Do you know how this can happen?

[haughtney1]

Mods, this is another moan directed at ASA, its not finger pointing exercise, more a fact finding moan as I'm trying to fathom the ineptitude of what I recently experienced.
Scene setting...
Big airways mega-cruiser approaching the end of its 13hr journey from its sandy furnace home base going to a pleasant Southern Australian destination.
Mega-cruiser has been in Australian airspace for 7 1/2 hours and has via CPDLC (datalink) been dutifully reporting ETA's and such.
5 minutes before computed TOD the lovely lady on the wireless issues the expected STAR clearance with a requirement to cross an intermediate waypoint....10 minutes!!! after the original eta.
Needless to say, I suffered sense of humour failure and ATC were advised that this was impossible, and would they like us to hold.
Order was restored after extensive/expensive vectoring to allow the various Saab 340's etc do their thing.
Needless to say I'm utterly flabbergasted that a first (cough cough) world ATC system can be this disorganised such that they advised us of the need to lose so much time with so little warning, I can live 2, 3, 4, 5....30 minutes if I'm given notice, but 5 minutes before TOD? not acceptable IMHO.(At destination there was no bad weather..disabled aeroplanes..navaid issues or closed runways)
Anyone got any thoughts?
BTW, not a slight on any controllers per se, we work with imperfect systems in an imperfect world, given that, how can this be allowed to happen if ASA are supposed to be a service provider?

Thoughts appreciated!

H1 :ok:

[blueloo]

They probably couldnt determine the Ego category until they spoke to you - they then had to rapidly apply a ten minute hot air & bluster emergency separation category at the last minute for the sake of all humanity. :E :E

[haughtney1]

They probably couldnt determine the Ego category until they spoke to you - they then had to rapidly apply a ten minute hot air & bluster emergency separation category at the last minute for the sake of all humanity.

Clearly theres still hope for humanity in this case :ok::E

Sooo your saying you don't know either?

[blueloo]

:E nup , no idea. But it does happen quite a bit.... Perhaps in the ops normal for ASA category

[porch monkey]

No idea. But welcome to our world. Cobt, radar all the way and we still get that and more.

[slice]

200nm of your destination

There's the problem right there. Why is this so? Is the question that has to be asked.

[TWOTBAGS]

Just because you are in the airspace for 7+ and guzzling 10T per hour in a sand encrusted dugong does not mean they are gonna let you in when you want.

ACA provide a Strategic Slot, NOC provide a tactical slot, Metron will use that best guess as you did leave 13hr + ago and then you are it.

Yes its a horses arse, no its not America or Europe, live with it.

If this is such a worry then wait until you see the new Flight Priorities Review Report and draft AIP ENR 1.4–10 ........

2015 Aeronautical Information Publication Flight Priorities Review (http://www.infrastructure.gov.au/aviation/atmpolicy/aipflightpriorities.aspx)

Have a read and tell them what you think next time a Saab cuts your grass onto 34L.......


ps. Haughtney does it want to make you go back to the Falcon or is it toooo comfy in the tripple?

[le Pingouin]

haughtney, the point is we give the 10 minutes (or whatever it is) as a starting point and we go from there. You let us know what you can achieve and we then vector or hold accordingly. We're not expecting you to achieve the impossible - it's letting you know the required delay.

slice, where have you been? We've had this discussion every few months for years. Pilots seem to think that because they can fly to cross the threshold to within 15 seconds (or whatever) that everything that influences a sequence is equally precise. It isn't. Closer in departures intrude, wind changes intrude, medevac traffic intrudes, less than perfect pilots intrude, go-arounds intrude, aircraft requiring a different runway intrude, aircraft being able to accept a different runway intrudes.

If we give you a 10 minute delay 1,000 miles out what is that based on? Certainly not reality. 23 aircraft haven't departed yet. Can you pick up 5 minutes in 200 miles because a couple of aircraft are accepting an alternate runway due to a few knots less crosswind than forecast?

[haughtney1]

TwoT,

Will always prefer the Dassault, the only bad thing about it was I couldn't stand up properly to pee :}

Back on message, I'm not moaning about the 10 minutes, thats not the issue, ATC delays are a fact of life, yep we deal with it. Giving 5 minutes notice of a 10 minute delay after knowing where we are going to be at what time, for the last 7 hours, thats just dumbass.

Or is that unreasonable?

Le Pin, but in the same breath what is a 10 minute delay 200 miles out based on? that 10 minutes represents 80-90nm for me, as you say reality? well where does 10 minutes come from? is it a contrived number? is it a standard delay? Does traffic magically appear at international airports? Don't you get a little advance warning of filed flights?
The point I'm making is that as a SERVICE provider, ASA are super quick at pointing out our deficiencies, yet when something as nonsensical or something as having the appeareance of being nonsensical is implemented etc etc and gets questioned, it appears too fall into the "too hard", or we have the "big picture you dont" basket. Even places like Mumbai and Delhi give you a better idea and a damn sight more notice of delays.

[TWOTBAGS]

H, mate....

I say its a horses ares
you say thats just dumbass

I see a pattern forming here..... Equus ferus caballus conbusit, by any other name.

It is obviously too much to ask and is only getting worse there has been a dumbing down of their profession as much as there has bee in ours to the point where the man up the stick would not know the difference between a Triple and Buck72.

Least of all an understanding of physical properties of 200T at 280 KIAS going down at 3000fpm 115nm from TD, dont even contemplate a min clean speed.

We have both experienced a lot better from places "not here" it is unfortunate that our people up the stick need a safety case to operate a boom mic

[swh]

I think it would only be fair for Australian registered aircraft then to be given 10 minute plus enroute holding prior to exiting the Australian FIR. Clearance not available. See how quick it gets fixed then.

How about a reduction in ATC fees by 50% per 5 minute delay ? There is zero cost incentive for ASA to fix this.

It is absolute B/S, I have flown cost index 0 for hours to drop 20 plus minutes as requested by ATC, hit the target within 10 seconds, to be held for a further 10 minutes low level.

Then we hear complaints from domestic carriers when they basically fly multiple narrow bodies in parallel on that same city pair for an occupied landing slot that was known before that domestic aircraft probably pushed back two sectors ago.

Same goes for a domestic carrier PER to SYD, ATC knows their landing slot hours out, why are they launching aircraft out of MEL for SYD for the same slot, instead of gate hold ?

All these costs are passed onto the Australian consumer, it is costing them millions, costing ASA next to nothing.

[Keg]

Cmon haughtney. It happens for the same reason that holding I to DXB is sometimes 20 minutes, sometimes 45 and sometimes 0 and track shortening well inside the trombone.

At least you're dealing with it only once every now and then (as am I). My heart goes out to those that cop this sort of stuff multiple times a day :ok:

[Savage175]

About 6-7 years ago ASA trialed an arrivals sequencing scheme whereby inbound heavies were given an RTA for the 200nm point around the time they crossed the WA Coast. Problem was, most decided to ignore the time and maintain their planned Mach no. Which brings us to the present. :ugh:

[haughtney1]

Keg, I'm not moaning about delays, far from it, such is life in busy airspace, my gripe is the stupendously late notification of such delays, particularly given the amount of time spent in the MEL/BNE FIR etc, its not as if appearing 200nm from destination is a surprise.

Savage 175, that sounds very much like a compliance issue rather than a process or systems issue, but taken a step further, why did the carriers not respect the RTA? was it because it was unmanageable for the aircraft? was it due to the RTA being inaccurate? i.e. get there early and land early, was it because despite the RTA operators had no confidence due to previously mentioned problems and that others not participating didn't experience delays? (just a question, not criticism)
Be all that as it may, what good reason or excuse can be given for such late notification of delays? no one seems to be able to answer this so far, apart from saying its the system...if it is the system, does anyone else think the system in this instance needs a little work?

[le Pingouin]

haughtney, the 10 minutes comes from Meastro. I'd love to be able to lock things in further out but it's a dynamic environment. Maybe you had a 4 minute delay that blew out due to another heavy requiring a different runway or having to accommodate medevac traffic or any other of a multitude of reasons.

I can explain how Maestro works in detail if wanted.

[haughtney1]

Le Pin,

My understanding of Maestro is that it is designed to optimise the landing sequence using the arrivals part of it, and it keeps recalculating etc etc, a bit like my Garmin.
My understanding is that the distance of 200nm from destination is user defined, rather than system specific? I did ask btw about our sequence on taxi in, no preceding arrivals for 6 or 7 minutes, no departures for 4 minutes, so I was and still am bit baffled.

[Troo believer]

Get over it Mate. Should have been flying into Brissie a couple of years ago Faaaa...k 55 minutes with no weather was my record and us maggot/a320 drivers do it 40-50 times a month. Delays are a fact of life unfortunately, take a vector descend hold whatever. Half the delays are normally caused by some big fat dugong back at final approach speed 10 miles out!😜

[BGQ]

And we all know who is no 1.... (The rest of the world)

Jokes aside

Those of us who fly around the globe to some of the busiest airports in the world have never been able to understand the continual slow down speed up slow down speed up again that goes on in Oz Airspace... Lovely people but no idea or perhaps the wrong tools. BNE is OK ...SYD and MEL :ugh:

I asked an Aussie controller at a conference why it happens .... his response.... why is it a problem?

[5miles]

Here's a few simple examples of why late notice delays can/do occur.

Missed approaches - have to fit them back in somewhere.
Whether it was pilot/controller error, weather, or whatever.
That re-sequencing is now an extra 2-3 minute delay for every other inbound aircraft.

Weather/runway changes - losing LAHSO in Melbourne means going from a max arrival rate of 44 to about 24 per hour. This may be caused by a momentary increase in xwind above 20knots. Do the math on the flow on effect.

Preceding traffic considers a high speed descent is 230knots at 40 miles.

Priority traffic. We don't get 7 hours notice of medevac flights, so if one pops up at an inconvenient time, sorry, but you're no.2.

...

[Capn Bloggs]

Big airways mega-cruiser
What's that, an just another international twin? ;)

10 minutes at 200nm? That's pretty tough. We get a "good" indication of the delay from ATC at 350-odd miles out. Enough time to duck down to your best "holding in a straight line" altitude and make the time.

Is Adelaide that busy?

[haughtney1]

Is Adelaide that busy?

Twas my second thought, right after my WTF? moment.

Come on Bloggsy..jealousy will get you nowhere....how big is a 717 again? :}

(at least thats what I think you drive...:ok:)

[Capn Bloggs]

Yes, yes, yes, I know, your centre tank holds more fuel than I weigh!! :{

[ACMS]

At least you have one of the quietest cockpits made, very nice.

[le Pingouin]

Le Pin,

My understanding of Maestro is that it is designed to optimise the landing sequence using the arrivals part of it, and it keeps recalculating etc etc, a bit like my Garmin.
My understanding is that the distance of 200nm from destination is user defined, rather than system specific? I did ask btw about our sequence on taxi in, no preceding arrivals for 6 or 7 minutes, no departures for 4 minutes, so I was and still am bit baffled.

Maestro works by using untouched landing times of all the arrivals - basically the system estimate for the fix plus the time it calculates (to the second I believe) you'll take from the fix to run around the STAR to the threshold. The sequence is simply the order of untouched landing times. This isn't set in concrete until quite late in the piece so you can jump around a bit at times.

It then takes the acceptance rate (time between arrivals), spaces the sequence accordingly and calculates landing times. It then calculates your time for the fix so you land at the required time.

Meaning if you get several aircraft with very similar untouched landing times it's possible to go back (or forward) several spots if estimates change a little. i.e. you can go from 0 delay to 10 minutes just like that. 10 minutes would be unusual but it's entirely possible.

We have plenty of other things to do besides fiddling with Maestro that have higher priority such as separation and coordination. We'll take a look at it from time to time but things can change rapidly and catch us unawares. Changes rely on us noticing them - we don't get an alert to warn us.

As to why the gap, it could have been they managed to shorten up some of the aircraft ahead and compressed the sequence a bit and you were a bit slower than expected. It could have been a space left for a transiting medevac chopper. We don't just leave holes for the fun of it.

[1Charlie]

The way traffic is sequenced in Aus is at the request of industry / airlines. They want aircraft absorbing all delay at cruise altitude, then staying on the STAR (because the FMC is more efficient than hand flying) all the way to touch down. If you're on the STAR all the way to touchdown how else can the sequence be organised. Speed up slow down. We all know you hate it, but the airline loves it. Sometimes I wonder why we bother because it's much more difficult than say sequencing like Heathrow. Just let em all cruise into the low level holding stacks, issue them standard speeds, then vector them onto final. So much easier than locking a dynamic sequence in at 200nm (40mins from now) when so much will happen between now and then. Especially if there is a bit of weather around, not just at the airport but enroute. While you're up there dodging cumulus the sequence is going to **** cause no one is achieving their RTA.

You being inside Aus airspace for 7 hours has nothing to do with it. You could be given a flow time then but it would most certainly be wrong. We can even see you on maestro well beyond 200nm but maestro can't see the aircraft that will beat you to the airport but haven't taken off yet. How do you flow a sequence with aircraft that aren't airborne yet? 200nm is just a number that seems to work best. In some circumstances when the traffic mix is right I've seen the sequence locked in at 350nm.

In a perfect world all this is great. You get your RTA in enough time to slow down and achieve it, descend at 250kts via the star all the way to touch down and everyone flows in like a zipper landing a perfect 4nm trail (for mixed mode) over the threshold. Very rarely is it a perfect world. But get used to it, Nextgen and Sesar are both based on the Aus ATC system. (Adjust speed to cross....)

Had the same thing happened to you at Heathrow, you would have stayed at your normal speed, done a lap of the holding pattern, probably two (10mins) at 5000', vectored onto final, then came here and told us how good Heathrow ATC (don't get me wrong it is very good).

[psycho joe]

Charlie, I'm sure that ASA management tell controllers that the system is broken because airlines/ industry want it that way, just as airline managers tell us line drivers that "ASA is heavily unionised and controllers won't change their practices". The truth may be a little from column A and column B but the fact remains that a 10 minute delay at 200 miles or less (common example) is not "absorbing all delay at cruise altitude"; but rather losing time on descent which whilst doable, is a major pain in the @rse in terms of energy management and efficiency.

You ask "How do you flow a sequence with aircraft that aren't airborne yet"?
Given that most traffic into capital primary's are RPT with a known schedule; I'd ask why cant you?

[Luke SkyToddler]

I can't see why you're getting your knickers all bunched up over it Haughtney,
the oz controllers apply some pretty insanely tight separations as it is - specially with the MEL 27 departures and 16/34 arrivals.

It happens anywhere in the world if you arrive at rush hour at a capacity constrained airport, specially one that has a mix of light turboprops and super-heavies and the occasional medevac etc.

It's just all about how they prefer to present the bad news to you ... the aussies tell you at TOD to cross Arbey with a 10 minute delay, and the brits tell you at TOD to expect 2 laps of the Lambourne hold. Doesnt make a blind bit of difference really except you then have to tell them ok we need a delaying vector. Kind of silly way to do it, but that's aussies for ya

[Capn Bloggs]

Given that most traffic into capital primary's are RPT with a known schedule; I'd ask why cant you?
That's pretty naive, Joe. Do you really expect multiple RPT aircraft could/would stick to their schedule plus or minus a couple of minutes so the flow would work with no slowdowns or re-sequencing?

a delaying vector. Kind of silly way to do it, but that's aussies for ya
Losing time in straight lines is better, fuel burn wise, than holding patterns. Nicer for the pax, too.

[le Pingouin]

That's pretty naive, Joe. Do you really expect multiple RPT aircraft could/would stick to their schedule plus or minus a couple of minutes so the flow would work with no slowdowns or re-sequencing?


Losing time in straight lines is better, fuel burn wise, than holding patterns. Nicer for the pax, too.


:ok: When I offer the choice of speeds and vectors or hold a large majority of pilots take the vectors.

Joe, even if everyone pushes back on time how does that account for different runways for departure and arrival, winds and Haughtney picking up 30 minutes over his 13+ hours in the air? Not to mention multiple aircraft scheduled to arrive at the same time.

The point is a dozen aircraft can end up all trying to land within a few minutes so there will be delays just because of the variables not accounted for by scheduling.

[Capn Rex Havoc]

Le Pingouin - I understand the variables involved, however, the system should be at least smart enough to know that aircrew cannot possibly lose 10 mins in 200 miles. Better to say "expect Approach time at X, or expect holding for x mins or say nothing and just radar vector.

[FL400]

Perth is locking in JULIM estimates and slowing ppl down with 400 NM to run. Is this more what you want?

[ACMS]

And while you're at it could you give YMML arrivals their ARBEY time 400nm out too?

Better still 1000 nm out ask me my ARBEY estimate, it will be very close.

[le Pingouin]

Rex, it's the controllers doing the asking. We aren't expecting you to do the impossible but are giving you the time and letting you work with your magic box to see what can achieved & going from there. Rather than some long spiel we just give the time and you come back with what you can achieve. I'll often add "let me know what you can achieve" if I think it's not possible on speed alone.

Personally if I think you can get it down to less than a pattern with speed I'll give you the time. I've seen some quite amazing time losses coming into ML from BN (into the wind I guess) when I was expecting a 4 or 5 min vector.

ACMS, an accurate estimate is great, but it won't make an iota of difference because it takes no account of all the aircraft who have yet to depart who will be getting there before you.

400NM out? The controller who will be fiddling with Maestro may very well not even be aware of you at that stage and is busy working the sequence and handling their other duties for the aircraft they already have. As a pilot are you thinking about your next leg rather than briefing for the arrival you're about to make? That's what you're asking for. It's not the way Maestro works.

[Tankengine]

The fact that you guys don't know about us from 400nm away says it all.:rolleyes:

We can lose time to make a fix time from a couple of thousand.;)

[oicur12.again]

A factor not often discussed is the random flying habits of poorly trained or under confident pilots.

Several carriers I have worked for are full of pilots who happily ignore ATC speed requests and pretty much do what ever speed they like on descent and will throw the anchor out at whatever point intrudes on their comfort factor.

The steely eyed missile men of ye olden days driving the 727 at 300 knots until less than 20 miles are gone, now replaced by kids who would rather stick like glue to an inaccurate DES profile and let the speed drift back to 260 knots than actually maintain an appropriate speed and run the numbers in their head.

Run the numbers in their head? Not anymore, no one teaches it. Many pilots these days have no clue about where they should be speed/height/distance.

Start training pilots a little better and forcing some flying discipline and things may work out a little better for ATC

Rant over.

[le Pingouin]

The fact that you guys don't know about us from 400nm away says it all.:rolleyes:

We can lose time to make a fix time from a couple of thousand.;)

I'm looking after a large chunk of airspace with maybe 20 aircraft to consider. Separation is the priority. I'll look at sequencing when I can, that's what it boils down to. My attention is quite necessarily focused on my airspace and immediate surrounds, not looking for aircraft to sequence a couple of hundred miles away.

[The name is Porter]

The fact that you guys don't know about us from 400nm away says it all.

We can lose time to make a fix time from a couple of thousand.

You seriously can't be that dim?

TAAATS knows about you the moment you depart a foreign country. If you want to slow down on departure from that foreign country just in case you might get a delay, fill your boots.

[psycho joe]

Quote:
Originally Posted by Capn Bloggs View Post
That's pretty naive, Joe. Do you really expect multiple RPT aircraft could/would stick to their schedule plus or minus a couple of minutes so the flow would work with no slowdowns or re-sequencing?


Losing time in straight lines is better, fuel burn wise, than holding patterns. Nicer for the pax, too.

When I offer the choice of speeds and vectors or hold a large majority of pilots take the vectors.

Joe, even if everyone pushes back on time how does that account for different runways for departure and arrival, winds and Haughtney picking up 30 minutes over his 13+ hours in the air? Not to mention multiple aircraft scheduled to arrive at the same time.

The point is a dozen aircraft can end up all trying to land within a few minutes so there will be delays just because of the variables not accounted for by scheduling.

That would be easier to swallow if we didn't have schedules and slot times, and if we weren't sitting at the gate watching a clock wind down as part of a Ground Delay Program. If I were to push back outside -5/+10 of my COBT then my friendly controller would remind me that I'm non compliant and can expect up to 60 holding. If I am compliant, then I can expect the same holding/last minute slow down/now quick speed up, as before the implementation of ground delay programs.

It's simply not acceptable to be tracked from one side of the country to the other, with a slot time, and COBT compliant to then be treated as a shock/ surprise at 200 miles. As airline Pilots, we work hard to be fuel efficient, only to then throw that efficiency out the window with a ridiculously inefficient descent.

[Capn Bloggs]

If I am compliant, then I can expect the same holding/last minute slow down/now quick speed up, as before the implementation of ground delay programs.
In my neck of the woods, the GDPs have resulted a big reduction in holding.

[Tankengine]

Porter, me dim?:hmm:
Have you heard of SEMAC?:confused:

I was given a plan on a 8+ hour flight the other day giving me a range of times to be at Rivet. As we were fast it allowed for a 7 minute delay at the gate if I wished.:zzz:

This is reality now! :ooh:

While not taking the delay at the gate we did fly at a speed to get us to Rivet to the minute.:ok:

Of course then we got holding.:ugh:

We can do it, as requested, can you?

[The name is Porter]

Sorry tank, that didn't come across well (embarrassment :\) apologies!

[5miles]

It's simply not acceptable to be tracked from one side of the country to the other, with a slot time, and COBT compliant to then be treated as a shock/ surprise at 200 miles.

Not acceptable..hmmm. I suppose one of the solutions to this then is to deny any weather deviations as it may delay following traffic who are otherwise compliant. That ain't gonna happen.

BTW, we used to give higher priority to certain long haul flights, but the airlines (ie. your bosses) felt it no longer required or didn't negotiate for it's continuance.

These complaints are about as fruitful as your pax whingeing when a flight is cancelled 2 hours before their flight, even though they booked 6 months ahead.

[le Pingouin]

That would be easier to swallow if we didn't have schedules and slot times, and if we weren't sitting at the gate watching a clock wind down as part of a Ground Delay Program. If I were to push back outside -5/+10 of my COBT then my friendly controller would remind me that I'm non compliant and can expect up to 60 holding. If I am compliant, then I can expect the same holding/last minute slow down/now quick speed up, as before the implementation of ground delay programs.

It's simply not acceptable to be tracked from one side of the country to the other, with a slot time, and COBT compliant to then be treated as a shock/ surprise at 200 miles. As airline Pilots, we work hard to be fuel efficient, only to then throw that efficiency out the window with a ridiculously inefficient descent.

You misunderstand the purpose of the ground delay program. It's to reduce delays, not eliminate them, by limiting the number of arrivals over a given time. Given the -5+10 "slack" in the system it can't prevent multiple aircraft trying to arrive at the same time, but reduces how many aircraft that is.

Seriously, into ML we rarely hold these day when conditions are as forecast and nothing untoward happens to interfere with the sequence. Delays don't often get above 8 minutes. Used to be we'd hold any day when conditions meant we had to reduce the acceptance rate, so we'd often have several bouts of holding a day.

It's a dynamic world and things don't always go as planned. You can stamp your feet as much as you want but that's the reality. I understand that you'd like your fix delay as early as possible but we just don't know what it will be with any certainty 2 hours out, 90 minutes out, even an hour out. We can give you a current guess but it will almost certainly be revised at least several times.

[Adamastor]

Slight drift but since it's been repeatedly brought up I find it interesting that the idea that GDPs should mean every flight gets zero delay on every flight still pervades the pilot community. The official target is that there will be a 60:40 split between ground holding assigned by the GDPs and airborne holding, not 100:0 as most people seem to think. The realists understand that flights do not operate precisely to schedule - never have, never will - and that introduces delays. If we really could operate to the minute, every operator, every flight, every day, then perhaps zero delay might actually be viable, but until that cold day in hell...... I'm with Cap'n Bloggs - I've seen huge reductions in airborne holding. As a further aside, ALL ground holding delay is absorbed by domestic operators only, internationals only get airborne holding, and since they get the same amount as domestics, i.e. only the 40%, they probably shouldn't be whinging too much about their lot - they already benefit from SIGNIFICANT preferential treatment!

[Capt Claret]

Imagine the howls of protest were the PPRuNe ATCOs to get on here and tell us how to fly our jets! :eek::E

[Capt Claret]

A better way of handling that situation would be something like "Reduce to minimum Mach no., 250kt on descent, expect vectors. Landing time is xxxx".


And if they did that, there would be a band of pilots saying, "why do that, I can descent to a lower level and absorb the delay and the pax won't be any the wiser. I should be given the landing time and be allowed to manage it as I see fit." :ouch:

[donkdonk]

post deleted

[haughtney1]

I don't think Haughney's having a go at the system so much as the unrealistic expectation of the ATC.

Puddle, exactly...perhaps my hyperbole was a bit much for some.

There is nothing like travelling full speed into the hold in London/Dubai/Hong Kong. Or getting vectored all over the sky without knowing where you are going to end up, except finally on a runway, like Singapore/JFK.
Rat, you are misrepresenting the concept of an EAT, or haven't been to London or DXB recently (The UK in particular is superb at providing track miles and EATs, and DXB will happily let you slow down if you ask). I'm glad you feel the Oz system is as you prefer it, for me getting thumped with a 10 minute delay 200nm from dest is nothing short of a scandal, particularly now given the comments previously made by others.
As I've said, I've got NO issue with delays, but give me some notice for fecks sake...unless its an emergency, delays are known quantities as the nature of the planning process to provide a delay actually ensures and plans for this. I cant believe it can be that hard to pass on the impending delay to an airborne inbound aircraft in a timely manner, after all don't most approach and enroute controllers talk to each other across the room or on the phone?
Or have I missed something?

[chuboy]

Ok, so you don't know whether it's going to be ten minutes' delay at 200nm or fifteen minutes... we all understand it's a dynamic beast. But surely you're going to know well ahead of time that there will be a delay of some sort?

[le Pingouin]

haughtney, it boils down to the fact that quite often I'm more than busy enough dealing with the traffic I have right now. I don't have time to go searching for aircraft 30 minutes outside my airspace. On many routes the first time I'll even bother looking at you is just before you call - not because I'm lazy or uncaring but because my priority is separation. If you aren't conflicting with anyone I can safely ignore you for now and deal with separating someone else.

Half the time I don't even have a coord line to the sector you're in 30 minutes prior to my airspace.

[willadvise]

chuboy
Sometimes.
At any given time I can see your delay but the sequence doesn't become set until all the aircraft ahead of you become "stable". If you ask what your delay is before all the aircraft ahead of your are stable you are probably not going to get an inaccurate time because
a) the flow has not had a chance to optimise the sequence by closing up any gaps in the sequence by direct tracking/max speed/different runway assignments.
b) aircraft have yet to depart that will be ahead of you in the sequence.
Because of these effects it is common to see a given aircrafts delay vary by 10 min within the space of 20-30 min.
We all know that you want your delay as early as possible. We all know that you hate "slow down, no speed up, no slow down again" If you are given a slow down before the sequence is stable there is a high probability it is going to be wrong. You can have your delay early and inaccurate or later and more accurate. Now think of this from an ATC point of view:- do I give out a bunch of inaccurate times only having to revise them later adding to my workload or wait until they become stable and do it once. If a give you a slow down to early and a gap opens up, you may not be able to increase enough to get back into that gap and a slot is lost and everyone loses. You may not be given your slowdown until you have overtaken an aircraft that you are ahead of in the sequence because you will restricted on descent. Particularly if there is a track miles issue with instrument vs visual stars.

haughtney1
If you can't understand why you are thumped with a 10 min delay at 200nm after reading all this then I cant help you anymore. But I will try to help you with the "unrealistic expectation"
We know that you probably can't make that time. It is just our way of saying that this is the time you are going to cross. Like any instructions we give, it is always subject to pilots ability to comply.
For example "ABC 123 turn left heading 360...ABC123 Unable due thunderstorms, best we could do is heading 340,
"ABC123 climb F390.....ABC123 unable we're to heavy we can accept F380"
"ABC123 increase to maximum speed....ABC123 unable due turbulence"

Do you see where I'm going with this? We make the assumption that you will tell us what you can do and I personally think it is a waste of time to add "let me know if you need vectors or holding" to every feeder fix time I issue.

[haughtney1]

Le Pin, so if I've got this right, your imperative is separation (which is of course your primary function, no argument from me).
Will advise, nicely put, and from your perspective it makes perfect sense, why wouldn't it, it is after all the system you operate in.
Like I keep saying..and repeating, I have NO problem with an ATC mandated delay.
If you guys genuinely believe that the level of service I've described previously is perfectly acceptable, then I guess no amount of customer input will change the way you think.

[le Pingouin]

As I've said previously, you're talking to the wrong end of the ATC animal. Your management needs to talk to our management for change to be implemented. We work within a system so, as such, work the way the system is designed to work. I have to work within the confines of the system as it exists. Provide me with a system that works the way you want it and I'll do it.

I'm sorry but as a line controller I sometimes don't have time to worry about the niceties. Maybe I'm too damn busy to consider you earlier than I absolutely have to so you get your 10 minute delay when you call me. Other times I'll have enough time to look out a bit and tell the sector that has you there's roughly a 10 minute delay so speed reduction approved. Assuming I can get a word in. Maybe they're really busy and here I am trying to bother them with non safety-critical information.

You have one aircraft to manage. I have 20 or however many so my attention is spread accordingly thinly.

I fully understand it's more efficient to manage a delay over a longer period and that more can be achieved the more warning you have but sometimes I just don't have the time to do anything about it.

I'll give you unrestricted climb to your desired level at the speed you want via your preferred routing when I can. When I can't you'll be held down, slowed down and vectored. Same goes for the delays. Sometimes you'll get it the way you want and other times you won't.

[Keg]

I'm glad you feel the Oz system is as you prefer it, for me getting thumped with a 10 minute delay 200nm from dest is nothing short of a scandal

And yet haughtney this is precisely what happens in Dubai and London! On occasion in Dubai the delay can be much more significant as well. It was also a regular thing into Singapore and Bangkok back in 2007. Sure they let you slow down, as will Ausse ATCO not that it does much good at 200 miles.

I'll admit that my international destination list is not extensive but four of my regular destinations are amongst the busiest in the world- and I operate into them at their busiest times of day. The Aussie system ain't perfect but it's no worse than anywhere else. :ok:

[Capn Rex Havoc]

Keg, I think the difference is, unlike Dubai, or London, they don't say for example - "Make Rivet at xx" which is undoable in the time frame they give. WILL ADVISE says to just say that we "can't make it" like in a heading during vectors in weather. But it is not the same, as with the heading, there is a chance the aircraft can take the heading, but with a 10min delay from 200nm, there is no chance of getting the jet to hover. So effectively it is a waste of bandwith. Like I said, Dubai, and London just put you in the hold and give you an ETA. Muscat, assign you a mach no in prep to for UAE's sequencing. Both these methods appear more effective that the way its being done in OZ.

Haugtntey- I hear you, and I get that you are not complaining about the delay.

[ACMS]

Hong Kong ATC simply say holding required, hold at Betty EFC 15, reduce speed as required if you wish. They don't give crossing times.
Then later on when you are in the hold they may advise a time to cross Mango but they invariably break you out of the hold at a required speed for radar vectors towards Mango anyway.......

They too slow you down speed you up and then slow you down again.

I remember going into Singapore years ago and being delayed around FL200 north of Nylon. Aircraft were being vectored for delaying tactics all over the shop, we passed just above the same QF 744. ( QF10 I think? ) 3 times 3 different directions!! It was a mess and thank goodness their Radar didn't fail......

I much prefer London sending you into the LAM hold, it's more orderly.

[willadvise]

Capn Rex Havoc
To address your point.
The instruction has to be issued at some point in time to make it clear that you have a required time to arrive at the feeder fix. So what should the phraseology be if you don't like the current way? "ABC123 can you cross ARBEY at time 46? .... ABC123 negative best time is 43....ABC123 roger expect vectors, cross ARBEY 46 at 250kts .... ABC123 ARBEY 46 250kts " or "ABC123 can you cross ARBEY at 46? ... ABC123 affirm ... ABC123 cross ARBEY at 46 at 250kts....ABC123 ARBEY 46 250kts"
How is this better than "ABC123 cross ARBEY at 46 at 250kts .... ABC123 ARBEY 46 250kts (we'll need vectors/holding)"

So you don't like being issued with unrealistic reductions. You are in essence asking us to make a judgement call as to who we think might be able to meet the time without holding or vectors. Easy for this example of a heavy for 10mins at 200nm, I am sure you won't make it. But what if was 7mins at 250nm or 4 mins at 210nm, we simply don't have the time to make a judgement about it being unreasonable or not. When we first started issuing feeder fix times I was amazed at how slow some aircraft can go especially after the pilots got the hang of it and would often issue times which I thought they would have no hope of making without vectors but they did. It is just much easier to issue the time then you tell us what you need. Don't take it personally or think that we have no understanding.

[willadvise]

If you guys genuinely believe that the level of service I've described previously is perfectly acceptable, then I guess no amount of customer input will change the way you think.

So you are still not happy?

You have asked "Do you know how this can happen?" We have explained why it can happen to you. I'll summarise for you:-
1) The sequence was not stable or has changed rapidly.
2) The controller was too busy.

If this doesn't convince you then I'll give it one last shot but then I give up.

"Safety, Comfort, Schedule". I believe most airlines have something along these lines. Schedule is the lower priority. Translate this to ATC, sequencing is the lower priority.

I invite you to tell us how the system can be improved considering all the factors raised in the previous posts. I am genuinely interested because it is something that we have all pondered for many years.

[haughtney1]

Sure Will:ok:

2 things would be a good start.

1.Advise me in good time (being pragmatic here) of expected or planned delays... (Given I'm datalink equipped it's a few strokes on the keyboard)

2. In the event of a delay...do as they do in the UK and Europe and increasingly in the US, advise us, send us to a fix to hold, and give us an onward EAT. :ok:

There 2 things that would make planet haughtney better for me.

P.S. If the controller is to busy, then isn't that an issue relating to safety and SA? Are you guys understaffed or something? Knowing about a delay in good time also allows me to plan further on the basis of a contingency, prudence being what it is, my priority is also safety, knowing about that 10 minute delay in advance could be the difference between me legally being able to get to destination or divert.
We can go back and forth as much as we like, I want this...you can only give me that etc..ultimately my neck is on the line everytime I plant my fat butt in the chair, yes you guys have enormous responsibility as well but your safety and well being is hardly an issue, to me when I hear "I'm too busy" it's the thin end of the wedge, what else one day might someone be too busy to pass on, you guys have that luxury, that safety valve, I don't.
In an imperfect world we make do, we improvise and we get the job done, if you use system and workload practicalities as reasons for being unable to provide some basic information..then maybe your organisation needs to look at how others seem to manage.
Not the guys on the front lines problem I know, god knows you have a bloody tough and thankless job at times, but as a team, we ought to be all moving in the same direction.
Too idealistic?

[Shark Patrol]

Not trying to take a shot at Australian ATC - I'm sure you (like us) are all working within constraints imposed by others. I also accept the point re last minute changes to the sequence, go-rounds etc, but humour me if you will.

I have probably been into JFK more than two dozen times and always arriving around 5pm local time (peak hour). In those two dozen times, I think I have been put in the holding pattern precisely twice. Granted that there is usually extensive vectoring in the Terminal Area, but I have also been given enroute speed instructions when not even half-way across the US that suggest that the JFK sequence is being worked on more than two hours out from the destination. Does anyone in the ATC world have knowledge of how the US system works compared to Australia, and why a sequence can be worked on two hours in advance into one of the busiest airports in the world, yet in Australia it happens at 200nm?

I also remember tracking through western Queensland very early one morning soon after the very short-lived ALOFT system (remember that one) had been scrapped. I asked the controller if the sequence into Sydney was being worked on yet and his response was "No ... the Flow doesn't start work till 5!" I must say that I had a bit of a chuckle about that one.

Once again, can I re-iterate that I am not taking shots here. I am genuinely intrigued as to how the US and AUS systems differ.

[willadvise]

haughtney1

Point 1. You have simply restated that I want to know earlier, but haven't given any useful suggestions as to how this can be achieved.
Point 2. This is really a question of semantics Giving you holding with a EAT is really no different to a feeder fix time + vectors/holding.

[BGQ]

I accept the reasons you provide... what I cannot accept is why I am so unlucky that just about every time I come to your country at least one of them is happening:{

[1Charlie]

Well someone used JFK as an example of one of the busiest airports in the world. Wikipedia shows the annual movement rate there is 410,000. They have two sets of parallel runways. Now compare that to Brisbane, which except under relatively rare circumstances is primarily a single runway operation with 226,000 movements in the last year. Now it should be easy to see that per runway Brisbane is moving more traffic than JFK and explain why you very rarely get no delaying action.

[CurtainTwitcher]

JFK has snow, icy runways, deicing, fog everything else the North Eastern US WX can dish up. Comparisons between movement rates between the relativity benign BNE weather & JFK don't make for a strong argument.

[1Charlie]

Alright let's use KLAX as a comparison. Brisbane weather, but without the thunderstorms. 666,900 per year on 4 parallel runways. 166,700 per runway plays 226,000.

This isn't a di@k measuring exercise. I'm trying to give some perspective to those who seem offended when they receive delaying action at what they seem to consider airports with no traffic.

[CurtainTwitcher]

This isn't a di@k measuring exercise.
Not trying to turn it into one. Having spent a fair bit of my life doing the CG/SMOKA/BLAKA/ELENI scenics, it would appear there is a major problem "The System", not the controllers at the front line. I find a good interplay between pilots & ATC to manage the traffic inside the 250nm ring from BNE. Strategic descents, slowdowns, pattern adjustment negotiations all work very well, however why do we have to go at warp speed as "know knows", some for 15+ hours until we hit the 250nm brick wall? I think that was haughtney1's point.

In you KLAX example again, what is the movement rate inside the LA basin itself? There are many fields in very complex busy airspace: LAX, Burbank, Orange County, Van Nuys, Long Beach - that covers just the major ones, all with jets. Again, not a valid comparison with any Australian field in terms of airspace & traffic density.

"The System", not the controllers is the problem, and it could be fixed with more money, however there has to be sufficient will to make that happen.

[1Charlie]

Delays don't have much to do with traffic density in the vicinity, you don't get an extra lap just because someone is arriving into an airport down the road. What I'm trying to say with the LA comparison is it's all about the runway rate. We can move around 55 per hour on a good day per runway, which is up there with any airport in the world. If the demand is for more than that the delays build up.

The 250nm brick wall is fairly common around the world. Like has been said earlier, places like Heathrow will tell you at top of descent to expect holding. Why didn't they tell you to slow down 15 hours out? The technology doesn't really exist to achieve what you are looking for yet. Airways NZ is the first in the world to operate a combined ground delay / airborne flow manager that they designed them selves. I've seen the system operating, you can scroll through the whole day and look at the sequence of aircraft that haven't departed yet. But like has been said earlier it can only work with what it can see. An aircraft gets airborne three minutes late because the cabin wasn't ready and they had to wait for an aircraft to land in Wellington before they took off, now they can't make their landing time in Auckland and that landing slot is lost forever because everyone was slowed down 15 hours out to make room for them. For this reason they still only pass the RTA to the pilot 40mins from touchdown which would work out to be about 200miles. This game just isn't predictable enough to achieve what you want.

[flightfocus]

Never fear all,

The promised land is visible on the horizon....

Have a look at this executive collection of buzzwords and catchy phrases. One Sky, the panacea that cures all ill's......

OneSKY Australia program | Airservices (http://www.airservicesaustralia.com/projects/onesky-australia/)

[Buttscratcher]

"By 2018, Australia will be providing air traffic control services using the most advanced and integrated air traffic control system in the world."
Now, anyone guess why this is probably true?

[le Pingouin]

Sure Will:ok:

2 things would be a good start.

1.Advise me in good time (being pragmatic here) of expected or planned delays... (Given I'm datalink equipped it's a few strokes on the keyboard)

2. In the event of a delay...do as they do in the UK and Europe and increasingly in the US, advise us, send us to a fix to hold, and give us an onward EAT. :ok:

1. I can only message aircraft I have control of so I still have to go looking for you, put your estimate into Maestro, make a guess as to what sort of delay you'll actually get (seriously, a lot can change between 300 and 200 miles), tell another controller I may not even have a direct comm line to and get them to make a dozen clicks to send you the message.

2. What's the difference between that and us giving you a time that you can choose to slow down as much or as little as you want and we absorb the rest with vectors or holding? That's what I don't get. Why does it make you feel better to be given a 10 minute hold at 200 miles than us telling you to reduce speed to lose 10 minutes with the implicit understanding that you'll tell us what you want to do?


There 2 things that would make planet haughtney better for me.

P.S. If the controller is to busy, then isn't that an issue relating to safety and SA? Yes it is, but it only takes a second or two to gain an appreciation of pending traffic, whereas it takes many times longer to provide the service you're asking for to just one aircraft. I can perform quite a number of my routine essential tasks in the time it takes to service just you with an guess as to a fix time when you're well outside my airspace. They don't have Maestro so can't do it themselves.

It's called workload management. The system we use just isn't designed to work the way that you want. Sure it can be achieved manually but that is labour intensive so isn't going to happen when I'm busy.


Are you guys understaffed or something? Knowing about a delay in good time also allows me to plan further on the basis of a contingency, prudence being what it is, my priority is also safety, knowing about that 10 minute delay in advance could be the difference between me legally being able to get to destination or divert.
We can go back and forth as much as we like, I want this...you can only give me that etc..ultimately my neck is on the line everytime I plant my fat butt in the chair, yes you guys have enormous responsibility as well but your safety and well being is hardly an issue, to me when I hear "I'm too busy" it's the thin end of the wedge, what else one day might someone be too busy to pass on, you guys have that luxury, that safety valve, I don't.
It's the nature of the job - workload isn't smooth. You can have 20 evenly spaced aircraft and be twiddling your thumbs or half a dozen and barely time to think. Loosely speaking staffing/sectors/the system is based on averages plus a margin. Sometimes the margins are exceeded and we just pedal faster to keep up. When you're busy the non-essential is moved to the back of the queue. That's what I get paid for - not forgetting to do the important things. While I won't physically fall out of the sky my neck is on the line every time I don a headset too.


In an imperfect world we make do, we improvise and we get the job done, if you use system and workload practicalities as reasons for being unable to provide some basic information..then maybe your organisation needs to look at how others seem to manage.
Not the guys on the front lines problem I know, god knows you have a bloody tough and thankless job at times, but as a team, we ought to be all moving in the same direction.
Too idealistic?The information is being provided, just not with the timing you'd like. I don't disagree that things could be done better, but not with the system as it currently is.

[The name is Porter]

ALL Pilots should be required to do a shift in an ATC centre at least once a year that encompasses peak time, not the bull**** PR visit that you sometimes make now.

ALL ATC's should be required to a famil day, sitting in the cockpit for the full duty day that includes at least one flight at peak time into a major airport, not a single famil flight that doesn't see what the crew have to deal with for a full duty day.

Guess why this doesn't happen now & will never in the future?

[WhisprSYD]

Some great discussion going on in here! Although the original question seems to have been answered I'll throw in my 2c.

The way the sequence works in my neck of the woods is that the outer (ex) procedural sectors are responsible for for setting FF estimates into MAESTRO at around 350-400nm out, this starts to stabilise the system and then these controllers can give an expectation of delay and a Mach # slowdown when it hits a certain size. I'm not entirely sure what the process is for East Coast sequences re locking into MAESTRO, but for PH early stabilisation and slowdowns were what was requested by industry and works best for us due to the nature of the traffic patterns (no inbounds for 3-4 hours at a time, then a sudden sequence of 30-40 when all the mining traffic turns around at the same time). That's the reason that we have the outer sectors responsible for that stage.

The next sectors (250nm out) are responsible for issuing the actual FF times, making sure MAESTRO has put aircraft the correct order (remember the original sequence is built off pilot estimates.. Which is why MAESTRO often tries to put the cheeky bugger in his F100 ahead of the 737 even though he's 20nm behind and 20kt slower).
Even at this stage your 'expect a 6-7 minute delay' may have blown out to 15 mins due to 3 departures from nearby aerodromes. I guess the reason these departures aren't all allotted times in the sequence before departing is that if they don't get away on time then there will be holes in the sequence and everyone gets punished as a result... Similar to when pilots give an unrealistic estimate for JULIM, become number 1, then despite getting direct and pushing 310 on the descent to JULIM they end up 2 mins late and every behind gets shafted...


From 250nm to 160nm pilots have the chance to let us know how close they can get to the issued time and this info helps the inner centre controllers figure out the most efficient way to achieve the rest..
The last 12 months, with the implementation of MAESTRO and the consolidation of the GDP, has seen a decent increase in the number of aircraft being able to achieve the delays without our intervention. We've gone from 20-30min delays + holding the majority of traffic twice a day, every Tuesday/Wednesday/Thursday to occasionally having 15-20 minute delays and maybe holding a couple of aircraft a week.

But to go back to the original post there are still some instances where we will have to hit someone with 10 or so minutes on short notice.. People have discussed go arounds, medevac, rwy changes etc.. But occasionally it will also just be a case of taking a little longer than usual to pick up the delay. An example is: at 400 miles you give your estimate which puts you in your own sequence.. No one in front of you for 4-5 mins and no one behind you for the same time. Procedural sector locks this in, sees no delay in maestro and moves on to their next job. You get transferred at 250miles, get your STAR, and still no delay in MAESTRO, and no one near you so your time at the fix is not pertinent. In the next 6 minutes 3 departures get away from 2 aerodromes within 100 miles, and someone finishes airwork and is ready to return. These aircraft all need to be sequenced and some will end up in front of you.. Chances are you are coming in from the north and all these departures came from the south so it's a different controller looking after them. Someone who is all over it will be aware of what's going on in surrounding sectors, assessing Maestro making sure all times are up to date, but it does happen occasionally that as per this example an aircraft might run through to 160 odd miles before the inner controller picks up that what was originally a sequence of 1 has become a sequence of 4 and your dreams of scooting through the terminal before the rush are shattered.

[psycho joe]

Thanks for the detailed explanation WhisperSYD. :ok:

[1Charlie]

Generally speaking should say the wind be calm, you're cruising at FL400 in your 77W. You're 200nm to run and have been asked to lose 10 mins. I'd imagine you're pretty close to min speed already at FL400. My question is would you rather stay at that altitude and speed and take a lap of the pattern, or descend lower to reduce the TAS and maybe take what you can 't lose with a vector. Technically speaking what would be more efficient. As soon as you've been assigned a delay you're now flying for best endurance instead of range. Is the best endurance going to be at mid levels as opposed to way up high? Or is it more efficient to stay high?

As a side note I was amazed on my last famil flight which was on an A388 from Auckland to Brisbane. Cruising at FL4XX at what was probably M.84 or so and 260 odd indicated or whatever it was and were assigned a delay of 15 minutes. I was very impressed at how slow the A388 can actually fly, we slowed down to about 210kts IAS and started a gradual descent for next 100nm or so. Still needed a lap of the pattern but it surprised me how flexible that aircraft is.

[CurtainTwitcher]

As a side note I was amazed on my last famil flight which was on an A388 from Auckland to Brisbane. Cruising at FL4XX at what was probably M.84 or so and 260 odd indicated or whatever it was and were assigned a delay of 15 minutes. I was very impressed at how slow the A388 can actually fly, we slowed down to about 210kts IAS and started a gradual descent for next 100nm or so. Still needed a lap of the pattern but it surprised me how flexible that aircraft is. 1Charlie, that is the crux of our beef! We can do amazing things with sufficient notice. The 250nm brick wall isn't really sufficient time for large losses.

On my machine fuel burn (including 5% allowance for racetrack hold) burn at altitude vs holding at 1500'
10,000' -4%
FL200 -7%
FL300 -7%
FL350 -6%

There isn't any benefit staying high to hold. By holding in a straight line you save 5% right off the bat. In general I find I only burn half the holding fuel by descending to say FL250 vs continuing at flight planned cruise altitude then entering the pattern to lose the same time. Slowing down at optimum altitude doesn't lose much time, due to relatively high minimum speed. Each aircraft will have its own profile, twins need to consider engine failure at min speed at high altitude, not so critical for an A380.

PER seem to have a good system, you blast off heading south, pass an estimate for JULUM, ATC get back with a crossing time and you use the next hour or two to lose the time, 15, 20 or even 30 minutes is possible with sufficient notice.

[willadvise]

I am going to answer inevitable question. Why can it be done in Perth but not in Sydney and Melbourne?

The vast majority of jet traffic for YPPH departs from outside 400nm YPPH. This means that a sequence generated for an aircraft at 400nm is going to be a reasonable approximation because it is less likely to be changed by another jet departure closer to YPPH
This is not the case for YSSY and YMML.

http://i57.tinypic.com/mlla10.gif

As you can see every departure from YSSY, YPAD, YSCB and tasmania is within 400nm of YMML.
Similarly for YSSY. Every departure from YMML,YSCB,YBBN is within 400nm.

This is why we have to wait till you are about 250nm for the sequence to become stable.

[Transition Layer]

WhisprSYD,

Thanks for the great detail you went into with your explanation, helps us understand things a bit more.

. Which is why MAESTRO often tries to put the cheeky bugger in his F100 ahead of the 737 even though he's 20nm behind and 20kt slower).

Glad to hear that you are aware this stuff goes on. Very frustrating for us too, as we know exactly where he/she is thanks to TCAS and we all know a 737 cruises faster than an F100!

Cheers,
TL

[le Pingouin]

To the ATCer's on this thread, thanks for the great job you do day in day out. Yes I admit I've sworn under my breath at you most days but it has never been personal and is more out of frustration than because of the job you are doing(I'm sure you have done the same with me). Like haughtney I get frustrated with the late notice, however, I get it is the system and I'd rather be given the option of losing that time myself than just being sent to a hold.

Thanks, I think most of us realise we're there to provide a service and do what we can within the confines of the system and the situation at hand. Sometimes it just all goes to poo and there's little we can do about it. Occasionally we're not on our game and make it harder. And yes, you get sworn at too, although I take the approach that life is too short to get overly worked up - I have to deal with the situation anyway so might as well fix it and move on.

Whatever you guys do please don't punish us all because of one airline. By all means send planet haughtney and his airline to the hold every time they need to lose time. Please let the rest of us make the situation work and beat them on efficiency. It's a lot easier and safer for everyone to be doing the same thing. Yes, it's possible to run aircraft through holding traffic but it's complicated and easy to screw up. Like many things, it's possible but the extra workload is a threat. That said I'm sure we could accommodate haughtney and co. if it was made known their preference was to hold.

Since the ground delay program and this airborne strategy has been introduced, I have had to do very little holding in Oz. In fact we managed to lose 12 minutes without a vector into BNE the other night and yes we could hear the doubt in the controllers voice as to whether we would make it or not. Yes we had to work harder to make it happen but I believe that we saved my company 800kgs of fuel in one sector while some others just bleat.And that's the crux of the discussion - by necessity you take the bottom up approach of managing a single aircraft while I have to take a more top down approach of managing a chunk of a whole system. You naturally want to optimise your single aircraft while I'm driven by system optimisation and the two don't always coincide. It's just the nature of the beast.

On average that means someone gets screwed for the benefit of the greater good. Better luck next time?

[WhisprSYD]

WhisprSYD,

Thanks for the great detail you went into with your explanation, helps us understand things a bit more.



Glad to hear that you are aware this stuff goes on. Very frustrating for us too, as we know exactly where he/she is thanks to TCAS and we all know a 737 cruises faster than an F100!

Cheers,
TL

No problem.
Yeah we try and police it to the best of our ability, and the fact that we can see exactly where all of you are on ADSB helps spot the obviously 'ambitious' estimates... It also used to be a pain in the ass switching aircraft around as it involved lengthy conversations with the flow, but MAESTRO has given us the license to use a bit of common sense in that situation.

That being said, it all comes down to the controller working too. Some of the newer, fresh faced and recently rated controllers still take a pilot's word as gospel, whereas those of us who have been around for a little longer have learned to be a bit more cynical when it comes to trusting all FF estimates.

[grrowler]

Similar to when pilots give an unrealistic estimate for JULIM, become number 1, then despite getting direct and pushing 310 on the descent to JULIM they end up 2 mins late and every behind gets shafted.... This f@ckwit behaviour seems to be happening a lot lately - and it's just as likely to be a 737 as f100.

I'll be honest, I don't understand why, in this age of technology, you need to be relying on a verbal fix estimate. However, why not give aircraft unable to make their fix time a 180 degree vector to the back of the queue - I reckon that might sort out the problem.

[Derfred]

CurtainTwitcher
In general I find I only burn half the holding fuel by descending to say FL250 vs continuing at flight planned cruise altitude then entering the pattern to lose the same time.

Huh? You just provided figures that show 1% or less burn difference at holding speeds between cruise altitude and FL250.

Additional fuel (up to 5% as per your figures) can be saved by flying in a straight line vs a racetrack hold. Vectors (if they are long ones) will consume less fuel than a holding pattern due to less turns. Turns burn more fuel (more thrust required to maintain speed).

So, yes, descending early and slowing with vectors will be slightly more fuel efficient than maintaining cruise and entering a holding pattern.

This saving will be something less than a theoretical maximum of 6%, as some turns are still required with vectors. Not "half the holding fuel" as you claim.

---

So, to the ATC'ers wondering which we prefer - the fuel savings are small so our answer may depend on other more significant factors which will change from day to day.

Such as:

1. Turbulence (why would I want to leave smooth air early?)
2. Icing
3. Workload (yours or mine?)
4. Fatigue (what's easiest?)
5. Personal preference of the pilot flying.
6. Personal experience of the pilot flying (e.g. first time in Oz? or fly 4 sectors/day out of BNE?)

So, if you have time, yes please ask our preference. I often request an early descent if it means achieving a short delay without vectors, but I won't if I suspect turbulence at lower levels, and I might not for a longer delay because vectors/holding is inevitable regardless.

Thanks for the explanations guys. Most of us get it, and most of us appreciate you are doing a great job with the resources and systems available. And yes, ATFM has helped quite a bit.

[Undercover Brother]

I can't believe I just read 5 pages of what might just be the actions of a slack / busy / inexperienced / 'not having a good day' ATC.

As a controller some days I know my "Service level" is better than others. Who doesn't go home occasionally thinking they didn't perform at 100%...

Needless to say, long haul aircraft arriving on the east coast rarely get a slowdown from me outside 200nm, would have to be stable 15-20+ minutes to warrant moving attention away from my holding/vectoring/sequencing to slow you down.

The main reason being is that I can control my sequence that is inbound via my feeder fix (spacing, arriving order, track shortening), and if I lock you in early and slow you down, the system continues to update your radar "estimate" for the feeder fix (noting you are now slower!), meaning you can actually drop behind traffic from another feeder fix that is not locked in! Talk about screwing you over!

We get by just fine nearly all of the time peoples.

[Plazbot]

Why does it make you feel better to be given a 10 minute hold at 200 miles than us telling you to reduce speed to lose 10 minutes with the implicit understanding that you'll tell us what you want to do?"

The last part of this quote I think sums up the bones of the topic starters issue. It is Air Traffic Control not Air Traffic Negotiation. Due to attitudes, training and culture in Australian Aviation, controllers let the aircraft tell them what they want to do as opposed to the other way around.

[le Pingouin]

C'mon, ATC the world over is full of negotiation and letting aircraft do what they want when that option is available. They get to pick the level they want to fly on the route they want to fly at the speed they want to fly. It's called flight planning. "Request flight level....". "Request direct.....". "Request ILS approach......". Sounds a lot like negotiation to me.

You don't control their descent point unless it's required. You don't control their rate of climb unless it's required. You don't control their descent speed unless it's required. You don't control how they meet their fix time unless it's required. I'm not flying their aircraft. If they request 20 miles left due weather I don't vector unless required.

How is letting an aircraft decide how much time they want to lose with speed and the rest with vectors or holding any different? I'm still controlling things. If I can safely and sensibly accommodate a request then why shouldn't I? I guess I can wave my willie around and shout "thou shalt do it my way or the highway" but why bother when there's an option and I don't care which way it's done?

[Plazbot]

Which is my basic point. This thread is Australian specific and I am assuming you are a current Australian controller and therefore you have the luxury of all that airspace to have options such as giving aircraft the choice. Much of the world is extremely limited with airspace size and complexity and therefore choice. I did have a bit of a smirk when I read a few of the other airports around the world being used as examples of better places to fly.

The US for example has a very mature ATFM system where they have many people dedicated to the task of moving aircraft all over the sky hundreds of miles away from their destination to manage not only landing capacity but sector capacity without making a single transmission themselves. Euro Control are similar. The Dubai example is an odd one. Aircraft arriving first hear about their delay somewhere between 6 and 15 minutes from their feeder fix. As a result they all go to the hold. In the extremely small airspace there, allowing an aircraft to truck on down on their own profile would see an enormous mess form in just a few minutes. Of note, No one ever complains or questions why any control instruction is given.

I recall in the early days of Maestro, techniques for sequencing turbo props consisted of turning them into the wind, telling them their feeder fix time and having them tell you when they had sat on the heading long enough to comply. Most major airports around the world would see that aircraft not only in the next sector but in some places the next country.

I'm not saying which is better just that the nature of the evolution of delaying techniques in Australia was influenced by available resources and in my opinion allows the controller to be 'lazy' for want of a better word.

The one aspect of the Australian method that baffles me us allowing aircraft to depart outside of their slot. This is an example of the overall culture of aviation in Australia I mentioned. This leads to the controllers feeling anxiety when hey have to give an aircraft the bad news because you know full well the pilot is going to question you and you need a pretty quick answer meaning that you end up double guessing everything you do.

[The name is Porter]

How hard is it?

'Adjust speed to cross _ _ _ _ _ at time _ _ at 250kts'

'Best we can do is time _ _'

'Turn right heading _ _ _, advise when the FMS shows time _ _ at _ _ _ _ _'

'Roger'

[Undercover Brother]

"The one aspect of the Australian method that baffles me us allowing aircraft to depart outside of their slot."

One of the many things that baffles me is an Australian controller is how overseas long-haulers depart on their slot time, we have 'trackmasters' in the hallowed "National Operations Centre" aka NOC who approve wondrous flextracks to allow aircraft save time and fuel, the then the same boffins at the NOC run ALOFT v3 aka "SEMAP" to tell which aircraft are non-compliant with their Sydney arrival times!

How brilliant do you think controllers feel telling them they are 10-30 minutes ahead of their time, only to have some slow down and be overtaken by trafic that should have been sequenced behind them. When Sydney Flow does arrive at 5am, they promptly ask WTF has happened?

How embarassing..

[Bula]

Personally I don't think it is that hard though I believe all our hands are tied.

There are two things which have to be considered for any new system. They are:

1) Controllability
2) Flexibility

As a pilot there is only one thing I can control when it comes to ATC flow management and that is what time we actually cross the feeder fix. Simply, the earlier I know, the more efficiently I can achieve that. If I have to hold inevitably so be it, though I shouldn't be told this approaching TOD. Personally I would like to be given an estimated crossing time on first contact with centre.

What I can't understand is why the system is not robust enough to allow for this? Ok, yes with 2 or 3 minute feed requirements and close in departures, weather diversions and go arounds the flow will change, however what I would like to see is a system developed that manages capacity. If too many aircraft are going to cross the feeder fix at time X and delays are developing greater than a couple of minutes, let the other guys know on departure well before the bottle neck, or before departure. We do it for Bad weather say between BNE and SYD with start approvals, why is it not the norm?

One method I find works quite well is the expected landing time.

"xxx123 Delays into Melbourne, expect landing time 0123, speed reductions approved"

Controllers, Just so you know when I hear this, this is what I do:

If it's a long week:

1. Select RTA Melbourne
2. Enter 0123

or

If it's not a long week

1. Assess the expected delay.
2. Reduce Cost index --> Assess time
3. Reaching CI 0, reduce descent speed to the minimum --> Assess Time
4. Reduce Airspeed from Max Range to Max endurance --> Assess time
5. Descend to a lower lever maintaining Max Endurance for an associated reduction in TAS/GS (dependant on forecast wind), to hold in a straight line.
6. Let ATC know if unable to make the crossing time.


Either way, the preference will always be to hold in a straight line at my most efficient holding altitude if need be with vectors/holding as a last resort.

I just wish the system had enough maturity and resources to have the information passed down the line earlier rather than later.

[Duff Man]

SEMAP notwithstanding, fly as fast as you can, as direct as you can, and you will be numero uno. Sequence gets firmish about 40 minutes out. Too many nearby regional airports to do otherwise. The original complainant should pull their head in, ATC are effectively giving an EAT. Always better to vector/hold on the way down to FL230 than over the burbs at A070.

A380s and <25,000kg acft will get f*ed around at Sydney regardless, thanks to this (https://www.atsb.gov.au/publications/investigation_reports/2008/aair/ao-2008-077.aspx).

[haughtney1]

Interesting map Will, explains a good deal, but also creates a couple of questions in my mind.
As I've said previously having been in the airspace for 8-9hrs, the system is aware via satcom datalink (which is used for and to determine separation outside of radar range...my understanding) of all the ETA's to the nearest minute.
If as you say the sequence isn't finalised until 250nm, then at what range is the planning started? Surely from a planning perspective, if something is finalised, then the starting point begins with the available information..i.e. aircraft already airborne and providing accurate estimates.
All things being equal, from a planning perspective, I would have thought that already inbound aircraft would be allocated their place in the sequence..and popup aircraft closer to destination estimating the feeder fix at an earlier time would merely be allocated an earlier time or advised of a delay. Given that the delay is now a known minimum quantity, why can't this be passed on? Yes we all know the environment is dynamic, yes by now I am aware that in terms of a plan..nothing is in place until I am practically on top of the airport....but a little bit of info helps.
The alternative based upon the explainations on here relating to finalising the plan is to merely fly at warpspeed and get to the front of the line before anyone else.
FWIW the other morning into MEL I was advised of our inbound delay about 40 minutes from destination, superb is a word I would describe the level of service I received on that particular day.

[The name is Porter]

The alternative based upon the explainations on here relating to finalising the plan is to merely fly at warpspeed and get to the front of the line before anyone else.

Come up to the front of the class :D you get 2 stars for paying attention :ok:

[Duff Man]

haughtney1, your thinking is sound. Your error is a misunderstanding of priorities as applied by ATC.

All things being equal, arrival delay is distributed evenly amongst all aircraft. This delay figure becomes fairly stable about 40 minutes out from dest based on estimate for the feeder fix. "Popup" aircraft have the same priority as long haulers, and will take your position in the sequence if it means delay is spread evenly.

It's analogous to a deli queue in the supermarket. You don't get your ticket until you get to the counter - even though you phoned the manager from your Audi when you left home.

[Nautilus Blue]

haughtney1 it's a bit more complicated then that. MAESTRO looks out to 2 and a half hours (I think, we don't use anything like that sort of lead time) but the sequence is subject to change until very close in. The sequence is sort of finalised at 250 miles ish but a short flight departing just ahead of you will still be placed in front of you. There is a point at which your position in the sequence is locked in, but for PH and I think the east coast as well that is set very close in (15 minuted rings a bell?).

Obviously long distance international flights would prefer that to be much longer, short range domestic wouldn't, and I guess there are more of them than you.

This means that the point at which we issue a FF becomes a trade off between giving as much notice as possible and waiting for a time that won't change much. Thats why for PH we use the system WhisprSYD described.

With regard to estimates, MAESTRO works on TAAATS estimates, which frankly for aircraft on descent aren't that good. They are based on miles to run, flight planned TAS, forecast winds and a table of standard descent profiles. For an international heavy, particularly an Airbus, the system estimate can easily be 4-5 early. So despite sitting in front of millions of dollars worth of computers that have been tracking each aircraft for hours, we still ask every aircraft for an estimate for the FF. Sometimes those estimates aren't that good either which leads to other problem as already alluded to.

Edited to add: PH still sets a max delay for flights form Africa and the Middle East to 5 minutes, but obviously AD and the east coast don't.

[1Charlie]

The distance at which the sequence can be locked in can be extended somewhat by requiring aircraft departing from close by airports to obtain their feeder fix time before they depart. The flow will then lock that aircraft into the sequence and is able to then lock in the other aircraft around it. Those aircraft are usually departing from aerodromes that aren't very busy and they can usually takeoff whenever they want to make sure they meet that time. You just couldn't get that from airports like Sydney, they may have to wait in a queue to cross a runway, then for an aircraft to land then the next 4 aircraft in front to take off.

The sequence doesn't become stable until all the aircraft that will land before you are either airborne, or have phoned up the flow and locked in their feeder fix time.

I know it's not the first position most pilots would want to famil on when they visit a TCU. Director is much more exciting. But flow control is a bit of a dark art, and you're questions haughtney would be answered in one visit. I highly recommend it it. It's too complicated and drawn out to explain it on a forum.

[Bula]

Out of curiosity, by how many minutes does the feeder fix time change on a normal day?

would an expected 15 min delay always lead to a minimum 5 minute delay 100% of the time?

Does a 5 minute delay always lead to a minimum 2 minute delay 100% of the time?

We can loose 2-4 minutes on the decent for little efficiency degradation. So if we know delays are 20 minutes into BNE, would it not be possible to assume you will atleast have 10 minutes holding, knowing realistically you will slide to 15 - 20 minutes given all other eventualities and if so is it possible to pass this information forward if one had the correct resources?


It's not perfect, however could be the balance, though it would be assessing the sequence at 500nm, not 250....

"ABC123, minimum MAESTRO delays of 5 minutes, speed reduction approved"

[1Charlie]

I don't think you can quantify the minimum delays but you're on the right track. Generally if the delays are 20mins or more they are passed to the aircraft much much earlier. Often times in this case aircraft will be told something like expect holding speed reduction approved

[Transition Layer]

Generally if the delays are 20mins or more they are passed to the aircraft much much earlier. Often times in this case aircraft will be told something like expect holding speed reduction approved


Yep, works quite well. I've actually been told to expect 20mins + delay into Perth when taxiing somewhere up in the Pilbara. Simply climb and cruise at min speed, stay low and you can absorb the majority of the delay. Thankfully days like that are pretty rare these days and usually weather related (although it's getting to that time of the year again!)

[Capn Rex Havoc]

Nautilus et al, so let me ge this straight - A while back I was given a slot time to be at YSSY, sent by ACARS via our company. It was sent to us while we were over the Indian Ocean. Should I disregard that, go as fast as I like, then wait for what happens at the 200nm mark?

Thats how it was going into Dubai a while back. Go fast - get to the hold at bubin - first in best dressed.

:ok:

[Capn Rex Havoc]

Plazbot- This was nothing to do with that farcical 'RTA' trial into Dubai. This was from Aus ATC on some sort of Aus trial.

[Plazbot]

Roger Roger.
..............