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TK B738 Crash At Amsterdam - Part 9  
User currently offlineHB-IWC From Indonesia, joined Sep 2000, 4503 posts, RR: 72
Posted (5 years 5 months 3 weeks 5 days 2 hours ago) and read 23330 times:

Please continue the discussion of this topic in this new thread.

Previous installments:

Part 1

Part 2

Part 3

Part 4

Part 5

Part 6

Part 7

Part 8

232 replies: All unread, showing first 25:
 
User currently offlineMD80fanatic From United States of America, joined Apr 2004, 2660 posts, RR: 9
Reply 1, posted (5 years 5 months 3 weeks 5 days 1 hour ago) and read 23289 times:

Why do you keep on about dual channel and they must have been in Autoland, read the previous threads and the reports from Boeing and the Dutch Authorities, they both state it was a single channel normal approach or are Boeing and the Dutch Authorities part of the conspiracy you have previously alluded to.

Where ya' been old man? I've mentioned dual channel exactly twice, and both were in reference to Boeing published (I assume) materials posted here. I discovered my mistake about 8 hours ago, 6 hours before you did.....but you needed to have something substantial to introduce your opinion of anyone using the dreaded "C" word in your presence.

Look, take a number okay? I haven't mentioned "C" anything in days. So can we leave it there? Please.


My issue the last couple of days has been the rush to convict dead pilots.

I have been trying to say that all mechanical data has yet to be investigated, much less published. The only thing you have to go on is a gut feeling. And this is scientific?

"Pilots did not monitor airspeed"
"Pilots did not keep hand on throttle"
"Pilots did not monitor instruments"

on and on.....

But, since when can you prove a negative.....that someone did NOT do something?

You can't......you have to presume something first, and that is that the aircraft was operating within known parameters. You can't know this yet, and if you could you would not be here chatting with us.

[Edited 2009-03-06 05:59:29]

User currently offlineRheinwaldner From Switzerland, joined Jan 2008, 2223 posts, RR: 5
Reply 2, posted (5 years 5 months 3 weeks 5 days 1 hour ago) and read 23205 times:

Quoting CityhopperNL (Reply 221):
No it does not. So as the pilots should have been aware of this, they can be blamed for allowing throttle levers to roll back.

I don't deny that. I just think the degree of systems going "crazy" is exceptional.

Btw this is a story that shows that systems should resolve deadly situations and not create them (from this forum http://www.pprune.org/tech-log/10958-b-737-autothrottle-2.html, year 2000, the design of the 737 looks not good in that thread):

Incidentally, it was in a F100 that my friends lived thanks to the Alpha-floor. Scenario was a fast, high, approach with the FO flying. Configuration was Flap 42, Gear down, Speedbrake fully out, Approach Idle thrust.

Feeling uncomfortable, the Captain instructed the FO to go-around, but the FO reverted to previous type and de-selected autothrottle (switch on end of thrust lever grip) instead of TOGA (trigger under thrust lever grip). He then wondered why the FD hadn't commanded a pitch up, so pitched up to approximately 20 degrees. Fortunately, the Alpha floor activated immediately and the Speedbrake re-stowed automatically, meaning that they recovered by about 200'AGL about a mile out from the runway. I am aware that this scenario has occurred more than once. In a 737 they might not have been so lucky.

Basically the same underlying problem: unawareness that the A/T was in the wrong mode (even caused by the pilot himself). Expectancy that the A/T would do its job.

This is another good reading about the systems-topic. You find examples how miserably pilots failed to deal with unanticipated system behaviour in a A320:
- http://www.aviationtoday.com/av/cate...ode-Errors-Through-Design_789.html


User currently offlineKhobar From United States of America, joined Mar 2006, 2379 posts, RR: 4
Reply 3, posted (5 years 5 months 3 weeks 5 days 1 hour ago) and read 23166 times:

Quoting CityhopperNL (Reply 214):
Yes, you are right, the moment that the FO put his hands on the throttle at such a low airspeed with the throttles in idle, he should have known what had caused the drop in airspeed. So that said, it's inexcusable that the pilots allowed the throttled to go back to idle once more. The BIG question is however; were these 6 seconds fatal in a sense that they caused the crash, or did they not matter anymore anyway.

(sorry, I don't know how to carry a quote to a new thread)

Did the 6 seconds make a difference? The F/O responded to the stick shaker which warns of impending stall. The aircraft was at 400 feet. F/O advanced the throttles which would immediately begin spooling up and increasing airspeed. All else being equal, the aircraft should have begun speeding up and out of the stall condition.

Is the DFDR data available to provide that level of detail yet?


User currently onlineMcdu From United States of America, joined Apr 2005, 1459 posts, RR: 17
Reply 4, posted (5 years 5 months 3 weeks 5 days 1 hour ago) and read 23168 times:



Quoting MD80fanatic (Reply 1):
I have been trying to say that all mechanical data has yet to be investigated, much less published. The only thing you have to go on is a gut feeling. And this is scientific?

"Pilots did not monitor airspeed"
"Pilots did not keep hand on throttle"
"Pilots did not monitor instruments"

on and on.....

But, since when can you prove a negative.....that someone did NOT do something?

Actually all of the above that you call speculation is fact. The airplane did not just fall out of the sky. It was placed in a negative energy state by the pilots monitoring the machinery. Pilots don't allow airplanes to get to 90kts without taking action. Here is something you might be forgetting. A pilot that is worth putting on the uniform can feel what the energy state of the airplane is without an instrument in front of him. It is this feel that no computer or simulator can adequately duplicate. Wind noise on the cockpit windows, seat angle, engine noise are all contributing factors to the energy state of the airplane. While you may want to defend the pilots, they were the ones monitoring and assuring the safety of these strapped in behind them. Fixing the errors way sooner would have not resulted in an accident.


User currently offlineMD80fanatic From United States of America, joined Apr 2004, 2660 posts, RR: 9
Reply 5, posted (5 years 5 months 3 weeks 5 days 1 hour ago) and read 23107 times:

Are you going to tell me there is a "hand pressure" sensor on the throttle grip?

Or that the DFDR says the throttles were commanded to idle, but were moved forward against this command, thus they had to be moved by a pilot. That is an assumption, not fact.
A fact is irrefutable. Can you positively say with complete certainty that three experienced pilots completely missed declining airspeed below safe limits, and would you bet all you have on it?

Those pilots threw their chips in when the cockpit door was locked. Something to think about.

If you guys are convinced at this point, so be it. I am not. When I am you will know about it.  Smile


User currently offlineSEPilot From United States of America, joined Dec 2006, 6896 posts, RR: 46
Reply 6, posted (5 years 5 months 3 weeks 5 days ago) and read 22992 times:



Quoting Mcdu (Reply 4):
Actually all of the above that you call speculation is fact. The airplane did not just fall out of the sky. It was placed in a negative energy state by the pilots monitoring the machinery. Pilots don't allow airplanes to get to 90kts without taking action. Here is something you might be forgetting. A pilot that is worth putting on the uniform can feel what the energy state of the airplane is without an instrument in front of him. It is this feel that no computer or simulator can adequately duplicate. Wind noise on the cockpit windows, seat angle, engine noise are all contributing factors to the energy state of the airplane. While you may want to defend the pilots, they were the ones monitoring and assuring the safety of these strapped in behind them. Fixing the errors way sooner would have not resulted in an accident.

 checkmark 
Excellent summary. I have not commented on this, because I have never flown a jetliner. But I can tell you that I do not need ANY instrument to tell me when I am near stall speed; the feel of the controls and the seat of my pants will tell me. I cannot believe that it is that different in a jetliner. The exception would be if it were on autopilot, which from what I can gather is not the case. If it had been on autopilot the approach would not have been so far off the glideslope.



The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
User currently offlineDingDong From United States of America, joined Jan 2007, 661 posts, RR: 0
Reply 7, posted (5 years 5 months 3 weeks 5 days ago) and read 22944 times:



Quoting MD80fanatic (Reply 5):
If you guys are convinced at this point, so be it. I am not. When I am you will know about it.  Smile

Okay. Put it differently: the Dutch Safety Board didn't report any initial findings of powerplant failure to provide required thrust. They'd probably have had said so by now if that was the case, but their recommendations to date has involved flight crew handling and general situational awareness, which the manufacturer has also essentially repeated. What do they know that we don't?  Smile

So... given what has actually transpired and what we know to date, what would be realistic possibilities for an aircraft falling so below Vref OTHER than engine failure? Also take into account what both the regulatory authority AND the manufacturer has already publically stated. The DSB already mentioned they did not see indications of wind shear amongst other common possibilities. Again, remember that the Boeing advisory was regarding a reminder of procedural handling, rather than of aircraft design issues. So what does that leave us with?

The reason why I ask is because the answer could provide potential ammunition to back up your what-ifs...



DingDong, honey, please answer the doorbell!
User currently offlineRedFlyer From United States of America, joined Feb 2005, 4318 posts, RR: 28
Reply 8, posted (5 years 5 months 3 weeks 5 days ago) and read 22945 times:

[Quoting SEPilot in Reply 229 from Part 8 of this topic]

Quote:
After reading most of the posts on all of these threads (I have not offered many posts because my knowledge of the particular issues here is limited) I think you have summed it up the best. The facts are that while there was a system failure, it was by no means incapacitating, and SHOULD have been easily dealt with, ESPECIALLY because the crew knew it had happened on that aircraft earlier. Why they let it get away from them is the issue, and that undoubtedly will be the focus of the investigation. I have not read anything about the CVR; I suspect that it will be pored over minutely, and hopefully will give some clues. But the bottom line here is that the plane was not in dire straits until the crew failed to monitor and maintain airspeed; in my experience as a private pilot that is one of the most unforgivable sins of piloting. The most important parameter of flying is airspeed; the second is altitude. Lose track of either one for very long and you are very likely to be in trouble, and it can cost your life.

Great analysis. I'm amazed how much emphasis is being given to the failure of one piece of equipment in this crash. Equipment failures happen all the time and it's what pilots train for regularly.

I noted with interest from the thread on the QF A330 incident how the equipment malfunctioned causing the aircraft to take a dump. Quick action on the part of the pilots resulted in a safe landing.

Quote:
The investigation to date has identified two significant safety factors related to the pitch-down movements. Firstly, immediately prior to the autopilot disconnect, one of the air data inertial reference units (ADIRUs) started providing erroneous data (spikes) on many parameters to other aircraft systems.

[emphasis added]

http://www.atsb.gov.au/publications/...ports/2008/AAIR/aair200806143.aspx

Not wanting to hijack this thread and discuss another mishap, but the fact is equipment failures will happen, and do. Pilot reaction, action, or dare I say inaction, is what's going to determine the outcome.



I'm not a racist...I hate Biden, too.
User currently offlineMir From United States of America, joined Jan 2004, 21562 posts, RR: 55
Reply 9, posted (5 years 5 months 3 weeks 5 days ago) and read 22856 times:



Quoting FlyingTLow (Reply 223):
Sorry if this has been answered in one of the previous 1600 posts, but I really don't have the patience and time to go through all of them:

On the 737 NG, does the A/T System seriously only have a SINGLE CHANNEL INPUT, or is it a DUAL CHANNEL system and the system nummber 2 did not work properly for some reason

There is only one autothrottle in the 737. I can't think of any airplane that has two.

Quoting Rheinwaldner (Reply 207):
The systems must work as the limited capability of the human brain can remember and behave within expected boundaries. Some small note in a thick book is not enough create the required awareness.



This is where TK's training comes in. A small note in a thick book isn't enough, but if every important thing in the manual were in big bold type, it would be a mess. It's the job of the training staff to make sure that pilots know things like this. "The autothrottle is connected to the left RA only" is not that hard to remember.

Quoting Reinwaldner (Reply 207):
Why is there a system that by intention is never used ("automatic retard in manual approach")?

It's used. It's use isn't common, but it's a tool if the pilot wants to use it.

Quoting Reinwaldner (Reply 207):
If it is never used how can pilots know it is there?

Again, training.

Quoting SEPilot (Reply 6):
The exception would be if it were on autopilot, which from what I can gather is not the case.

We know the approach was started with the autopilot on. I don't remember anything about it disengaging.

-Mir



7 billion, one nation, imagination...it's a beautiful day
User currently offlineOldtimer From United Kingdom, joined Aug 2006, 191 posts, RR: 1
Reply 10, posted (5 years 5 months 3 weeks 4 days 23 hours ago) and read 22721 times:



Quoting MD80fanatic (Reply 1):
Where ya' been old man? I've mentioned dual channel exactly twice, and both were in reference to Boeing published (I assume) materials posted here. I discovered my mistake about 8 hours ago, 6 hours before you did.....but you needed to have something substantial to introduce your opinion of anyone using the dreaded "C" word in your presence.

It is obvious you know very little about a/c and there systems from the statements you have made on this forum, I agree with MCDu, there is proof on your so called negative quotes. Ths DFDR will record throttle inputs both manual and a/t related so wind in your neck middle aged man.. Incidentally, I only brought up the C word as an afterthought because your dual channel threads were written well after the report was issued.



Oldtimer, I should have known better!
User currently offlineCityhopperNL From Netherlands, joined Feb 2009, 74 posts, RR: 0
Reply 11, posted (5 years 5 months 3 weeks 4 days 23 hours ago) and read 22712 times:



Quoting Rheinwaldner (Reply 2):
Basically the same underlying problem: unawareness that the A/T was in the wrong mode (even caused by the pilot himself). Expectancy that the A/T would do its job.

This is another good reading about the systems-topic. You find examples how miserably pilots failed to deal with unanticipated system behaviour in a A320:

Absolutely my friend, so as I said a couple of times earlier, apart from any guilt that the pilots may bear for this crash, airplanes are being improved after every crash and so will Boeing scrutinize and if needed improve the AT systems on its aircraft to prevent these kind of situations in the future.

Quoting Khobar (Reply 3):
Did the 6 seconds make a difference? The F/O responded to the stick shaker which warns of impending stall. The aircraft was at 400 feet. F/O advanced the throttles which would immediately begin spooling up and increasing airspeed. All else being equal, the aircraft should have begun speeding up and out of the stall condition.

Is the DFDR data available to provide that level of detail yet?

I am with you on this, in fact personally I suspect that the 6 seconds did matter, because the stick shaker warning is designed to come up when the aircraft is still recoverable, so not after the plane has entered a deep stall. And it is because of this that I expect the investigation to reveal crucial mistakes were made by the crew. However, data that can confirm this has not been published yet, so in that respect I'm sure you will agree with me that it's too early to draw conclusions yet; for that we will have to wait until the full investigation has come to an end.

[Edited 2009-03-06 07:50:31]

User currently offlineBahadir From United States of America, joined Oct 2001, 1779 posts, RR: 10
Reply 12, posted (5 years 5 months 3 weeks 4 days 23 hours ago) and read 22634 times:

Great article on a turkish aviation webpage. I will leave it for some other people to traslate it as i need to leave pretty quickly, but the highlight of the article is the training and how you never stop learning after you 'make it' to the airlines.

http://www.airkule.com/default.asp?page=yazar&id=173



Earthbound misfit I
User currently onlineMcdu From United States of America, joined Apr 2005, 1459 posts, RR: 17
Reply 13, posted (5 years 5 months 3 weeks 4 days 23 hours ago) and read 22450 times:



Quoting Mir (Reply 9):
There is only one autothrottle in the 737. I can't think of any airplane that has two.

The B777 has a left engine and right engine autothrottle. This gives full autothrottle control on operative engine during Single Engine ops.


User currently offlineFlyinTLow From Germany, joined Oct 2004, 521 posts, RR: 0
Reply 14, posted (5 years 5 months 3 weeks 4 days 22 hours ago) and read 22324 times:



Quoting Mir (Reply 9):

There is only one autothrottle in the 737. I can't think of any airplane that has two.

Sorry, put the question wrong. Is the Autothrottle system designed with ONLY ONE SINGLE RA INPUT, in other words only the LH RA? Or does it normally use both RAs (so DUAL INPUT) and for some reason appearently it only used one during the approach?



- When dreams take flight, follow them -
User currently offlineKhobar From United States of America, joined Mar 2006, 2379 posts, RR: 4
Reply 15, posted (5 years 5 months 3 weeks 4 days 22 hours ago) and read 22175 times:



Quoting RedFlyer (Reply 8):
Not wanting to hijack this thread and discuss another mishap, but the fact is equipment failures will happen, and do. Pilot reaction, action, or dare I say inaction, is what's going to determine the outcome.

I posted this exact incident in Part 7. Not only does this illustrate that equipment failures can and do happen, but this particular incident is eerily similar to the one being discussed. Read it carefully - erroneous input from ONE OF THREE ADIRU's caused the pitch changes in a similar way that ONE OF TWO RA's (apparently) caused the throttle changes, key part being ONE OF x.

I have a question: with regards to the Turkish crash, the LRA failure is supposed to have caused the AT to retard to idle, and the conclusion is that, for one, had the LRA not failed, the plane would have "known" it was still at 1950 feet and nothing bad would have happened.

Okay, fine. However, what if the LRA had failed the other way - the plane was at a low altitude, just about to touch down say, and suddenly registered 1950'. Could that cause a safety problem?


User currently offlineFlyinTLow From Germany, joined Oct 2004, 521 posts, RR: 0
Reply 16, posted (5 years 5 months 3 weeks 4 days 22 hours ago) and read 21965 times:



Quoting Khobar (Reply 15):

Okay, fine. However, what if the LRA had failed the other way - the plane was at a low altitude, just about to touch down say, and suddenly registered 1950'. Could that cause a safety problem?

Been thinking about that as well, and that is why I am so astonished. How can such a crucial part of the Autoland feature soley be based on ONE SINGLE INPUT? If true, then I am actually quite astonished that this error has not occurred before in the long 737 history.

I also want to bring up two other incidents that pop to my mind (thanks for the link RedFlyer) where system anominalies caused deaths (both A320, but still):

- Air Inter A320: due to a system misdesign the aircraft descended with 3000 fpm instead of a FPA of 3.0°

Even though this accident's main factor was the misdesign of the aircraft (the authorities put a partial blame on Airbus and AI had to redesign this part of the system), the MAIN CAUSE of the accident was the pilots not showing the necessary situational awareness of the approach (high speeds, high V/S, low power, etc.). I think those two situations show a rather big similarity.

- Lufthansa A320 in WAW: Again, due to a design flaw, the aircraft did not decelerate after touchdown resulting in a runway overrun.

In this situation, after the system flaw, the pilots were not able to react to it anymore. But still, this accident blamed huma error as the main cause for the accident, and Airbus never took any blame or anything, just altered the design "on their own part".

What I am trying to proove, both times a system malfunction played a big role in the outcome of the accidents, once with the pilots being able to become active, once not. And both times the outcome of the investigation was human error.

Just a short thought...

Thilo



- When dreams take flight, follow them -
User currently offlineSbkom From United States of America, joined Feb 2009, 85 posts, RR: 0
Reply 17, posted (5 years 5 months 3 weeks 4 days 21 hours ago) and read 21838 times:

Back again!  Smile

This new thread seems to be more factual than the previous one! I will try to summarize a few points:

- Everybody agrees there is some degree of pilot error. Some think more some think less because of contributing factors.

- We all noticed the emotional explanation of the Turkish press and TALPA. It seems like these were the initial reactions, most of them are in line with the findings, the remaining people are still digesting that but they will end up accepting the facts. There is no need to analyze their culture here (except if it contributes to the accident), going into philosophical discussions on realty vs truth, and what this means in different cultures.

- Some people here still think that some assumptions are facts. One example is RA fault being previously known, logged or not. According to the articles I've read, it is not clear. This fault may not have been known by the pilots, and it was (most likely) not even logged by the previous pilots, this malfunction was discovered in DFDR readings of the last 25 hours. The two known maintenance items for that plane was a) Master Caution alarm b) something with the flaps, and they are fixed.

I suggest we stick to the very little data that is available to us, and avoid heated discussions over accusations.

After all, we are not here to judge how immoral is to crash an airplane, or the trust of the passengers etc etc, and we are not here to find how bad the pilot was, how guilty he was.

We are here to find, speculate on these human errors, find, discover, speculate about the contributing factors and aircraft systems so we learn from the mistakes. No one needs a morale or ethics lesson on the subject, but we need the possible causes to be analyzed by professionals and/or enthusiasts like us.

Thanks.


User currently offlineGokmengs From United States of America, joined Mar 2005, 1123 posts, RR: 2
Reply 18, posted (5 years 5 months 3 weeks 4 days 21 hours ago) and read 21775 times:



Quoting Mir (Reply 9):
This is where TK's training comes in.

I don't think we are at a point that we can determine this crash pilot error, hence your assumption and insinuation that TK Pilot Training is inadequate is extremely premature and a meritless accusation at best.
I am willing to bet that many 737-800 pilots some probably TK landed many times with this mechanical problem many times without incidents, although I'm not ruling out the possibility pilot error in this crash I think to say definitively their training or expertise etc. caused this crash is unfair.



Gercekleri Tarih Yazar Tarihide Galatasaray
User currently offlineSpitfire From France, joined Feb 2001, 801 posts, RR: 7
Reply 19, posted (5 years 5 months 3 weeks 4 days 21 hours ago) and read 21565 times:



Quote:
Quoting Sbkom (Reply 17):
We are here to find, speculate on these human errors, find, discover, speculate about the contributing factors and aircraft systems so we learn from the mistakes. No one needs a morale or ethics lesson on the subject, but we need the possible causes to be analyzed by professionals and/or enthusiasts like us.

I agree with most of your post.

For the last part, we need the CVR transcription to know and understand what they were doing, talking, shouting,.....in the cockpit during this approach.

[Edited 2009-03-06 10:09:45]

[Edited 2009-03-06 10:10:50]

[Edited 2009-03-06 10:11:26]


Sabena ... Never to be forgotten (12 years already , what a shame !! )
User currently offlineSbkom From United States of America, joined Feb 2009, 85 posts, RR: 0
Reply 20, posted (5 years 5 months 3 weeks 4 days 21 hours ago) and read 21511 times:

Gokmengs,

The question is not whether or not this RA problem brought the plane down. RA problem was maybe the main contributor to the events, but just like you said many pilots could land the plane without crashing.

The real reason behind the crash is loss of speed and maybe some altitude, but mainly the loss of situational awareness of the pilots. If the pilots realized that the speed was lower than the ref speed and acted on time, this accident would not occur.

Therefore, a pilot error is the main cause.

There can be alleviating factors, other contributing factors, but assuming that the engines were working (that is one of the confirmed data we have to base our theory on), the pilots had the ability to fly the airplane.

Now if we are discussing how this could be eliminated, among other things, pilot training can be one of the issues. Nothing unfair about this.


User currently offlineAAR90 From United States of America, joined Jan 2000, 3471 posts, RR: 47
Reply 21, posted (5 years 5 months 3 weeks 4 days 21 hours ago) and read 21518 times:



Quoting FlyinTLow (Reply 14):
Is the Autothrottle system designed with ONLY ONE SINGLE RA INPUT, in other words only the LH RA? Or does it normally use both RAs (so DUAL INPUT) and for some reason appearently it only used one during the approach?

Left RA input ONLY.

Quoting FlyinTLow (Reply 16):
Been thinking about that as well, and that is why I am so astonished. How can such a crucial part of the Autoland feature soley be based on ONE SINGLE INPUT?

If left RA is inop, the plane is not legal for an autoland (or any approach requiring use of RA). For HUD equipped planes, the entire HUD system may NOT be used.

Quoting Sbkom (Reply 17):
but we need the possible causes to be analyzed by professionals and/or enthusiasts like us.

Is 8 years as aircraft mishap investigator for USN good enough for you? End result of this mishap should read: Causal Factor - Pilot Error. Pilots not monitoring aircraft, pilots not taking positive control of aircraft in a timely manner. Contributing Factor - System Failure: Left RA incorrect readings. I haven't bothered reading all the posts, but of the ones I have read too many folks are focused on too small a window of time/events. There is no excuse for 100+ seconds of idle thrust with no throttle movements! 100 seconds where the "mishap chain-of-events" was allowed to progress unempeded.



*NO CARRIER* -- A Naval Aviator's worst nightmare!
User currently offlineSEPilot From United States of America, joined Dec 2006, 6896 posts, RR: 46
Reply 22, posted (5 years 5 months 3 weeks 4 days 21 hours ago) and read 21479 times:



Quoting FlyinTLow (Reply 16):

Been thinking about that as well, and that is why I am so astonished. How can such a crucial part of the Autoland feature soley be based on ONE SINGLE INPUT? If true, then I am actually quite astonished that this error has not occurred before in the long 737 history.

I think the reasoning is that this feature is only activated below 2500 feet, when the pilots should be monitoring everything very, very closely. This is probably also why Boeing has the autothrottle move the levers, so the pilot can just rest his hand on the levers and know as soon as the autothrottle changes anything. The autothrottle is not the autopilot; it is useful for reducing pilot workload, but during final approach the pilots are supposed to be fully engaged with what the aircraft is doing and shouldn't have let the speed decay anywhere near that much. Normally, if the autothrottle misbehaves it will not have catastrophic consequences and the pilots should quickly realize what is happening. In that sense it is far less critical, and probably has a lot less backup, than the autopilot. Remember, the autothrottle cannot look out the window and realize that "Hey, I'm nowhere near landing"; it only knows what it gets for inputs and has no way of confirming its validity. Redundancy would be nice, but it also adds cost, complexity, and possibility of other errors.



The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
User currently offlineSbkom From United States of America, joined Feb 2009, 85 posts, RR: 0
Reply 23, posted (5 years 5 months 3 weeks 4 days 21 hours ago) and read 21369 times:



Quoting Spitfire (Reply 19):
For the last part, we need the CVR transcription to know and understand what they were doing

Actually we need the CVR, and other DFDR data too. The only data we have comes from an external source, and a report (not the raw data) of the Dutch investigators.

For instance, I forgot to mention on my previous post, I have conflicting information about the a/c being on the glideslope. It seems like it was following the glide path due to the autopilot, but losing airspeed because the AT was in retard mode (idle).

A good number of people here assume that the a/c was under the glide path, and they are questioning that. The initial graph posted here (in thread 4 I think) showed the glideslope and the actual glide path being slightly below the glideslope (and parallel to it except the last seconds) but someone mentioned that the data was not normalized, and the a/c was indeed on the glideslope which I think the autopilot should try maintain.


User currently offlineSbkom From United States of America, joined Feb 2009, 85 posts, RR: 0
Reply 24, posted (5 years 5 months 3 weeks 4 days 21 hours ago) and read 21344 times:

Quoting AAR90 (Reply 21):
Is 8 years as aircraft mishap investigator for USN good enough for you? End result of this mishap should read: Causal Factor - Pilot Error.

I respect your professional experience!
More importantly, I agree on the above statement   given the data we have.

[Edited 2009-03-06 10:27:14]

[Edited 2009-03-06 10:48:48]

25 Mir : Yeah, I guess that would be why it has two autothrottle switches. Should have remembered that. One RA input only, and that's from the left side. But
26 Sbkom : Don't agree, I discussed that before. I am sorry but this is a serious flaw. In this particular case, only a programming change is needed to make it
27 WPIAeroGuy : Even if both sensors are connected to the A/T its still not a redundant system, at best you will be able to show an RA disagree (which is already don
28 Post contains links Sbkom : http://uk.sys-con.com/node/866847 "Dutch Investigators have now released data revealing that the instrument primarily responsible for this accident, t
29 Woody71 : Are you sure about this? Not that I think you're wrong but I've been working on avionics systems for more than twelve years and while I don't know mu
30 Sbkom : This is not the only way. I explained this in detail in the previous archived thread. I don't want to repeat.
31 PeterPuck : The autopilot is not a computer.
32 FlyinTLow : No, I think you misunderstood me. I am not talking about the LH RA being inoperative. According to the preliminary investigation, the data recorder r
33 RedFlyer : As someone else pointed out in one of the other threads, the RA did not 'fail', it merely gave erroneous readings. (I'm not interjecting myself into
34 Sbkom : We are not talking about the autopilot, but the autothrottle (AT)
35 Sbkom : msg 114 in part 8 says: Please do not think only hardware failure, where the electronics fail and stop sending information. There is programming fail
36 Pylon101 : Still I sense some kind of attitude of US and EU a.netters towards pilots when a crash occurs, and Turkish or Arab pilots are involved. Or Asians, if
37 MD80fanatic : They checked the engines and plumbing, and all looks normal. So? Powerplant looks good, but what of one of the other systems that directly support th
38 MD80fanatic : excellent point! Take notes everyone.
39 Hiflyer : FROM: THE BOEING COMPANY TO: MOM [MESSAGE NUMBER:MOM-MOM-09-0063-01B] 04-Mar-2009 05:29:01 AM US PACIFIC TIME Multi Operator Message "- Both engines
40 Woody71 : You are correct, it didn't fail. However, I was curious how a system as critical as the a/t would take it's altitude input from only one altimeter, w
41 JoeCanuck : Unless it is later revealed otherwise, here is what we know about the state of the aircraft; The engines, controls and all flight instruments were wo
42 NCB : One of first things you're told when learning to fly: forget your sensations, trust your aircraft and instruments. Indeed. Only they could not act on
43 DingDong : Actually, I was thinking that this early into the investigation, all they could reliably look at was probably the CVR and DFDR readouts. DFDR was wha
44 TristarSteve : The autothrottle has one computor and one motor which drives both throttles. There is no redundancy in the B737NG AT. So why give it two inputs. If i
45 Woody71 : Thanks for the info. But I must respectfully disagree with the above statement, at least for this instance.[Edited 2009-03-06 12:34:56]
46 JoeCanuck : Not monitoring the aircraft as it flies through the glideslope at 600' agl, and/or drops to -40kts vref, doesn't strengthen the case for the pilot Th
47 Doktor71 : And I am really curious about the reason.
48 Sbkom : OK, I will try to write scenario based on the data we have today: 1- Everything is normal until base/final 2000 feet. 2- AP and AT are selected, the c
49 NCB : As said previously, I don't think that they would have ignored the stick shaker, which came in around Vref minus 20kts. They didn't. They had only ar
50 Hiflyer : In another thread a poster states that his group ran a 733 simulator thru some of the known parameters of this incident twice with the same results. B
51 Smeg : Absolutely true. But to trust the instruments, they had to have been looking at them. Particularly the airspeed indicator. If they had been looking a
52 NCB : 10-20 seconds is pretty short for seat of the pants sensations. I have a potential explanation for this. F/O was flying, at the stick shaker he advanc
53 NCB : Very good analysis!
54 JoeCanuck : When you are that close to the ground, you are only going to have seconds, regardless of what you are doing. TOGA can be initiated after the wheels t
55 NCB : Maybe it wasn't... we don't know that yet. Maybe crew got speed awareness 2 seconds before the stick shaker? Please read Sbkom 's analysis, it gives
56 JoeCanuck : I read it but it doesn't ring right to me. The speed never should be allowed to get to the point where the stick shaker activates. 20kts is a huge sp
57 Max777geek : Yeah, you're right. Why spend money in a double hydraulic system, electrical system, fuel system double engines and yokes when one of everything coul
58 Post contains images DingDong : No. It means... if it fails...... Turn off A/T and hand-fly to a successful landing. Why do you think the A/T is a deferrable item not required for s
59 JoeCanuck : ...then you have highly trained pilots who are fully capable of flying an airplane without an autopilot.
60 Max777geek : Of course, but how do you state that it is failed, prior to do that ?
61 BuyantUkhaa : No, apparently those 100 seconds had already started earlier - the source of many misunderstandings. The engines were at idle much earlier to bleed o
62 NCB : Unless the crew didn't know that the A/T relies on only one unfiltered input... B737NG pilots who knew about this, raise your hands. B737NG pilots wh
63 Max777geek : maybe they'll still need autothrottle, then.
64 Post contains links Sbkom : http://www.openatc.com/THY1951/ See above postings. Estimated to be between 30 sec max to 13.4 seconds. And it probably didn't fly below the glideslo
65 JoeCanuck : Which changes what, exactly? The crew either noticed the aircraft going below vref and/or the glideslope and did nothing, or they didn't notice until
66 Mir : The ethnicity of the pilots has nothing to do with it. This has lasted primarily because the investigators released their initial findings so quickly
67 Post contains links Vikkyvik : From http://www.flightglobal.com/articles...ots-to-altimeter-fault-boeing.html : "This reading apparently prompted the autothrottle to transition to
68 Sbkom : Everything was so perfect. I guess they were suicidal. You are right.
69 Derik737 : Hmmm, I wonder why then the right Radio Altimeter output bus is wired to pins A3 and B3 of connector D10009B on the autothrottle computer? This bus i
70 Mir : It's a very good idea, and at most carriers it's mandatory. But remember that the RA error happened at 2000' - they still had 1000' to go before they
71 Vikkyvik : Aware of that. Had they been stabilized at 1000' though, the throttle wouldn't have been at idle anymore and their speed would be stable (both in a n
72 NCB : How would you explain that A/T would let information from left override right instead of detecting a difference and not using a "disengage" logic as
73 Mir : Yes, they probably would have. I find it hard to believe that TK does not have a stabilized approach requirement. One more thing to look at. -Mir
74 JFernandez : Actually, might be worth expanding upon this, since there seem to be quite a few factors: - LH RA giving incorrect data - Maintenance issue involving
75 AAR90 : 20,000+ total hours, 18,000+ commercial aviation hours with 6000+ hours as B738 Captain, I would not consider my civilian experience to be lacking...
76 Virgin744 : Here's a thought that's been on my mind lately, and its kind of directed at us computer geeks and those who's profession is anchored in engineering in
77 Glideslope : Outstanding Post. Situational Awareness is compromised the more you get into the AP+AT 5 miles out.
78 Starlionblue : Of course it is a computer. It takes inputs, performs calculations, and produces outputs. Planes have landed safely with autoland systems for decades
79 Mir : That's why you ARE sitting there prepared to manually override the autopilot if it's not doing what you need it to do. We use autopilots because they
80 Virgin744 : Okay I'll accept that in bad weather it makes sense for autoland to be used so long as the pilot is prepared to take control rather than let the syst
81 Vikkyvik : Can you imagine how much money that might cost? Airlines will no longer be able to shoot anything higher than a CAT1 approach. If they want to be abl
82 StealthZ : I saw this over on pprune, it mirrors my one of my own thoughts... Without doing a lot of research it seems to me that flights with extra crew are ove
83 Starlionblue : What makes you think the pilots are not ready to take control at any moment? They are. Also, as Mir mentioned, automation reduces pilot workload. Thi
84 Derik737 : The philosophy in the 737 (from my perspective based on the information I have) is that systems dependent on radio altitude typically use one radio a
85 Virgin744 : Errr, well they didn't do a very good job here then did they? I'm not saying that. Would you let your car drive you all the way home without taking c
86 Boeing747_600 : Fine. I'll give you 24 hours to prove that the information put forth by the Dutch authorities was inaccurate. If you dont, then I'm sorry, but logic
87 Post contains images Sbkom : Guilty until proven innocent eh? Nice. This insistence of mentioning over and over that the pilot is guilty, criminal, bad, incapable etc etc must gi
88 Theredbaron : Knowing that the 737 lands somewhere in the world every 2 minutes or less, and we dont have 3 crashes each day, I am sure there were a LOT of small m
89 Starlionblue : Indeed. But in all the other cases the automation is making the flight safer. You can't base a big doctrine change on one exception. That's what chec
90 ChrisK2 : Hi there, after having read every message (or so I believe) in these 9 threads throughout the last 10 days or so, I thought I'd post a few points that
91 Post contains images Boeing747_600 : I wasnt addressing the people you're referring to in the "we" category above. I was specifically addressing the comment in reply 18 suggesting that i
92 Boeing747_600 : Wouldn't IDLE have been annunciated as the engaged Speed mode on the PFD due to the faulty LH RA? When you've dropped below the approach speed and ar
93 AAR90 : Nope. The Autothrottle system only reacts to left RA input and only for "retard" mode starting at 27 feet (left) RA. You can fly a right-side only (A
94 ChrisK2 : Hi AAR90, So, if I get that right, you are saying that if the left RA is truly "inop" (and was disabled prior to the flight), the functions associated
95 ChrisK2 : Yeah, that's one of the bigger mysteries in this whole sad story anyway ... and there was a third guy in the cockpit. So strange that things could ha
96 Max777geek : That makes me evaluate positively about boeing systems designers
97 Pagophilus : Be thankful that aicraft computers don't run on Windows. There do happen to be stable systems out there, anything made by Microsoft just doesn't happ
98 Hotje : So far the analysis presented by the investigators seem to me only based on the data recorder and not the voice recorder. I'm inclined to conclude tha
99 TristarSteve : Not really. The AT only uses the RA during an autoland. The RA only works below 2500ft. So you can use the AT for the flight, but must disconnect it
100 DingDong : Having seen how software engineers for mission critical systems do their job (college roommate was an intern at a firm that developed hospital heart
101 Post contains links Ciaran : Surely, if you aren't sitting there prepared to manually override the system at a second notice then you're pretty naive to expect everything to work
102 Starlionblue : Oh please. Windows systems can be made very stable, if subjected to rigorous design and testing. The whole "Windows is crash prone" meme derives from
103 DingDong : Indeed. Sadly, many bank ATMs are now Windows-based after the migration off OS/2 (which IBM has since discontinued). Heart-warming to hear the occasi
104 TristarSteve : Yes, our IFE system has a Windows background. ( and Linux in there as well!) But one thing to note about aircraft computors, The main operating syste
105 Starlionblue : The term you are looking for is "embedded". This does not make it more or less stable. Certainly it enables faster boot and less dependence on moving
106 C17AdamJ : The pilots failed to fly the airplane. Call it lack of system knowledge on the F/O's behalf, but it comes down to a basic lack of proper technique, du
107 MilesDependent : Am I correct in saying that a cause of the crash was that the auto pilot suddenly thought the aircraft was at -8 feet instead of 1,950, and that it wa
108 MD80fanatic : You're entitled to your opinion, and you have stated it. I have one too but I will reserve it for when data more substantive emerges. On most acciden
109 MD80fanatic : Is this like a logical reality TV show? You are again asking Sbkom to prove a negative....and with a ridiculous time limit to boot. This just isn't f
110 MD80fanatic : My Guess is Boeing's "memo" or whatever....that said all powerplants were functioning properly was meant primarily as an initial observation....which
111 Hiflyer : FROM: THE BOEING COMPANY TO: MOM [MESSAGE NUMBER:MOM-MOM-09-0063-01B] 04-Mar-2009 05:29:01 AM US PACIFIC TIME Multi Operator Message This message is s
112 Hiflyer : Several items in the Boeing Memo stand out very clearly. First "While the complex investigation is just beginning, certain facts have emerged from wor
113 AAR90 : Not sure where he is getting his data ["my perspective based on the information I have"], but it really is that simple. The right FCC tells the autot
114 Post contains links Khobar : "Because of the altimeter's false reading, for 100 crucial seconds the plane's autothrottle drastically cut power to the engines as the airplane desc
115 Theredbaron : To me this part means, this crew Did not monitor primary Flight Instruments. The CVR will tell what the heck distracted them. Best Regards TRB
116 Osiris30 : MD80: I've tried in several of these threads to link you to factual information that you continually disregard. You are looking for there to be a sys
117 PW100 : Correct! First of all I'm not a pilot but an engineer, so I may not be able to judge this correctly. Having said that, I don't think were getting the
118 Sbkom : MS80fanatic, Actually he is quoting gokmengs, not me. I just jumped in seeing this statement (Msgs: 86 and 87) Thanks.
119 AirbusA370 : Which Design Assurance Level does the 737's A/T and RA system have? DAL-A, I suppose. By this definition, a failure condition may lead to a catastroph
120 PW100 : So what you're saying is that putting the landing gear down, or selecting flpas 15 or 30 is also very unsafe today, as this task purely relies on hum
121 PlanesNTrains : As someone else said, we know very little about that crash at this time. We can speculate, but that's pretty much run its course while we wait for FD
122 PW100 : With all due respect, I don't think these discussions [well except for some posts in Part 1 of this installment] would have been any different if thi
123 ChrisK2 : Hi again, I beg to differ! When I write "automatism", I am referring to the A/T. (The question whether it - technically - is possible or reasonable to
124 Mir : Having a third person in the cockpit can be greatly beneficial. To put it simply, three sets of eyes are better than two, and the third person is not
125 AirbusA370 : No, I'm talking about automated functions. E.g. would you allow a computer to decide the status of the flaps or the landing gear depending solely on
126 Boeing747_600 : Hey! No Name calling! I though RETARD was only on airbuses. On the B744 PFD, the engaged pitch mode switches to IDLE (not RETARD) when the RA drops t
127 Mir : Actually, it has been mentioned that it will. "RETARD" is a callout on Airbuses, but I don't think it's ever annunciated. But while the 744 and 737NG
128 XT6Wagon : The RA system is NOT there to keep the plane in the air. Its there to assist the pilots in landing by providing more information. I don't even know w
129 Catdaddy63 : Are TK's 738's equipped with a HUD system? Having the approach data and the speed tape on the display would have made the speed loss and resulting pit
130 Boeing747_600 : Really?! Where? I'm talking here about nose pitch up which is an A/P function and not an A/T function. Isnt this limited to Cat-IIIc only? ... which
131 Boeing747_600 : Yes. This is actually a warning to the crew that manual intervention may be required, even though the A/T is still functioning. Yet another signal po
132 Mir : Well, there's a question of what's legal and what the airplane will do. In terms of legality, of course you need both autopilots on. But it was menti
133 Mcdu : My sensations have kept me out of the rocks for over 20 years of airline flying, so pardon me if I disagree with what you are saying. What I am descr
134 NCB : That's what you have GPWS "landing gear" warnings for. Flaps and gear are non-automated items, they can't do anything without direct pilot command. A
135 Post contains links DingDong : A brief timeline of altimeter history: 1924: Lloyd Espenschied invents the first radio altimeter. 1928: Paul Kollsman invents the first accurate baro
136 PW100 : Exactly my point . . . the human intervention factor can be relied upon after all to perform such critical tasks. That was exactly my point, and that
137 NCB : I agree but A/T failure is slightly different from what happened here. A/T failure would usually sound an alarm bell and disconnect, with as result,
138 Cubastar : I think that you are absolutely correct. A well trained pilot, especially one with extensive flying time, should have been able to have had ample war
139 Post contains images BuyantUkhaa : A comemmoration service was held today, attended by the Turkish and American ambassadors, two ministers and survivors. They also visited the wreckage,
140 N6168E : quoting Spitfire reply 14 in Part 8 - Unexpected removal of the Flight Director Command Bars during approach After reading most of the previous posts,
141 Osiris30 : We'll forgive you (just this once :P ) but it was mentioned back in thread 8 I believe and off and on since. That's been my entire point for a while;
142 JoeCanuck : Complacency is a normal human reaction to a lack of stress over an extended period of time. The more things don't go wrong, the less we worry about it
143 XT6Wagon : maybe like some people have random drug testing, they need to implement random sim testing. One morning you go to your first flight of the day, and i
144 Mir : Several problems with this: 1) Airliner sims are ridiculously expensive. For this reason, airlines like to keep them running a lot, to get all the us
145 AAR90 : You are referring to two very different points in time. When the throttles moved to idle, the plane was near 2000 ft AGL and there was plenty of time
146 Boeing747_600 : Well that would explain a flare at the (correct) RH RA but only IF the A/P were still engaged, which I'm guessing was clearly not the case at the fla
147 JFernandez : Gosh, looks like the wreckage is still all there. It is now 10 days after the crash. Any idea when things are going to be moved away?
148 Gonzalo : That image is really, really sad, even when i personally think the crew actions ( or in-actions ) were - by far - the most important factor in the ch
149 TristarSteve : This si something that bugs me. They had a single channel approach, and therefore were going to disengage the AP and AT and land manually. Why did no
150 Oldtimer : What bandwagon. I have not put out one theory on the cause of this accident. I am an ex engineer not a pilot or investigator and I leave the theories
151 Khobar : Well, it was mentioned in Part 8: "The Flight Director is something that shows up on the PFD that provides instructions to the pilot on how to fly th
152 Post contains links DingDong : I honestly can't tell if you're serious or being tongue-in-cheek here so my sincerest apologies if you were indeed being serious. The 'description' y
153 OldAeroGuy : Not correct. Flap load relief (ie retraction) due to overspeed functions with no direct pilot input.
154 ChrisK2 : Hello, Yes, I was thinking of the latter moment (not sure whether I actually spelled it out). And here's my point: Since, at the first mentioned point
155 Gonzalo : Finally !!!! I was trying to find one decent picture of the FD / comm bars in my database for help in the explanation, but among 10.000 pics it will
156 Derik737 : From the Boeing 737 AMM SDS 22-11-00-097: Single Channel Flare Automatic flare is for dual channel approach, however, since it is part of the A/P des
157 Draigonair : Friend of mine did the flight in the sim and one thing he said about the last moment. The plane was trimmed up fairly high and when he gave full power
158 Spitfire : Anyway even in a standard Go Around at Vref+5, instead of pulling on the yoke (as some could think) you have to PUSH a lot while trimming forward a l
159 AAR90 : I think the key word here is "can." When I first got on the 738 AA was not certified for HUD approaches and was certified for dual-A/P approaches. At
160 JFernandez : Based on the witness descriptions, this might very possibly be what happened.
161 Spitfire : One thing that could be interesting to know is how did they simulate the "error" in the LH RA ( -8 feet). If they just pulled the LH RA circuit breake
162 Boeing747_600 : That the A/P was still engaged past the point when the pilots detected the stall is not entirely clear at this stage. Not necessarily. The primary so
163 Derik737 : I would assume your SOP would instruct you to disconnect before the A/P would flare in single channel. When in single channel, it definitely will not
164 Khobar : Well, I thought it was about as helpful as the original description. Now that was about as perfect an answer as I've seen. Good job.
165 Boeing747_600 : Not surprising, personally. I would imagine that you have to push quite a bit to maintain airspeed! Isnt there a natural nose pitch-up tendency witrh
166 Boeing747_600 : That late point appears to have been after the infamous 6 second delay between the Capt taking control and his last ditch attempt at applying thrust
167 Spitfire : Indeed, with 4 engines a/c like B747, A340 nr 1 and 4 give you a 'pitch down' 2 and 3 a 'pitch up'. On the DC10 , 1 and 3 = pitch up , #2 pitch down
168 Post contains links BuyantUkhaa : Wreckage removal is planned to start on Tuesday, on Wednesday the cockpit section will be removed, the main fuselage section on Thursday, and the emp
169 Mir : Yeah, it is counter-intuitive. But if you're following the FD it's easy to just follow the command bars. And if you're not using the FD, the airspeed
170 Post contains links Boeing747_600 : Generally true, especially with twins. However as Spitfitre pointed out, with 4 wing-mounted engines, you can get a zero pitch tendency (up or down)
171 Rheinwaldner : For that specific example the discussions relevaled that among all 738 pilots the behaviour was not recallable from memory. True, but all reasonable
172 Max777geek : That's why automation is there for, in terms of confrontation with other installed systems (and comunication and exclusion of possibly faulty systems
173 Starlionblue : How many discussions have we had only on this board about "Airbus FBW takes control away from the pilots"? Now we have a situation where Airbus feels
174 ChrisK2 : Hi, When you're the first to introduce new stuff (e.g. FBW, A320-style), you'll often have a hard time making it really work, ironing out the software
175 Boeing747_600 : Absolutely. Even while I personally put upwards of 90% of the blame for the TK1951 crash on the pilots, I will readily concede that had there been a
176 Mir : That's why I said it was likely, not definite. And my comment was more about when you have a thrust line below the CG. If you have two engines above
177 Rheinwaldner : Possibly (and likely) the previous approaches were not hot and high thus the power cut was detectable very early and far more obvious because immedia
178 Khobar : These things are not so clear cut as you imply. The TAM A320 crash is a case in point. Thrust levers were in different positions and the "computer" i
179 Gokmengs : I don't think thats what I did there, but if you take it that way my apologies for not being clear, I thought your post was insinuating that TK pilot
180 Rheinwaldner : These are two different things: one is made to accept differentiating values (throttle), the other must never deliver differentiating values (L RA an
181 Spitfire : Don't you think that this kind of maneuver has been done hundreds of time during the test flights of the B737, from the -100 to the -900? Do you thin
182 Gonzalo : You read my mind !!!! That's exactly what i'm thinking. The fact that one specific crew screwed up doesn't mean that the critical parameters of the a
183 Post contains images Boeing747_600 : Speaking of re-read, how about reading my follow-up in Reply 126 and attempting a response to the queries I've raised there?!  Secondly it didnt tak
184 Mir : If memory serves, there should have been a difference in autothrottle indication. If you set a lower speed in the MCP window, the throttles may go to
185 Post contains images Boeing747_600 : Here's what I believe could be a practical suggestion for detecting A/T anomalies due to either erroneous input, or an A/T servo malfunction, on both
186 Spitfire : This is absolutly correct. When monitoring an automatic approach the PF MUST AT ALL TIME have one hand on the stick and the other one on the throttle
187 Boeing747_600 : Correct. In fact one could argue that the training appears to have been adequate enough in that the same LA RA failure did not have the adverse impac
188 Boeing747_600 : If this already an explicit stipulation in procedures worldwide, then is it possible that even though the PF of TK1951 had his hand on the throttles,
189 Spitfire : When your are flying ( manual or automatic) approaches, you have, as I said before, always one hand on the stick ( joystick or joke) and another on t
190 Max777geek : There was no discrepancy, the throttle were commanded to stay where they were, and the thrust was the commanded one. The speed was not increasing bec
191 Boeing747_600 : I inadvertently made that mistake once at a video game arcade. A little background - At Dave and Busters, they have this somewhat decent (at least by
192 Spitfire : Well I'm as as your 737 instructor / spectator ....
193 Boeing747_600 : At 44, I'm no spring chicken myself, so hopefully I will learn to do a better job of keeping the scotch tape on my mouth than I did when I was a mere
194 Spitfire : What I wrote above was certainly not against you and your very well analysed posts !
195 Spitfire : Because the PF nor the PNF, nor the 3rd one in the cockpit didn't see the speed descending below the Vref and the BLACK and RED portion of the speed
196 Max777geek : Ahhhh, thank you very much, so now it comes out my posts weren't very well analyzed ? Thank you very much, indeed !
197 AAR90 : Every one that I know of, but I do not know what TK's procedures are/were. Most airlines denote Pilot Flying (PF) and Pilot Monitoring (PM) [as oppos
198 Max777geek : True, but that didn't make the AT thinking more speed was needed, as the airplane was on ground and needed to stop. That's the main cause of the disa
199 Boeing747_600 : What?!?! you mean on real B777s, you dont get a message that says "Make Landing on Runway" flash across the HUD as you turn onto finals?! Oh! I meant
200 Max777geek : Im sure an amateur may have a very realistic idea as before Sept 11th may have had hundreds of cockpit rides. Nothing even comparable to the ones act
201 Spitfire : Thank you! By this post you prove once more you don't know anything about the real life in a cockpit, how to fly a big jet ! The RA has NOTHING to do
202 Post contains links Spitfire : Quoting Max777geek (Reply 200): Im sure an amateur may have a very realistic idea as before Sept 11th may have had hundreds of cockpit rides. Nothing
203 Max777geek : Nothing in my answer was meaning that, but if I sounded alike, I probably write better than I fly. Nothing in the turkish cockpit showed they had app
204 Max777geek : What in my words that it might be "a very realistic idea" differs from yours "very helpful experience" in your view ? Im sure of it if you passed you
205 Spitfire : FROM: THE BOEING COMPANY TO: MOM [MESSAGE NUMBER:MOM-MOM-09-0063-01B] 04-Mar-2009 05:29:01 AM US PACIFIC TIME Multi Operator Message This message is s
206 Qualitydr : It certainly appears that way, Spitfire. I'm withholding final assessment, however, as I don't know what sort of discussion was going on in the cockp
207 Mir : On real B777s, you turn onto final, not finals. -Mir
208 Bridge : Wouldn't there have also been other indicators before the shaker that one of the three might have noticed? Would there have been significant buffeting
209 AAR90 : AA B777s do not have a HUD. At least I don't think so, but since I've never been inside a B777 before.... Just keep repeating the obvious. Eventually
210 Bridge : The evidence so far indicates that the crew was unable to recover from said stall. Again, forgive my relative ignorance - wouldn't the shaker have ac
211 Khobar : The problem is that it would not apply to Airbus a/c because they do not have servo controls on the throttles. IOW, the throttles do not move by them
212 JFernandez : According to the investigation (http://www.flightglobal.com/articles/2009/03/04/323388/crashed-turkish-737s-thrust-fell-after-sudden-altimeter-step-c
213 AAR90 : Apparantly true. No, and the A/P never entered "flare" mode either. The A/T went into RETARD mode. Not quite accurate. You "reduce pitch" (nose attit
214 Boeing747_600 : Point taken. But I've heard both final and finals used quite interchangeably. If you listen to enough ATC chatter, you'll hear a dozen of each on any
215 Osiris30 : You turn off A/T or hit TOGA I believe however, on the Airbii (Airbii drivers please jump in here) that manual input on Airbus aircraft turns off A/T
216 Mandala499 : We won't know that for sure until someone reveals the CVR details or what's in it. And for the "must be poor training" advocates... Poor training or
217 Rheinwaldner : I think that too. How can the following happen then?: That sounds alarming. One could question rightfully that this should have become known earlier
218 Mir : Absolutely. I have no problem with either term, but some on here do (and strongly so), thus the basis of the joke. -Mir
219 StealthZ : These two statements confuse me, does the 'bus have A/T or not? If they do and the throttles do not move by themselves does it mean the FBW decides o
220 Starlionblue : - AFAIK all Airbuses have autothrottle. Certainly all FBW Airbuses do. - On FBW Airbuses the throttles do not move while the autothrottle system is e
221 Spitfire : That's right, and I can assure you that this is quite disturbing at the beginning of the Airbus training. You have to look at the engine instruments
222 StealthZ : Absolutely, thanks for the info, clarifies the subject for me. Cheers
223 JFernandez : That's the one thing about this crash that irks me. Did this aircraft really spool up twice in a stall condition without *TOGA* being pressed?
224 BuyantUkhaa : From what I understood, it first spooled up without TOGA being pressed, yes. Then the A/T retarded the throttles again, then the captain hit TOGA and
225 JFernandez : Ok, thanks. It wasn't clear to me whether or not TOGA was hit when the Captain took over.
226 AAR90 : I don't know about the 733, but in the 738 the yoke pressure is NOT excessive during stall recovery even with full nose up trim. More than normal? Ye
227 Mir : Or the autothrottles were off. -Mir
228 SEPilot : In that case the crew might not even have noticed the discrepancy, if they were looking at the other RA or the main altimeter. Without the AT it woul
229 Mir : Which might explain why it was never written up. -Mir
230 Boeing747_600 : I second that. Very neat synopsis of Airbus A/T operation by Spitfire. If I had to take a stand, I'd say that the Boeing's A/T scheme is conceptually
231 Post contains links Kappel : The Dutch media is reporting today that KLM had 17 instances in the last half year where the radio altimeter on a 737 malfunctioned. http://www.luchtv
232 Post contains links PanAm_DC10 : Please continue the discussion at the following thread TK B738 Crash At Amsterdam - Part 10 Thank you
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TK B738 Crash At Amsterdam - Part 3 posted Wed Feb 25 2009 06:10:53 by HB-IWC
TK B738 Crash At Amsterdam - Part 2 posted Wed Feb 25 2009 03:44:01 by HB-IWC
TK B738 Crash At Amsterdam posted Wed Feb 25 2009 01:49:48 by Luvaulter
BA B772 Crash Lands At LHR - Part 6 posted Sat Jan 19 2008 12:26:32 by B747forever
BA B772 Crash Lands At LHR - Part 5 posted Fri Jan 18 2008 11:54:38 by ANCFlyer
BA B772 Crash Lands At LHR - Part 4 posted Fri Jan 18 2008 01:13:30 by 777ER
TK B738 Crash At Amsterdam - Part 7 posted Wed Mar 4 2009 04:46:30 by HB-IWC
TK B738 Crash At Amsterdam - Part 6 posted Fri Feb 27 2009 00:58:38 by PanAm_DC10
TK B738 Crash At Amsterdam - Part 5 posted Wed Feb 25 2009 18:35:07 by WILCO737
TK B738 Crash At Amsterdam - Part 4 posted Wed Feb 25 2009 09:52:20 by HB-IWC
TK B738 Crash At Amsterdam - Part 3 posted Wed Feb 25 2009 06:10:53 by HB-IWC
TK B738 Crash At Amsterdam - Part 2 posted Wed Feb 25 2009 03:44:01 by HB-IWC
TK B738 Crash At Amsterdam - Prelimenary Report posted Tue Apr 28 2009 05:01:24 by MerNion
TK B738 Crash At Amsterdam posted Wed Feb 25 2009 01:49:48 by Luvaulter