Originally Posted by neville_nobody
(Post 10664950)
Except that is not what the chart says. By your logic if you were told to go-around at 1000' you would fly all the way to the runway end then start the right turn. By that time you would be level at 2000'.
By the looks of the ground track the crew flew the Missed Approach correctly as they started the go-around just above the minima. So they had to climb to 600' first before commencing the turn which took away some of their separation from the 330. They were a little late in the turn but as mentioned above the 737 is a handful in a unexpected go-around. The turn is at 600' not at the MAP. If they started at turn at 220' then they would have turned straight into the cranes at the port. So they flew the MAP correctly as they were pretty close to the minima |
The AIP is quite clear - you climb to the missed approach point and then follow the missed approach instructions. If I were issued a go around at 1000’, I would be continuing to the MAP (roughly .5nm from departure end threshold) before turning, and if that means I’m at 2000’ before starting the turn, then so be it. |
If anything is clear... there is confusion amongst the industry about how these things are meant to be flown. Usually it never matters. But in this instance, it has brought to the surface a potential confusing issue. Which is what the ATSB are checking :)
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11 ON THE SENSATIONALISM SCALE
So The New Daily has reported on the loss of separation incident thus:
Qantas planes in near miss above Sydney under guidance of trainee air traffic controller Emma Ellsworthy 9:49am, Jan 17, 2020 Updated: 9:51am, Jan 17 Australia’s transport safety authority is probing whether a trainee air traffic controller is to blame after two Qantas planes came within 152 metres of each other over Sydney. The incident – which occurred last August – was so serious, one of the aircraft’s emergency collision avoidance systems was activated. Details of the near-miss are contained in a preliminary report by the Australian Transport Safety Bureau (ATSB), which was released on Thursday and categorised the incident as “serious”. It happened after an Airbus A330 was cleared to take off from Sydney Airport at the same time a Boeing 737 was about to land. The A330 travelled just 152 metres below the 737 aircraft in a tense few seconds described as “very close” by the plane’s captain, who radioed the control tower straight away. The ATSB’s report found the “loss of separation” between the planes occurred when both aircraft turned to the right. Only the A330 was supposed to do so. The aircraft’s airborne collision avoidance system – a last-resort safety mechanism – was activated as a result. Both planes ascended after the close shave, with the A330 climbing 1500 metres and continuing to Melbourne, while the 737 went about 900 metres higher before landing safely. The trainee was working supervised in the tower, the report found. He had worked as an air controller at other airports and was training to take up the position at Sydney Airport. The report also found the aircraft maintained a 796m lateral distance. In a statement, Qantas said: “Even if both aircraft stayed on the same flight paths, they were not in danger of colliding”. “We’re continuing to work with the ATSB on their ongoing investigation.” Dr Stuart Godley, the ATSB’s Director of Transport Safety, said the investigation would now probe the planes’ instruments as well as air traffic control procedures, controller training and flight data. |
Originally Posted by Paddleboat
(Post 10664918)
Indeed! Certainly a possibility.
It was put to me that the reason a breakdown in separation was inevitable regardless of the 737's lateral track was due to the A330's lack of climb performance, at least relative to the 737. Your reasoning I believe supports my position. If the 737 had turned at the correct time and followed the path in my quick and dirty diagram, then there would have been more than sufficient time, given the A330 is back at 180kts until established on the radial, and the 737 is accelerating, for their to be vertical separation as provided by the respective procedures by the time their tracks intersected, if they would at all. Bear in mind the 737 single click toga gives 1000-2000fpm... So the bus would outperform massively in this circumstance. |
Originally Posted by neville_nobody
(Post 10664993)
Except on a precision approach the missed approach point is the DA/DH, it is not a fixed point on the ground like on a NDB/VOR/RNAV. So you are not going to continue descending to that They want you to turn right away not fly 335 for 3 miles then turn. Same on 16L.
a. the point of intersection of an electronic glide path with the applicable DA/RA Height; (ie the corresponding point on the GS with 220’) b. anavigationalfacility;or c. afix;or d. a specified distance from the FAF, or e. a waypoint. A published missed approach procedure must not be flown unless commenced at the MAPT. If a missed approach climb is initiated before the MAPT, the aircraft must track to the MAPT before commencing the missed approach procedure. Of course you won’t continue descending. They very much do want you tracking to straight ahead to that point before the turn, and not turning early. There shouldn’t be any debate about this...... |
Whatever you pilot fellows read, don't fall for the 'trainee ATC' bull****. The trainee has a rated ATC sitting/standing beside them, watching every move.
There's only so much an ATC can do, can't fly the plane for you. That's been recognised, operationally, procedures changed to reflect this some time ago. This, to me, looks like an airspace design issue. Everyone let down, pilot, pax. ATC. What a **** show. |
Originally Posted by Mick/ABC
Only the A330 was supposed to do so.
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I tend to agree with Porter. Crappy design.
A few rough estimates; At 400 ft they’d be about 1200m from the MAPT as the crow flies. They’d be doing maybe 82m/sec. Time how long it takes you to say ATC : “Qantas 123 this isn’t going to work, carry out the standard missed approach procedure” QF: “ Ahhh understood standard missed approach procedure, Qantas 123 going round” PF “ Righto, we’re gunna go round” PM “ Yip” PF “ Going round Flap fifteen” three second pause for the actions PM” positive rate” PF “ gear up” It takes me between 17 and 20 seconds if I do it at a pace I think is realistic/likely. So now you’re 400m past the MAPT climbing back through 400ft and doing exactly as the procedure calls for, tracking 335 waiting for 600ft where you’ll begin your turn onto 070. How long does that take? 200ft at 1000fpm is another 12 seconds and 980m. So now, after flying the machine nicely, you’re 1.4km past the MAPT. So my thoughts are that if everything goes really well, you’re going to be over the runway when you turn but very likely is that you’re going to be well down the runway as things rarely go exactly to plan. All it would take is one drawn out communication and you are turning where this aircraft turned having done the job very nicely. |
"Go Around, follow the 330, he's doing 140" would have worked. :E
"Too close, I'm switching to guns!" :} |
Originally Posted by The name is Porter
(Post 10665068)
Whatever you pilot fellows read, don't fall for the 'trainee ATC' bull****. The trainee has a rated ATC sitting/standing beside them, watching every move.
There's only so much an ATC can do, can't fly the plane for you. That's been recognised, operationally, procedures changed to reflect this some time ago. This, to me, looks like an airspace design issue. Everyone let down, pilot, pax. ATC. What a **** show. |
Was the spacing that tight? Looks like the 330 may have been getting airborne about when the maggot went round
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Originally Posted by Capn Bloggs
(Post 10665090)
I sent the ABC an email about that and that has now been removed. :ok:
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Interesting discussion on the event.
I do this approach often and when PM I usually ask my sidekick if in the event of a GA where they intend to turn on to 070. I get about as many variations as given above. It is a Sh!t design that allows the varying interpretations. Only 1 is correct and I'm not sure it's the one coded into the FMC. However 2 lines in the report Table Summary of key events stand out. Time 1831:04 The ADC-E instructed the A330 flight crew to line up runway 34R. The 737 was on final approach at about 2.8 NM. Gutsiest move I ever saw Mav. |
Originally Posted by 73qanda
(Post 10665114)
So now you’re 400m past the MAPT climbing back through 400ft and doing exactly as the procedure calls for, tracking 335 waiting for 600ft where you’ll begin your turn onto 070.
Flight data showed the 737 flight crew commenced the right turn when climbing through about 1,300 ft AGL (above ground level). At that time the aircraft was approximately 1,500 m north of the runway threshold. |
Originally Posted by Back Seat Driver
(Post 10665213)
However 2 lines in the report Table Summary of key events stand out. Time 1831:04 The ADC-E instructed the A330 flight crew to line up runway 34R. The 737 was on final approach at about 2.8 NM. Gutsiest move I ever saw Mav. |
There shouldn’t be any debate about this...... Given the confusion out there and this incident some clarification is obviously required. |
Neville,
Get the AIP changed. The obvious intent of the procedure design is not in line with the AIP rules re tracking to a MAPT before turning. |
Nev,
I don’t mean to be contrary but for the sake of clarity the AIP is clear re the expectation of tracking: https://cimg3.ibsrv.net/gimg/pprune....80b5ce6d1.jpeg if you go around from 2000’, the expectation is that you will track to the Mapt then turn. Not turn straight away. |
Track to the mapt. It's clear.
I've always been given a heading for the many GAs I've had in Sydney. |
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