Airprox between 2 a/c inbound to Dublin
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Airprox between 2 a/c inbound to Dublin
Last edited by ShannonACC; 12th Feb 2017 at 08:20. Reason: Fixed link
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Wonderful new world where every incident even minor like this one get published and debated on You Tube with kids discussing what should have been done!
I suppose next will be the name, photo and address of the controller together with his Facebook profile ...
I suppose next will be the name, photo and address of the controller together with his Facebook profile ...
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ATC Watcher. Wasn't it that sort of information that resulted in the murder of a controller some years ago, following the mid-air in Swiss airspace?
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What has been made of that video in Daily Fail and some Irish papers is just beyond belief (near collision, identifying EI-433 and FR-9451, which was 20nm behind EI-433 and FR-9431 and was instructed to stop descent at FL220 subsequently after EI-433 was re-assigned to FL210).
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I do not know what was on the controller's mind, obviously. I can't tell whether he misinterpreted the altitude difference, whether he computed the cleared target altitude FL200 vs. actual altitude of FR-9431 (which was 800 feet), ... All I can say that at the time when he reported the 737 descending 800 feet below FR-9431 was at FL192 and EI-433 was at FL210 subsequently levelling off at FL210 according to Mode-S.
From the Mode-S data it is clear that separation with the clearances in effect was not assured (in particular as EI-433 descended much faster than FR-9431), however, an actual loss of separation had not occurred.
The instructions were clearly issued in time to not permit the situation develop into a loss of separation and recover into a scenario where separation was assured again. I am not saying anything against the controller, his plan obviously didn't work out as he intended - I am just upset with what was made out of this by a couple of media (based on the headline of the video).
From the Mode-S data it is clear that separation with the clearances in effect was not assured (in particular as EI-433 descended much faster than FR-9431), however, an actual loss of separation had not occurred.
The instructions were clearly issued in time to not permit the situation develop into a loss of separation and recover into a scenario where separation was assured again. I am not saying anything against the controller, his plan obviously didn't work out as he intended - I am just upset with what was made out of this by a couple of media (based on the headline of the video).
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Austrian Simon : I am just upset with what was made out of this by a couple of media (based on the headline of the video).
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Just to confirm: I have it now officially, that there was no loss of separation at all. The controller restored the scenario in time to avoid a loss of separation (it was only a loss of separation assurance therefore).
I have further confirmed, that the audio has been manipulated/faked. The sounds of the autopilot disconnect wailer as well as the "Traffic! Traffic!" advisory are not present on any other recordings that became available to me in the meantime, including (but not only) LiveATC.
According to information I have received from Ireland during our research the thread initiator here (as well as on boards.ie) and the video author most likely are the same person (and I have more information about that person, which however would be inappropriate to be mentioned here).
I have further confirmed, that the audio has been manipulated/faked. The sounds of the autopilot disconnect wailer as well as the "Traffic! Traffic!" advisory are not present on any other recordings that became available to me in the meantime, including (but not only) LiveATC.
According to information I have received from Ireland during our research the thread initiator here (as well as on boards.ie) and the video author most likely are the same person (and I have more information about that person, which however would be inappropriate to be mentioned here).
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Yes - the Youtube video seems to have gone private last evening.
All is not what it seems in perhaps more ways than one on this ...
So it is an interesting one – to further straighten one misunderstanding at least, I agree that the close call, if there was one, can only have been between EI433 and FR9431, and not the trailing FR9451 at all.
The lead pair had both descended rapidly coasting out from Wales, and both picked up extra speed in doing so, but the Ryanair soon bled off the speed, and had started slowing more noticeably. The Shamrock steadily closed on it.
EI433 then descended from FL240 – and FR9431 may have chosen that moment to slow even further to as little as 267 kts. Maybe they were well into planning a likely diversion at that point. EI433 was ordered "turn left immediately for traffic turn left and maintain FL200".
At some stage afterward, FR9431 also turned left and diverted to Shannon at FL170 although I only heard the heading clearance of 250, not the level. The stray 267kts ADS-B plot for FR9431 also carried an altitude of 19800. The next plot I have seen was 297kts at 19275. EI933 had been further ordered to "Climb FL210" which was acknowledged, so I think we might conclude that EI433 at that time was lower than FL210 and had not in fact levelled at FL210 until ordered to climb back up there.
Meantime FR9431 may still have been as high as 19800. If that is the case maybe that's where the controller's eye view of an 800 feet separation comes in.
On coming out of their traffic avoiding manoeuvre, EI433 nevertheless seems to have crossed over the top of FR9431’s track whether that's before or after FR9431 I can't offer a view. They’d regained and maintained FL210 (if they’d ever significantly passed through that level). Meanwhile, FR9451, not having had to do any avoiding reverse S, had caught up some and slotted in closer behind EI433 at FL220 as they both approached the hold. I’ve seen and heard nothing suggesting any unmanaged proximity between those two save for the controller double checking FR9451 had maintained FL220 after EI433 had reminded they were still at FL210.
I say “reminded” because there had been further exchange seemingly initiated by EI433 after the TCAS discussion was over - EI433 said he was maintaining FL210 and the controller said "Thank you for that" Then the controller immediately checked with the FR9451 behind that they were maintaining FL220.
We presume ATC had a continuous altitude readout on RYR51RP (FR9431) via Mode S.
Conversely for clues after the event we only have intermittent third party collated ADS-B and joined dots – maybe some unjoined ones too. The lowest ADS-B derived altitudes I have seen at the relevant time were 20900 for EI433 versus 19275 at approximately the same half minute for FR9431. Simon may have access to more detail.
It was a busy lunchtime at EIDW, and one which has suffered a bit in the telling I think.
However, contrary to some opinions here, I'd say it was very much worth the telling as accurately as possible.
As “just another day in aviation” it doesn’t sit comfortably as a normal one ... The ATC RT was pretty slick as usual, but some of the PP RT wasn't – a number of PP’s weren’t sitting comfortably with uncertain hold delays and were asking ATC about them in a number of different ways. The controllers were trying to keep pace with EATs. One I think asked ATC for an ETA and the controller pointedly responded about the EAT. Another when reading back a clearance said “Let me see” in the middle of his transmission. Another soaked up 5 valuable seconds exactly when ATC were probably already anxious to get in their “turn left immediately” order.
I think before FR9431 decided to divert, someone (them?) said something to the effect that “That’s impossible” at around the time that the controller had said “There are fifteen ahead of you”.
I'd be surprised if anyone denied that the hesitant RT added to the stress levels of everyone on frequency.
I remain somewhat perplexed that the LiveATC.net recording seems not to present the clip of the negotiation for diversion of FR9431 on heading 250 until a couple of minutes after "the 737 800 feet below you / we see him descending ... on TCAS" ATC/EI433 exchange. That’s only because if you check the joined dots from ADS-B data presented in the usual places on the web, it looks like FR9431 diverted before the supposed close call. However, "looks like" isn't the same as "actually happened".
As Simon says, I heard no Autopilot disconnect or Traffic Traffic warning on LiveATC.net’s clips either. I guess it is all to do with editing one way or the other ...
All is not what it seems in perhaps more ways than one on this ...
So it is an interesting one – to further straighten one misunderstanding at least, I agree that the close call, if there was one, can only have been between EI433 and FR9431, and not the trailing FR9451 at all.
The lead pair had both descended rapidly coasting out from Wales, and both picked up extra speed in doing so, but the Ryanair soon bled off the speed, and had started slowing more noticeably. The Shamrock steadily closed on it.
EI433 then descended from FL240 – and FR9431 may have chosen that moment to slow even further to as little as 267 kts. Maybe they were well into planning a likely diversion at that point. EI433 was ordered "turn left immediately for traffic turn left and maintain FL200".
At some stage afterward, FR9431 also turned left and diverted to Shannon at FL170 although I only heard the heading clearance of 250, not the level. The stray 267kts ADS-B plot for FR9431 also carried an altitude of 19800. The next plot I have seen was 297kts at 19275. EI933 had been further ordered to "Climb FL210" which was acknowledged, so I think we might conclude that EI433 at that time was lower than FL210 and had not in fact levelled at FL210 until ordered to climb back up there.
Meantime FR9431 may still have been as high as 19800. If that is the case maybe that's where the controller's eye view of an 800 feet separation comes in.
On coming out of their traffic avoiding manoeuvre, EI433 nevertheless seems to have crossed over the top of FR9431’s track whether that's before or after FR9431 I can't offer a view. They’d regained and maintained FL210 (if they’d ever significantly passed through that level). Meanwhile, FR9451, not having had to do any avoiding reverse S, had caught up some and slotted in closer behind EI433 at FL220 as they both approached the hold. I’ve seen and heard nothing suggesting any unmanaged proximity between those two save for the controller double checking FR9451 had maintained FL220 after EI433 had reminded they were still at FL210.
I say “reminded” because there had been further exchange seemingly initiated by EI433 after the TCAS discussion was over - EI433 said he was maintaining FL210 and the controller said "Thank you for that" Then the controller immediately checked with the FR9451 behind that they were maintaining FL220.
We presume ATC had a continuous altitude readout on RYR51RP (FR9431) via Mode S.
Conversely for clues after the event we only have intermittent third party collated ADS-B and joined dots – maybe some unjoined ones too. The lowest ADS-B derived altitudes I have seen at the relevant time were 20900 for EI433 versus 19275 at approximately the same half minute for FR9431. Simon may have access to more detail.
It was a busy lunchtime at EIDW, and one which has suffered a bit in the telling I think.
However, contrary to some opinions here, I'd say it was very much worth the telling as accurately as possible.
As “just another day in aviation” it doesn’t sit comfortably as a normal one ... The ATC RT was pretty slick as usual, but some of the PP RT wasn't – a number of PP’s weren’t sitting comfortably with uncertain hold delays and were asking ATC about them in a number of different ways. The controllers were trying to keep pace with EATs. One I think asked ATC for an ETA and the controller pointedly responded about the EAT. Another when reading back a clearance said “Let me see” in the middle of his transmission. Another soaked up 5 valuable seconds exactly when ATC were probably already anxious to get in their “turn left immediately” order.
I think before FR9431 decided to divert, someone (them?) said something to the effect that “That’s impossible” at around the time that the controller had said “There are fifteen ahead of you”.
I'd be surprised if anyone denied that the hesitant RT added to the stress levels of everyone on frequency.
I remain somewhat perplexed that the LiveATC.net recording seems not to present the clip of the negotiation for diversion of FR9431 on heading 250 until a couple of minutes after "the 737 800 feet below you / we see him descending ... on TCAS" ATC/EI433 exchange. That’s only because if you check the joined dots from ADS-B data presented in the usual places on the web, it looks like FR9431 diverted before the supposed close call. However, "looks like" isn't the same as "actually happened".
As Simon says, I heard no Autopilot disconnect or Traffic Traffic warning on LiveATC.net’s clips either. I guess it is all to do with editing one way or the other ...
Last edited by slip and turn; 15th Feb 2017 at 10:05. Reason: I have tried and maybe failed to make this easier to read.
As an aside, beware of data from FR24 and other online sources that appears to show speed and altitude at the same point in time. That's not how ADS-B works - those two parameters are never sent in the same transmission and may therefore be misleadingly populated with stale values in the published data.
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Yes noted Dave Reid, and that is just another reason why I say others including Simon may have access to a better (authoritatively recorded) picture. Fact is 267kts stands out as unexpectedly slow and 19800 unexpectedly high in whatever (short) real time period included those two reports, and the 20900 report from E1433 descending faster close behind.
As you can see, I do believe there's still good stuff to be learned from Monday lunchtime ten days ago at EIDW.
The big picture surely is that EIDW was busier than some pilots that day really set out to face. It wasn't just inconvenience of hold delays. It required a sharpening up of everyone on frequency. Not everyone was suitably resourced to be sharp enough soon enough to foresee all eventualities.
EAT's were not being volunteered for a time by ATC because the resource to calculate them appeared not to be instantly available e.g. "get back to you on that", "...someone behind me is just working on it" or words to that effect, and of course ultimately the "fifteen ahead" were heard a number of times. That alone created some uncertainty in all who were monitoring the frequency which they were forced to absorb and to immediately review with their own situation. The first clear EAT I heard (may easily have missed others) was one given some minutes after the traffic avoidance order. I remember that one was for an EAT of 1344. The traffic avoidance order occurred around 1310-1313? - I have no exact timings for the audio I have heard.
Consequently we assume, on hearing "fifteen ahead" a Ryanair whom we presume would be intimately familiar with EIDW seemingly announced "that's impossible" perhaps after realising that 15 x 2 minutes = 30 minutes or some similar rule of thumb, and diverted to Shannon after already mixing it with fast Dublin approach traffic. That of course was not ideal. Had they known more, and known earlier, they'd have presumably diverted earlier.
Fifteen ahead is a challenge at Biggin Hill on a sunny afternoon, but at a major airport with possibly questionable flow system (in my mind, I am finding it possible to question it!), there maybe better things to be learned.
But if better minds than mine who monitor EIDW flows on a daily basis have decided there is nothing to be learned, then all we can say is ok, maybe Monday lunch in Dublin is well worth preparing for especially if they're using 16 - better than tea no biscuits!
In closing, I think ten years ago and probably several time since, some of the general problem with flow control has been summed up quite well in this here thread on Descent Speeds!
As you can see, I do believe there's still good stuff to be learned from Monday lunchtime ten days ago at EIDW.
The big picture surely is that EIDW was busier than some pilots that day really set out to face. It wasn't just inconvenience of hold delays. It required a sharpening up of everyone on frequency. Not everyone was suitably resourced to be sharp enough soon enough to foresee all eventualities.
EAT's were not being volunteered for a time by ATC because the resource to calculate them appeared not to be instantly available e.g. "get back to you on that", "...someone behind me is just working on it" or words to that effect, and of course ultimately the "fifteen ahead" were heard a number of times. That alone created some uncertainty in all who were monitoring the frequency which they were forced to absorb and to immediately review with their own situation. The first clear EAT I heard (may easily have missed others) was one given some minutes after the traffic avoidance order. I remember that one was for an EAT of 1344. The traffic avoidance order occurred around 1310-1313? - I have no exact timings for the audio I have heard.
Consequently we assume, on hearing "fifteen ahead" a Ryanair whom we presume would be intimately familiar with EIDW seemingly announced "that's impossible" perhaps after realising that 15 x 2 minutes = 30 minutes or some similar rule of thumb, and diverted to Shannon after already mixing it with fast Dublin approach traffic. That of course was not ideal. Had they known more, and known earlier, they'd have presumably diverted earlier.
Fifteen ahead is a challenge at Biggin Hill on a sunny afternoon, but at a major airport with possibly questionable flow system (in my mind, I am finding it possible to question it!), there maybe better things to be learned.
But if better minds than mine who monitor EIDW flows on a daily basis have decided there is nothing to be learned, then all we can say is ok, maybe Monday lunch in Dublin is well worth preparing for especially if they're using 16 - better than tea no biscuits!
In closing, I think ten years ago and probably several time since, some of the general problem with flow control has been summed up quite well in this here thread on Descent Speeds!
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s&t, Rwy 16 is a backup runway for EIDW used a very few times a year when we get strong south-easterly winds or when main runway is out of service for whatever reason. Main runway is 10/28 which employs a state-of-the-art arrival/point merge system
https://www.eurocontrol.int/sites/de...-in-dublin.pdf
use of Rwy 16 is bad news, everyone involved knows it, there are no high speed exits, planes have to taxy all the way to the end of runway to exit, heavier b737/a320 have to backtrack a tiny bit for line-up, it's a massive pain.. so if arriving traffic hears you have 15 ahead of you, you are realistically looking at 15x3 mins or more + departures that will take forever to line up.. anyway, not a normal day at EIDW by any means.. there's not much ATC/crews can do to improve - runway itself needs upgrades, but I don't think it's going to happen - main focus is to build a parallel runway for 10/28 at the moment.. like I said, usage during peak hours of rwy 16 is so rare, it's not on top of anyone's priority list
https://www.eurocontrol.int/sites/de...-in-dublin.pdf
use of Rwy 16 is bad news, everyone involved knows it, there are no high speed exits, planes have to taxy all the way to the end of runway to exit, heavier b737/a320 have to backtrack a tiny bit for line-up, it's a massive pain.. so if arriving traffic hears you have 15 ahead of you, you are realistically looking at 15x3 mins or more + departures that will take forever to line up.. anyway, not a normal day at EIDW by any means.. there's not much ATC/crews can do to improve - runway itself needs upgrades, but I don't think it's going to happen - main focus is to build a parallel runway for 10/28 at the moment.. like I said, usage during peak hours of rwy 16 is so rare, it's not on top of anyone's priority list