Ueberlingen collision Trial started
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Ueberlingen collision Trial started
The trial is prosecuting for the moment 8 Skyguide ( the Swiss ATC Service provider ) officials. after the collision that occured on 02 July 2002.
It Started last Tuesday, with the audition of 2 senior management staff of Zurich ACC, who rejected all responsibility, and declared that the " fault" lies solely with the air traffic controller on duty that night ( who unfortunately will not be there to defend himsef ).
But the judge seem to want to look deeper into the system, and he could overturn some stones.
The trial is expected to last a few weeks.
It Started last Tuesday, with the audition of 2 senior management staff of Zurich ACC, who rejected all responsibility, and declared that the " fault" lies solely with the air traffic controller on duty that night ( who unfortunately will not be there to defend himsef ).
But the judge seem to want to look deeper into the system, and he could overturn some stones.
The trial is expected to last a few weeks.
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"It Started last Tuesday, with the audition of 2 senior management staff of Zurich ACC, who rejected all responsibility, and declared that the " fault" lies solely with the air traffic controller on duty that night ( who unfortunately will not be there to defend himsef )."
As I remember it, this ATCO was left on his own, without STCA, doing two jobs on radar screens separated by 20 yards and some of the telephone system on MTX? And they want to blame him? In my view his principal error was to allow management to put him in that position in the first place.
If they get away with pinning the blame on this ATCO then every ATCO out there is in deep water: It means ATSPs can run their system in a seriously flawed state without being liable when the guy on the front line is unable to make up for those inadequacies. It is not the job of the ATCO to make up for shortcomings in ATC system design and that he should have been asked to do so is unacceptable.
If their defence wins the day then it is time to hang up the headset.
.4
As I remember it, this ATCO was left on his own, without STCA, doing two jobs on radar screens separated by 20 yards and some of the telephone system on MTX? And they want to blame him? In my view his principal error was to allow management to put him in that position in the first place.
If they get away with pinning the blame on this ATCO then every ATCO out there is in deep water: It means ATSPs can run their system in a seriously flawed state without being liable when the guy on the front line is unable to make up for those inadequacies. It is not the job of the ATCO to make up for shortcomings in ATC system design and that he should have been asked to do so is unacceptable.
If their defence wins the day then it is time to hang up the headset.
.4
Whilst it is true that ATC are primarily responsible for correct vertical separation of en-route IFR traffic, TCAS was introduced as an essential safety complement for those rare occasions when ATC errors occur.
But TCAS is only of any use if the crews know how to use it correctly!!
TCAS RA directions always override ATC instructions!
On 1 Jul 2002, the Bashkirian Airlines Tu 154 and DHL Boeing 757 were on a collision course at FL360. This is what happened in the 50 seconds following the first TCAS Traffic Advisories:
21:34:42 Both aircraft receive TAs
21:34:49 ATC instructs Tu 154 to descend to FL350
21:34:56 Boeing 757 issued “Descend, descend” RA. Crew responds correctly
21:34:56 Tu 154 issued “Climb, climb” RA. Crew continues to descend
21:35:03 ATC instructs Tu 154 to increase descent rate
21:35:10 Boeing 757 issued “Increase descent” RA. Crew responds correctly
21:35:19 Boeing 757 advises ATC they are responding to TCAS RA
21:35:24 Tu 154 issued “Increase climb” RA. Crew continues to descend
21:35:32 Both aircraft collide overhead Überlingen
But TCAS is only of any use if the crews know how to use it correctly!!
TCAS RA directions always override ATC instructions!
On 1 Jul 2002, the Bashkirian Airlines Tu 154 and DHL Boeing 757 were on a collision course at FL360. This is what happened in the 50 seconds following the first TCAS Traffic Advisories:
21:34:42 Both aircraft receive TAs
21:34:49 ATC instructs Tu 154 to descend to FL350
21:34:56 Boeing 757 issued “Descend, descend” RA. Crew responds correctly
21:34:56 Tu 154 issued “Climb, climb” RA. Crew continues to descend
21:35:03 ATC instructs Tu 154 to increase descent rate
21:35:10 Boeing 757 issued “Increase descent” RA. Crew responds correctly
21:35:19 Boeing 757 advises ATC they are responding to TCAS RA
21:35:24 Tu 154 issued “Increase climb” RA. Crew continues to descend
21:35:32 Both aircraft collide overhead Überlingen
...the thin end thereof
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I wouldn't read too much into the fact that the Skyguide officials have laid the blame at the door of the ATCO. Given that they are facing criminal charges it's hardly surprising that the central plank of their defence is that the blame lies solely with the late Peter Nielsen. It doesn't of course, in reality, but given this is a criminal trial the defendants don't need to prove anything, least of all that someone other than them was responsible. So don't infer that an acquittal by the criminal court is an imputation of responsibility on the controller.
In reality what happened that night was a combination of systemic failings at Skyguide, serious mistakes by Nielsen which arguably amounted to gross negligence, national differences in SOPs which led the Bashkirian crew to ignore the TCAS RA, and just plain bad luck.
In reality what happened that night was a combination of systemic failings at Skyguide, serious mistakes by Nielsen which arguably amounted to gross negligence, national differences in SOPs which led the Bashkirian crew to ignore the TCAS RA, and just plain bad luck.
Last edited by Wedge; 19th May 2007 at 19:52.
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Wedge
It seems that you have a greater grasp of the detail of this than I do. You have made a strong statement about Peter Neilsen's part in the accident - I wonder if you would share the detail of his mistakes? Could it in any way be argued that his mistakes were provoked by the situation he was in?
What I find incredible is that (as I understand it) he was required to be monitoring 2 radar screens, 20 yards apart by himself. Surely, that is an unacceptable situation for any ATCO to be put in and it ought not to get through the safety case?
As far as the management is concerned, it seems to me that they willingly removed a number of the safety nets in order to get essential work done without first providing mitigation of the increased risks. That action directly exposed the system and Mr Neilsen. Regardless of what other errors were made, that strikes me as negligent.
.4
It seems that you have a greater grasp of the detail of this than I do. You have made a strong statement about Peter Neilsen's part in the accident - I wonder if you would share the detail of his mistakes? Could it in any way be argued that his mistakes were provoked by the situation he was in?
What I find incredible is that (as I understand it) he was required to be monitoring 2 radar screens, 20 yards apart by himself. Surely, that is an unacceptable situation for any ATCO to be put in and it ought not to get through the safety case?
As far as the management is concerned, it seems to me that they willingly removed a number of the safety nets in order to get essential work done without first providing mitigation of the increased risks. That action directly exposed the system and Mr Neilsen. Regardless of what other errors were made, that strikes me as negligent.
.4
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Oh dear ! The subject of this post is the trial, not to re-do the investigation.
I suggest that you look again in the Bfu report to find your answers.
TCAS flaws have been highlighted as a result of this collision and it is very simplist to suggest, as it is done here, that the757 crew responded correctly and the Tu154 did not.
As to the supposed "gross negligence" of the controller on duty, let me just say that this view is not shared by the vast majority of the people involved in the investigation, and even ,as far as I can see, also not by the defence lawyers.
How the judge will go is still uncertain.
I suggest that you look again in the Bfu report to find your answers.
TCAS flaws have been highlighted as a result of this collision and it is very simplist to suggest, as it is done here, that the757 crew responded correctly and the Tu154 did not.
As to the supposed "gross negligence" of the controller on duty, let me just say that this view is not shared by the vast majority of the people involved in the investigation, and even ,as far as I can see, also not by the defence lawyers.
How the judge will go is still uncertain.
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TCAS RA directions always override ATC instructions!
Can you confirm you are basing that allegation on definite knowledge that at the time, the Russian Company SOPs, authority legislation, equipment and Training were of a similar status to that on which you base your statement?
Without having investigated the accident in great depth, but to some degree, then it seems there were ATC "system" failings that enabled that system to fail. That TCAS then failed as well was unfortunate, but it was a relatively "immature" system, particularly for say some former "Eastern Block" nations/operators, and "rules" to which you and I operate, especially today, might not have applied then, to that crew...
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At the time, my company SOPs were that a TCAS RA was to be followed unless the target could be identified and was no threat. That SOP has since changed removing the proviso. Other companies have done the same.
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Re the Russian SOP w.r.t. TCAS: I recall from some discussion groups a few years back that there had been a dispute on the flightdeck of the Tu-154 between the captain, PF and the check captain, acting as the PNF. The check captain allegedly overrode captain's decision to heed the TCAS and insisted to descend as instructed by ATCO, exactly in line with the Tu-154 manual. Also as far as I remember, the main SSR was u/s and a backup unit was being used (not sure if that meant the processor-screen or a complete radar-feed).
Found the report, here, in German, it states three systemic causes: the TCAS issue compounded by failure to standartize (in the end, who will pressure Russia) requirements and harmonize units, and the other two are down to the Skyguide management. I hope the name of P. Nielsen comes clear out of this trial too.
Found the report, here, in German, it states three systemic causes: the TCAS issue compounded by failure to standartize (in the end, who will pressure Russia) requirements and harmonize units, and the other two are down to the Skyguide management. I hope the name of P. Nielsen comes clear out of this trial too.
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exactly in line with the Tu-154 manual
Question ímho is therefore - did Bashkirian drivers ever go a REAL trainig in it, ie did they really learn to obey it???
(NOT blaiming them but possibly their company!!!)
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His statement was more or less "oh, yes, we have it but if it is u/s we go anyway". This, well noted, on a "better" airline going to the "West" frequently.
If you can get 2 TCAS u/s aircraft in the same part of the sky AND an ATC "system" failure sufficient to cause a collision, it's not your day
As HF says, even in the West, training and SOPs have been tightened post this incident. In the East, life tends to be more "control based" and a larger cultural change needed to blindly obey a piece of kit contrary to an ATCO. Hanging the Russian crew out to dry (also dead) is as bad, IMHO, as hanging the ATCO out...
If you can get 2 TCAS u/s aircraft in the same part of the sky AND an ATC "system" failure sufficient to cause a collision, it's not your day
I pray the aftermath of the Uberlingen collision doesn't happen again.(with respect to Mr Nielsen's fate.)
At least in part due to the media, IMHO.
Although there was an ATC failure, Mr. Nielsen tried his damndest to cope as best he could.
The Bashkirian Airlines crew had all received TCAS training and the TCAS operating manual used for their course was quite specific concerning RAs and contradictory ATC clearances - even though the Tu-154 manual was rather less so. There was a 'seat swap' in progress as the co-pilot got back into his seat after the first TA - he made the point several times that the subsequent RA was very specifically ordering a climb......
Read the report in full, I would suggest.
The Bashkirian Airlines crew had all received TCAS training and the TCAS operating manual used for their course was quite specific concerning RAs and contradictory ATC clearances - even though the Tu-154 manual was rather less so. There was a 'seat swap' in progress as the co-pilot got back into his seat after the first TA - he made the point several times that the subsequent RA was very specifically ordering a climb......
Read the report in full, I would suggest.
This question has been troubling me since the accident, hopefully someone more knowledgeable of ATC than myself can resolve it for me.
Was it not the case that the Tupolev had been allowed by the previous sector to cruise at a non-standard level?
That being so, on transfer to the sector in which the accident took place, should that not have been made clear to the receiving sector?
Naively, I would'nt have that you'd be handed over to another sector at a non-standard level without either their acceptance, or an instrution to adjust ( climb/descend ) to a standard level for the sector you are entering.
There are many areas of the world where non-standard level cruise is widely-used, and indeed encouraged. I've used it myself on several occassions, but always in the perhaps misguided notion that in addition to TCAS, we enjoyed this further protection.
Any thoughts?
Was it not the case that the Tupolev had been allowed by the previous sector to cruise at a non-standard level?
That being so, on transfer to the sector in which the accident took place, should that not have been made clear to the receiving sector?
Naively, I would'nt have that you'd be handed over to another sector at a non-standard level without either their acceptance, or an instrution to adjust ( climb/descend ) to a standard level for the sector you are entering.
There are many areas of the world where non-standard level cruise is widely-used, and indeed encouraged. I've used it myself on several occassions, but always in the perhaps misguided notion that in addition to TCAS, we enjoyed this further protection.
Any thoughts?
According to MEL of the aircraft I've flown, it is allowed to dispatch with TCAS inop, but ATC permission has to be sought and in Europe it is usualy given.
That piece of kit is intended to save lives when conventional methods of aircraft separation have failed and that's what everyone needs to know, regardless of his cultural background. I find it hard to believe that russian peacetime culture puts obedience to authority above self-preservation. More likely the russian crew was never fully acquainted with the TCAS principles of operation and procedures to be followed in case of RA. Not their fault, mind you - it was fault of their trainning dept and Russian CAA.
Mine didn't. Since we got TCAS in 2000. it was always policy to follow TCAS RA unless it sends you toward terrain, thanks to safety pilot who understood TCAS very well.
It was not immature and it didn't fail over Ueberlingen - it worked as designed. My apologies for perhaps being narrow-minded, but I can't see flaws in TCAS itself in this case.
Indeed, at ZAG ACC there were only 2 ATCOs covering consoles usualy occupied by 6 of them and just as Adria DC-9 was handed over from mid to upper sector an told to stop sqawking alt (per procedure at the time) one of them had to take physiological break. It didn't help much that the overworked remaining ATCO panicked and issued instructions to DC9 crew that lead to collission. He was later sentenced by Yugoslav court to 5 years in prison but was released after year and half, after retrial. Other controllers and ATC organzation were acquitted at the first trial.
Not quite similar. To have coordinated TCAS resolution advisory manuevre, there have to be two aircraft equipped with TCAS and S mode transponders. RA's can be issued against altitude reporting targets and with plain A mode there can only be traffic advisory. And if transponder is off (as it seems to be case in Brazil), TCAS is helpless.
larger cultural change needed to blindly obey a piece of kit contrary to an ATCO
At the time, my company SOPs were that a TCAS RA was to be followed unless the target could be identified and was no threat. That SOP has since changed removing the proviso. Other companies have done the same.
That TCAS then failed as well was unfortunate, but it was a relatively "immature" system
TCAS flaws have been highlighted as a result of this collision
Sounds as though we may have some parallels here with the 1976 Zagreb collision..
And yet, something all too similar happened again.(Brazil)
Been in the TU Sim several times (other sim however) and talked to a lot of TU crews. All of them concurred that if a TCAS goes off they are not going to heed ATC commands but to follow TCAS no matter what. One put it brutally by saying "Why should I listen to the one who put me into a situation for the TCAS to go off in the first place?" While I find this a tad one sided, as a TCAS alert can be triggered by pilots mistakes as much as ATC mistakes, the gist of it is, when a TCAS goes off I'll follow it first and ask questions later.
Obviously the worst case scenario is if one guy follows TCAS and the other doesn't. So, if you get a TCAS RA and can't rely on the other guy to act on it, then things will go pearshaped very quickly.
I reckon that the Ueberlingen accident has brought that message home to just about all the TCAS users who care to read up on it. So let's hope that this will never ever happen again.
Obviously the worst case scenario is if one guy follows TCAS and the other doesn't. So, if you get a TCAS RA and can't rely on the other guy to act on it, then things will go pearshaped very quickly.
I reckon that the Ueberlingen accident has brought that message home to just about all the TCAS users who care to read up on it. So let's hope that this will never ever happen again.
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In fact, if one guy follows the TCAS and the other doesn't, you'd probably still be alright most of the time. It's when one follows it and the other _does_ take action, but the opposite action than they should, that things will go pear shaped.
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On the TCAs issue : caution not to mix pre-Ueberlingen ( July 2002) ACAS training guidelines , with post Ueberlingen. The current ones are quite different.
At the time, the training guidelines were not that obvious : an RA was an " advisory" not a " command" to be followed with closed eyes regardless of anything else. The contradiction between an ATC clearance" against RA direction was not that clear.
Most AIPs ( including the German one that legally was in force at the time and place of the collision ) said that unless in Emergency pilots should not deviate from ATC clearances, and an RA was never defined as an emergency.
In our case the ATC instruction was BEFORE the RA. So a bit of kindness for our Russian colleagues.They did some things wrong perhaps, but so did everybody else that night. But all this is in the BFU report.
Back to the original thread :
Latest from the trial : 7 of the 8 defendants accused the late controller on duty as the only person responsible. . He turns out to be the perfect scapegoat .Even his colleague ( the one that went to bed at 2300 ) said it was all the other controller fault, as it was up to him to check what the technicians were doing and what were the consequences. The judge asked him " But why did not you ask them yourself ,as when you went off duty you saw all of them waiting to come in the OPS Room ? : his reply :" It was not my task, and even if I had asked them, I would not have been able to understand their responses , I am not a specialist "
Pathetic defense ...I do not know which lawyers are advising them, but I do not think this will impress the judges much.
At the time, the training guidelines were not that obvious : an RA was an " advisory" not a " command" to be followed with closed eyes regardless of anything else. The contradiction between an ATC clearance" against RA direction was not that clear.
Most AIPs ( including the German one that legally was in force at the time and place of the collision ) said that unless in Emergency pilots should not deviate from ATC clearances, and an RA was never defined as an emergency.
In our case the ATC instruction was BEFORE the RA. So a bit of kindness for our Russian colleagues.They did some things wrong perhaps, but so did everybody else that night. But all this is in the BFU report.
Back to the original thread :
Latest from the trial : 7 of the 8 defendants accused the late controller on duty as the only person responsible. . He turns out to be the perfect scapegoat .Even his colleague ( the one that went to bed at 2300 ) said it was all the other controller fault, as it was up to him to check what the technicians were doing and what were the consequences. The judge asked him " But why did not you ask them yourself ,as when you went off duty you saw all of them waiting to come in the OPS Room ? : his reply :" It was not my task, and even if I had asked them, I would not have been able to understand their responses , I am not a specialist "
Pathetic defense ...I do not know which lawyers are advising them, but I do not think this will impress the judges much.
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as always...there was complete set of mistakes, but ultimately controller on duty cleared two planes on conflicting route to the same level. this tragedy is sad reminder for all of us professionals. and a lesson - they will always blame the last in the chain.