E190 near collision Mildura May 16 - ASI bulletin 56
What is the "nonsense", Capn B?
In order to provide a rational solution to a problem, one first has to identify the problem and the causes of the problem.
The problem is the increased risk of mid-air collisions near aerodromes compared with other phases of flight.
The cause of the problem in this case was not inexperienced GA pilots. Nor was it insufficient two-way communications.
The 'solution' is to do what the rules and good airmanship have required for around 100 years.
IMNSHO, and based only the ATSB report, the pilots of XGY and XGA failed to comply with the requirements of the rules and good airmanship. Aircraft attempting a straight in approach v aircraft completing a circuit? No rocket surgery working out who was obliged to give way (a "wide berth") in that situation.
I was merely making the supplementary point that if the assumption is that GA pilots are not going to comply with the requirements of the rules and good airmanship, there is only one, inevitable, solution. Even that solution is no guarantee.
If you think about it rationally.
In order to provide a rational solution to a problem, one first has to identify the problem and the causes of the problem.
The problem is the increased risk of mid-air collisions near aerodromes compared with other phases of flight.
The cause of the problem in this case was not inexperienced GA pilots. Nor was it insufficient two-way communications.
The 'solution' is to do what the rules and good airmanship have required for around 100 years.
IMNSHO, and based only the ATSB report, the pilots of XGY and XGA failed to comply with the requirements of the rules and good airmanship. Aircraft attempting a straight in approach v aircraft completing a circuit? No rocket surgery working out who was obliged to give way (a "wide berth") in that situation.
I was merely making the supplementary point that if the assumption is that GA pilots are not going to comply with the requirements of the rules and good airmanship, there is only one, inevitable, solution. Even that solution is no guarantee.
If you think about it rationally.
The 'solution' is to do what the rules and good airmanship have required for around 100 years.
In a jet you are doing 3-4 miles a minute from 20 miles, with speed restrictions, mode annunciations, CTAF Calls, stabilisation requirements, not to mention actually flying the aircraft around the circuit without stalling or overspeeding.
None of those in themselves alone are a bad thing however I think we are at the tipping point now where there is way to much input from exterior forces in actually getting the job done. The 'seen to be doing something' management culture that now pervades aviation will ultimately contribute to an accident.
This one is a classic example for the rulemaker types. Two aircraft did as they were supposed to followed all the rules yet nearly collided.
How about less rules, less 'requirements' and let pilots fly the damn thing.
Last edited by neville_nobody; 18th Jan 2017 at 02:26.
Two aircraft did as they were supposed to followed all the rules yet nearly collided.
As I read it:
- ZPJ on base to 09.
- XGA conducting a straight-in to 09.
- There is a clear rule specifying who has to give way to whom in that situation.
If that rule does not apply in circumstances that led to a "near collision" between an aircraft on base and an aircraft on a straight-in, the rule is meaningless.
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The "near collision" seems to have happened after both aircraft went around.
ZPJ instructed XGA to go around and position to south of the airfield.
ZPJ then missed their turn to final, went around and tracked to the same place they sent XGA.
Before XGA was instructed to go around I think things were OK, they were behind ZPJ in distance to the runway and more than 500' higher when ZPJ got the traffic alert. I assume the jet approach speed is greater than the GA8 so that should work. The XGA pilot was probably of the opinion that they had given way to the traffic in the circuit.
ZPJ instructed XGA to go around and position to south of the airfield.
ZPJ then missed their turn to final, went around and tracked to the same place they sent XGA.
Before XGA was instructed to go around I think things were OK, they were behind ZPJ in distance to the runway and more than 500' higher when ZPJ got the traffic alert. I assume the jet approach speed is greater than the GA8 so that should work. The XGA pilot was probably of the opinion that they had given way to the traffic in the circuit.
An aircraft "instructing" another to do something is a bad idea.
I vaguely remember attending a CASA roadshow years ago where they played a short audio clip. It was of a Dash-8 launching out of somewhere with traffic already in the circuit or on approach. The Dash took off having never quite worked out where the traffic was and demanded the other traffic climb or turn (can't remember which). It was by shear luck that they didn't hit.
I vaguely remember attending a CASA roadshow years ago where they played a short audio clip. It was of a Dash-8 launching out of somewhere with traffic already in the circuit or on approach. The Dash took off having never quite worked out where the traffic was and demanded the other traffic climb or turn (can't remember which). It was by shear luck that they didn't hit.
An aircraft "instructing" another to do something is a bad idea.
).There are plenty of scenarios where it is advantageous to "take control" and ask for a level-off or maintain a track. Lud Slud and Dick et al hate being told what to do, but I've made more concessions to lighties than have been made to me. Why do you think ATC exists?
Apart from why the cowboy approach by the lighty from the west, the important question is... why was the EJet captain "preoccupied with PF duties and did not comprehend all the radio broadcasts." He/She was the most important (experienced/skilled) part of the whole thing. He/She has to be on top of what is going on.
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You guys are off the mark. 'Instructing' the aircraft concerned was a desperate measure to avoid a collision so 'instructing' to avoid a collision is the best course of action at the time.
Bloggs, the GA aircraft made the first broadcast at 11,000' at 10nm probably while the jet joined xwind, flaps were running and operational talk existed. The ATSB said that both aircraft made all the required calls, however the radio call to conduct a straight in approach by XGA actually happened at the end of the exchange with other traffic at 7nm and with no other call after that.
A jet is configuring in the circuit at that time getting set up for landing, not twiddling thumbs listening for conflicting traffic (that's not expected). The mental traffic model has already been created earlier. If the jet guys are configuring, setting flap, operational conversation and miss a call that has not been expected earlier, then you can assume problems. In a high workload environment, the first to go is your hearing, just providing balance to your comment.
Bloggs, the GA aircraft made the first broadcast at 11,000' at 10nm probably while the jet joined xwind, flaps were running and operational talk existed. The ATSB said that both aircraft made all the required calls, however the radio call to conduct a straight in approach by XGA actually happened at the end of the exchange with other traffic at 7nm and with no other call after that.
A jet is configuring in the circuit at that time getting set up for landing, not twiddling thumbs listening for conflicting traffic (that's not expected). The mental traffic model has already been created earlier. If the jet guys are configuring, setting flap, operational conversation and miss a call that has not been expected earlier, then you can assume problems. In a high workload environment, the first to go is your hearing, just providing balance to your comment.
Last edited by Utradar; 18th Jan 2017 at 09:48.
I would normally advise against QLink style 'Instruction' over the radio, eg- Do this so we can take a 10 knot tailwind and save 30 seconds. However, in some cases it is certainly required. By no fault of their own, some smaller aircraft pilots do not have the proper appreciation of Jet/Turboprop operations let alone a 'commercial operation'. I find often the safer option is to slow it up and let the 172 finish his circuit rather than direct him to remain upwind or extend downwind, but I appreciate this isn't always the easiest thing to do with commercial pressure coupled with the speed of a Jet or Q400.
I thought I'd read it all on PPRuNe Downunda, and then someone comes along with a reference to "instructions" from one aircraft to another.
I know what my response to an "instruction" from another aircraft would be.
(Thanks for your post AndrewR. I think I need to read the report more closely. If what happened was as you described, it kinda puts a different slant on things.)
I know what my response to an "instruction" from another aircraft would be.
(Thanks for your post AndrewR. I think I need to read the report more closely. If what happened was as you described, it kinda puts a different slant on things.)
Clearly not. I've been labouring under the misconception that I knew what the terms "instruction" and "take control" meant.
Good luck with your amateur ATCing! The odds are always in your favour.
Good luck with your amateur ATCing! The odds are always in your favour.
As I mentioned earlier, 'insolence' could be one contributing factor to the lack of appropriate, professional interaction exhibited by a small minority of GA pilots when operating in CTAFs.
I am sure that Lead Balloon enjoys a faux aura of expertise while discussing piston engine operating principles and airmanship at the local aero club whilst jabbing his wine glass in animated excitement, splashing it's contents on those around him as they once again roll their eyes.
I am sure that Lead Balloon enjoys a faux aura of expertise while discussing piston engine operating principles and airmanship at the local aero club whilst jabbing his wine glass in animated excitement, splashing it's contents on those around him as they once again roll their eyes.
Originally Posted by Balloon
Good luck with your amateur ATCing!
As you seem to be able to have a rational discussion without switching to skygod mode, andrewr, I'd be interested in your perspective on this from the report:
I interpret that to mean that while ZPJ was on base, XGA was on final from a straight in approach. The fact that XGA appeared stationary to the crew suggests to me that the aircraft were on relative tracks that were highly likely to intersect at the same time in the same place. (I came to these conclusions while sloshing wine at the local aero club....)
You said:
Is that based on any 'inside knowledge'?
If XGA appeared stationary in ZPJ's cockpit, ZPJ would have appeared stationary in XGA's cockpit, thus raising the question whether the pilot of XGA's opinion was correct (even assuming XGA saw ZPJ and had that opinion).
Why do you think they were "OK" in that circumstance?
(And Compylot and Bloggs: Clearly we operate in vastly different places, because I've never heard or had any 'insolent' interaction on any CTAF, or heard any benevolent skygod give 'mutally agreed instructions' or 'take control' in any CTAF. But maybe I just insolently leave my VHF switched off....
My only advice to you is when you switch to amateur ATC mode, ya better get it right. As I observed before, the good news for you is that the odds are vastly in favour of not having a collision, even before you open your mouth.)
ZPJ joined the Mildura Airport circuit on the crosswind leg for a left visual circuit to land on runway 09.
On the base leg of the circuit, the flight crew on board ZPJ heard their traffic collision alert system (TCAS) announce a traffic advisory (TA) aural alert (see TCAS limitations on approach). They glanced at their TCAS display to check the relative position of the traffic, which indicated it was to their right (position 1 in Figure 1). The flight crew looked out the right window of the flight deck and identified the traffic to their right and high against the skyline. The traffic appeared to them to be stationary in the windscreen relative to their own aircraft and with a high closure rate (from TCAS data the aircraft were 1.25 NM apart at the time of the TA alert).
On the base leg of the circuit, the flight crew on board ZPJ heard their traffic collision alert system (TCAS) announce a traffic advisory (TA) aural alert (see TCAS limitations on approach). They glanced at their TCAS display to check the relative position of the traffic, which indicated it was to their right (position 1 in Figure 1). The flight crew looked out the right window of the flight deck and identified the traffic to their right and high against the skyline. The traffic appeared to them to be stationary in the windscreen relative to their own aircraft and with a high closure rate (from TCAS data the aircraft were 1.25 NM apart at the time of the TA alert).
You said:
Before XGA was instructed to go around I think things were OK, they were behind ZPJ in distance to the runway and more than 500' higher when ZPJ got the traffic alert. I assume the jet approach speed is greater than the GA8 so that should work. The XGA pilot was probably of the opinion that they had given way to the traffic in the circuit.
If XGA appeared stationary in ZPJ's cockpit, ZPJ would have appeared stationary in XGA's cockpit, thus raising the question whether the pilot of XGA's opinion was correct (even assuming XGA saw ZPJ and had that opinion).
Why do you think they were "OK" in that circumstance?
(And Compylot and Bloggs: Clearly we operate in vastly different places, because I've never heard or had any 'insolent' interaction on any CTAF, or heard any benevolent skygod give 'mutally agreed instructions' or 'take control' in any CTAF. But maybe I just insolently leave my VHF switched off....
My only advice to you is when you switch to amateur ATC mode, ya better get it right. As I observed before, the good news for you is that the odds are vastly in favour of not having a collision, even before you open your mouth.)
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Is that based on any 'inside knowledge'?
Table 2 gives the altitudes, Time 3 was the TA with ZPJ at 733' on base, XGA at 1300' on a 3.5 miles final. I don't know the exact approach speeds, but I would guess that from 3.5 miles XGA could slow down enough to give e.g. 60 seconds spacing at touchdown.
However, with a closer look at the figures something looks sus. The positions were taken from ZPJ TCAS I think. They have XGA doing 2.4 miles in 43 seconds, or about 200 knots - in a GA8? I'm not sure how accurate those positions really are.
If XGA appeared stationary in ZPJ's cockpit, ZPJ would have appeared stationary in XGA's cockpit, thus raising the question whether the pilot of XGA's opinion was correct (even assuming XGA saw ZPJ and had that opinion).
Why do you think they were "OK" in that circumstance?
Why do you think they were "OK" in that circumstance?
Also they were about to turn final, so if they were on a collision course before changing direction, pretty much by definition they would not be once they turned final (as long as they didn't collide on base, obviously.)
Thanks AR
Very interesting.
It would be ironic if the "instruction" turned a benign situation into a close call. (I've been surprised sometimes when ATC has told heavy metal that they might get a TCAS RA from me, even though they are what seems to me to be a looooong way away. e.g. me late downwind and the heavy metal on long final. Someone very close to me who flies heavy metal says the SOP is to disable functions of the TCAS when operating into various busy airports OS, due to the volume of nearby traffic. But maybe I misunderstood the detail.)
Serious question for the heavy metal drivers: So you're on base at YMIA and a GA guy doing a straight in approach to the same runway is a collision risk but isn't on frequency or ignores the "instruction". What's the plan? I assume that because this is an obvious risk (or is it "threat" these days?) there's a pre-briefed plan.
(I know what you're likely to after you land, but what's the in-air plan?)
Very interesting.
It would be ironic if the "instruction" turned a benign situation into a close call. (I've been surprised sometimes when ATC has told heavy metal that they might get a TCAS RA from me, even though they are what seems to me to be a looooong way away. e.g. me late downwind and the heavy metal on long final. Someone very close to me who flies heavy metal says the SOP is to disable functions of the TCAS when operating into various busy airports OS, due to the volume of nearby traffic. But maybe I misunderstood the detail.)
Serious question for the heavy metal drivers: So you're on base at YMIA and a GA guy doing a straight in approach to the same runway is a collision risk but isn't on frequency or ignores the "instruction". What's the plan? I assume that because this is an obvious risk (or is it "threat" these days?) there's a pre-briefed plan.
(I know what you're likely to after you land, but what's the in-air plan?)
Someone very close to me who flies heavy metal says the SOP is to disable functions of the TCAS when operating into various busy airports OS, due to the volume of nearby traffic. But maybe I misunderstood the detail.)
The TCAS has many modes, "The Overseas Busy Airport Function, or OBAF, The Sydney Airport Parallel Runway Operation Mode, or SAPROM and even the Remote Area CTAF Function, or RACF, although I believe that this is an option that only Australian operators can purchase.
If you'd taken the time to Google this then you wouldn't be wasting our time here!
As for
Serious question for the heavy metal drivers: So you're on base at YMIA and a GA guy doing a straight in approach to the same runway is a collision risk but isn't on frequency or ignores the "instruction". What's the plan? I assume that because this is an obvious risk (or is it "threat" these days?) there's a pre-briefed plan.
Hopefully we'd all end up alright, I mean there might be a few dents here and there but nothing too serious
(..and how "Someone very close to me who flies heavy metal" are we talking here? Like 'wink wink' close or 'claws in the air, rooaaar go you good thing' close?)
The threat of traffic in an OCTA airfield would be briefed in the approach briefing during cruise. However a specific "plan" wouldn't exactly be detailed as the exact circumstances and relative positions aren't known would require differing actions. Generally should such traffic as you describe be encountered the plan would generally be see and avoid, separate ourselves vertically as well as horizontally, wait for said traffic to become clear (land or exit the circuit etc) and then proceed.
It is not a recommended practice to disable in anyway the TCAS functions for anything other than an engine failure where it is directed by the checklist due to the lack of performance requirements to comply with possible instructions, thus forcing another TCAS aircraft to comply with a resolution. I can't speak for ops overseas, but in Aus, it is not practice to turn off TCAS in anyway... what's the point in having it then?!?
Typically the thing that make things hard is a/c not making calls due to lower requirements these days and also perceived lack of need by the GA/smaller aircraft. Typically jets are doing 250knots from 30nm out which means they will enter the circuit (at approx 200knts) in around 7-9mins from that point. Things happen pretty quick and wider berths than expected are preferred as a result. We also want to prevent TCAS events (paperwork!) which are time based and whilst we know the parameters of such events, we don't see the exact real time limits/points that these will trigger.
The working environment is pretty busy as soon as you get a couple aircraft in the area. Crew co-ordination, configuration, ATC running on another radio at the same time giving traffic info, all the while trying to separate yourself from other aircraft. Add to this traffic magically appearing at 5nm-10nm without so much as a position report or response and it gets intense quickly. This has happened to me multiple times for varying reasons...
Earlier it was said that they "instructed" the go around as a last ditch effort, esp seeing as from their point of view (and my interpretation of the regs) they had right of way. This sounds about right and simply an extreme example. Typically anything we ask of another aircraft whilst trying to separate is a request more than an "instruction". Eg "if you could remain north of centreline until we depart south" is just us simply trying to ensure some sort of separation. It's hardly "ametuer atc".... it's professional pilots trying to ensure the safety of their aircraft with other pilots who may or may not be cognizant of our spacing requirements. Of course no aircraft is required to comply with any "request" and thats fine, we don't expect you to if you have right of way, so we'll typically just wait.
For the most part, despite my few bad experiences, usually GA/slower aircraft are more than helpful and usually more than willing to slow up/be # 2/give way etc etc and even usually offer it without us even requesting. I can tell you it's greatly appreciated and an absolute pleasure to share the airspace with you guys. I also understand that there are some situations which can be a pain for them and some of our guys push the friendship with straight in's onto rwy's with tailwind when other aircraft are using the reciprocal. I can't speak for all but personally will only try said jazz when it doesn't conflict with any known traffic in the area that has right of way.
It is not a recommended practice to disable in anyway the TCAS functions for anything other than an engine failure where it is directed by the checklist due to the lack of performance requirements to comply with possible instructions, thus forcing another TCAS aircraft to comply with a resolution. I can't speak for ops overseas, but in Aus, it is not practice to turn off TCAS in anyway... what's the point in having it then?!?
Typically the thing that make things hard is a/c not making calls due to lower requirements these days and also perceived lack of need by the GA/smaller aircraft. Typically jets are doing 250knots from 30nm out which means they will enter the circuit (at approx 200knts) in around 7-9mins from that point. Things happen pretty quick and wider berths than expected are preferred as a result. We also want to prevent TCAS events (paperwork!) which are time based and whilst we know the parameters of such events, we don't see the exact real time limits/points that these will trigger.
The working environment is pretty busy as soon as you get a couple aircraft in the area. Crew co-ordination, configuration, ATC running on another radio at the same time giving traffic info, all the while trying to separate yourself from other aircraft. Add to this traffic magically appearing at 5nm-10nm without so much as a position report or response and it gets intense quickly. This has happened to me multiple times for varying reasons...
Earlier it was said that they "instructed" the go around as a last ditch effort, esp seeing as from their point of view (and my interpretation of the regs) they had right of way. This sounds about right and simply an extreme example. Typically anything we ask of another aircraft whilst trying to separate is a request more than an "instruction". Eg "if you could remain north of centreline until we depart south" is just us simply trying to ensure some sort of separation. It's hardly "ametuer atc".... it's professional pilots trying to ensure the safety of their aircraft with other pilots who may or may not be cognizant of our spacing requirements. Of course no aircraft is required to comply with any "request" and thats fine, we don't expect you to if you have right of way, so we'll typically just wait.
For the most part, despite my few bad experiences, usually GA/slower aircraft are more than helpful and usually more than willing to slow up/be # 2/give way etc etc and even usually offer it without us even requesting. I can tell you it's greatly appreciated and an absolute pleasure to share the airspace with you guys. I also understand that there are some situations which can be a pain for them and some of our guys push the friendship with straight in's onto rwy's with tailwind when other aircraft are using the reciprocal. I can't speak for all but personally will only try said jazz when it doesn't conflict with any known traffic in the area that has right of way.
I'd also like to add that the CTAF freq at Mildura is shared with two other close by aerodromes. I can't tell you the number of times coming into Mildura that a lot of the CTAF calls are garbled by multiple aircraft at multiple aerodromes making calls. It's a joke and the y shouldn't be using the same freq...and in my opinion could have likely played a part in this conflict.