E190 near collision Mildura May 16 - ASI bulletin 56
Thanks for all of that, Biatch. My long experience is also that GA/slower aircraft are more than willing to volunteer to adjust their track and circuit join to give RPT, RFDS etc aircraft priority. I've literally never heard any terse or insolent exchanges between the former and the latter.
I understand what you're saying about not having a specific plan.
So I'll change my question to: You're on base at YMIA and there's an aircraft on a straight in approach to the same runway. You assess there to be a high risk of collision. The aircraft is not responding to any calls from you. What do you do?
I'm assuming that compylot's decision to collide is the result of a lack of skill and experience (or is perhaps an insolent and immature response). I'd like to hear from someone who knows what s/he's doing, as my loved ones could be seated down the back.
I understand what you're saying about not having a specific plan.
So I'll change my question to: You're on base at YMIA and there's an aircraft on a straight in approach to the same runway. You assess there to be a high risk of collision. The aircraft is not responding to any calls from you. What do you do?
I'm assuming that compylot's decision to collide is the result of a lack of skill and experience (or is perhaps an insolent and immature response). I'd like to hear from someone who knows what s/he's doing, as my loved ones could be seated down the back.
I think sarcasm is at play there mate... poorly executed... but hey, it's pprune!!
To answer your specific scenario ... hoping (and assuming) that we had said aircraft in sight to our right... personally I would make a clearing and climbing turn away from the aircraft on the straight in approach. That would be a left turn towards upwind. Which is exactly what the skipper had elected to do.
Now the final report mentions the PM advised of further conflicting traffic crosswind. So the PF then elected to a go around toward the south of the centreline but parallel to the rwy. Fair enough, and the best of a bad situation, just that the XGA A/C had assumed that the jet would be continuing their approach and not going around due to their approach not meeting stabilisation criteria. And this is as I read it, where the worst of the conflict occurred. Probably not enough time in the seconds that this decision was made to communicate it effectively, and thankfully the pilot of XGA recognised this and was able to see and avoid. This is exactly the reason why we generally need or want a larger buffer/space around us than what smaller aircraft are used to or may expect.
Hate to armchair quarterback it, but seeing as you asked my opinion, I may have elected to climb to a height above circuit/MSA as well. May or may not have helped or been necessary... but looking back on it with hindsight, it might have been something entering my plan of evasion... and now that I've thought about it more for another min or two while writing this, the skipper may not have wanted to do that as XGA was above him already and a rapid climb may have seemed to make it worse. It's just so hard to tell without actually being there....
You can see how the situation became very intense very quickly with only 2 other aircraft in the circuit/area. (the third chasing aircraft wasn't really involved in the conflict, although it also broke off approach to the south.) Jets aren't really made to share a circuit with GA aircraft. Lots of guys prefer 5nm straight approaches, even with tailwind, to avoiding doing circuits with other aircraft.
To answer your specific scenario ... hoping (and assuming) that we had said aircraft in sight to our right... personally I would make a clearing and climbing turn away from the aircraft on the straight in approach. That would be a left turn towards upwind. Which is exactly what the skipper had elected to do.
Now the final report mentions the PM advised of further conflicting traffic crosswind. So the PF then elected to a go around toward the south of the centreline but parallel to the rwy. Fair enough, and the best of a bad situation, just that the XGA A/C had assumed that the jet would be continuing their approach and not going around due to their approach not meeting stabilisation criteria. And this is as I read it, where the worst of the conflict occurred. Probably not enough time in the seconds that this decision was made to communicate it effectively, and thankfully the pilot of XGA recognised this and was able to see and avoid. This is exactly the reason why we generally need or want a larger buffer/space around us than what smaller aircraft are used to or may expect.
Hate to armchair quarterback it, but seeing as you asked my opinion, I may have elected to climb to a height above circuit/MSA as well. May or may not have helped or been necessary... but looking back on it with hindsight, it might have been something entering my plan of evasion... and now that I've thought about it more for another min or two while writing this, the skipper may not have wanted to do that as XGA was above him already and a rapid climb may have seemed to make it worse. It's just so hard to tell without actually being there....
You can see how the situation became very intense very quickly with only 2 other aircraft in the circuit/area. (the third chasing aircraft wasn't really involved in the conflict, although it also broke off approach to the south.) Jets aren't really made to share a circuit with GA aircraft. Lots of guys prefer 5nm straight approaches, even with tailwind, to avoiding doing circuits with other aircraft.
Last edited by Biatch; 20th Jan 2017 at 01:31.
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Your post shows that you're completely unaware at the workload of flying a jet in a circuit and the encounters that jet pilots have with unbroadcast traffic which I would say is kinda risky, wouldn't you?
Whenever I've flown into one of these aerodromes if I hear a turboprop/jet coming in. 'You go first mate, I'll hang out here' it's no issue. I've had the odd turbo say, 'no worries, you go first, we'll slow up'
Comes down to a bit of courtesy, airmanship and education.
As a VFR charter operator I am more than willing to slow down/adjust runway etc to go No. 2 to an inbound RPT that has advised the same ETA. I do get rightly pissed off however, after offering this to have said RPT actually hit the circuit several minutes after the advised ETA. Particularly when I have slowed down considerably to accomodate them - could have landed, unloaded pax and had aircraft in hangar and doors closed. Might not be so helpful next time.
Thanks again, Biatch.
The intriguing question is: Would there have been a lower risk of collision if ZPJ had just commenced a climb from base as soon as the risk of collision with XGA was perceived, and XGA had just continued its approach? (That's why I provided a scenario in which the equivalent of XGA pressed on, regardless.)
If I'd been XGA I think I would have just called 'going around and tracking parallel 09 to the south' as soon as I realised there was an aircraft on base, set full power and climbed at best rate and tracked slightly to the south of runway 09. In the circumstances as described in the report, I don't see how that would have resulted in any greater risk of collision than what actually happened. ZPJ has me in sight, and knows where I'm going. I have ZPJ in sight and can watch and listen where he decides to go. We both know about the other traffic.
However, as you say this is just Monday morning quarterbacking. Much rather someone else than me in these situations.
The intriguing question is: Would there have been a lower risk of collision if ZPJ had just commenced a climb from base as soon as the risk of collision with XGA was perceived, and XGA had just continued its approach? (That's why I provided a scenario in which the equivalent of XGA pressed on, regardless.)
If I'd been XGA I think I would have just called 'going around and tracking parallel 09 to the south' as soon as I realised there was an aircraft on base, set full power and climbed at best rate and tracked slightly to the south of runway 09. In the circumstances as described in the report, I don't see how that would have resulted in any greater risk of collision than what actually happened. ZPJ has me in sight, and knows where I'm going. I have ZPJ in sight and can watch and listen where he decides to go. We both know about the other traffic.
However, as you say this is just Monday morning quarterbacking. Much rather someone else than me in these situations.
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LB if you've seen the movie 'Sully' you'll know there's an amount of time called the 'human factor'. Hindsight is always 20-20.
More complex issues exist here. The ATSB calls for an Alerted search that uses radio and TCAS to know where to look. What defences exist when this fails? Both have limitations. Radio - eg (wrong frequency, turned down, wrong location where broadcast), different airports - same frequency. TCAS - delays in updating during turns, other aircraft not having transponders on or not equipped.
The ATSB has not delved into these more complex issues.
More complex issues exist here. The ATSB calls for an Alerted search that uses radio and TCAS to know where to look. What defences exist when this fails? Both have limitations. Radio - eg (wrong frequency, turned down, wrong location where broadcast), different airports - same frequency. TCAS - delays in updating during turns, other aircraft not having transponders on or not equipped.
The ATSB has not delved into these more complex issues.
Last edited by Utradar; 20th Jan 2017 at 11:33.
Hi U
Good points.
However, I think all those more complex issues are trite. That is, they are all well known.
Every now and then, lots of the holes in the pieces of Swiss cheese are going to line up. Fortunately, the chances of them all lining up are extraordinarily remote and, as in this case, no collision occurred. Whether that outcome in this case was a matter of good luck rather than good management is, I reckon, moot. We don't know whether decisions and actions other than those that were made and implemented would have resulted in the aircraft remaining further apart than they ended up being.
That doesn't mean that nothing should be done to mitigate even those risks. However, when you think through what the mitigation options would be, and how much they would cost, and that they would still be no guarantee of collision risk-free skies, you get back to reiterating the basic requirements of the rules and airmanship that have been around for around 100 years. ('Affordable safety' is a fact of everyday life, not a radical theory. That's why not all roads are divided, there aren't traffic lights at every intersection and there's only a millimetre of insulation between you and a voltage that will kill you.) It may get to the point that the volumes of traffic at YMIA are such as to justify further mitigations - CAGRO, Class D, revival of the AFIZ concept - but they are no guarantee.
I'd be interested in others' views on whether my decision - if I were in XGA - to go around and track to parallel runway 09 to the south as soon I became aware of the aircraft on base, and announce that on CTAF - is a good one or a not-so-good one. (I fly into and out of YMIA occasionally.)
Good points.
However, I think all those more complex issues are trite. That is, they are all well known.
Every now and then, lots of the holes in the pieces of Swiss cheese are going to line up. Fortunately, the chances of them all lining up are extraordinarily remote and, as in this case, no collision occurred. Whether that outcome in this case was a matter of good luck rather than good management is, I reckon, moot. We don't know whether decisions and actions other than those that were made and implemented would have resulted in the aircraft remaining further apart than they ended up being.
That doesn't mean that nothing should be done to mitigate even those risks. However, when you think through what the mitigation options would be, and how much they would cost, and that they would still be no guarantee of collision risk-free skies, you get back to reiterating the basic requirements of the rules and airmanship that have been around for around 100 years. ('Affordable safety' is a fact of everyday life, not a radical theory. That's why not all roads are divided, there aren't traffic lights at every intersection and there's only a millimetre of insulation between you and a voltage that will kill you.) It may get to the point that the volumes of traffic at YMIA are such as to justify further mitigations - CAGRO, Class D, revival of the AFIZ concept - but they are no guarantee.
I'd be interested in others' views on whether my decision - if I were in XGA - to go around and track to parallel runway 09 to the south as soon I became aware of the aircraft on base, and announce that on CTAF - is a good one or a not-so-good one. (I fly into and out of YMIA occasionally.)
Originally Posted by Biatch
ATC running on another radio at the same time giving traffic info
Perhaps there was some yabbering on Centre that distracted the Ejet captain so that he couldn't comprehend or hear XGA.
It would have been nice to read the radio transcripts of the CTAF...
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Did the incident really happen?
According to the tracks shown in the report, the GA-8 was going faster than the ERJ190. It averaged 200 knots for a period of 43 seconds. At one point it travelled 1 mile in 15 seconds i.e. 240 knots.
Is this plausible?
The majority of the report seems to have been compiled from the ERJ TCAS data during it's turn from base to final/upwind. What if the turn made the TCAS data inaccurate? When the ERJ straightens out on upwind, the GA-8 track shows a very sudden turn to the south. Could that have been the TCAS correcting the calculated position, once it had a stable reference?
If you use a more likely 120 knots for the GA-8, the closest point of approach is more like 1 mile, instead of 0.1 mile.
The GA-8 was behind the ERJ, so the ERJ wouldn't be able to visually confirm the distance. It is interesting that there is little information from the GA-8 pilot's point of view, other than confirming they sighted the jet about 2 miles away after the radio call. He should have been able to see the whole situation immediately in front of him.
Maybe they looked at the TCAS and asked the pilot if he saw the jet 200 metres in front of him and he said "There was no jet 200m in front" so they wrote a report about the difficulties of see and avoid, instead of investigating whether the GA-8 was actually where the TCAS said it was.
On the balance of probabilities between a GA-8 doing 200 knots almost running up the back of an ERJ 190, and inaccurate TCAS data during the turn, my money would be on the inaccurate TCAS data.
It would be interesting to see actual tracks from both aircraft's GPS instead of the tracks derived from TCAS.
According to the tracks shown in the report, the GA-8 was going faster than the ERJ190. It averaged 200 knots for a period of 43 seconds. At one point it travelled 1 mile in 15 seconds i.e. 240 knots.
Is this plausible?
The majority of the report seems to have been compiled from the ERJ TCAS data during it's turn from base to final/upwind. What if the turn made the TCAS data inaccurate? When the ERJ straightens out on upwind, the GA-8 track shows a very sudden turn to the south. Could that have been the TCAS correcting the calculated position, once it had a stable reference?
If you use a more likely 120 knots for the GA-8, the closest point of approach is more like 1 mile, instead of 0.1 mile.
The GA-8 was behind the ERJ, so the ERJ wouldn't be able to visually confirm the distance. It is interesting that there is little information from the GA-8 pilot's point of view, other than confirming they sighted the jet about 2 miles away after the radio call. He should have been able to see the whole situation immediately in front of him.
Maybe they looked at the TCAS and asked the pilot if he saw the jet 200 metres in front of him and he said "There was no jet 200m in front" so they wrote a report about the difficulties of see and avoid, instead of investigating whether the GA-8 was actually where the TCAS said it was.
On the balance of probabilities between a GA-8 doing 200 knots almost running up the back of an ERJ 190, and inaccurate TCAS data during the turn, my money would be on the inaccurate TCAS data.
It would be interesting to see actual tracks from both aircraft's GPS instead of the tracks derived from TCAS.
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By bet is XGA spent most of time talking to XGY on company frequency ie distracted and that's why they never heard any calls from ZPJ. What frequencies was the pilot of XGY monitoring. Was XGY on CTAF, did they here ZPJ?
What about the other twin in the circuit and the other RPT traffic from the north, what calls did they hear from ZPJ and XGA?
What about the other twin in the circuit and the other RPT traffic from the north, what calls did they hear from ZPJ and XGA?
It is a bit weird, andrewr.
How steep would the descent have to be to get to 200 - 240kts GS?
According to Table 2, it took ZPJ 15 seconds to go from point 2 to point 3, and 28 seconds to go from point 3 to point 4.
And according to the report, the "TCAS data is indicative only"....
XGA, with XGY in-trail, was about 7 NM from Mildura Airport tracking to the north-east to intercept a 5 NM final position, at 140–150 kt airspeed, descending at about 2,000 ft per minute.
According to Table 2, it took ZPJ 15 seconds to go from point 2 to point 3, and 28 seconds to go from point 3 to point 4.
And according to the report, the "TCAS data is indicative only"....
Last edited by Lead Balloon; 21st Jan 2017 at 03:49.
This is neither necessary nor a good idea. Call "changing to CTAF...", turn down the ATC volume (but not off) and then you can concentrate on the CTAF. The only possible traffic that ATC would pass to you after you have changed would be traffic that commences taxi... which you will: 1/hear on the CTAF and 2/hear on the FIA freq when he makes his taxi call. Perhaps a "popup" or traffic alert might prompt ATC to call you in the blind, but vary rarely.
Without knowing the driving force behind the "must", I would be hesitant to out of hand write it off as not necessary or less safe or the like. I would guess that the benefit of ATC providing traffic of aircraft in the area out ways the threat of having two radios running, esp when if it is a bit much a pilot can just turn it down a tad as you pointed out.
I wouldn't also presume to be able to think of all the possibilities or scenarios where ATC may still be able to provide critical information. Especially as in my opinion the reporting/broadcast requirements are so much lower these days. Terms like "vicinity" are useless in the regs, and whilst a 10nm call inbound for a small GA aircraft is commensurate with its performance, high performance aircraft would still like to hear from it before 10nm.
Originally Posted by Biatch
I wouldn't also presume to be able to think of all the possibilities or scenarios where ATC may still be able to provide critical information.
Originally Posted by Biatch
Terms like "vicinity" are useless in the regs, and whilst a 10nm call inbound for a small GA aircraft is commensurate with its performance, high performance aircraft would still like to hear from it before 10nm.
You should arrange to give some "mutually-agreed instructions" to Biatch's employer and all GA aircraft, Capn.
The irony is that XGA may not have been the aircraft that got closest to ZPJ during that flight.
The irony is that XGA may not have been the aircraft that got closest to ZPJ during that flight.
More potshots from the peanut gallery LB... 
Sorry, I sped-read your previous post and didn't absorb this bit. If you haven't "changed to..." ATC will keep calling you until you reply; it doesn't matter that you have the radio "turned down a tad" resulting in more workload on the ATC freq when you should be dealing with the CTAF traffic.
Originally Posted by Biatch
esp when if it is a bit much a pilot can just turn it down a tad as you pointed out.
Off the top of my head, and this has happened to me. Traffic at 20nm thinking he is not traffic, not broadcasting or possibly listening on ctaf, but thankfully squawking 1200. Our TCAS had not picked him up due to whatever reason (it's not perfect and has its blind spots/flaws) but ATC chimed him and gave him as unidentified traffic intentions Unknown.... We were able to level off 2000ft above, TCAS then picked him up... And we proceeded after passing. Never made contact.
This large associated risk of this situation, though it may happen rarely, may (in the company's view) warrant the possible threat of having two Comms on.
It seems that REX does have the policy of going off act, as I hear them making the call you're referring to. I can't remember Qlink's policy.
Wholeheartedly agree, and we all know who is responsible: Dick Smith and his yank NAS.
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Having flown quite a bit in the US where the traffic densities **** all over the GAFA, they seem to be doing something right. Australian airspace is over regulated and full of arse guarding useless information masquerading as 'service'
I would take their system over the Australian system any day of the week.
I would take their system over the Australian system any day of the week.
Compylot commented on Lead Balloon's comment: "Someone very close to me who flies heavy metal.."
I know one of LB's younger siblings who's an experienced B777 Captain for an overseas airline.
I know one of LB's younger siblings who's an experienced B777 Captain for an overseas airline.
This is neither necessary nor a good idea. Call "changing to CTAF...", turn down the ATC volume (but not off) and then you can concentrate on the CTAF.
What is the world coming too??? This is at least the second time in recent memory I have agreed with Bloggs.
As to the point of the thread, clearly nothing has changed since the PCH ( or was that PHC) report, and the entitlement assumption by Regionals is a strong as ever, as is the assumption that anybody flying a GA aircraft is automatically of lesser qualifications and experience.
As for the "standard" of the ATSB effort, why am I not surprised.
Tootle