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Turkish airliner crashes at Schiphol

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Turkish airliner crashes at Schiphol

Old 8th Mar 2009, 11:52
  #1821 (permalink)  
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4dogs - agreed, of course. but..........

If it is a 737 you are talking about in your sim 'scenario', you should know that trim is part of the Boeing rec for nose high recovery?
only as a way of ensuring that adequate elevator response was available.
- that is what this is all about.
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Old 8th Mar 2009, 12:00
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I believe it was NASA decades ago that discovered that human beings are poor monitors of automation. It's better to have the automation monitoring the humans.

Think of the nuclear incidents at Three Mile Island and Chernobyl. The operators didn't react until things had become critical - but like a "factor of disbelief".

I also recall at an early CRM course in the early 1980s that a symptom of loss of situational awareness (ie not being totally aware of what is going on around you) is an intuitive feeling that things are not quite right but not knowing exactly what's wrong. A gut feeling that things are not right is the subconscious mind's way of quietly knocking on the door of the brain and saying "Check it Out!".
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Old 8th Mar 2009, 12:12
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@PEHowland:

On my car, if I manually override the cruise control (i.e. put my foot on the throttle) the cruise control disengages until I manually reengage it.
Not sure what car's have to do with plane systems, but anyway just fyi my VW accelerates and does not disengage the cruise control, when I step off the gas it decelerates and goes back to original speed. My Renault does the same. Cruise control is not disengaged when you accelerate.

The same with A/T, I believe the post further up sums it up. The apparent expectation that A/T would disengage when manual trust was applied is wrong. After manual trust was given both hands on stick to manage pitch, A/T went back to retard.

Questions:

1. Is this behavior documented and clearly communicated/trained?
2. If not, perhaps Boeing should look at disengaging A/T when thrust is changed manually?
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Old 8th Mar 2009, 12:15
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If you erroneously blame the radalt, then you should also erroneously blame:

The autopilot, for not being programmed to drop out when below a safe speed.
The A/P in the 737 is more clever than that, in some circumstances (not on APP) it will pitch down to regain speed

The autothrust, for not having an always-on alpha prot / alpha floor functions, and "Speed speed" callouts.
I still stick to my belief that the A/T has alpha prot in the case under scrutiny, and of course we have speed callouts during landing.

The displays, for not flashing a radalt discrepancy.
I will be happy if this gets implemented and maybe also no RETARD in such circumstances


The dome light, for not flashing when peril is detected.
no comment

Sometimes a crew come out as unable to alter the course of events.
Most often, an accident is a chain reaction where a crew come out as unable to alter the course of events

One could deduce that the failure of the RA and A/T movements 'caused' the accident.
The lawyers will, and they're making the same kind of mistake as you are.

At most airlines I have flown at, I would venture to say that this event COULD NOT have happened if pilots followed company policy regarding stabilization. The big culprit here is not the RA or AT. Its the desire to push a bad approach.
What will stop everyone else from doing this in the future? Make sure PF is actually F, and strictly observe stable approach criteria. Our lot make it mandatory to be fully configured at 1000' (in all conditions) and you should be stable.
Remember those interview questions: have you ever arrived late to an appointment, have you ever told a lie, have you ever pushed a rushed approach a little bit too far

Regarding the
If pilots followed
part ... if my aunt had b.... she would be my uncle.

T Captain 'training' and a reminder of the need to put safety above commercialism.
Purely speculative

It appears that whoever initiated it failed to disconnect the 'malfunctioning' autothrottle.
I don't think they hit TOGA, they seem to simply have advanced the throttles without hitting TOGA or disengaging them.

For those of you who want to redesign the RA's and AT's. Why not a automatic pull up and TOGA on a GPWS warning,just incase the pilot would be too distracted to do it himself
Maybe you are saying: I already know the crew's to blame, let's not look into anything else, hang'em high ?

but I am prepared to admit the cause was the human element.
me too

training and flying ability of airline pilots in general
But give the PF a slight distraction as the autopilot is levelling off, and there's a good chance they'll bust their altitude. Why? Because they're not actually flying the aircraft!! Ask any trainer worth their salt.

Next time you're PF, have a good honest look at how often you're not actively flying the aircraft and then think about this thread.
I expect that there will be some serious recommendations in that sense.

737 systems and the way they interact and whether some of the bells and whistles are really needed
In that sense, too

re-emphasis and more training on low speed low level recoveries and upset recovery
That wouldn't hurt either
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Old 8th Mar 2009, 12:20
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Turkish airliner crashes at Schiphol

I would like to add to my previous post :
How the crew allowed this aircraft to enter this Undesired Aircraft State is what we are trying to understand, not to judge, but never to repeat.
Personally, Flight Safety's,sterile cockpit, below 10,000" should always be applied ( even and especially on Training flights, and whatever mistakes be explained on the ground ). This will give the crew all the time to Aviate ( Fly the aircraft ), Navigate, then Communicate.
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Old 8th Mar 2009, 12:36
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For those unfamiliar with the magnitude of the thrust pitch couple on the 737 here is an illustration. Some years ago, on the same sim my company uses now, an experiment was carried out. A dual channel (auto land) approach was carried out down to minimas. The TOGA button was then pressed, the A/P disconnected and a go around was flown without any pitch input by the “handling” pilot. The max pitch attitude achieved was 80 degrees! In response to a couple of low speed encounters recently in this type, I was given some go arounds in similar circumstances during my last recurrent training. I did use both hands on the column to apply full down elevator but the A/C continued to pitch up well beyond 20 degrees before the nose down trim regained pitch authority. The thing that I remember most is the incredible buffeting which was almost shaking us out of our seats. I remember reading somewhere about low frequency vibrations affecting the cognitive process and they definitely phased me to some extent. In my company it is the monitoring pilot who assures TOGA thrust is achieved during manoeuvres of this nature. The handling pilot stands the thrust levers up and presses the TOGA button. If the thrust levers had been closed during the recovery then I think F/O Bernoulli would have handed over control to Capt. Newton! (To quote my trainer). For those who advocate using less thrust to maintain full pitch control I have to disagree. I would rather lose some pitch authority for a few seconds in exchange for full TOGA thrust.
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Old 8th Mar 2009, 12:43
  #1827 (permalink)  
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Originally Posted by ant1
Purely speculative
- come on fer C****s sake - we are all in this together (well, most of us) - PLEASE quote the whole relevant part of my post rather than cherrypick! You could have saved that line of yours. I posted:
[quote]T Captain 'training' and a reminder of the need to put safety above commercialism.

Please note, although I do consider the TC to be largely to blame based on what I know so far, that is a personal opinion and not substantiated. Reviewing the above does NOT need to depend on my being right.[
/QUOTE]

There's never any harm in reviewing a reminder of the need to put safety above commercialism now, is there?.

Incidentally, having thought more about it, I suspect 'alpha floor' (or MSR) would NOT be available with a RETARD signal? If it was, where was it?

CH - a reduction in power once the a/c has unstalled MAY be the only way to control pitch. Read the QRH.
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Old 8th Mar 2009, 13:23
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Bobcat4 . . . "I'm still curious about Safta's findings. Is it really non-recoverable when fully back-trimed? Anyone tried this in the sim (737NG)?
Safta had mentioned in his post that he had waited eight (8) seconds of stick shaking before initiating a recovery in a 737 classic simulator. This is impractical reality. In real life no pilot in his right mind will listen to and feel the stick shaker rattle for 8 seconds before taking action. 8 seconds is a loooooong time! A stick shaker event is an emergency, it's an aural and physical warning system between your legs and the reaction time is no more than 2 seconds at worst. Also, be mindful that no simulator has true airplane fidelity.
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Old 8th Mar 2009, 13:24
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BOAC,
CH - a reduction in power once the a/c has unstalled MAY be the only way to control pitch. Read the QRH.
Approach To Stall Recovery
The following is immediately accomplished at the first indication of stall,
buffet or stick shaker.

Pilot Flying
• Advance the thrust levers to
maximum thrust.
• Smoothly adjust pitch attitude*
to avoid ground contact or
obstacles.
• Level the wings (do not change
flap or landing gear configuration).

Pilot Not Flying

• Verify maximum thrust.
• Monitor altitude and airspeed.
• Call out any trend toward

terrain contact.

Note:
*At high altitudes it may be necessary to decrease pitch
attitude below the horizon to achieve acceleration.

I don't see any reference (or requirement IMHO) to reduce thrust initially but there is a reference to reducing it or even rolling the aircraft for nose high recovery. Is that what you meant?
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Old 8th Mar 2009, 13:26
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It seemed to me the sentence was pointed at the event at hand, my apologies if that wasn't the case.

I agreee that during RETARD alpha floor would not be available. My comment was in reply to a sentence which BTW I think was not yours.

What I meant is alpha floor is, I believe, present when it has to be, of course not during RETARD which is quite logical. The only problem with RETARD here seems to be that it happend on disagreeing RAs.
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Old 8th Mar 2009, 13:31
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ch - the stall SHOULD be over once power is on and the alpha is reduced. It should be instantaneous at low level. What you then had was a nose high 'upset'? Your QRH should have this info. May I quote back to you part of my quote wot you quoted back to me etc etc......?
once the a/c has unstalled
ant1 - we are travelling in circles - the whole post was 'pointed' at this accident, hence its presence on THIS thread. Hence my amplification of my position.

My later post was to comment on
I still stick to my belief that the A/T has alpha prot in the case under scrutiny
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Old 8th Mar 2009, 13:41
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Hi,

Just wondering about one thing. Since the 737 is a tough plane to control in a manual go-around situation with regard to powerful pitch-power couple, I was thinking about what kind of situation the THY crew has faced. Has the autopilot trimmed the aircraft exactly how much to keep it on the glide, whilst speed was decaying. Now, when you apply TOGA power in this kind of trim condition, would that render the pitch behaviour of the aircraft almost uncontrollable (as in impossible to prevent too much nose up, and uncontrollable even with full down elevator) and a subsequent stall?

Tero
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Old 8th Mar 2009, 13:42
  #1833 (permalink)  
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teropa - the previous 1700 or so posts will answer that question. Have you looked?
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Old 8th Mar 2009, 14:01
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Last edited by Rainboe; 17th May 2009 at 21:38.
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Old 8th Mar 2009, 14:03
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BOAC

Yes, I did follow this thread quite actively before, but since it's mostly filled with BS, it takes a day to wallow through all of that. If you had the answer, why not just post it?

Tero
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Old 8th Mar 2009, 14:05
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BOAC: I now see what you meant, don't get carried away, comment withdrawn.
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Old 8th Mar 2009, 14:21
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It seems to me that the parallels between this flight and the TOM incident are remarkable. I hope one day the AAIB might actually care to publish what happened at Bournemouth. It strikes me that the only major difference was the initial stick-shaker altitude.
My experience when practising very low speed recoveries from the landing config in the NG is that it is Hard Work. If you don't trim you've had it. I suggest everyone requests to try it out in the sim at the next opportunity. It's taxing. And in the sim you are expecting it.....

So to echo most posts here.....monitor your pitch and power properly, particularly when you are near the ground!
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Old 8th Mar 2009, 14:22
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TOGA

Has the autopilot trimmed the aircraft exactly how much to keep it on the glide, whilst speed was decaying. Now, when you apply TOGA power in this kind of trim condition, would that render the pitch behaviour of the aircraft almost uncontrollable
I've followed this from the beginning too, but if the information is already posted, I apologise, but.....

Is one of the automatic functions performed by TOGA a full-rate reduction of nose up trim and application of nose down trim to compensate for the onset of thrust-induced nose up attitude?

Or does that need to be done manually?
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Old 8th Mar 2009, 14:30
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Alfa floor

This funtion in ILS aproach only flashing the Ambar ASA A/T light when detected the A/T can´t maintain the MCP speed and slow to 1.3 vs
In V/S mode the AP/FD change to LCHG pitch mode
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Old 8th Mar 2009, 14:33
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Thumbs down


Last edited by Rainboe; 17th May 2009 at 21:40.
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