MEL Tower — Go Slow?
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Sydney has 3 runways that seem to function as 2 runways 99% of the time.
The big difference is that Melbourne has 2 runways, which seem to function as 1 runway quite often. That’s when the holding happens.
The holding advisory doesn’t change when Melbourne is likely to be running single runway. A pilot familiar with the Melbourne single runway issues can look at the forecast winds and predict this, but not all pilots have this local knowledge. In fact even the forecast winds are not necessarily a good predictor, as pilots only get the average forecast wind directon, not the variation, and a variation of above 5TW on 27 closes the duty runway.
Is it likely to help when/if a 09/27 parallel opens? Or will the third runway be hampered by the same issues as the existing 09/27? (i.e. south-easterly component continuing to reduce the airport to single runways? Or will it open a 09 option? Or course a strong northerly will still be a problem.)
The big difference is that Melbourne has 2 runways, which seem to function as 1 runway quite often. That’s when the holding happens.
The holding advisory doesn’t change when Melbourne is likely to be running single runway. A pilot familiar with the Melbourne single runway issues can look at the forecast winds and predict this, but not all pilots have this local knowledge. In fact even the forecast winds are not necessarily a good predictor, as pilots only get the average forecast wind directon, not the variation, and a variation of above 5TW on 27 closes the duty runway.
Is it likely to help when/if a 09/27 parallel opens? Or will the third runway be hampered by the same issues as the existing 09/27? (i.e. south-easterly component continuing to reduce the airport to single runways? Or will it open a 09 option? Or course a strong northerly will still be a problem.)
le pingouin you said
I said
meaning plenty of places there are more than a few aircraft in the sky and don't have the issues Melbourne does!
I'm not so sure Sydney gets
as you put it. Yes it does happen, particularly during the 6-9am period, but not all day and generally less holding than Melbourne.
There seems to be something unusually bad about the Melbourne system, from sequencing to airborne delays often when there are few aircraft in the TMA. I don't know exactly what it is nor do I point the finger at someone making it that way, however there's plenty of feedback here to support that there IS a problem.
You might be able to nail the fix time to 10 seconds from a 1000 miles out, fantastic. But it just doesn't work well in the real world when there are more than a few aircraft in the sky.
Australia nor Melbourne, are the only airports in the word that suffer from these problems
I'm not so sure Sydney gets
vectored all over the sky, 250 knot descent?
There seems to be something unusually bad about the Melbourne system, from sequencing to airborne delays often when there are few aircraft in the TMA. I don't know exactly what it is nor do I point the finger at someone making it that way, however there's plenty of feedback here to support that there IS a problem.
From experience of Mel some time ago operating a 747. The most inefficient use of runway occupancy. Line up clearance not given until landing aircraft past you at holding point, no” line up after landing 737” etc. And on even severe CAVOK days being denied lineup/ takeoff clearance because of landing traffic a dot in the distance. In most other Countries you’d get at least one heavy off and in USA perhaps two, in the separation ATC seemed to require.
The lack of conditional line up clearances is a CASA problem, not ATC. It’s got to do with the stop bars
GA Driver, how many times have you been given a fix time into Sydney coming in through the ML FIR? Rarely. I don't work Brisbane so can't say how they do it from that side. I know because I work the sectors that feed into the sectors that do the sequencing. They use speeds, vectors with generally a 250 knot descent, and holding, not fix times assigned to aircraft to achieve the Maestro times. Into Melbourne coming from the south, clockwise around to north you'll usually be given a time with vectors to lose the rest, until we go to holding. I know because I work those sectors.
Few aircraft in the TMA? How many aircraft can you fit inside 30 miles when there's an average 2.5 minutes between arrivals onto say RWY 16? Correct, the answer isn't that many. If they're all coming from the north it's 5 or 6 with the first touching down.
Few aircraft in the TMA? How many aircraft can you fit inside 30 miles when there's an average 2.5 minutes between arrivals onto say RWY 16? Correct, the answer isn't that many. If they're all coming from the north it's 5 or 6 with the first touching down.
I don’t disagree with your numbers, the amount of aircraft you can fit, nor the sectors you control. Simply put and as I said above, we don’t get this amount, or frequency of delay into Sydney as Melbourne does.
Whether you apply feeder fix times or controlled descent speeds into SY is irrelevant to this. I didnt imply anything to the contrary.
How do I know this? Because I fly it most days as much as you control it.
You appear to get very defensive of any critique to this sequencing. As I said before I’m not having a shot at you personally, but as above, there is something unique (and ordinary) about the sequencing into Melbourne that appears to incur additional delay.
I have often wondered how the maestro holding gets worked out and is there any feedback to anyone further down the line (ie. from
the tower) as to how it worked out! No sh!t stirring, Genuine question.
Whether you apply feeder fix times or controlled descent speeds into SY is irrelevant to this. I didnt imply anything to the contrary.
How do I know this? Because I fly it most days as much as you control it.
You appear to get very defensive of any critique to this sequencing. As I said before I’m not having a shot at you personally, but as above, there is something unique (and ordinary) about the sequencing into Melbourne that appears to incur additional delay.
I have often wondered how the maestro holding gets worked out and is there any feedback to anyone further down the line (ie. from
the tower) as to how it worked out! No sh!t stirring, Genuine question.
So that limitation should be advised to ATC before taking up the runway that someone else could be using....
GA Driver, how many times have you been given a fix time into Sydney coming in through the ML FIR? Rarely. I don't work Brisbane so can't say how they do it from that side. I know because I work the sectors that feed into the sectors that do the sequencing. They use speeds, vectors with generally a 250 knot descent, and holding, not fix times assigned to aircraft to achieve the Maestro times. Into Melbourne coming from the south, clockwise around to north you'll usually be given a time with vectors to lose the rest, until we go to holding. I know because I work those sectors.
Few aircraft in the TMA? How many aircraft can you fit inside 30 miles when there's an average 2.5 minutes between arrivals onto say RWY 16? Correct, the answer isn't that many. If they're all coming from the north it's 5 or 6 with the first touching down.
Few aircraft in the TMA? How many aircraft can you fit inside 30 miles when there's an average 2.5 minutes between arrivals onto say RWY 16? Correct, the answer isn't that many. If they're all coming from the north it's 5 or 6 with the first touching down.
If trying to provide information and possible reasons is defensive? Given the tone of many of the posts is it any surprise? Industrial action? Really?!?
The tower doesn't care less about Maestro - it's just a tool for providing an ordered stream of arriving aircraft and they're not fussed about how it's achieved. The idea is Maestro puts aircraft in more or less the right place but arrivals tweaks the sequence to an extent and TMA tweaks it further - some for separation and some to account for the dynamics of the aircraft around you. Sometimes Maestro's wind and performance model isn't so crash hot and you get dead heats from different direction. I'll emphasise this - Maestro is a sequencing tool at the threshold and not a separation tool.
How it works: Maestro calculates your estimate for the feeder fix based on winds, levels in your flight plan (and as altered in-flight either automatically or manually as the auto doesn't work) and the TAS in your plan (and as updated manually by us on advice from you). It then calculates a time from the fix to the threshold via the STAR based on winds and performance data (based on historical data collected for type and airline). This sets an order but as your fix time is periodically recalculated by Maestro the order isn't fixed yet - this stage is called "unstable" as your position in the sequence isn't set.
The flow sets the acceptance rate - however many seconds between arrivals based on wind (your groundspeed is lower down final with stronger wind) the mode of ops (biased towards arrivals or departures) and type of approaches being used. No. 1 goes through untouched. No. 2 gets a fix time calculated (if necessary) based on the acceptance rate and 250kts from the fix. No. 3 gets a fix time to fit it the required time behind no. 2, and so forth. If there are several aircraft with untouched landing times within a few seconds the the sequence can jump around a lot - you might go from no. 1 to no. 5, so from no delay to 10 minutes (or whatever).
The next stage is "stable" where the sequence can still change but usually not with out manual intervention. Left to its own devices Maestro will make you "stable" 15 minutes from the fix - it won't update your untouched fix estimate further. Generally we'll set this quite a bit earlier to stabilise the sequence - we'll set an untouched fix estimate based on what we think you'll achieve (based on observed performance) or what we think you can achieve with track shortening and high speed if there's a gap. Once stable Maestro won't automatically change your untouched fix estimate but the order can still be changed by a close in departure getting away and being added to the sequence, or if we manually change it. Also blocks can be added to accommodate things like medical traffic into Essendon if needed or adding extra spacing behind A380s. Your feeder fix time can also change if an aircraft has their untouched fix time adjusted, placing them ahead of your untouched time.
There are two other phases, super-stable and frozen but they don't really have any further impact on times changing, other than for instance putting a go-around back in the sequence, but that's all manually done by the flow. FWIW we also have to insert Essendon traffic into the Melbourne sequence when vis is poor, although that's not too often. Adding a slot for Essendon medevac traffic is far more common.
Whether you are issued a time and vectors to lose the rest (if necessary) or a hold depends on how long the delays are going on for - at some stage the delays just get too large to absorb sensibly with speed reduction and vectors from a controller workload perspective. Maestro has reduced the amount of holding we do and the ground delay program has reduced it further. I can't quantify this but I certainly do less holding now than I have in the past.
The tower doesn't care less about Maestro - it's just a tool for providing an ordered stream of arriving aircraft and they're not fussed about how it's achieved. The idea is Maestro puts aircraft in more or less the right place but arrivals tweaks the sequence to an extent and TMA tweaks it further - some for separation and some to account for the dynamics of the aircraft around you. Sometimes Maestro's wind and performance model isn't so crash hot and you get dead heats from different direction. I'll emphasise this - Maestro is a sequencing tool at the threshold and not a separation tool.
How it works: Maestro calculates your estimate for the feeder fix based on winds, levels in your flight plan (and as altered in-flight either automatically or manually as the auto doesn't work) and the TAS in your plan (and as updated manually by us on advice from you). It then calculates a time from the fix to the threshold via the STAR based on winds and performance data (based on historical data collected for type and airline). This sets an order but as your fix time is periodically recalculated by Maestro the order isn't fixed yet - this stage is called "unstable" as your position in the sequence isn't set.
The flow sets the acceptance rate - however many seconds between arrivals based on wind (your groundspeed is lower down final with stronger wind) the mode of ops (biased towards arrivals or departures) and type of approaches being used. No. 1 goes through untouched. No. 2 gets a fix time calculated (if necessary) based on the acceptance rate and 250kts from the fix. No. 3 gets a fix time to fit it the required time behind no. 2, and so forth. If there are several aircraft with untouched landing times within a few seconds the the sequence can jump around a lot - you might go from no. 1 to no. 5, so from no delay to 10 minutes (or whatever).
The next stage is "stable" where the sequence can still change but usually not with out manual intervention. Left to its own devices Maestro will make you "stable" 15 minutes from the fix - it won't update your untouched fix estimate further. Generally we'll set this quite a bit earlier to stabilise the sequence - we'll set an untouched fix estimate based on what we think you'll achieve (based on observed performance) or what we think you can achieve with track shortening and high speed if there's a gap. Once stable Maestro won't automatically change your untouched fix estimate but the order can still be changed by a close in departure getting away and being added to the sequence, or if we manually change it. Also blocks can be added to accommodate things like medical traffic into Essendon if needed or adding extra spacing behind A380s. Your feeder fix time can also change if an aircraft has their untouched fix time adjusted, placing them ahead of your untouched time.
There are two other phases, super-stable and frozen but they don't really have any further impact on times changing, other than for instance putting a go-around back in the sequence, but that's all manually done by the flow. FWIW we also have to insert Essendon traffic into the Melbourne sequence when vis is poor, although that's not too often. Adding a slot for Essendon medevac traffic is far more common.
Whether you are issued a time and vectors to lose the rest (if necessary) or a hold depends on how long the delays are going on for - at some stage the delays just get too large to absorb sensibly with speed reduction and vectors from a controller workload perspective. Maestro has reduced the amount of holding we do and the ground delay program has reduced it further. I can't quantify this but I certainly do less holding now than I have in the past.
paris, fix times don't work so well when you've got aircraft coming from different directions converging on a common point a fair way out from the fix - they can end up being in the wrong order due to wind direction. Easier in some ways to peel them off and turn them in when the spacing is right.
paris, fix times don't work so well when you've got aircraft coming from different directions converging on a common point a fair way out from the fix - they can end up being in the wrong order due to wind direction. Easier in some ways to peel them off and turn them in when the spacing is right.
If trying to provide information and possible reasons is defensive? Given the tone of many of the posts is it any surprise? Industrial action? Really?!?
The tower doesn't care less about Maestro - it's just a tool for providing an ordered stream of arriving aircraft and they're not fussed about how it's achieved. The idea is Maestro puts aircraft in more or less the right place but arrivals tweaks the sequence to an extent and TMA tweaks it further - some for separation and some to account for the dynamics of the aircraft around you. Sometimes Maestro's wind and performance model isn't so crash hot and you get dead heats from different direction. I'll emphasise this - Maestro is a sequencing tool at the threshold and not a separation tool.
How it works: Maestro calculates your estimate for the feeder fix based on winds, levels in your flight plan (and as altered in-flight either automatically or manually as the auto doesn't work) and the TAS in your plan (and as updated manually by us on advice from you). It then calculates a time from the fix to the threshold via the STAR based on winds and performance data (based on historical data collected for type and airline). This sets an order but as your fix time is periodically recalculated by Maestro the order isn't fixed yet - this stage is called "unstable" as your position in the sequence isn't set.
The flow sets the acceptance rate - however many seconds between arrivals based on wind (your groundspeed is lower down final with stronger wind) the mode of ops (biased towards arrivals or departures) and type of approaches being used. No. 1 goes through untouched. No. 2 gets a fix time calculated (if necessary) based on the acceptance rate and 250kts from the fix. No. 3 gets a fix time to fit it the required time behind no. 2, and so forth. If there are several aircraft with untouched landing times within a few seconds the the sequence can jump around a lot - you might go from no. 1 to no. 5, so from no delay to 10 minutes (or whatever).
The next stage is "stable" where the sequence can still change but usually not with out manual intervention. Left to its own devices Maestro will make you "stable" 15 minutes from the fix - it won't update your untouched fix estimate further. Generally we'll set this quite a bit earlier to stabilise the sequence - we'll set an untouched fix estimate based on what we think you'll achieve (based on observed performance) or what we think you can achieve with track shortening and high speed if there's a gap. Once stable Maestro won't automatically change your untouched fix estimate but the order can still be changed by a close in departure getting away and being added to the sequence, or if we manually change it. Also blocks can be added to accommodate things like medical traffic into Essendon if needed or adding extra spacing behind A380s. Your feeder fix time can also change if an aircraft has their untouched fix time adjusted, placing them ahead of your untouched time.
There are two other phases, super-stable and frozen but they don't really have any further impact on times changing, other than for instance putting a go-around back in the sequence, but that's all manually done by the flow. FWIW we also have to insert Essendon traffic into the Melbourne sequence when vis is poor, although that's not too often. Adding a slot for Essendon medevac traffic is far more common.
Whether you are issued a time and vectors to lose the rest (if necessary) or a hold depends on how long the delays are going on for - at some stage the delays just get too large to absorb sensibly with speed reduction and vectors from a controller workload perspective. Maestro has reduced the amount of holding we do and the ground delay program has reduced it further. I can't quantify this but I certainly do less holding now than I have in the past.
The tower doesn't care less about Maestro - it's just a tool for providing an ordered stream of arriving aircraft and they're not fussed about how it's achieved. The idea is Maestro puts aircraft in more or less the right place but arrivals tweaks the sequence to an extent and TMA tweaks it further - some for separation and some to account for the dynamics of the aircraft around you. Sometimes Maestro's wind and performance model isn't so crash hot and you get dead heats from different direction. I'll emphasise this - Maestro is a sequencing tool at the threshold and not a separation tool.
How it works: Maestro calculates your estimate for the feeder fix based on winds, levels in your flight plan (and as altered in-flight either automatically or manually as the auto doesn't work) and the TAS in your plan (and as updated manually by us on advice from you). It then calculates a time from the fix to the threshold via the STAR based on winds and performance data (based on historical data collected for type and airline). This sets an order but as your fix time is periodically recalculated by Maestro the order isn't fixed yet - this stage is called "unstable" as your position in the sequence isn't set.
The flow sets the acceptance rate - however many seconds between arrivals based on wind (your groundspeed is lower down final with stronger wind) the mode of ops (biased towards arrivals or departures) and type of approaches being used. No. 1 goes through untouched. No. 2 gets a fix time calculated (if necessary) based on the acceptance rate and 250kts from the fix. No. 3 gets a fix time to fit it the required time behind no. 2, and so forth. If there are several aircraft with untouched landing times within a few seconds the the sequence can jump around a lot - you might go from no. 1 to no. 5, so from no delay to 10 minutes (or whatever).
The next stage is "stable" where the sequence can still change but usually not with out manual intervention. Left to its own devices Maestro will make you "stable" 15 minutes from the fix - it won't update your untouched fix estimate further. Generally we'll set this quite a bit earlier to stabilise the sequence - we'll set an untouched fix estimate based on what we think you'll achieve (based on observed performance) or what we think you can achieve with track shortening and high speed if there's a gap. Once stable Maestro won't automatically change your untouched fix estimate but the order can still be changed by a close in departure getting away and being added to the sequence, or if we manually change it. Also blocks can be added to accommodate things like medical traffic into Essendon if needed or adding extra spacing behind A380s. Your feeder fix time can also change if an aircraft has their untouched fix time adjusted, placing them ahead of your untouched time.
There are two other phases, super-stable and frozen but they don't really have any further impact on times changing, other than for instance putting a go-around back in the sequence, but that's all manually done by the flow. FWIW we also have to insert Essendon traffic into the Melbourne sequence when vis is poor, although that's not too often. Adding a slot for Essendon medevac traffic is far more common.
Whether you are issued a time and vectors to lose the rest (if necessary) or a hold depends on how long the delays are going on for - at some stage the delays just get too large to absorb sensibly with speed reduction and vectors from a controller workload perspective. Maestro has reduced the amount of holding we do and the ground delay program has reduced it further. I can't quantify this but I certainly do less holding now than I have in the past.
Optimal trajectories is all about individual aircraft and we're dealing with a whole system - optimising that is a different problem to optimising an individual aircraft. It's nothing about trusting pilots. It's about limited ability to lose time with a tailwind vs a headwind. And which phase of flight pilots choose to lose the time - some reduce a lot in the cruise, others do it all on descent. The convergence is some distance from the feeder fix so you can have considerable difference in ground speed - e.g. 480kts ground speed from the north vs 380kts from the SW. The spacing will be good eventually, but until the ground speeds are comparable separation can be an issue. I've had extreme cases where ground speeds have been 200kts different due to wind direction and a huge headwind increase over a couple of thousand feet. Front aircraft 5 miles ahead at the turn opened up to over 10 before it has slowed. Maestro does not provide separation.
Optimal trajectories is all about individual aircraft and we're dealing with a whole system - optimising that is a different problem to optimising an individual aircraft. It's nothing about trusting pilots. It's about limited ability to lose time with a tailwind vs a headwind. And which phase of flight pilots choose to lose the time - some reduce a lot in the cruise, others do it all on descent. The convergence is some distance from the feeder fix so you can have considerable difference in ground speed - e.g. 480kts ground speed from the north vs 380kts from the SW. The spacing will be good eventually, but until the ground speeds are comparable separation can be an issue. I've had extreme cases where ground speeds have been 200kts different due to wind direction and a huge headwind increase over a couple of thousand feet. Front aircraft 5 miles ahead at the turn opened up to over 10 before it has slowed. Maestro does not provide separation.
How do you get a common track for all the RIVET arrivals into Sydney? They have to converge somewhere......
Different types, different weights, different companies - all perform differently even when the aircraft is doing it. An AIrbus heavy will often be 10,000ft lower than a 737 at 100 miles. Sorry, it's all wonderful when you're the only aircraft in your bit of the sky but it doesn't work so well when you're not. We have to separate you the whole time, not just at the feeder fix. That's why you can't just do your own thing.
Different types, different weights, different companies - all perform differently even when the aircraft is doing it. An AIrbus heavy will often be 10,000ft lower than a 737 at 100 miles. Sorry, it's all wonderful when you're the only aircraft in your bit of the sky but it doesn't work so well when you're not. We have to separate you the whole time, not just at the feeder fix. That's why you can't just do your own thing.
I’d be very surprised if any 737 operator had an OPT that didn’t predicate the 27 take off performance data on a 90 degree line up. The tops dogs at Air Services surely meet regularly enough with the Chief Pilots to be fully aware of this kind of critical operational information though and considering that they are all part of their respective ‘leadership teams’ I’m sure they ‘cascade’ the information down to the ATC’s and line pilots. All part of a days work to keep the working boys and girls singing from the same hymn sheet. I’m sure those sorts of Leadership Tasks are completed before lunch and certainly before considering critical KPI drivers such as discretionary fuel uplift and OTP.
Maybe its time to stop catering for the LCD all the time. Why doesn't the industry bring the standard up instead of continually ratcheting it down. Regulation doesn't solve LCD issues, it just drags everyone down with it.
Incidentally, I was SLF on a flight Cairns to Brisbane the other day and we were held for 25 mins on the ground prior to departure due to whatever issue ATC had at Brisbane. I know it wasn't weather or a runway disaster. Same happened Perth - Brisbane recently. I simply cannot fathom that Australia has such a volume of traffic that aircraft are held on the ground prior to departure to ensure a slot on the other side of the country. Talk about a broken system. Wait till the volumes really ramps up....oh yeah that won't be until 2100.
Incidentally, I was SLF on a flight Cairns to Brisbane the other day and we were held for 25 mins on the ground prior to departure due to whatever issue ATC had at Brisbane. I know it wasn't weather or a runway disaster. Same happened Perth - Brisbane recently. I simply cannot fathom that Australia has such a volume of traffic that aircraft are held on the ground prior to departure to ensure a slot on the other side of the country. Talk about a broken system. Wait till the volumes really ramps up....oh yeah that won't be until 2100.
Originally Posted by Paris Hiltons
The concept of pilots choosing when and how to lose time is also old fashioned and any residuals in this area are gradually being addressed by airlines and hopefully the ANSPs. The pilot correctly would set the time at a fix and let the aircraft do the rest - anything else such as manual intervention results in operational and cost efficiency losses.
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Quote:
Originally Posted by morno 
The lack of conditional line up clearances is a CASA problem, not ATC. It’s got to do with the stop bars
The international hub I now work at has at least 1,200 movements a day - every day! We can push 46 departures and 36 arrivals an hour on a two RWY - one in, one out set up. We have stop bars everywhere. We can give an aircraft a conditional line up clearance behind the one in front that has a conditional line up clearance to line up behind the one on the RWY. Using stop bars no less. Oh the humanity........
The goal is to be as efficient as possible and get everyone moving. Make it work. Procedures have been developed to achieve that outcome. It can be done and is being done elsewhere in the world. The parochial, "that's how we have always done it" 'leaders' need to stop patting each other on the back and get on the with the game.
Some other examples of Australia being left behind in the ATC world.......NATS time based sep.............RECAT-EU...............Dubai Capacity Enhancement..
As that famous philosopher Mr F. Bueller once said, "life moves pretty fast...."