QF and DJ in a very near miss on Sunday over Melbourne

[markis10]

Qantas, Virgin planes in near miss

Andrew Heasley

December 9, 2010
QANTAS is involved in another air safety investigation after a near miss involving one of its aircraft, a Boeing 767, with a Virgin Blue Boeing 737 over Melbourne's northern outskirts on Sunday.

Qantas, Virgin planes in near miss


I normally treat these with a grain of salt, however on looking at WebTrak it seems this is very much news:

 

[jb747]

I'm not sure that I'd describe 3.5 kms laterally, and no TCAS interest, as a 'very near' miss.

 

[markis10]

Looking at the closure rate of the 76 and the fact the standards were compromised by a third I would beg to differ, it should not have got to that stage given the traffic shown is not indicative of a high workload and there plenty of alternate tracks to allow a faster trailer to climb through.

 

[jb747]

Looking at the closure rate of the 76 and the fact the standards were compromised by a third I would beg to differ, it should not have got to that stage given the traffic shown is not indicative of a high workload and there plenty of alternate tracks to allow a faster trailer to climb through.

It was most certainly an infringement of the standards. But, the media 'very near miss', and then conveniently leaving out the lateral separating, only looking at the vertical, makes it appear much closer than it was. For instance aircraft regularly come within 700 metres at the same height, and it isn't a near miss, but normal operation.

So, whilst I am less concerned about the raw numbers than you, the real question is 'how did the standards breakdown occur?'. Did ATC forget to separate them? Did one or the other aircraft get the height wrong?

 

[markis10]

ATCs generally dont rely on memory to do their job, and at that time of the day I doubt it's fatigue, when I get a chance I will have a listen to the tapes to get an indication of what went wrong. There are too many of these happening of late, and while it's not a head to head, it's still one of the worst examples I have seen given the tools available to me post my ATC career.

It should be noted this occurred under Departures Control, which is very much a senior atc position within the Area Approach Control Centre at MEL.

 

[jb747]

ATCs generally dont rely on memory to do their job, and at that time of the day I doubt it's fatigue, when I get a chance I will have a listen to the tapes to get an indication of what went wrong. There are too many of these happening of late, and while it's not a head to head, it's still one of the worst examples I have seen given the tools available to me post my ATC career.

I'm not normally a user of WebTrak, but have you watched this play the whole way through? There is something very odd in the playback, which actually makes me wonder if we are even talking about a real event.

2:21:07 the aircraft are 6 k apart V @ 2286M, Q@1984M
2:21:27, 5.5 km, V@2534M, Q@2315M
2:21:47, 5.0 km, V@2789M, Q@2647M
2:22:07, 2.1 km, V@2908M, Q@2877

The Virgin aircraft basically sits in the one spot from about 2:21:47. The image you've used, is from roughly 2:22:17...at which point the 767 has caught the stationary 737 (and it has been stationary for about 20 seconds). Hell, if Virgin are going to stop dead in the sky, then no wonder ATC can't keep up with them....

 

[markis10]

It does look odd on webtrak, given there is an ATSB investigation clearly there was a breakdown so the investigation will make interesting reading:

Investigation: AO-2010-104 - Breakdown of separation - Boeing 767-338, VH-OGU and Boeing 737-700, VH-VBH, Melbourne Aerodrome 300 deg M 28 Km, Victoria, 5 December 2010

 

[NM]

Perhaps Virgin Blue were testing the new Harrier 737

 

[oz_mark]

The thing with Webtrak is that it is mostly about allowing you to find what the noisy plane that flew over you was. One of its limitations is that it only shows aircraft below 3000 metres (as hopefully anything above that wouldn't be causing you to wake up!). After watching several jet departures they do have a habit of stopping in mid-air just as they approach the altitude of 3000 metres, before disappearing off the screen.

I'd hazard a guess and suggest the DJ plane was higher than you can make out from the Webtrak site. While closer than they should have been, I don't think it was 28m!

 

[markis10]

The ATSB have published their findings which have resulted in changed ATC procedures:

Investigation: AO-2010-104 - Breakdown of separation - Boeing B737-7Q8, VH-VBF and a Boeing B767-338, VH-OGU, near Melbourne Airport, Victoria, 5 December 2010

When the aircraft were transferred from the aerodrome controller to a departures controller, there was 3.4 NM (about 6.3 km) separation between them. The departures controller expected them to climb at a similar speed, and did not recognise the loss of separation assurance. The controller's actions to manage the compromised separation were not fully effective. At one point, radar separation had reduced to 1.9 NM (3.5 km) and vertical separation to 500 ft.
On 12 October 2011, a similar breakdown of separation occurred at Melbourne between an Airbus A320-232 and a Boeing Company 737-8BK. This incident involved different controllers to those involved in the 5 December 2010 incident.
The ATSB identified a safety issue in that the procedures for takeoffs at Melbourne Airport allowed for aircraft to depart relatively close to each other, with no documented requirements to ensure jet aircraft would maintain a set climb speed or to require flight crews to advise air traffic control if that speed could not be achieved. Although the Melbourne procedures were based on those used in Sydney, the Sydney procedures specified a minimum climb speed. The safety assessment report for the Melbourne procedures did not include a detailed comparison of the procedures used in the two locations. In response to the identified safety issue, Airservices Australia has commenced action to establish a standard speed profile for use at radar terminal area aerodromes in Australia, and to ensure that pilots of jet aircraft notify air traffic control when operating at a significantly lower speed than stipulated in that profile.