Turkish airliner crashes at Schiphol
Per Ardua ad Astraeus
Join Date: Mar 2000
Location: UK
Posts: 18,579
Likes: 0
Received 0 Likes
on
0 Posts
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?
- that is what this is all about.
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.
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!".
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!".
Join Date: Oct 2008
Location: Universe
Posts: 71
Likes: 0
Received 0 Likes
on
0 Posts
@PEHowland:
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?
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.
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?
Join Date: Jul 2004
Location: Europe
Posts: 241
Likes: 0
Received 0 Likes
on
0 Posts
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 autopilot, for not being programmed to drop out when below a safe speed.
The autothrust, for not having an always-on alpha prot / alpha floor functions, and "Speed speed" callouts.
The displays, for not flashing a radalt discrepancy.
The dome light, for not flashing when peril is detected.
Sometimes 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.
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.
Regarding the
If pilots followed
T Captain 'training' and a reminder of the need to put safety above commercialism.
It appears that whoever initiated it failed to disconnect the 'malfunctioning' autothrottle.
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
but I am prepared to admit the cause was the human element.
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.
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.
737 systems and the way they interact and whether some of the bells and whistles are really needed
re-emphasis and more training on low speed low level recoveries and upset recovery
Join Date: Feb 2008
Location: Earth until ..........
Posts: 35
Likes: 0
Received 0 Likes
on
0 Posts
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.
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.
Join Date: Mar 2006
Location: England
Posts: 114
Likes: 0
Received 0 Likes
on
0 Posts
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.
Per Ardua ad Astraeus
Join Date: Mar 2000
Location: UK
Posts: 18,579
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by ant1
Purely speculative

[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.
Join Date: Jun 2001
Location: UTC +8
Posts: 2,626
Likes: 0
Received 0 Likes
on
0 Posts
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)?

Join Date: Mar 2006
Location: England
Posts: 114
Likes: 0
Received 0 Likes
on
0 Posts
BOAC,
Pilot Not Flying
terrain contact.
Note:
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.The following is immediately accomplished at the first indication of stall,
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).
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
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.
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?
Join Date: Jul 2004
Location: Europe
Posts: 241
Likes: 0
Received 0 Likes
on
0 Posts
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.
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.
Per Ardua ad Astraeus
Join Date: Mar 2000
Location: UK
Posts: 18,579
Likes: 0
Received 0 Likes
on
0 Posts
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......?
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
once the a/c has unstalled
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
Join Date: Dec 2001
Location: Finland
Age: 44
Posts: 121
Likes: 0
Received 0 Likes
on
0 Posts
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
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
Join Date: Dec 2001
Location: Finland
Age: 44
Posts: 121
Likes: 0
Received 0 Likes
on
0 Posts
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
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
Join Date: Apr 2008
Location: UK
Posts: 44
Likes: 0
Received 0 Likes
on
0 Posts
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!
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!
Join Date: Jul 2007
Location: UK
Posts: 16
Likes: 0
Received 0 Likes
on
0 Posts
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
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?
Join Date: Jul 2008
Location: buenos aires
Age: 77
Posts: 17
Likes: 0
Received 0 Likes
on
0 Posts
Alfa floor
This funtion in ILS aproach only flashing the Ambar ASA A/T light when detected the A/T canīt maintain the MCP speed and slow to 1.3 vs
In V/S mode the AP/FD change to LCHG pitch mode
In V/S mode the AP/FD change to LCHG pitch mode