Mid Air collision over S Germany

[radar707]

Reports of a mid air collision betwen a DHL B757F and a Bashkirian TU154 over Germany at FL350.
Buildings on the ground near lake constance are ablaze, 2 confirmed dead, one would assume that all on board both aircraft have perished.
Collision happend in Zurich upper Airspace at FL350.

How could this happen???????????


May God have mercy on the souls of those who have lost their lives

[Fox3snapshot]

The possibilities are endless radar707....this is after all aviation.

Time will tell.

:confused:

[120.4]

May God also console the poor ATCO who watched it happen.

There was an incident at Heathrow a few years ago where traffic off LAM and BNN were on the usual headings, at the same level. The ATCO, well known on these forums, tried to descend one and got no answer. So he went to the other and got no answer. They got to 4 miles apart, slightly crossing tracks and dead ringers before the BNN traffic stumbled back onto the frequency. From the recording, I would say... another 30 seconds would have been too late. He thought he was going to watch a midair happen and it must have been a most awful few moments. Just watching the recording was hearthumping and I knew they missed!

This poor soul in Switzerland will always have to live with this, where ever the responsibility lies. God bless him.

Point 4


:(

[Delta Whiskey]

Yup - saw film of it on the news tonight - my heart goes out to all the victims in the aircraft and on the ground - seems there were a lot of kids on the Tupolev whaich makes it even worse.

As for the poor sods in front of their radars, what can you say - they must be shattered, and I hope the Swiss or whoever have a strong and supportive union to help them through this.

:(

What happened to TCAS - is it not mandatory in that airspace?

[Asda]

Here's the link to the BBC

Tragic.

http://news.bbc.co.uk/hi/english/world/europe/newsid_2081000/2081332.stm

[Barnaby the Bear]

It seems from the reports that the Russian pilot didn't respond to ATC, and the DHL pilot descended in response to TCAS.
Was the Russian on the wrong frequency? Or was his avoidance system faulty? Or neither?
Who knows. The worst irony, as the bbc quoted, was that the children on the Russian flight had the flight specially chartered so that they would not miss any of their holiday. The parents believed their children were already enjoying themselves.

Let's hope they recover the black boxes in order to find out the true reason for this tragedy, to help avert another one.

:(

[lukewarmskywa*ker]

Interesting that much of the speculation so far has concentrated on the fact that the Tup154 may not have been listening, or may have been 'lost' on another frequency.

Both the BBC and Sky News have had experts along who state that this temporary communication failure is rare. In my experience (at whatever center) a/c getting the wrong frequencies, misdialling or otherwise being temporarily incommunicado is a daily occurrence.

Without really wishing to join in the speculation, I would like to ask whether these occurrences, and particularly this incident, would be possible if all a/c and all centers (other than just Maastricht) had a/g link?


All our thoughts are with the victims, their families and the controllers at their respective units. There but for the Grace of God......:(

[A Nonny Mouse]

Have a look at the post by Volume on the reporting point forum (copied below). It implies that it was standard practice for the controller to instruct one of two a/c at the same level to start descent only 50 seconds before collision, and this is in fact what happened. By missing just one call, a disaster happened.

This seems very strange practice to me, and definately not SOP as stated in previous reports from the Swiss!

The report seems to be from the German Aviation Authority.



_______________________________________

02.07.2002 05:00
BFU Press release
Actual Aircraft Accident


On July 1st 2002, 23:35 MESZ (21:35 UTC), well above the Bodensee a midair collision happened with a B757-200 (DHL) and a TU154 (Bashkirian Airlines – Russian Ferderation). The RNAV-Route Salzburg-Traunstein-Kempten-Trasadingen was used by the TU154 while B757 flew along RNAV-Route ABESI-AKABI-TANGO, both aircraft approached each other at FL 360. The collision took place close to AKABI at FL 354. At the time of occurrence both aircraft were under control by Zürich ACC.
The accident is under investigation by the BFU.

An investigation team is out to arrive at the accident site and to meet the investigation team of the Police in Friedrichshafen.

Momentarily the follwing is known: B757-200 / TU154

Aircraft Operator: DHL / Bashkirian Airlines
People aboard): 2 / ca. 57 + 12
Departure Aerodrome: Bergamo / Moskau
Destination: Brüssel / Barcelona
Flightplan:
Mode of operation: Cargo / Charter PAX-Transport
People killed:
People hurt:
Aircraft damage: Both aircraft crashed
Third party damage: Buildings and environmental damage
Phase of flight): cruise
Type of accident: Mid Air Collision

As soon as new information is available, it will be published on the BFU-internet-homepage or released.

Ergänzung der BFU-Presseinformation von 05:00 Uhr
(Supplemental Information, 5am UTC)

Eine erste Auswertung des Sprechfunkverkehrs der Schweizer Flugsicherung mit den beiden Flugzeugen hat ergeben, dass die Besatzung der TU 154 ca. 50 Sekunden vor dem Zusammenstoß die Anweisung bekam, von Flugfläche 360 auf Flugfläche 350 zu sinken. Dieses Sinken war für den Weiterflug nach Barcelona notwendig und war gleichzeitig eine Maßnahme, um einen Höhenstaffelung zu der Boeing B 757 herzustellen.

(Analyzing swiss radio recording, the 154 was advised to sink from FL360 to FL 350 50 seconds prior to the collision, this altitude change was already planned for the flight to barcelona and an action to achive separation with the 757)

Während die Besatzung auf eine erste Aufforderung nicht reagierte, reagierte sie auf eine zweite Aufforderung und begann den Sinkflug ca. 25 Sekunden vor dem Zusammenstoß. Kurze Zeit später begann auch die Boeing 757 aufgrund einer TCAS RA zu sinken. TCAS bedeutet „Traffic alert and collision avoidance system". Dies ist ein Gerät, das die Besatzung eines Flugzeuges vor anderem Flugverkehr warnt und der Besatzung Anweisungen gibt, wie zu reagieren ist, um einen Zusammenstoß zu verhindern.

(Ignoring the first advise, the 154 crew started to descend 25 seconds before the crash, shortly AFTER the 757 also started a descent due to an TCAS RA [...])

Warum die Warnung dieses Gerätes ebenfalls zu einem Sinkflug der Boeing 757 führte, ist noch unklar und wird Gegenstand weiterer Untersuchungen sein.

(Further investigations will show why the warning advised a descend for the 757)


So maybe someone put the blame on the russians much to early ?



Verry, verry sad, condolences to all involved

[StuckMic_com]

It seems from the reports that the Russian pilot didn't respond to ATC, and the DHL pilot descended in response to TCAS.

Just read this myself at CNN (http://europe.cnn.com/2002/WORLD/europe/07/02/midair.crash/index.html) in the paragraph titled 'Double descent'.

[Vlad the Impaler]

Just spent half the evening reading through the posts on "Reporting Points" forum. Some interesting stuff on there. Everybody in the media has been quick to jump on the russian crew as they are an easy horse to beat. If it is true that Swiss ATC had two Co-ordinated in at FL360 (from different centres) on crossing tracks and then failed to attempt to resolve the situation until they were 8-10nm apart then that is a bit frightening. I know we are all human and we all make mistakes which is why STCA, TCAS and the like evolved. It was also said by swiss ATC that they have medium term conflict alert but it was down for maintainence. Surely it will all come out in the wash....
But for the grace god go us all and lets spare a thought not just for the families of those killed in this tragedy, but the poor guy or guyess at the console who, regardless of any blame or not, saw it happen on the tube. I'm that is something that will stay with them forever and I hope to god I never have to deal with it................................................

[Fox3snapshot]

To much reliance on "gadgets and Gizmo's", lets get back to raw ATC and flight operations and also use some of the more basic, and yet effective ATC tools at hand. Radar is wonderful, but at the end of the day the triple redundant radars (as always so proudly advertised by manufacturers!!!) do fail, ours only 2 days ago..... my point is that it is still important not to forget the basics of our procedural standards and build a bit of "fat" into the program to allow for, poor comms, possible language problems, co-ordination failures, radar failures etc. It should be noted that quite a few of these issues are human factor related and on last check we are all human.

I am sure for the controllers that have been in the business long enough and have filled their "little bag of tricks", that one of the most dangerous times is when it is quiet. Having had a few good scares on these grounds, I ensure now that during these times I am proactive with conflict resolution because I have let myself down before through complacency. This point is made not necessarily to the actual case at hand, which investigation is still only in its infancy, but more as a wake up call to us all in every aspect of the industry to ensure we all maintain our highest possible standards and support each other to provide the best and safest service possible.

It goes without saying that regardless of who is responsible, the controllers and supervisors at this centre will be enduring the most horrific time of the lives and it is important we make sure that we give them the support they need.

:(

[120.4]

I have just been hearing about another incident at LL yesterday involving a Shuttle off BNN which went PLOC (prolonged loss off communication). It went for about 15 miles across the top of LL (fortunately pre co-ordinated) and down the south side without talking.

So why have the Russians been blamed so quickly for this mid-air? Yes they didn't respond as quickly as one would like but surely, a system which allows crossing traffic to get that close at the same level before taking action is at the root of the cause?

The first lesson I learned at the college was that in this game sod's law works double but because things rarely go wrong, we have come to expect that they won't. It seems to me that, driven by commercial pressure, we are no longer allowing for the possibility of system failure and there are circumstances within the London TMA which could allow such an accident to happen here.

Point 4



:(

[lukewarmskywa*ker]

Nice point 120.4

It may turn out that, as normal in these circumstances, the blame is shared around.
But I really feel for the controllers involved, whatever happens, because I know that they will feel (probably correctly) that even if they acted to the letter of standard ops proc, they could have done something else, something extra, and averted this.

I'm very sorry for all involved, and us too. The last couple of days at work have been strange. Crews nearly never miss a call now, and everyone's a little bit more circumspect and sombre. In a way I look forward to the day the sick jokes start, then I know we will have started to recover.

But maybe it'll take us all some time.

[DOVER 8 MIKE]

accidents like this should not happen with today technology in uncongested skies at night... who or whatever is to blame will come out in the end.... prayes go out to all those who lost thier lives and thier families...

In my opinion non TCAS aircraft should not be allowed to fly in european airspace... why bother making oneperson compliant and not the other(s)....

GOD BLESS ALL INVOLVED

[BwatchGRUNT]

On a preventative note is it correct that the Swiss centre is the only other privatised ATCC in Europe, and did I hear that there was only one controller on the radar. Let that be stern warning to anyone still prepared to undertake both Tactical and Planner roles at LACC against the regulations - and management, lets hope this tragic event will prevent you from ever considering single manning of night shifts as a solution to our desperate staffing situation.

I feel as much for the families as the controller involved, a terrible tradgedy and one which we have to agree could have been prevented and MUST not be allowed to happen again. Whatever the issue, voice your opinions through all available channels and do not allow your concerns over safety to be brushed asside, we need the system to be as safe as possible.

[Lon More]

Dover8Mike wrote: In my opinion non TCAS aircraft should not be allowed to fly in european airspace... why bother making oneperson compliant and not the other(s)....

This seems to be totally irrelevant in this case, however the greatest offenders are the various governments themselves. A large percentage of "state" aircraft are neither TCAS or RVSM equipped.

May their gods be with them

[Euroc5175]

BBC news are now reporting that due to the 'conflict alert' system (STCA?) being off-line for maintenance, the procedures are for 2 controllers to man the sector (presumably as T & P). An extra set of eyes and ears to make up for the absence of the automated conflict alert, whether that be STCA or Medium Term Conflict Detection.

One of these controllers was reportedly on an "unauthorised break" when the accident happened.

The finger seems to be being pointed at the Russian crew. However, if, and it is only an 'if', both the aircraft were co-ordinated in at FL360, the controller has accepted a planning conflict that should be resolved by tactical means, i.e. vectoring or climb/descent, when on frequency. The fact that reports indicate instructions to change level were only given a minute prior to the accident occurring would suggest that 'avoiding action' was being instigated rather than a routine deconfliction of traffic. Vertical separation should of course be provided before the loss of lateral separation (presumably 5nm in the airspace concerned). Unfortunately, initial indications suggest that ATC error may be the root cause of the accident.

[AREA52]

This should be a serious reminder to all ATC management of the responsibility of controllers and the job they do.

Yes this accident happened at night and complacency may have been a factor,as we know can happen when sectors are quiet.

However, management should now be very cautious on pushing flow rates up and providing very little contingency for when it does go wrong. The number of current overloads at LACC shows the position that people are being put into.

Sectors should never be working above 90% capacity to allow for unusual events, bunching or over delivery of traffic.

I hope it doesn't take something similar in the UK for management to take note!

And they think we are overpaid????:confused:

:(

[BDiONU]

Obviously we don't have all (or any?) facts from the press reports, generally all speculation. But I do wonder, if its true, that if the Russian failed to respond in time to the avoiding action given why the Controller never issued avoiding action to the DHL? Or why it wasn't given to both considering they must only have been about 15 miles apart if its true that the first descent instruction was given to the Russian at 50 seconds before impact.

[Ahh-40612]

PUZZLED!!

Just watched BBC1 6pm news talking about Swiss STCA being off for maintenance.

Followed up by saying that 'UK ATC say that their safety systems are never switched off'.

What about weekly shutdowns and DD+C events???
Everything goes off - or am I dreaming?

[MacDoris]

News also said tonight "this could never happen in UK airspace as there are always two controllers controling each aircraft".
Maybe at NERC (or maybe not) where there is the whole planner tactical thing going on, but what about other units where its just the guy (or gal) on the tube?

[BDiONU]

Uuuummm, STCA is not a safety tool, just a nice to have (although it saved my bacon a couple of times when I was an ATC!). Hence it can be off for Bypass mode at LATCC, DD&C etc. at LACC and so on.

Had a bit of a ruckus when I discovered this from the engineers! Seems that if it was safety then it would be a cat 2 tool with multi redundancy etc etc. Cost a fortune. As it is its a cat 5 (might have the numbers wrong, Engineers correct me please!) and costs a LOT less!!

[ATC Watcher]

Saddest day in European ATC for decades.
Our thoughts should be for the poor guy that was alone on that frequency that night, (his life as he knew it is gone, we all know this), and for the parents of those that perished , mostly children whose lives were taken by a sequence or errors.
Warning my friends, do not jump to conclusions on the Russians.
from my info, the TU154 crew spoke very good english ( confirmed by the previous controllers in EDDM )was RVSM ( confirmed by the overfly over Linz HMU an hour before ) and according to Eurocontrol database was one of the few TU154s equipped with TCAS.
The poor guy in LSZH was alone and the main system was in maintenance, therefore probably no OLDI as well as no STCA, verbal coordinations / estimates etc.. you get the picture.
The " unhautorised break " of the second guy is bull**** . Everyone that makes night shifts knows what Imean.
Now the rest below is speculation from my part :
For me this could be another TCAS induced error, where one pilot got an RA, the other got an opposite RA but which was conflicting with the (possibly emphatic )ATC clearance received.If traffic info was passed ( looks like it ) the russian pilot might have diregarded the Climb coordinated RA he probably received.
If you were in the TU 154 captain seat and had made visual with the 757, and got an ATC clearance to descent immediately, would you be 100% sure you would have reversed the manoeuvre on account of a TCAS RA ?

Anyway the main result of this is that in a few months or years a young guy will find himself in front of a judge , with 70 families of those who died in the room, and he likely will go down , failed by a system and his bosses. That makes me feel extremely bad.

The one that has never sat alone on a postion a night can throw the first stone....

[G-SPOTs Lost]

ATC Watcher

Im not ATC but thanks for that sincere post, hope the controller and families can come to terms with what has happened

[Stan Woolley]

I was unfortunate enough to have a close, opposite direction same level (FL330) airmiss about seven years ago. We had TCAS on the a/c but it was u/s at the time and not mandatory in Europe. Luckily we were VMC and I saw the guy coming.

The only point I would like to make is that it is very difficult to visually judge the relative level of other traffic, especially now with RVSM and 1000'separation. It is even harder at night and sometimes cloud layers can add confusing optical inputs.

My condolences to all affected.

[Lon More]

Conjecture - If the STCA was on maintenance, how much more of the system was compromised? That is, as Watcher pointed out, OLDI, EPCM/strip printing, track labels etc. It's possible that the controller only had c/s and Mode C displayed.
I heard that the system at Maastricht went down this morning as a result of on-line testing during the night and the Code Assignment Tables being full???

[ATC Watcher]

Thanks G spot ( I like your name )

While browsing through the skyguide web site I found this ( unfortunaley only in French :

Zurich, le 3 juillet 2002, 14:30 heures

Dans une interview qui a malheureusement déjà été publiée, M. Maag, responsable du centre de contrôle aérien (ACC) de Zurich, s´est exprimé de façon peu claire au sujet d´une consigne de service selon laquelle le travail de contrôle est effectué par un homme seul. Le fait que l´un des deux contrôleurs aériens en service prenne sa pause après en avoir convenu avec son collègue correspond aux consignes de service officielles. En effet les - Single Manned Operation Procedures - pour le service de nuit prévoient cette manière de faire qui ne porte donc nullement atteinte aux prescriptions en vigueur.

skyguide, swiss air navigation services ltd
Media Relations


Renseignements état-major de crise:

+41 1 816 62 05
+41 1 816 62 06
+41 1 816 62 07


( It basically says that the Head of Zurich ACC screwed up in an interview to the media and that single manned operations during night is not only legal but part of the regulations in use in Zurich ! )
Management at his best once more.

[Kalium Chloride]

This could never happen in UK airspace...


Famous last words. I'll bet they'd have said the same about German and Swiss airspace a week ago. :rolleyes:

[Scott Voigt]

Come the midnight shift over here we are ALWAYS with just one person on the radar. In our areas we have three people on duty with two radar positions open. One on each radar and one delivering flight strips while it is busy and then as break relief when things slow down...

regards

[NERC Dweller]

This is a truely tragic event and my thoughts go out to the bereaved and the ATC on duty that night.

To correct a few inaccuracies that have appeared on this thread regarding STCA at LACC

1) T3C5 - The ALP servers (These provide the STCA warnings) are a dual redunant pair. If the PAS (Primary Address Space) fails then the SAS (Secondary Address Space ) will take over.

Although not considered a safety system the coding and testing of the application is the same as any other system. I was also surprised to find this out, but as someone explained you don't use STCA to control aircraft. Given recent events that thinking may change.

2) Ahh-40612 - STCA is unaffected during DD&C or NAS shutdown at LACC. The TDU has a complete set of Servers and these are running providing the same services as OPS (including STCA). STCA also works purely on Radar and therefore has no need for flight plan data.

[sector8dear]

What a truly awful thing to happen. I can not express in words how I feel for those affected.

Can we please learn from this (bean counters take note) THIS IS REAL AND REAL PEOPLE GET HURT!!!!!

Safety IS the only consideration - not how cheaply you can provide a service.......one little mistake and.....there but for the grace of God etc etc.

What a pittance is a few more salaries against the deaths of children going on holiday....

God sometimes I wish I was not in this line.

[BmPilot21]

Lon More, you say that TCAS not being fitted to the Russian a/c is irrelevent in this case. If it had a functioning TCAS, then it would have co-ordinated an RA with the DHL, and had both RAs been obeyed, then it would have prevented this accident. TCAS RAs should always be obeyed, even if contrary to an ATC demand.

Two questions : can anyone confirm whether the Russian a/c was TCAS equipped? It may have been inoperative.
Also, whilst it is not mandatory for RVSM, I thought TCAS was mandatory in European airspace - is there a 'lead in' time to allow operators to modify there a/c, or should they all have it by now. Perhaps it ought to become a requirement in RVSM.

Seems a bit worrying if there was only 50 secs or so allowed to resolve the known conflict. We all know that blocked frequencies, pilots dialling the wrong frequency up, or pilots not hearing instructions happen every day - and can easily take minutes to resolve.

I hope we can all (pilots and controllers) learn lessons from this
and make sure it doesn't happen again - next time it could be over Manchester etc with even worse consequences. I hope this will change the way that controllers and the infratructure are being treated and run right now, and should be a wake up call for all.

[NorthernSky]

Let's stop this rubbish about TCAS. If one aircraft is fitted, and the other has a functioning altitude reporting transponder, then they 'should not' hit.

If both have TCAS, the RAs will be co-ordinated, and they 'should not' hit.

If all pilots have always reacted correctly to TCAS RAs, then my name is Graham Norton. Too little training, and of the wrong type, has led to enormously widespread mis-understanding of TCAS by those involved in its use.

Now if the TCAS action was downlinked to ATC and linked into STCA, in order to allow controllers to back-up the TCAS RA guidance, THAT would be a step forward.

Mind you that's like saying that TCAS shouldn't be necessary. It wasn't, until recently. Now, it's preventing collisions every day. Just not on July 1st.

All this analysis aside, let's not forget the families who are left behind. They don't know enough about this business to achieve a change. We do, and if we can bear their loss in mind, we can take steps in the right direction.

[mysteryman]

Evening

Newsnight has just quoted Russia as saying they had
the TCAS turned off for maintanance
and swiss still saying they had an unauthorisied break
Yet we all breathe a sigh of relief
Thank God this wasn't here here in the UK
(sorry condolences to all the families)
MM

[Lon More]

BmPilot Read the much more comprehensive posts in the Reporting Points Forum. Both aircraft were TCAS/RVSM compliant.
I was merely pointing out that the statement made was irrelevant when the biggest "offenders" are also the lawmakers.

[followme]

Terrifying for the controller who had to watch it unfold, terrifying for the pilots scrambling for an adequate resolution which was never forthcoming. We all know controllers make mistakes. We all know pilots make mistakes. We all know TCAS makes mistakes. When all facts are brought forth the correct action must be taken. There is no room for complacency from controllers, pilots, engineers, management...we are a team...we protect lives...priority number 1.

My thoughts and prayers go out to all involved...

[Llamapoo]

I think there are some other messages that management need to take on board while they frantically try to find a controller or dead flight crew to pin the blame on.

Spotting conflicts and acting in good time is 'bread-and-butter' controlling (although I don't know what conditions were affecting the controller in charge when it happened). Yet a lot is being spoken about the Medium-term conflict detection being off. Don't Skyguide use strips or some sort of electronic data presentation? In which case couldn't the controller spot to a/c at 360?

Have the Skyguide management procured a system that ultimately de-skills the controller? Has use of the system left the controller without his/her bread-and-butter skills? Maybe management should be prepared to hold up their hand and share responsibility for decisions made a long-time ago, probably on the basis of financial (i.e. staffing) grounds, that may have contributed to this terrible tragedy.

NATS is looking at a variety of controller aides that will ultimately relegate the controller to the role of monitor. These may make us more efficient and safe, but without a fall-back mode. Let's hope management stop chasing the profit motive and consider the implications for controller skill.

If they don't, let's hope they start to take responsibility for their roles in any future incident.

[Go for 5, Get 3]

NorthernSky
BMPilot21

I am not a pilot, therefore the basics of TCAS aside, I will not pretend to understand company requirements etc. However, TCAS is not infallible and it may be worth looking at the thread on this Forum titled nasty incident and in particular the posts by Capt Pit Bull.
It shows how easily these perfect sytems can be fooled!!

[Cross Check]

G45G3

Careful - CPB's very informative post speaks nothing of anything being fooled. The TCAS, within its operational constraints, is determining/negotiating a course of action to achieve minimum separation based on information continuously available to it and can, if calculated necessary, reverse it's decision - one possible reason why... one or both crews didn't follow (or were slow to follow) an issued RA. Hesitation because of momentary confusion serves only to reduce the margin of separation. In fact ARINC pointed out at NBAA last year that operational data indicates that typical RA response is slower and weaker than that assumed by TCAS resulting in less than desired separation being achieved. Improper response, lack of responses or slow response to RAs continue to result in aircraft getting closer than desired.

An update on TCAS v7 - ARINC (http://www.nbaa.org/@@2ArvCi6FzAEK/2001/ppt/tillotson.ppt)

TCAS may be your last resort when the system and "see and avoid" aren't working for you - like in the middle of the night over Lake Constance (God rest their souls in peace).

[ioco]

Hello,

I am new here. A very close family friend was on board one of the aircraft that went down in Germany on July 1rst and I am trying to get a few answers. I have asked this question in other forum's but have yet to get an answer that makes any sense so I am trying here.

I used to be a very frequent flyer on business and on many occasions (pre 9/11) was invited to the flight deck on many aircraft, on many airlines, and even had an opportunity to observe landings and take-offs.

On these occasions I learned a little bit, and one thing that made me feel very safe was what a little screen that showed other aircraft in the vicinity. You folks have an acronym for it but I can't remeber what it is called. I remember one Captain telling me that it was adjustable, and could be tuned for various distances from the aircraft. You used a longer range when at altitude, and a closer range on approach.

If the two aircraft had this gizmo set to maximum range - how much notice (in distance or time) would they have received from this on-board anti-collision equipment.

Thanks for your help.

[Standard_Departure]

Hello there Ioco,

Please accept my most sincere condolences for your loss.

The equipment you refer to is called TCAS (Traffic Collision Avoidance System).

There are some parameters of the system that can be configured, one of these parameters is the vertical (height above or below) aspect, the other is range (forward distance).

There is another parameter, angle from the nose (left and right) but I don't know if this is adjustable or not..

Assuming that the other aircraft was inside the angle (in this case about 90 degrees), I believe the maximum distance is about 40 nautical miles.

The aircraft would have been travelling at about 450 knots (ground speed), that equates to about 7.5 nautical miles /minute. Therefore, if all the parameters were set to maximum, and my above assumptions are correct. The other aircraft would have been displayed for about 5 minutes.

Hope this helps.

[ioco]

SD,

Thank-you for this. It does however just raise a number of other questions that I guess we will all have to wait for answers to.

thanks,

[ATC Watcher]

J ust to complement what has just been said,
watch out Ioco not to jump to conclusions too hastily.
30 to 40 NM is correct IF the display was set up that way, and if it was the other a/c only appears as a symbol of info, i.e. not to be reacted upon.
Also I doubt very much that the crews were glued to their TCAS screen, as there was no reason at this place, time and Altitude to keep watching the TCAS screen.
The real warning, with an audio, came much, much later. The CVR tapes will tell you exactly how much.
You will know by early next week, as the tapes are damaged and need repair before being exploited.. My sincere condoleances for your loss.

[lukewarmskywa*ker]

Hello Ioco,
I wish you and your friend's family all possible strength. And I hope you find some answers quickly.
TCAS is Traffic Alert and Collision Avoidance System. The Alert word is important, because you need to know that TCAS is not just a last-ditch tool, but it also provides information to the crew to supplement their 'situational awareness'.

There are two forms of message that TCAS passes the crew, the first is Traffic Advisory(TA). In this case the system detects that there may be traffic in the vicinity which could pose a threat. However, it obviously has no knowledge of instructions passed to either it's own aircraft or any other by ATC. In this way, it maintains its independence from the rest of the ATC system, but it therefore also at times passes information to the crew which although useful, certainly would not cause or instruct the crew to deviate from their ATC instructions.

The second type of message is a Resolution Advisory (RA), in this case the system detects that the aircraft is in imminent danger of a collision. It calculates the best option to avert this collision, and gives a visual warning and an audible alert (eg 'climb, climb ') to the crew.
It is intended that this instruction from TCAS takes precedence over any instruction from ATC.

In this case it may be that a TA was passed to the crew at around the 90sec/ 1 min stage (note this is entirely speculation!!), but as I mentioned earlier, although this may give some kind of warning to the crew, they will not take any action based on this (although in reality crews very often call the controller and state that they have got a Traffic Advisory, and basically ask for some reassurance).

Not until the 15 to 25 second stage before collision will the TCAS system issue a RA to instruct the crew to take evasive action regardless of their ATC clearances.

Some news programmes I have seen tend to give the impression that TCAS is some kind of automatic flight control system which will climb or descend the aircraft without the crew's involvement. It absolutely is not. It is only a warning and instructive system.

Sincerest condolences,
Lukewarm

[Goldfish Watcher]

As these are anonymous forums the origins of the contributions may be opposite to what may be apparent. In fact the press may use it, or the unscrupulous, to elicit certain reactions.,

[lukewarmskywa*ker]

Naturally true Goldfish.

Interesting though that you write..

In fact the press may use it, or the unscrupulous

There's a difference?

[ioco]

Thanks for the information and your kind thoughts.

If GW is concerned about my post - there is no need to be.

[5milesbaby]

To maybe clear up a point, I had an aircraft last week inform me they had just lost their RVSM approved status due to the TCAS packing up. Seem to remember when the trials began over the Atlantic, a/c had to have 2 of 3; INS, GPS, and one other, and only 2 out of 3 needed to work, but then I could just be dreaming.......and things obviously change!!!

[Kiting for Boys]

New to this Forum but just heard BBC announce that the Russian pilot told the Swiss ATCO that they had a proximity warning which prompted the order to descend. The Germans say that their controllers had been watching for two minutes and trying to warn Swiss.

God have mercy on the dead and comfort the living

Text from BBC website:

According to German authorities, cockpit warning systems told the Tu-154 to climb and the cargo jet to descend, just 45 seconds before the collision.
But voice recorders reveal that one second later, Zurich air traffic controllers told the Russian pilots to descend.
The Russian crew did not respond, so the Zurich control tower repeated the order 14 seconds later, investigators say.
The Russian plane responded and the two aircraft collided 30 seconds later.

Although the aircraft were flying over Germany at the time, they were under the control of the Swiss air traffic control body, Skyguide.
Investigations are being carried out by both Swiss and German authorities.

The Swiss inquiry is looking into the possibility of homicide through negligence, which carries a three-year jail term for anyone found guilty.

Irregularities
Earlier, the German weekly Der Spiegel reported that German air traffic controllers had tried to warn Skyguide that the planes were on a collision course
But all attempts reportedly failed as the telephone network at Skyguide was down at the time for maintenance.

While Skyguide had initially pointed the finger at the Russian pilot's failure to respond promptly to the air controller's warning, it has been revealed that there were several other irregularities at the control centre on the night in question.

In addition to work apparently being carried out on the telephone network, the centre's collision warning system was down for maintenance and only one controller was on duty at the time of the crash.

The controller, who warned the Russian pilot to change course just 44 seconds before the collision, has been described as overburdened by a German team investigating the crash.

[FWA NATCA]

Investigators are now saying that the Russian plane received a TCAS resolution to climb, and a descent instruction from the controller which he apparently complied with, the DHL 757 received a resolution advisory to descend.

I wonder why the Russian pilots chose to ignore the resolution to climb, don't they have to follow what the TCAS tells them?

Mike

[Max Angle]

In response to the post above about TCAS, it is NOT required for flight in RVSM airspace. It is worth noting in the light of this accident that our (and I guess most other operators) TCAS can be out of service for up to 10 days before it is fixed under the current dispatch regulations. During that time the aircraft is still able to fly in RVSM airspace and as far as I know ATC do not have to be informed of the defect. I suspect we may see a reduction in the allowable time to perhaps 24 hours or 3 flights which I think is the time allowed for things like GPWS and flight recorders.

Lets hope that some good can come out of the ashes of this one and things will be a bit safer as a result.

[ioco]

Sorry for the ignorance, but thanks to you all for a great deal of information.

What is RSVM?

[ioco]

Cancel that.

RVSM?

[410]

Hello, gents. This is my first post on this particular site, but visitors to ‘Reporting Points’ may recognise my ‘handle’. If I may use a few random quotes from this thread to illustrate my pet cause, the introduction of offset tracking (which I accept would not have prevented this particular tragedy):

From ’Fox3snapshot’: “…my point is that it is still important not to forget the basics of our procedural standards and build a bit of "fat" into the program to allow for, poor comms, possible language problems, co-ordination failures, radar failures etc.”

From ’120.4’: “The first lesson I learned at the college was that in this game sod's law works double but because things rarely go wrong, we have come to expect that they won't.” (my boldface)

From ‘Flanker’: “I was unfortunate enough to have a close, opposite direction same level (FL330) airmiss… Luckily we were VMC and I saw the guy coming.”

Finally, one last quote from this thread: “This could never happen in UK airspace...” My bet is that until a week ago, there would be many of you who would have said: “This could never happen in Western European airspace...

Some of you may care to take the time to read the following two submissions that have been on the Pprune Tech/Safety board for more than five years now:
http://www.pprune.org/go.php?go=/pub/tech/MidAir.html
and
http://www.pprune.org/go.php?go=/pub/tech/MidAir2.html

So do we wait until the scenario ‘Flanker’ gave us in the quote above actually results in a head-to-head midair before we lock yet another proverbial stable door behind a long gone horse? Or do we all, pilots and ATCOs alike, INSIST upon the speedy implementation of an embedded offset for all operations above 10,000’ for appropriately equipped aircraft?

I urge anyone reading this to consider this suggestion beyond (what seems to be) the immediate knee jerk reaction of saying “it can’t be done”. It is not a slight on the professionalism of ATCOs, just an acceptance that mistakes can – and, as has just been proven, do – occur in the most professional organisations. Why do we insist on placing pilots in a position of quite literally dodging speeding bullets when the technology is staring us all in the face that would ensure those ‘speeding bullets’ will pass exactly ‘.n’ miles abeam of them – every time?

[Nugget90]

TCAS equipment serviceability has proved to be pretty good, but when a fault does appear, it tends to be something that cannot be fixed by a simple box change. For example, a problem with an aerial may not easily be rectified at a line station.

It is therefore reasonable to allow the aircraft time to return to its major base where rectification can be carried out. Remember, some aeroplanes may be on the other side of the world when the fault materialises. Therefore, the 10 day period has been thought reasonable either to allow that aeroplane to return to base or, if it is a small/medium sized aeroplane without comprehensive spares support facilities at home, time to get a repair kit shipped out.

One other point worth bearing in mind. It is extremely unlikely that two aeroplanes, both with unserviceable TCAS, will find themeselves in a situation that needs TCAS to resolve. Where only one of a pair has serviceable TCAS, the manoeuvre perfomed by its pilots should produce a sufficient difference of altitude to ensure that no collision occurs. (This would be also true if the other aircraft didn't have TCAS anyway.)

[romeowiz]

A few words from one who was close to it:
being an incident investigator at the unit next to Swiss Radar (we expected DHX611)and taking care of our controllers this particular night I was running a few replays of the incident. Emotions were extreme. We saw it coming, our STCA (short time conflict alert) flashed the labels in bright red 132(!) seconds before the impact. Our controllers tried to reach Zürich over all landlines they had but could not get through until it happened. This is a horrible feeling. An incident like this showed up some times before but passed as a "close shave". It´s man against machine; TCAS says acft1 climb, acft2 descend. Controller´s solution is acft1 descend, acft2 climb. Both are ok but should have the same participants. Here we had two solutions with only one participant each. DHX611 (Dilmun) performs a TCAS descent, BTC2937 (Bashkirian)has a corresponding TCAS-RA "climb" but believes the controller and descends, too.
Both acft too close and too fast to let TCAS switch the RA for the "Dilmun" into a climb. Only solution for TCAS: "increase descent". This is from 1.500fpm to 2.500fpm, normally. Such a rate is ridiculous for a TU154 being asked to "expedite descent" . Both acft hit at FL354 in the descent.
Our thoughts are with the victims and with the one survivor: the controller at Skyguide who was in charge. We consider he cannot be happy no more for the rest of his life.

What can we do to solve this "man against machine" problem?

Edited to remove text which could identify the poor soul involved ..... PPRuNe Radar

[actas]

In all the discussion I see in this and other threads there is one thing that I miss and I think it is something we must not forget. Whatever happens and whatever incidents or accidents may occur, there will always be a very significant difference in approach between Air Traffic Controllers and Pilots and that is the fact that the Pilots life is directly at steak and not the life of the Air Traffic Controller.

All the discussion about lives being ruined anyway cannot take away that fact.

PS.

I am both

[NigelOnDraft]

romewiz

<<What can we do to solve this "man against machine" problem>>

Its all laid out - you obey TCAS every time there is a conflict. As shown here, its the "backstop" when ATC or pilots fail to ensure the separation. Its rate of reaction, the fact there are (ideally) 2 co-ordinated actions given, its direct input to the pilot, and the fact it can "see" far quicker than ATC the effect of any action being taken.

What is needed, and probably will come out of this incident, is more training for crews and ATC as to the benefits and pitfalls of TCAS. Benefits mean ATC (and pilots) will hopefully trust it to sort out the vertical separation when things have already "gone wrong" - and restrict their own efforts to lateral separation.

I do not know how much training / sim practice the Russian crew had with TCAS - a guess is it was not enough to pick the correct choice of the 2 shouted instructions.

Whatever ATCOs think of TCAS, and I can understand their warieness of the system, encouraging anyone not to follow the SOPs is what will lead to more incidents like this one. The TCAS RA must be obeyed first, inform ATC when able / ASAP, but keep listening to and obeying that TCAS... The hopefully this will be the last incident of this type...

NoD

[Chilli Monster]

NigelonDraft

Extolling the virtues of TCAS is all well and good - but have you read Nasty Incident (http://www.pprune.org/forums/showthread.php?s=&threadid=58576) . There's a lot more to using TCAS than blind obedience - as this incident points out.

CM

[Bern Oulli]

Reading my way through this thread, and the one on "Reporting Points", I have found that I have learned more about TCAS in the last week than I ever knew. It has also made me aware of how little we in the UK teach our trainee controllers about TCAS. How much training goes on at operational units on this subject 'cos it's 2/3 of b*gger all at "the place where I work?

[CUNIM]

As a controller over twenty years on the job, I am desperately unhappy about the incedent, but I would ask just one question, were the controllers properly trained to see procedural conflicts? I have the feeling that the current attitude is "Trust the software" and you will be OK. This I have seen as the modern attitude from the system designers - happily not all. The STCA was off but for a procedurally trained controller, that would not have been a problem. I just cannot help thinking that, not only "but there for the grace of God" were the controllers trained to the levels that were extant in the past?

I feel that it is about time that the controllers were placed in the system design team rather than being an after thought. Sorry systems engineers, but the question needs putting. I know the answer to the last point, yes we include controllers, but do you listen? And act?

[theblipdriver]

hello romeowiz,
i agree with you in every point. i know many people from zurich acc (i was training as a atco, but got fired during training. tough job). it is HORRIBLE! everyone knows it could have happened to anyone, and the fingerpointing from the medias, even though the causes were not known, is too quite hard for them. and of course, everyone thinks he understands atc. the controller was late in descending, so he is guilty....
the most unbeliavable thing is the chance of such a thing to happen. just imagine - the STCA U/S, first phone line U/S, not beeing able to contact EDNY on the second line, second atco on break, a clearance to descend just one (!!) second after the tu got his climb-RA, and two aircraft ending up in the same bit of airspace at the same time, ending the life of 70+ people...
thanks god the one aircraft was not a pax jet with 200+ people. even what happened is tragic - it could have been far worse. oh, and no casualities on ground...

my feelings are with the families of the victims, and with the atco. don't forget him, he did his job, and now his life will never be the same as before

al

[NigelOnDraft]

CM...

Not ideal - BUT if the TCAS RA(s) had been followed, no collision would result. I know its not ideal - that an aircraft ends up "busting its level" and the next one down, but the system could not do anything else?

The route cause was probably someone descending too rapidly - and hopefully that lesson will come out of that instance.

There's only 2 ways to go - either ditch TCAS altogether, OR everyone follow it religiously. A half way house where some follow it, some query it, some ignore it has resulted in one mid air and one near mid air in the last 10 days or so alone...

The best advice was from CPB on that thread - the TA is your chance to intervene - reduce the VS!

NoD