Airprox over Central Scotland

[Philflies]

Having just read the report it makes interesting reading. Amazed that both sets of crew took each others avoiding instructions from ATC. That's really not great PR for pilots at any level or qualification.

Yes TCAS was there as another level of protection so the risk is lower than that currently being hyped by the media. But to the layman you can understand a certain level of apprehension when aircraft instructed to avoid then increase their convergence!

Alas, for all the 'anonymising' of the report, the Airpox board does slip up a little by referring on one occasion to the 'B748'. Narrows down the operators somewhat.

[HOMER SIMPSONS LOVECHILD]

It's maybe my gashness, but I'll be honest in that I have never responded to an "avoiding action" instruction by disconnecting the automatics as this would (I think) increase, what can become, a high workload situation. Likewise, I've never seen anyone else do it.

Wow , how many "avoiding action" instructions have you received? I've got around 12000 hours in busy airspace and I've never received one. If I ever do I hope to follow my company SOPs and disconnect and fully expect my FO do the same!
Hopefully you are confusing a routine turn from ATC to ensure separation with a full on "Avoiding action!..." call. Time to get your head into that manual and clear that one up before your next flight perhaps.

[VFD]

I am going to jump in here with little knowledge.
I just find it interesting that we have two aircraft on a converging course that it requires ATC to require both aircraft to take evasive action.

My first thought would be that ATC should have only needed to vector, change altitude, or slow down one aircraft from the converging course long before the situation degraded to the point of requiring both to evade.
Hence, there would only be one set of instructions.
Again, I do not know.

[PAXboy]

May one guess that the CVR was not pulled - due to them being far from dest? So we'll never know what the crews actually heard. Only that could narrow down the cause.

Better to be talking about this than a prang. For both FC to pick up the wrong side of the TX is a VERY unusual circumstance. So unusual that it may not happen again for a significant time. Given the news, it will help everyone to think about it. Thus, a good outcome.

[Capn Bloggs]

I would hope that I'd notice a TCAS return, inside 10nm, same level, getting closer, and start asking questions...

[The Fat Controller]

VFD, you CANNOT use speed in this situation.

As for issuing instructions to both aircraft, that doubles your chance of one doing it correctly, sadly not what happened in this scenario.

[captplaystation]

Capn Bloggs

Like he said

[WHYEYEMAN]

I was always taught from a very early stage that if you hear the words 'avoiding action' or 'immediately' associated with any ATC clearance then you disconnect the autopilot and 'just do it'. I have never practised it in recurrent sim sessions however which is a shame as it would take less than a minute to do as part of a LOFT excercise.

[Trackdiamond]

ontimeexceptACARS...Tenerife runway vs Zagreg mid air

I read you mate! But some walked away from that Tenerife cockup (PanAm)..a mid air collission is more severe..only in this case smaller crafts were the subject...Trident and. DC9...I was therefore referring to the severity rather than absolute numbers perished.You have a point though..relative speaking!

In terms of absolute comparisons..ofcourse it resembles the Tenerife disaster..similar types and categories involved...conflicting course, R/T cockups, possible CRM deficiencies...only major difference is..it took place is first world airspace with supposedly first class airline pilots..with ELP 6 transmissions no doubt! Its like we have not learn anything after over 3 decades! I think it is a good idea to incorporate a more realistic ATC/Traffic scenario rather than have SFI mimicking ATC..to have multi dimentional scenarios with conflicting ATC instructions for the crew to react to...to sharpen situation awareness...and during failures management phase at that!Also to have provisions in CVRs to be able to extract data during any requested time frame during the flight captured.

[Ian W]

Originally Posted by WHYEYEMAN

I was always taught from a very early stage that if you hear the words 'avoiding action' or 'immediately' associated with any ATC clearance then you disconnect the autopilot and 'just do it'. I have never practised it in recurrent sim sessions however which is a shame as it would take less than a minute to do as part of a LOFT excercise.

I am amazed that a standard safety call from ATC is not practiced in simulators. And from comments here avoiding action is often second guessed by flight crew - whose lives are at risk due to their delay.

Most deconflictions are taken by planning the aircraft transits through the sector and the crew are unaware as they just follow the clearance they have received. However, when something goes awry the controller may have to act quickly and expects the aircraft to turn at once, there is no time for collaborative decision making and gentle FMC half rate turns.

TCAS is a really useful short term safety system but it will only see 'cooperating' aircraft that are transmitting/transponding on 1090/1030MHz. There have been mid-air collisions with one aircraft not transmitting. The controller almost always has a far better 'picture' of what is going on around the aircraft than the limited situation awareness of the flight crew who should not rely on TCAS to see everything. Time for second guessing is after the avoiding action is completed

[MCDU2]

We did ATC avoiding action scenarios a few years back in the sim. Our OPS manual now reflects that the AP is to disconnected in order that an increased bank of turn can be achieved. Our airline is all airbus and hence if you left in the AP at high cruising levels then all you would get is a gentle 1g turn. Interestingly enough we were briefed that a number of other airlines across Europe refuse to allow their pilots to disconnect the AP so to plan on an ATC avoiding action event to become a TCAS RA.

[fenland787]

eglnyt

ATC recordings are recorded "off air" so the signal has been transmitted....... they are a good record of what the controller transmitted but only that, you need the aircraft voice recorder to be sure of what reached the aircraft and its relationship to other distractions

Right, thanks for that info, it's a very sensible way to ensure the record of what was transmitted is accurate and valid.

I appreciate it's probably not a factor in this case*, but it seems to me that if that was the evidence referred to in the report to imply the transmissions were received clearly then, as you say, without the aircraft voice recorder it's stretching it a bit!

*That said, something caused four people in two crews to make similar errors about what they heard...so there has to be a common factor relating to comms surely?

[Capn Bloggs]

Not watching the TCAS/not doing anything about it? Happens elsewhere too:

On 6 April 2012, a Boeing 737 and an Airbus A330 aircraft were on converging tracks at FL 360 (en route surveillance-based control). As the aircraft approached each other at the same level, the controller received a short term conflict alert (STCA) and noticed the aircraft were 5.2 NM (9.63 km) apart. The controller issued instructions to both aircraft to achieve vertical separation, which was established when the distance between the aircraft reduced to about 3.5 NM (6.48 km). See ATSB investigation AO-2012-048.

although in this case, "The controller immediately instructed the flight crew of the A330 to descend to FL350. The crew acknowledged and advised that they could see the traffic on their TCAS". Bit late for that...

Our airline is all airbus and hence if you left in the AP at high cruising levels then all you would get is a gentle 1g turn.

Not much of a turn!

[bubbers44]

Sometimes you have to do what makes you feel safest. I was in a climb one day as a brand new FO on a B737 and at 3700 ft was told to level at 4,000 ft because of opposite direction traffic at 4300 ft. Knowing I couldn't do that at our rate of climb looked out the window and saw no aircraft so accelerated climb verifying no aircraft rather than pushing nose down into blind area. 20 seconds later passing about 5,000 ft approach said your traffic just passed below you at 4,000 ft. I told the captain what I was going to do of course but blindly following last second instructions from ATC may not always be the safest thing to do.

This happened in the earlly 80's prior to TCAS.

[Al Murdoch]

Lucky there wasn't someone above you at 5,000 I guess.

[RoyHudd]

Usual rubbish from our experts who don't fly long-haul, or don't fly aircraft

TCAS never instructs turns.

TFN disaster involved full loss of life.

TCAS shows targets at long ranges.

The jeering at an airprox between 2 legacy carriers is being made by idiots and is misplaced. 2 so-called third-world carriers would have been much likelier to not rectify the original mistakes, and even bump into each other.

[Lon More]

From the report I'm a bit confused about the Sector management. It seems to me that initially the Sector was only manned by one controller. Is this SOP?
Überlingen and Zagreb spring to mind, everything chugging along normally, no problem for one controller, then it all goes wrong

[ROSUN]

Whilst recognising the need for anonymity in the report, it may have been useful to see if there was any similarity between the callsigns for these two aircraft.
Frequently I hear ATC instruct for example "BirdSpeed 231 ... " followed by "BirdSpeed 321 ..."
If the two companies alluded to earlier are the ones concerned they use a mixture of numeric & alpha numeric callsigns.
Also I'm not sure if one of the operators (if the hypothesis is true) readback method of callsign preceding the confirmation of understanding of the instruction causes any confusion to:
a) ATC
b) Other aircraft in the vicinity.
When this is heard on R/T it is almost as though it is a confirmation that because the callsign comes before the instruction it is deemed as a matter of fact that the instruction has been understood as the callsign was returned correctly. Well, my simple brain hears it like that!

[crewmeal]

I suppose now the Daily Mail have found out about Airprox they will report every incident reported such as:

Fighter pilot used weapons radar to avoid colliding with passenger jet | Mail Online

Sensationalism at it's best (or worst which ever way you look at it)

[bubbers44]

Even luckier I didn't level at 4,000 ft because we were cleared to 7,000 ft.