ATC DELAYS
Join Date: Nov 2001
Location: uk
Posts: 1,122
Likes: 0
Received 0 Likes
on
0 Posts
From the charts the STAR ends at TD.After TD it's as directed by ATC.
With a heading you can use radar separation and have directions after TD.If aircraft are left on STARs then you don't know it they are going to wander slightly,so you can't really prove separation against other aircraft.
IMHO
With a heading you can use radar separation and have directions after TD.If aircraft are left on STARs then you don't know it they are going to wander slightly,so you can't really prove separation against other aircraft.
IMHO
Last edited by throw a dyce; 28th May 2013 at 11:39.
Join Date: Feb 2002
Location: Hongkers
Posts: 469
Likes: 0
Received 0 Likes
on
0 Posts
captaindbusdriver
While it may seem that you are often being vectored very close to the STAR, the controller is doing this to ensure the turn to intercept and spacing with the preceeding aircraft is as accurate as possible.
In my experience, pilots often have an overly-optimistic view of their aircraft's navigational performance. Often pilots will say, "Just tell me the time and I'll be there +- 1 minute."
Pffft, thats like light years when we are running a 100 second sequence!
Come to the Centre for a visit and watch the many and varied ways that different FMS try to achieve the desired track. Any time a large turn is involved, such as turn from base to intercept, the point at which aircraft commence their turn can be significantly different. (RF turn excepted)
To give an indication of the accuracy required, as a rule of thumb, for every 0.2NM excess between arrivals, we lose about 1 slot per hour.
This is the sort of tolerance Final Director os working turn to.
In your case yesterday, perhaps you could have been let go on own nav, but when you are in the middle of an arrival sequence of 35-36 per hour as witnessed today, then its much easier to pin everybody down rather than tut-tut after you turn .3 miles too late when the horse has bolted. That lost gap then ripples through the rest of the hour and into the next often. Do that a few times an hour and the whole thing goes for a ball of chalk.
Hope that helps.
Honestly, you should take up some of the offers on other threads to come and have a look.
In my experience, pilots often have an overly-optimistic view of their aircraft's navigational performance. Often pilots will say, "Just tell me the time and I'll be there +- 1 minute."
Pffft, thats like light years when we are running a 100 second sequence!
Come to the Centre for a visit and watch the many and varied ways that different FMS try to achieve the desired track. Any time a large turn is involved, such as turn from base to intercept, the point at which aircraft commence their turn can be significantly different. (RF turn excepted)
To give an indication of the accuracy required, as a rule of thumb, for every 0.2NM excess between arrivals, we lose about 1 slot per hour.
This is the sort of tolerance Final Director os working turn to.
In your case yesterday, perhaps you could have been let go on own nav, but when you are in the middle of an arrival sequence of 35-36 per hour as witnessed today, then its much easier to pin everybody down rather than tut-tut after you turn .3 miles too late when the horse has bolted. That lost gap then ripples through the rest of the hour and into the next often. Do that a few times an hour and the whole thing goes for a ball of chalk.
Hope that helps.
Honestly, you should take up some of the offers on other threads to come and have a look.
Join Date: Nov 2001
Location: uk
Posts: 1,122
Likes: 0
Received 0 Likes
on
0 Posts
I used to let BA 757s self position on a similiar approach when they requested in the UK,but only if there was nothing else around.They could intercept the LOC at anything between 4 miles to 15.
I even said to one that if I had vectored him on the profile that he'd just flown,he would have phoned in complaining.
I would listen to Bekol on the visit offer.
I even said to one that if I had vectored him on the profile that he'd just flown,he would have phoned in complaining.
I would listen to Bekol on the visit offer.
Last edited by throw a dyce; 28th May 2013 at 13:22.
Join Date: Feb 2002
Location: Hongkers
Posts: 469
Likes: 0
Received 0 Likes
on
0 Posts
Seeing as the thread is about delays, just a word on scheduling and in-built delay that has nothing to do with ATC.
When airlines take part in the schedule coordination process, twice yearly, they know (or at least they should know) that built-in delay is part and parcel of the mechanism.
Indeed they must know, when some schedule 5 or 6 of their own flights with exactly the same EOBT or ETA.
Why? Well, some people have this impression that flights are given their own "exclusive" slot and if everybody just stuck to it then all would be well and good- no delay.
Not so.
Slots are not an exclusive thing- they are normally at 5 minute intervals i.e. there are only 12 slots in an hour. Now as soon as you hand out 33 arrival slots in an hour, as happens at HKIA, some flights necessarily end up with exactly the same slot. To exacerbate the process, of course many carriers heading for somewhere with a curfew or other restriction will apply for and be given the same slot. The maechanism makes sure that no more than 6 or 7 are coincident, but that straight away means if you are the last guy, you have an inbuilt delay of 6 times whatever the arrival/departure interval is. In our case about 9-10 minutes. That is considered acceptable by the carriers when they sign up to the deal. In fact in the busier hours of the day, the schedule delay accumulates to around the 15 minute mark at HKIA. Even with everyone operating spot on schedule. throw in a bit of slippage and you can see how delays of up to 20 minutes are becoming common place at the busier end of the week.
ATC delays? Nup. Scheduled delay. The airlines know it and accept it. Maybe they don't explain it well enough to you guys.
P.S. Just for the sake of clarity, the delays are not because too much traffic is being scheduled at HKIA.
Our nominal final spacing is 4NM, as about 65% of traffic are heavies and require that for Wake Turbulence Sep. About 20% of pairs will require 5 miles for Wake turbulence. (the Heavy/Medium ratio is pretty much the reverse of EGLL seeing as we were comparing apples and oranges before)
So on average we run about 4.25NM spacing.
At about 25 seconds per mile in still air, that equates to about 106 seconds. We presume nominal headwindwind component of 10 knots, therefore a slightly longer interval ~ 110 seconds.
When you do the math, you'll find it comes out pretty much spot on 33 per hour. Hence the declared capacity.
P.P.S. Other major airports, like EGLL (seeing as everyone is enamoured with the way they operate), schedule to the same IATA guidelines.
In fact they state that a schedule is "good" if average arrival delay does not exceed 10 minutes and no individual aircraft's delay exceeds 20 minutes.
HK is still below those thresholds for scheduling.
When airlines take part in the schedule coordination process, twice yearly, they know (or at least they should know) that built-in delay is part and parcel of the mechanism.
Indeed they must know, when some schedule 5 or 6 of their own flights with exactly the same EOBT or ETA.
Why? Well, some people have this impression that flights are given their own "exclusive" slot and if everybody just stuck to it then all would be well and good- no delay.
Not so.
Slots are not an exclusive thing- they are normally at 5 minute intervals i.e. there are only 12 slots in an hour. Now as soon as you hand out 33 arrival slots in an hour, as happens at HKIA, some flights necessarily end up with exactly the same slot. To exacerbate the process, of course many carriers heading for somewhere with a curfew or other restriction will apply for and be given the same slot. The maechanism makes sure that no more than 6 or 7 are coincident, but that straight away means if you are the last guy, you have an inbuilt delay of 6 times whatever the arrival/departure interval is. In our case about 9-10 minutes. That is considered acceptable by the carriers when they sign up to the deal. In fact in the busier hours of the day, the schedule delay accumulates to around the 15 minute mark at HKIA. Even with everyone operating spot on schedule. throw in a bit of slippage and you can see how delays of up to 20 minutes are becoming common place at the busier end of the week.
ATC delays? Nup. Scheduled delay. The airlines know it and accept it. Maybe they don't explain it well enough to you guys.
P.S. Just for the sake of clarity, the delays are not because too much traffic is being scheduled at HKIA.
Our nominal final spacing is 4NM, as about 65% of traffic are heavies and require that for Wake Turbulence Sep. About 20% of pairs will require 5 miles for Wake turbulence. (the Heavy/Medium ratio is pretty much the reverse of EGLL seeing as we were comparing apples and oranges before)
So on average we run about 4.25NM spacing.
At about 25 seconds per mile in still air, that equates to about 106 seconds. We presume nominal headwindwind component of 10 knots, therefore a slightly longer interval ~ 110 seconds.
When you do the math, you'll find it comes out pretty much spot on 33 per hour. Hence the declared capacity.
P.P.S. Other major airports, like EGLL (seeing as everyone is enamoured with the way they operate), schedule to the same IATA guidelines.
In fact they state that a schedule is "good" if average arrival delay does not exceed 10 minutes and no individual aircraft's delay exceeds 20 minutes.
HK is still below those thresholds for scheduling.
Last edited by bekolblockage; 28th May 2013 at 14:17.
Join Date: Nov 2007
Location: nfa
Posts: 134
Likes: 0
Received 0 Likes
on
0 Posts
People forget that there are a lot more operators in and out of CLK than just CX. Not everybody is flying a A330 or B777 with it's up to date performance capabilities. That being said, comparing CLK to Beijing or Delhi it does well. Problem arises when it gets compared to other major airports that CX regularly operates to - JFK, ORD, LAX, LON, PAR, ......, even SYD. The shortcomings with ATC become acute when compared internationally, not just with Shenzhen et al. Whether it's experience based, due to airspace restricted or whatever is irrelevant.
Carry the extra fuel.
Carry the extra fuel.
Last edited by bm330; 28th May 2013 at 16:19. Reason: sp
Join Date: Jun 2004
Location: Earth
Posts: 12
Likes: 0
Received 0 Likes
on
0 Posts
THE FUB
in controllers perspective we dont distinguish CPA HDA CRK UAL etc etc, we only see aircraft type, profile when we do sequencing, and when we are busy, punishing anyone just means punishing ourselves, for the fact that we still have to give a well-spaced traffic with similar profile into next sector, delaying one flight by one slot involves tremendous workload no one would even think about it when its busy.
indeed pilots are all cooperative when given specific instructions, i don´t really feel anyone are too deliberately incooperative at all. there´re cocky ones, there´re ones with poor english, there´re private jet newbies to hong kong, maybe once in a while they are not always on very top of situations but indeed all are cooperative.
in controllers perspective we dont distinguish CPA HDA CRK UAL etc etc, we only see aircraft type, profile when we do sequencing, and when we are busy, punishing anyone just means punishing ourselves, for the fact that we still have to give a well-spaced traffic with similar profile into next sector, delaying one flight by one slot involves tremendous workload no one would even think about it when its busy.
indeed pilots are all cooperative when given specific instructions, i don´t really feel anyone are too deliberately incooperative at all. there´re cocky ones, there´re ones with poor english, there´re private jet newbies to hong kong, maybe once in a while they are not always on very top of situations but indeed all are cooperative.
Join Date: Jun 2004
Location: Earth
Posts: 12
Likes: 0
Received 0 Likes
on
0 Posts
for getting the feeling of how it´s like to do sequencing, try this
ATC-SIM: a web-based air traffic control simulator
it´s nothing too real but easier =)
ATC-SIM: a web-based air traffic control simulator
it´s nothing too real but easier =)
Join Date: Feb 2002
Location: Hongkers
Posts: 469
Likes: 0
Received 0 Likes
on
0 Posts
People forget that there are a lot more operators in and out of CLK than just CX.
Thanks to the guys that made the effort to come and take a look yesterday. Hopefully things made a bit more sense.
Well done to Bedder for organizing.
Join Date: Jun 2005
Location: UAE
Posts: 210
Likes: 0
Received 0 Likes
on
0 Posts
ATC DELAYS?
Congratulations to Bekol, Bedder and others for their informative responses.
To Captainbusdriver and others at the pointy end , AIRCRAFT DELAY other AIRCRAFT not ATC and several PILOTS have been brought to task in other parts of the world after making PA announcements blaming ATC for delays which were entirely due to Company Scheduling.
To Captainbusdriver and others at the pointy end , AIRCRAFT DELAY other AIRCRAFT not ATC and several PILOTS have been brought to task in other parts of the world after making PA announcements blaming ATC for delays which were entirely due to Company Scheduling.
Join Date: Nov 2001
Location: uk
Posts: 1,122
Likes: 0
Received 0 Likes
on
0 Posts
CPA used to schedule 4 departures from E1,E2,E3,and E4 all at the same time.
Then another airline wanted to push out of S21 at the same time.
For those sports fans who don't know CLK,unless you come up with a very cunning plan involving Red/Blue/Green pushbacks someone HAS to wait.
One CPA driver got extremely shirty with me(swore over the R/T
) when I said about 10-15 min delay your number 4 to push out of that corner.
If it was the UK I would have cancelled his clearance and told him to phone the ATC supervisor for a chill pill.Not in HK.You get no support especially if you're a Gweilo,but the situation was because of airline scheduling and bad airport layout.
Probably still happening.
Then another airline wanted to push out of S21 at the same time.
For those sports fans who don't know CLK,unless you come up with a very cunning plan involving Red/Blue/Green pushbacks someone HAS to wait.
One CPA driver got extremely shirty with me(swore over the R/T
) when I said about 10-15 min delay your number 4 to push out of that corner.If it was the UK I would have cancelled his clearance and told him to phone the ATC supervisor for a chill pill.Not in HK.You get no support especially if you're a Gweilo,but the situation was because of airline scheduling and bad airport layout.
Probably still happening.
CPA used to schedule 4 departures from E1,E2,E3,and E4 all at the same time.
Join Date: Feb 2002
Location: Hongkers
Posts: 469
Likes: 0
Received 0 Likes
on
0 Posts
To the Captain of CX103 Friday before last, who kept refering to our destination as "BrisVegas" in every PA (Yeh its funny the first 3 times, after that ...):
Thought you sounded ok mate, til you got to TOD and announced "Well, ATC have got us again. They got us going out of HK last night (we were delayed about 4 mins pushing back) and now they're gunna get us again on the way into BrisVegas this morning- they've just given us an 8 minute delay".
As Rule 3 posted
Thought you sounded ok mate, til you got to TOD and announced "Well, ATC have got us again. They got us going out of HK last night (we were delayed about 4 mins pushing back) and now they're gunna get us again on the way into BrisVegas this morning- they've just given us an 8 minute delay".
As Rule 3 posted
AIRCRAFT DELAY other AIRCRAFT not ATC and several PILOTS have been brought to task in other parts of the world after making PA announcements blaming ATC for delays
Last edited by bekolblockage; 11th Jun 2013 at 11:13.
Join Date: Jan 2009
Location: Kowloon
Posts: 103
Likes: 0
Received 0 Likes
on
0 Posts
Okay, BB: I get you on the BrisVegas thing - it sounded cool (ish) about 20 years ago, now its just old hat and I wish guys would stop saying it. It's cringeworthy enough when a 20-something DJ says it, let alone an adult.
To be strictly fair, it IS atc that delay aircraft, after all, any transmission that asks an aircraft to slow down comes from ATC, not another aircraft.
Bottom line: who's the service provider? I'm pretty sure that ATC provides a service, not the other way around (and yes, I get that in this day and age, we both need each other).
If you can't land every aircraft that arrives at an airport - without delay - then find out which rules (both legal and local) are keeping you from your objective as a service provider. As a pilot I go to airfields that can land aircraft with a 3nm spacing and others that need 4 or 5nm. Hello: it's not hard to prefer the more efficient airport. Same people, same aircraft, different rules?
Money is always an issue- I don't expect (though I would like to) to go to the supermarket and have every single checkout open all the time, just so I don't have to wait. Sometimes it works that way, but most of the time I spend some time "in the hold".
When you have to stay late at work, because it is busy, do you say to your wife upon returning home: I got delayed by too many aircraft, or too much wx, or not enough ATCs?
What do you suggest we tell our passengers when we have to lose some time? (I tell them that the airspace is very busy and that we are "being sequenced" by ATC).
To be strictly fair, it IS atc that delay aircraft, after all, any transmission that asks an aircraft to slow down comes from ATC, not another aircraft.
Bottom line: who's the service provider? I'm pretty sure that ATC provides a service, not the other way around (and yes, I get that in this day and age, we both need each other).
If you can't land every aircraft that arrives at an airport - without delay - then find out which rules (both legal and local) are keeping you from your objective as a service provider. As a pilot I go to airfields that can land aircraft with a 3nm spacing and others that need 4 or 5nm. Hello: it's not hard to prefer the more efficient airport. Same people, same aircraft, different rules?
Money is always an issue- I don't expect (though I would like to) to go to the supermarket and have every single checkout open all the time, just so I don't have to wait. Sometimes it works that way, but most of the time I spend some time "in the hold".
When you have to stay late at work, because it is busy, do you say to your wife upon returning home: I got delayed by too many aircraft, or too much wx, or not enough ATCs?
What do you suggest we tell our passengers when we have to lose some time? (I tell them that the airspace is very busy and that we are "being sequenced" by ATC).
I've heard that 15 expat controllers are to leave HKG. Is that right anyone?
Replacements have been recruited and are being trained but its hard to replace that sort of experience level overnight.
Well done Govt Policy & THB.
Last one out the door, please turn out the lights.
Last edited by LapSap; 11th Jun 2013 at 12:06.
Join Date: Feb 2002
Location: Hongkers
Posts: 469
Likes: 0
Received 0 Likes
on
0 Posts
China Flyer
I trust you see the difference between your sensible announcement that
to being told
(To be honest, I'm not too sure what most pax think when they are told they are being "sequenced" or "vectored" by ATC. Half our trainees wouldn't know until into their sim training.)
While you raise some valid ways to improve our handling rate, I also would hope you realize that we might have considered many of these things already, after many of us have had 35+ years working in several ATC units around the world. There are reasons why some can't be done or perhaps can't be done right now but will be done once we have the required prerequisites in place e.g. runway occupancy times.
I think I explained fairly clearly earlier why it is unrealistic to expect every aircraft to be handled "without delay", no matter how efficient ATC. Please reread.
I'm not sure what "preference" has to do with the final spacing we use. Of course we too would much prefer not to have to give you 5 miles behind a heavy if you're flying one of those "light twins". Unfortunately ICAO have some rules that prevent us from giving you an inverted view of the HK-Macau-Zhuhai bridge construction. Again, I explained earlier why our nominal spacing was 4NM at present.
the airspace is very busy and that we are "being sequenced" by ATC
...ATC have got us again. They got us going out of HK last night ....... and now they're gunna get us again...
While you raise some valid ways to improve our handling rate, I also would hope you realize that we might have considered many of these things already, after many of us have had 35+ years working in several ATC units around the world. There are reasons why some can't be done or perhaps can't be done right now but will be done once we have the required prerequisites in place e.g. runway occupancy times.
If you can't land every aircraft that arrives at an airport - without delay - then find out which rules (both legal and local) are keeping you from your objective as a service provider. As a pilot I go to airfields that can land aircraft with a 3nm spacing and others that need 4 or 5nm. Hello: it's not hard to prefer the more efficient airport.
I'm not sure what "preference" has to do with the final spacing we use. Of course we too would much prefer not to have to give you 5 miles behind a heavy if you're flying one of those "light twins". Unfortunately ICAO have some rules that prevent us from giving you an inverted view of the HK-Macau-Zhuhai bridge construction. Again, I explained earlier why our nominal spacing was 4NM at present.
Last edited by bekolblockage; 11th Jun 2013 at 14:10.
Join Date: Sep 2009
Location: Retired-ville
Posts: 402
Likes: 0
Received 0 Likes
on
0 Posts
Well I for one, would like to thank the large numbers of guys in ATC who are shortly to retire, for giving me that feeling of 'Its nice to be home' as I get back to the HK FIR.
It is a shame such a wealth of experience is about to walk out of the door, the last few years have already shown a decline in the overall ability of the system to manage an increasingly busy airspace. This is evidenced moreso when bad weather puts a spanner in the works, and the new local controllers relevant lack of experience becomes glaring in the cluster f@ck that often ensues.
It is a great shame that the govt has not, and still does not, appreciate the value of experienced expat controllers, and has been content to let this experience pot slowly empty.
Like many situations, it's only when someone goes to the cupboard and sees that it's bare, will they realise their error.
I'll certainly miss ol' gravel voice whose tolerance with Chinese carriers stuffing up always gives us a laugh when he gives them a serve.
Enjoy retirement guys.
On the subject of crew not managing timings, I'm not sure about the 777, but for the CX Airbus', lack of making an allocated time would be pure laziness, apathy or don't know how to do it accurately-itis. In general, with free range of speed and/or the clearance to adjust the hold to say pass over Mango at 55, the 'bus can if some cerebral effort is put towards the task, easily make a TOT of +\- 5 secs. The -400 can often do the same, so I would have thought 777 should be better/easier to make an exactly on time Time over fix.
It is a shame such a wealth of experience is about to walk out of the door, the last few years have already shown a decline in the overall ability of the system to manage an increasingly busy airspace. This is evidenced moreso when bad weather puts a spanner in the works, and the new local controllers relevant lack of experience becomes glaring in the cluster f@ck that often ensues.
It is a great shame that the govt has not, and still does not, appreciate the value of experienced expat controllers, and has been content to let this experience pot slowly empty.
Like many situations, it's only when someone goes to the cupboard and sees that it's bare, will they realise their error.
I'll certainly miss ol' gravel voice whose tolerance with Chinese carriers stuffing up always gives us a laugh when he gives them a serve.
Enjoy retirement guys.
On the subject of crew not managing timings, I'm not sure about the 777, but for the CX Airbus', lack of making an allocated time would be pure laziness, apathy or don't know how to do it accurately-itis. In general, with free range of speed and/or the clearance to adjust the hold to say pass over Mango at 55, the 'bus can if some cerebral effort is put towards the task, easily make a TOT of +\- 5 secs. The -400 can often do the same, so I would have thought 777 should be better/easier to make an exactly on time Time over fix.
Last edited by LongTimeInCX; 12th Jun 2013 at 05:08.