Air Asia Indonesia Lost Contact from Surabaya to Singapore

[roulishollandais]

Originally Posted by Captain_log

[...]'watching the lights blink happily at me', why interfere? Fortunately for me that's where i excel at fault finding, hence why im paid to do what i do.

Unless ANY Pilots subjected to a high degree of automation are not spending X hours a week in training simulators with frequent random issues, i don't see how they manage to stay alert and are able to react to non standard events that need to be resolved quickly.

10,000hours experience means nothing if 99% is spent watching and not reacting. Plain obvious i know, but are there higher 'refresh training' requirements for pilots operating highly automated aircraft?

That is how I see systems and automation safety, whose complexity and cost are much higher than classical flight, and we don't need that.

[c.j.shrimpton]

So what is the primary indication on the EADI - Pitch or path?

[Sop_Monkey]

Ancient

Well power as an abrupt and large amount of power input with under slung engines causes a nose up pitch change. If the pitch up can't be controlled with the THS, then this would exasperate the situation, or cause a secondary, more pronounced stall. At high altitude you can afford to take the altitude loss. Throttling back to idle would help to lower the nose, with under slung engines.

[c.j.shrimpton]

I ask because on the Falcon 900EXEASy, the EADI more prominently displays path angle with the true pitch angle being less obvious. Anyone used to following the path director would need to adjust their interpretation of this instrument if they needed to directly set a "raw" pitch attitude. The "classic" 900EX has a more conventional display of pitch angle as the primary display with the path angle indicator being secondary. This makes a subtle difference in the displays between the aircraft in normal flight regimes but could be quite confusing if the aircraft had a high pitch angle with a large descending flight path.

Is any of this relevant on the Bus?

We are all asking the same question - how could three pilots fail to appreciate a high pitch attitude and steep descent was indicating that the aircraft was in a full stall?

edit. Sorry I can't work out how to insert a picture to illustrate.

[physicus]

I hope none of you "stall - lower nose and add power" advocates are real world airline pilots... lower nose, yes, but with that power adding you have to be very gentle. It simply is not that simple.

Any pilot or wannabe pilot, take the 1h40 of your life and watch that very essential presentation: https://www.youtube.com/watch?v=HVt6...s&noredirect=1

[fireflybob]

Stall recovery is such a basic part of abinitio training that we are aways surprised when another pilot makes the same mistake. Something is clearly going wrong in the human factors department. Is some basic animal instinct taking over the brain ? What other clues could we give to break the panic reaction ?

Well I was shouted down before but it's misleading to say you recover from a stall by "lowering the nose". To recover you need to move the control column/stick/sidestick (centrally) forward until the stall identification ceases - this applies whether it's a Tiger Moth or an A320 (ok yes I know some parts of the recovery might be type specific) - and before anyone jumps on this I have extensive experience in light and heavy (transport) a/c.

Even in basic training I still hear people muttering "lower the nose"!

[Sop_Monkey]

Bob

Well in a stalled condition the first consideration in recovery action is to "unload the wings". As most airline flying is S & L, "lowering the nose" would go a long way to achieving this, in most scenarios.

I do stand to be corrected, as the day I stop learning, for me is the day to give up..

[Aluminium shuffler]

Physicus, don't throw insults if you're not going to get it all right - adding power at high altitude is always going to be a gradual affair as the engines respond slowly up there. They also have relatively little thrust in the cruise due to the low air density, so aggressively firewalling the thrust levers from a high alt stall is not going to be the source of control issues and will be easily overcome by elevator pressure, especially if you remember to trim. Low speed and low altitude and yes, it is a major issue.

[fireflybob]

As most airline flying is S & L, "lowering the nose" would go a long way to achieving this, in most scenarios.

SOP,

But that is precisely the point - you want a recovery technique which is going to work every time!

[Radix]

Originally Posted by AfricanSkies

Equipment failure should not cause a stall, whichever way you look at it.

Noone says it did. Pilot's actions appear to have done.

Originally Posted by AfricanSkies

And in the event that the aircraft enters a stall, it should be recoverable.

You are confused. The aircraft is recoverable, be it with difficulty. As long as the crew follow the right steps.

You would be wise to study some Boeing crashes re. stalling and crew confusion. Turkish 1951, Asiana 214. Your Airbus argument is flawed.

[The Ancient Geek]

Colgan Air was not an Airbus or a Boeing. It was a turboprop.
The common factor is the pilot hauling back on the stick in response to a stall.

Please note that we do not have any clear evidence that this is the case here but it is looking rather likely - only the final report will tell.

Why would any trained pilot be so bl**dy stupid ?

Something wierd is happening, this can only be explained by some kind of psychological reaction to the unexpected.

More automation to stop pilots crashing is probably not the solution, maybe we could filter out pilots suseptible to this reaction by putting everyone into into unpredictable and varied extreme stresses in the simulator and adding a stall at random. Anyone who fails is obviously made of the "wrong stuff" and should not be a pilot.

Any other suggestions ?.

[Leightman 957]

SOP monkey

SOP monkey: "I do stand to be corrected, as the day I stop learning, for me is the day to give up.."

I wish there was more evidence of this attitude in posts, and second the request for more civility. I don't see where being huffy has helped any post.

Certainty that one is right when events later show one was wrong enter into a lot of accidents.

[fireflybob]

I think D P Davies in his classic book "Handling the Big Jets" (written in the 1960s but still has some great guidance) states that the probability of an actual stall in commercial operations was one in ten million (or was it one million - would have to check?) but the probability of a stall warning was much higher at one in 100,000.

Obviously it is important that pilots know how to recover from a stall but far better to prevent the aircraft from stalling in the first place. Notwithstanding stall warning systems this requires a knowledge of the a/c performance and also correct monitoring of vital parameters such as pitch attitude, airspeed, power etc.

If you see ten degrees or more pitch up at cruising altitudes in a swept wing jet transport you better start making a correction before you get a stall warning.

Even before an a/c stalls and/or the stall warner operates (assuming from level flight or thereabouts) the first warning signs are low and reducing airspeed, high nose attitude and reduced control effectiveness.

[tdracer]

One thing I dislike about the Brand A use of a verbal "STALL, STALL" (instead of a stick shaker) is that humans have a tendency to filter out aural inputs when concentrating or highly stressed. Meaning the STALL warning may not even be heard when it's most needed.
Problem is, I'm not convinced that a stick shaker is much better - I can think of at least two Brand B crashes where the pilot pulled back in response to an erroneous overspeed indication and stalled, then apparently dismissed the stick shaker as 'Mach buffet' due to the perceived overspeed.

[IcePack]

reduced control effectiveness.

In normal law not in an FBW Airbus.

[FDMII]

silverstrata;

The accepted definition of the "deep stall" or "super stall" is that of Davies', which refers solely to the blanked T-tail designs.

[silverstrata]

Australapithicus:

Silversrata....just...no.

Sorry, Austra, why?
Your statement as it stands is tantamount to an ad-hominem, and I don't like abuse. Please explain yourself further.

[fireflybob]

In normal law not in an FBW Airbus.

Icepack, quite!

[NigelOnDraft]

Or even easier, just have an auto power reduction as the aircraft hits the stall. Pull the power off, and I bet the nose will drop just like a C152.

Ummm... whilst your conclusion might be true, I am not so sure how well it would work with, say, a Stall Warning on takeoff?

"Stall Warning on Takeoff" is an A320 Memory Drill, and taking the power off I cannot recall as part of the drill In fact, the complete opposite is the case

Had such a device been installed on AF447, the power would have reduced at the first hint of a stall, the nose would have dropped

Disagree - at the first hint of a stall, he just kept pulling back. As others have said, there is not much thrust / couple at cruise Altitude.

PS Does the A320 have a stick shaker, like the 737?

No.

[silverstrata]

The accepted definition of the "deep stall" or "super stall" is that of Davies', which refers solely to the blanked T-tail designs.

A deep stall is any stall that cannot be remedied with elevators.

For what it's worth. I fly Airbus, and it has NEVER been marketed or 'sold' to me as being un-stallable. Look at the damn attitude display and the speed !!!!

When it was identified in the 1960s that rear engined T-tail aircraft could enter a deep stall, stick pushers and shakers were added until it was almost impossible to enter that condition.

We now have a situation where underslung engined aircraft can also enter a deep stall, if the thrust remains at cruise or higher. And this applies to both Airbus and Boeing designs.

In normal law, an Airbus should never enter this state, but in alternate law it certainly can (as can Boeing twins). There is no reason why a stick pusher or a thrust reducer cannot be applied in these cases, where the aircraft is in alternate law. A thrust reduction at the point of stall, will lower the nose quite sharply (if the stick is neutral or forward of neutral) and make the exit of the stall relatively simple.