor - the rest was carnage.

I would suggest you ponder about what Machinbird said. Maybe there needs to be another category of accidents: "Loss of Control-Unrecognized or Not Understood Control Configuration Change."

The Kazan 737 crash would probably be a candidate for this. Very low level stall, nose dive, all caught on camera. You really should take your beta blockers before watching that video.. *joke*

[a_g]

Torqued: Air Asia Crash Highlights Risks of In-flight Troubleshooting | Business Aviation: Aviation International News (http://www.ainonline.com/aviation-news/blogs/torqued-air-asia-crash-highlights-risks-flight-troubleshooting)

The other significant lesson from this crash is related to maintenance. There were repeated write-ups and deferrals of the rudder trim limiter system. The accident report does not delve into why this was allowed to occur and why the aircraft was not taken out of service until the problem could be found. Repeat items have to be dealt with in a timely manner and not deferred over and over so that crews are not put in the position of having to deal with known problems.
Air Asia flight turns around after 'technical issue' - CNN.com (http://edition.cnn.com/2017/06/25/asia/air-asia-flight-turns-back-technical-issue/index.html?sr=twcnni062517air-asia-flight-turns-back-technical-issue0425PMVODtopLink&linkId=39084342)