Go Back  PPRuNe Forums > Flight Deck Forums > Rumours & News
Reload this Page >

Turkish airliner crashes at Schiphol

Rumours & News Reporting Points that may affect our jobs or lives as professional pilots. Also, items that may be of interest to professional pilots.

Turkish airliner crashes at Schiphol

Old 8th Feb 2011, 05:24
  #2801 (permalink)  
 
Join Date: May 2002
Location: Permanently lost
Posts: 1,785
Likes: 0
Received 0 Likes on 0 Posts
Without trawling through the complete thread I thought that the RA failure had triggered 5 warnings to the crew. After all, wasn't this the reason they had configured to take all navigation information from the "B" system (for want of a better word). What was unknown was that the system would still take its height information from the right radar altimeter.

To play devil's advocate here, the crew had a very limited time to come to the realisation that something was wrong. For a considerable time after the aircraft had intercepted the ILS the speed was reducing to VREF so the thrust levers were at idle. When the crew did realise that the speed was decreasing below that speed the thrust levers were advanced (by the captain, I think) but he then took his hands off them and, of course, they retarded to idle.

Limited time, reconfiguring the aircraft, instrument conditions, a FO under some pressure and a trap lurking in the aircraft system..........the holes were lining up.
PLovett is offline  
Old 8th Feb 2011, 07:37
  #2802 (permalink)  
Per Ardua ad Astraeus
 
Join Date: Mar 2000
Location: UK
Posts: 18,579
Likes: 0
Received 0 Likes on 0 Posts
I have inadvertently, I think, confused the picture on RADALT u/s - certainly the 'collar' was in force, but the 'old' MEL required

"Approach Minimums or operating
procedures do not require its use"

and this obviously did not 'flag up' the trap that awaited, since detailed knowledge of the role of RADALT 1 is required to see that coming. In that respect I reckon Boeing were 'at fault' as they did not differentiate between RADALT 1 and 2 failure except in the effect on GPWS, and certainly an OPS note about the effect on the A/T 'RETARD' would not have gone amiss.

However, as we know the No 1 RADALT was not 'U/S' and therefore not MEL'd, so this is actually incidental to the accident which was primarily caused by 3 pairs of eyes looking the wrong way.
BOAC is offline  
Old 8th Feb 2011, 09:09
  #2803 (permalink)  
 
Join Date: Jul 2007
Location: Germany
Posts: 1,034
Likes: 0
Received 7 Likes on 2 Posts
I find Dekker's report most informative but cannot agree with all his conclusions.

For example he maintains that the crew were not rushed although they were vectored in above the glide, descended with gear down flaps 15 to 1000 and then configured straight to flaps 40 and then apparently only at the prompt of the training captain.

The trainee, who is pilot flying, leaves the autopilot in till 400 feet and is obviously behind the aircraft as he fails completely to notice the drop in speed.

Dekker plays down the concept of gates and appears to be saying that unstabilised approaches are quite a regular event. I did however like the idea of safety pilots rewarding crews for performing go-arounds with a bottle of wine or something similar.

He provides a balanced view but one which is extremely, some might say excessively fair to Turkish Airlines. He stresses many positive aspects about their training for example, but plays down that they are regularly well down the safety rankings. He lists the facts; very experienced captain, new copilot who is transitioning from fighters and safety pilot with 700 hours on the 737. The captain is refered to by an honorific. But then he concludes there is no evidence that CRM is a factor.

I really like the idea of no blame culture and there is no question that there were a number of contributory factors, not least poor vectoring, a technical glitch and an inexperienced pilot flying. But I think this really was avoidable. There were at least four points where the crew could have regained the initiative.

On the intercept heading they could have pointed out to the controller that they would prefer a less agressive heading, particularly given the visibility.

Once established they could have slowed down and full configured giving themselves more time, before capturing from above.

At 1000 feet in imc they should have performed a mandatory go-around due to not being fully configured, spooled up or anywhere near vref.

At 400 feet and stall warning more precise actions which we practice regularly in the sim should have prevented ground contact.

I find the report well written and thought provoking. But to me this accident is like Handy's frog anecdote. If you throw a frog in boiling water it will jump out. If you put it in cold water and slowly heat it up the frog will boil to death. In other words an insidious trail of small factors added up to a major and very avoidable accident.
lederhosen is offline  
Old 8th Feb 2011, 11:25
  #2804 (permalink)  
 
Join Date: Jul 2008
Location: UK
Age: 69
Posts: 475
Likes: 0
Received 0 Likes on 0 Posts
I have to disagree with many of the points being made. Life is actually quite simple if you just follow a few basic rules.

The MEL is clear in as far as what constitutes a failure. The rad alt was u/s as per the mel description of a faulty system, had been detected as u/s on previous legs, but had been ignored.

The procedure is simple, enter the fault in the tech log and the CB will be collared.

The reason for doing this is that the manufacturer Boeing are/were well aware of the consequences of a failure with this system. Boeing are not responsible for informing pilots how to bypass procedures in order to keep flying.

Had that one simple action been followed we would have no discussion. This viewpoint does not detract from the discussion about unexpected anomalies following failures.

And before you all launch into attacking this viewpoint lets just go back to the Spanair accident.

Pliots are human and make genuine mistakes. It cannot be avoided. They are supposed to select flaps before take off but there is a history of forgetting. As its important a take off warning system is installed in order not to get caught when that forgetful day comes.

If you now do not handle a fault correctly that appeared over 20 times in the days/weeks preceding Madrid then forgetting to select flaps turns into a tragedy.

You can talk all you want about modern aircraft and their capabilities and weaknesses but once again the biggest single weakness here was getting around the regulations.

XL test flight not in accordance with recommendations
easyjet near accident, not entering problems in the tech log
spanair repeated fault not dealt with properly
turkish repeat fault not dealt with properly
korean 747 stansted fault not dealt with properly

you are licensed to fly and are not engineers
engineers are licensed to fix, let them do it at the first opportunity

you never know, it may save your butt

dekker has inadvertently set back safety with this report because it ignores the true root cause (not following procedures) as mentioned in earlier posts here.
Safety Concerns is offline  
Old 8th Feb 2011, 12:11
  #2805 (permalink)  
 
Join Date: Jun 2002
Location: Wor Yerm
Age: 68
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
Help me out chaps, in which page/s or which report/s does it categorically say that this crew were aware of the Rad.Alt. fault before flight. And where does it categorically state that the crew fully understood the implications of this failure. Also, which numpty designs a system with the same name for two functions - the same one that calls a relic (all be it a pretty reliable one) from the sixties "modern" and "new generation?" Would the current 737-800 pass current certification tests? And why not?

PM
Piltdown Man is offline  
Old 8th Feb 2011, 12:39
  #2806 (permalink)  
 
Join Date: Jul 2008
Location: UK
Age: 69
Posts: 475
Likes: 0
Received 0 Likes on 0 Posts
Within the scope of the investigation data from the quick access recorder29 (QAR) of the accident aircraft was also analysed. The data showed that erroneous radio altimeter heights occurred 148 times in a period of 10 months (1143 flights). Only a minor number of these occurrences were
reported by pilots as a technical anomaly in the aircraft maintenance and performance log and resulted in corrective actions as shown in table 1.
It can also be concluded that when incidents are not reported information is lost and because of that not only the operator but also the aircraft manufacturer is not made fully aware of the number of significant incidents.
Reports
The investigation revealed that reporting on problems concerning radio altimeter systems was limited. This situation was not limited to Turkish Airlines. Failure to report such problems limits the effectiveness of existing safety programmes. This can result in an inaccurate assessment of risks
by both airlines and aircraft manufacturers, limiting their ability to manage risks.
The Dekker report ignores these facts from the accident report.

Reports
The following factor also played a part. Analysis of the flight data showed that only part of the problems with the radio altimeter system had been reported by Turkish Airlines pilots.

Two further comparable incidents had occurred shortly before the accident flight. The pilots in question indicated that the irregularities could not be reproduced on the ground, and did not recur during their return flights. The crews did not, therefore, report the incident. At other airlines as well, analysis of flight data showed that the number of times when erroneous radio altimeter readings occurred in one of the radio altimeter systems was several times the number of reports actually made by pilots.

By not reporting incidents, the information is lost, with the ultimate result that neither the airline nor the aircraft manufacturer is made fully aware of the number of significant incidents. Since risk analysis is based partly on the reporting of incidents, failure to report also has an unintentional impact on the degree to which Boeing was in a position to determine the scope of a potential problem.

The Board considers that complaints and defects should always be reported timely and completely. Reports are essential to determine the urgency for realisation of solutions and by that for the proper performance of the system of safety within aviation.
Safety Concerns is offline  
Old 8th Feb 2011, 12:52
  #2807 (permalink)  
 
Join Date: Apr 2002
Location: FUBAR
Posts: 3,348
Likes: 0
Received 0 Likes on 0 Posts
Whilst agreeing with Safety Concerns assertations, Rad Alt snagged then fixed = no crash, it is NOT the primary cause.

The primary cause is simply that none of 3 experienced aviators monitored the airspeed from 1000ft until the stick shaker. PF had 4000hrs even if low hrs on type, and all fixed wing aircraft requires speed and normally thrust to maintain it on an approach. The 3rd set of eyes on the jumseat called SPEED at 100kts, 44kts less than the commanded speed, he was therefore asleep or felt inhibited to speak up. The Human Factors report emphasises VERY strongly the understanding nature of the LTC, so are we supposed to assume that the safety pilot was also fixated on checklist completion ?

Reading the rather pro THY pro LTC report can perhaps lead one to understand why they fouled up. It WAS however by any reasonable definition a rushed approach. PF was maxed out, didnt call for flap40, PNF suggested /accomplished, didnt call for checklist ,PNF likewise prompted, responded incorrectly. . Landing Gear? please. . . Oh down three greens
PNF in an effort to slow down the action suggested 1 at a time , and tried to allow the checklist to be completed normally.

Rushed approaches like these can and are flown safely very day. To do so however requires ALL crew members to be on the ball.

Whether due to authority gradient, denied in the report but subtly present I would suggest, fatigue, or whatever, these guys quite simply were NOT.

The Rad Alt was the mousetrap, the rushed approach the cheese, the choice to stick their fingers in to retreive it was the choice of the crew.
captplaystation is offline  
Old 8th Feb 2011, 13:11
  #2808 (permalink)  
 
Join Date: Jul 2008
Location: UK
Age: 69
Posts: 475
Likes: 0
Received 0 Likes on 0 Posts
again, pilots are human and make mistakes. That part is normal and unavoidable.
It is due to numerous accidents over the years that many onboard systems are just that, onboard.

Accepting you are going to make a genuine error one day is half the battle. Thats why we have procedures, thats why we need to stick to them.

You can continuously question the skills of this crew or any other crew but they placed their faith in the technology bringing them safely to a point in time. It was misplaced faith as the aircraft was not serviceable and there was no indication in the log book despite numerous failings on previous days and during take off.

The accident reports I listed were all avoidable if one single common action had been followed, stick to procedures.

Many of you here posting about the qualities of the crew would have done exactly the same in their shoes and you do so everyday. You place your trust in the equipment working properly. Therefore snag it, when it doesn't do what it should.

If you did that we would have less accidents to discuss.

Again this is not taking anything away from other cockpit issues out there. But don't dump on a crew when you do exactly the same as them, you just got lucky.
Safety Concerns is offline  
Old 8th Feb 2011, 14:09
  #2809 (permalink)  
 
Join Date: Jul 2007
Location: Germany
Posts: 1,034
Likes: 0
Received 7 Likes on 2 Posts
I agree wholeheartedly about everyone making mistakes. One of the most useful aspects of Pprune for me is reading about and trying to learn from those that other people have made. However I simply cannot agree that most people would have 'done exactly the same in their shoes and do so everyday'.

In this case they captured from above, happens occasionally no big deal.

Failed to slow down configure and complete checklist by vmc gate when they were in imc conditions, definitely a big deal.

Left both autopilots engaged below 400 feet with nobody minding the shop, absolute no no.

If you fly the 737 and think this is normal or know many people who do then I am genuinely shocked.
lederhosen is offline  
Old 8th Feb 2011, 14:50
  #2810 (permalink)  
 
Join Date: Dec 2003
Location: Tring, UK
Posts: 1,884
Received 28 Likes on 16 Posts
I thought the HF report was very well written and covered many points, sometimes looking from different/unusual directions. The section on FMA use (or not!) was interesting and warrants much greater exposure.

What I don't really accept, in common with other posters, is that there was much degree of stability in the the approach. To me, it was a classic rush job: turned in early, too high and fast, went through 1,000' in IMC a) with idle thrust, b) not fully configured, c) way above Vref and d) landing checks not even started.

Quoting from the report: "There is, of course, no generic set of criteria that would make an approach “rushed.”" - I'm afraid I'm going to disagree there, too - most reputable airlines plus ICAO, EASA et. al. use 1,000'R, some allow 500R in VMC (not applicable here). The fact that they were so distracted by executing the landing checklist below 1,000' that basic monitoring was lost, speaks volumes.

There was a long discussion of the technical aspects of why the autothrottle behaved as it did but is that really relevant? At the end of the day, the crew were faced with a failure of the A/T system, i.e. it didn't advance the thrust levers when required. At that instant it is simply "a failure": if at that moment any other sort of technical problem had rendered the A/T U/S, the end result would have been the same...

Overall, though, I found it a very good read with some excellent background material and liked the author's style.
FullWings is offline  
Old 8th Feb 2011, 16:32
  #2811 (permalink)  
 
Join Date: Jan 2008
Location: uk
Posts: 857
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Safety Concerns
The Dekker report ignores these facts from the accident report.
Although we here have only just found the Dekker report, I believe it predates the accident report, and therefore can be excused from not knowing its conclusions. In fact, I think parts of the Dekker report are actually in the accident report (haven't verified, but got definite "I've read that bit before" feeling).


Another point where Dekker differs from the final report, is that he states (as a finding) that the aircraft was irrecoverable at stick shaker, (there is little attention paid to the recovery effort, possibly as consequence of this assumption). Dekker also points to the Bournemouth 737 incident, and seems to be saying that a 737 at stick shaker, with pitch-up trim, is so difficult to recover that the crash is pretty much certain.

In contrast, the final report states that the a/c was recoverable at stick shaker, and recommends approach-to-stall procedure and training changes.


Also, there seems to be a, possibly very significant, factual discrepancy between the reports as regards timelines, which may lead to the differing conclusions above:

Dekker has this:

09:25:47.5 stick shaker onset
09:25:48 Power applied to throttles. Throttles halfway up, then back to idle.
09:25:49
09:25:50 Captain: “I have.” Safety pilot: “Speed.”
09:25:51 A/T OFF
09:25:52 Full power applied Safety pilot: “100 knots.”
While final report has (my emphasis):

Once the captain had taken over control, the autothrottle
was disconnected, but no thrust was selected at that point. Nine seconds after the commencement
of the first approach to stall warning, the throttle levers were pushed fully forward


Which look quite different to me - anyone got any better insight ?
infrequentflyer789 is offline  
Old 8th Feb 2011, 17:11
  #2812 (permalink)  
 
Join Date: Jul 2008
Location: UK
Age: 69
Posts: 475
Likes: 0
Received 0 Likes on 0 Posts
The bit I did like from Dekker's report was his hindsight diagram. Most posters here are commenting with hindsight. To avoid getting into the pre event situation, follow procedures.

Of course any event can crop up at any time and catch people out. The point I am making is that there is a definite trend creeping up on us and that is complacency and non adherence to procedures.

The whole point of procedures is to reduce risk. We cannot cover every possibility but following procedures should cover most.

XL test flight not in accordance with recommendations
(no accident if test flight procedures followed)

easyjet near accident, not entering problems in the tech log
(no incident if problem entered in tech log)

spanair repeated fault not dealt with properly
(no accident if repeat item repaired even if flap setting forgotten)

turkish repeat fault not dealt with properly
(no accident if enterd in tech log and follow MEL procedure, pull cb ra 1 inop no influence on A/T)

korean 747 stansted ADI fault not dealt with properly captain crashed aircraft following defective adi
(no accident if repair before flight or set inop if MEL allows)

So yes, you could try and find excuses/explanations for all these happenings or you could just emphasize that procedures must be followed to the letter.

Or you could properly investigate why so many are overlooking procedures. The common thread linking all these accidents is not flying skills as such, it is human behaviour.
Safety Concerns is offline  
Old 8th Feb 2011, 21:54
  #2813 (permalink)  
 
Join Date: Jun 2002
Location: Wor Yerm
Age: 68
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
A few posts back, I came up with my own recommendations and suggested three. I'll now add another two. Get Boeing to change the FCC software so that the autopilot disconnects as Vss is approached. To have an autopilot that will fly an aircraft into a stall and bloody well trim it there is not acceptable in the 21st century. So the last one has to be to prevent nose-up trim being applied by the A/P when flying at less than selected speed. Make the bugger pull a bit. In this way at least the nose will drop when the A/P is disconnected - and you'll have a flyable aircraft.

Safety Concerns may be right about writing stuff in the tech. log but he has to be speaking about his own company, it's not a trend in all. I'll guarantee that when I fly tomorrow there will be entries in my tech. log regarding door noise and others about worn erosion tapes. We are working on eradicating these as quickly as we can. As for other posters, gates, rushed approaches, checklists and guff like that were not the important things in this incident. What I believe happened was that at aircraft failed in such a way, partly through poor design and partly through component failure that a bunch of useful people were not aware that they had passed the point where recovery was possible - in an allegedly modern aircraft.

Yes, extra margins probably would have helped as would have being stabilised by 1,000' but unless we have more information about how the crew was operating and what was going on in the mind of the Training Captain, we'll never know. For all I know, maybe he was going to use this approach as a "This is not how we do it at THY" exercise for both of the F/O's. To say that this is the way Turks operate, as some have implied, is insulting.

As for changing the way aircraft are flown, would we be better off if all approaches flown on 737s commenced above the glide were performed A/T Off? And would it be worthwhile having having recurrent "A/P On" stall awareness and recovery training, both level flight and approach regimes?

Over...

Last edited by Piltdown Man; 9th Feb 2011 at 08:04.
Piltdown Man is offline  
Old 9th Feb 2011, 23:22
  #2814 (permalink)  
 
Join Date: Jun 2000
Location: Australia
Posts: 4,198
Likes: 0
Received 24 Likes on 10 Posts
would we be better off if all approaches flown on 737s commenced above the glide were performed A/T Off? And would it be worthwhile having having recurrent "A/P On" stall awareness and recovery training, both level flight and approach regimes?
And wouldn't we be better off if the airlines insisted that their pilots keep in regular hand flying practice without the extra baggage of flight directors and autothrottles? All these loss of control accidents stem from one main cause. And that is lack of pure flying competency brought upon by blind reliance on button pushing.

One only has to read the Kenya Airways Boeing 737 accident report where the captain crashed the aircraft vertically while applying totally confused control inputs. And that was less than two minutes after take off. And all because he was unable to engage the automatic pilot in IMC. This accident and many others similar - is deadly proof of what is inevitable because of lack of today's pilots basic flying skills.

Despite numerous high class research papers warning of the dangers of automation dependancy, regulators and airlines are turning a blind eye. Of course this is a generalisation. But Blind Freddy could see why loss of control is now the primary reason for crashes.
Centaurus is offline  
Old 10th Feb 2011, 11:31
  #2815 (permalink)  
 
Join Date: Mar 2002
Location: EU
Posts: 644
Likes: 0
Received 0 Likes on 0 Posts
PM
Also, which numpty designs a system with the same name for two functions
Deja vue... it's the same one that uses one horn for two functions (Helios!)
golfyankeesierra is offline  
Old 10th Feb 2011, 13:38
  #2816 (permalink)  
 
Join Date: Jun 2002
Location: Wor Yerm
Age: 68
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
And wouldn't we be better off if the airlines insisted that their pilots keep in regular hand flying practice without the extra baggage of flight directors and autothrottles? All these loss of control accidents stem from one main cause. And that is lack of pure flying competency brought upon by blind reliance on button pushing.
I can't totally agree with this, but you are probably not far off. I'm sure that there are many people who can remember flying hand-flown approaches to minimums on a regular basis into places like Jersey and Guernsey. Not only was the visibility poor, but the air was normally very rough and it always appeared to be close to crosswind limits - all on (sharp pencilled) minimum fuel. So no stress then! This was done with neither FD, A/P nor A/T. You got the knack in the end and got rather good at it but it was no safer for the passengers, especially if something went 'twang' or if there was problem elsewhere. Later on, having a "full house" so to speak, meant that you could monitor the aeroplane and interfere only to land (or go-around). As flight crew what we might not do enough is to practice visual, hand-flown, non-precision (unless you fly for RYR, that is) approaches and automatic landings each with and without A/T with enough regularity. By doing this you get to push all the knobs and buttons and get used to the aircraft "speaking to you." But this guy was just learning and the inbuilt traps got the two "minders." As for my airline, on the fleet I fly, if we have a problem it's getting your colleagues to use the autopilot.
Piltdown Man is offline  
Old 10th Feb 2011, 20:42
  #2817 (permalink)  
 
Join Date: Jul 2007
Location: Switzerland
Age: 78
Posts: 112
Received 10 Likes on 3 Posts
keep thy airspeed up

While the Dekker report certainly points out a lot of relevant human factors, it ignores a most important fact in the last episode of the drama.

The stickshaker goes off and one of the crew members shouts "speed". The throttles are advanced, but the spool-up is not really monitored. Now, whatever may have happened beforehand, false ra sensor, glide capture from above, automation surprise and possibly a rushed approach, an impending and recognized stall was not really triggering the survival mode of any the three pilots in the cockpit.

A stall warning and consequently the need to get back airspeed places itself on top of all flying priorities regardless of the kind airplane you fly, from ultralight to heavy.

Get the power on, make sure the engines produce what they were built for and have an eye on the angle of attac/trim before even considering any other possible issues is just pure flying basics. Mr Dekker gives us reasons why the speed could decay without recognition, but not why an experienced (on stall-prone military jets) and well trained crew failed to recover properly from the impending stall. Could it have something to do with the intention of smooth flying with a load of passengers and possibly hiding the fact to the other crew members that something went terribly wrong?
clearedtocross is offline  
Old 10th Feb 2011, 23:47
  #2818 (permalink)  
 
Join Date: Jul 2009
Location: Not far from a big Lake
Age: 82
Posts: 1,454
Likes: 0
Received 0 Likes on 0 Posts
Idle Thoughts

I was reading on another thread regarding engine accel times and noted a discussion regarding engine flight idle/ground idle being different throttle settings on the 738.
Would a RADALT indicating the aircraft on the ground also cause ground idle to be selected instead of flight idle?
I'd think not, because it would foul up potential for a GA, but it doesn't hurt to ask.
Machinbird is offline  
Old 11th Feb 2011, 06:55
  #2819 (permalink)  
Per Ardua ad Astraeus
 
Join Date: Mar 2000
Location: UK
Posts: 18,579
Likes: 0
Received 0 Likes on 0 Posts
Signalled by flaps, gear and WOW. As far as I know, no signal from either RadAlt and no MEL note.
BOAC is offline  
Old 11th Feb 2011, 13:47
  #2820 (permalink)  
 
Join Date: Jul 2009
Location: Not far from a big Lake
Age: 82
Posts: 1,454
Likes: 0
Received 0 Likes on 0 Posts
Signalled by flaps, gear and WOW. As far as I know, no signal from either RadAlt and no MEL note.
Thanks BOAC.
Machinbird is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.