Dubai New SID STARS debate
Previously, aircraft absorbed track miles in a holding pattern. Now the miles will still be flown but in the so-called trombone instead of in a racetrack. Vectors will still be applied.
Lol, true, the GAF factor seems to be decreasing a lot lately... inducing many 
moments for quite a few of us...
See now that would be an ideal solution except you forget it probably doesn't make much difference since many of our pax seem to see the s/b sign coming on as a flashing "Go Pee Now" sign and it takes longer to get them sitting down again (unless of course you are me and just keep knocking on the door til they come out of the lav shame faced, seems to work a trick to tell them we can't land til they do and they are making everyone else late
)
moments for quite a few of us...See now that would be an ideal solution except you forget it probably doesn't make much difference since many of our pax seem to see the s/b sign coming on as a flashing "Go Pee Now" sign and it takes longer to get them sitting down again (unless of course you are me and just keep knocking on the door til they come out of the lav shame faced, seems to work a trick to tell them we can't land til they do and they are making everyone else late
)
Join Date: Jun 2009
Location: Not UK
Posts: 199
Likes: 0
Received 0 Likes
on
0 Posts
I have nothing but respect for our controller colleagues, however, I am bound to wonder at some of the techniques used early this morning.
Reduce to 230 kts in the descent, headings in the region of 60 degrees off track, one way and then t'other.
Then increase to 250 for about 2 minutes, then back to to 230!
How can 230kts at 10,000ft with 125 track miles to run on the STAR be described in anyway as efficient?! Not to mention the light chop frequently encountered at that level.
Is it the mix of heavy and medium, and the high density periods?
Many years at LGW, with its single runway, elicit nothing more than massive respect and admiration!
Reduce to 230 kts in the descent, headings in the region of 60 degrees off track, one way and then t'other.
Then increase to 250 for about 2 minutes, then back to to 230!
How can 230kts at 10,000ft with 125 track miles to run on the STAR be described in anyway as efficient?! Not to mention the light chop frequently encountered at that level.
Is it the mix of heavy and medium, and the high density periods?
Many years at LGW, with its single runway, elicit nothing more than massive respect and admiration!
Join Date: Sep 2001
Location: Sandpit
Posts: 312
Likes: 0
Received 0 Likes
on
0 Posts
The heavy/ medium mix isn't really a problem - only 1 more mile.
However, when you add the whales into the picture, including the fact that they are so slow in the last 5 miles that we have to give an EXTRA 2 miles spacing in the sure and certain knowledge that it WILL erode, it quickly has an effect!
However, when you add the whales into the picture, including the fact that they are so slow in the last 5 miles that we have to give an EXTRA 2 miles spacing in the sure and certain knowledge that it WILL erode, it quickly has an effect!
The arrival speed that was once 250 knots is now 230. Once 1 aircraft gets to the fix, everyone else gets the speed when there is any form of a sequence. Expect it from LABTA and ENASA from 7pm local onwards till 2am and if you don't get it that is a bonus.
Guy D,
The whale has a Vapp in the 140kt range, which is pretty close to everything else except a 773 or an MD11.
Taking that the last last 5nm takes 2.5ish min you would need to have a 160kt Vapp aircraft following (ie 773 or MD11) to lose the 1nm in 3min or a 190kt Vapp aircraft to lose the 2 nm in 3min, so I can't figure how this final 5nm applies to the whale only, as it would be for all 140kt Vapp aircraft right? Could you explain it to me please?
The Don
The whale has a Vapp in the 140kt range, which is pretty close to everything else except a 773 or an MD11.
Taking that the last last 5nm takes 2.5ish min you would need to have a 160kt Vapp aircraft following (ie 773 or MD11) to lose the 1nm in 3min or a 190kt Vapp aircraft to lose the 2 nm in 3min, so I can't figure how this final 5nm applies to the whale only, as it would be for all 140kt Vapp aircraft right? Could you explain it to me please?
The Don
Join Date: Sep 2001
Location: Sandpit
Posts: 312
Likes: 0
Received 0 Likes
on
0 Posts
Don,
Not sure whether it is linked to the huge area of drag surfaces available or other factors come into play but the 380 loses speed much more quickly than just about everything else that flies in here (even the 330s), after the speed limitation expires. Our radar only shows groundspeed at the mo and it usually shows them grounding at 135 kts or so - often already at 5 miles out, where almost everything else is still showing 160-170. That's half a mile a minute of difference, which would already give at least 1 mile of reduction on final.
Experience has shown that spacing continues to reduce and, short of asking the following traffic to fly 140kts 8-9 miles out (which I personally hate to do - others don't) or go-around, the only other way of ensuring adequate spacing when the 380 touches down (as we are required to do - there is NO leeway) is to provide it when the second a/c turns inbound. I personally always use 2 miles extra - depending on the winds, this always reduces by more than a mile and often by the full two.
Not sure whether it is linked to the huge area of drag surfaces available or other factors come into play but the 380 loses speed much more quickly than just about everything else that flies in here (even the 330s), after the speed limitation expires. Our radar only shows groundspeed at the mo and it usually shows them grounding at 135 kts or so - often already at 5 miles out, where almost everything else is still showing 160-170. That's half a mile a minute of difference, which would already give at least 1 mile of reduction on final.
Experience has shown that spacing continues to reduce and, short of asking the following traffic to fly 140kts 8-9 miles out (which I personally hate to do - others don't) or go-around, the only other way of ensuring adequate spacing when the 380 touches down (as we are required to do - there is NO leeway) is to provide it when the second a/c turns inbound. I personally always use 2 miles extra - depending on the winds, this always reduces by more than a mile and often by the full two.
Join Date: Feb 2000
Location: Oz
Age: 62
Posts: 71
Likes: 0
Received 0 Likes
on
0 Posts
Guy,
What am I missing? If the lead traffic, worst case, instantly slows to 140 @ 5 miles, as it touches down the following fraffic is still @ 6 miles doing 160 if the lead is a 380. As you said above, the separation will reduce by approx 1 mile. Surely this is built into your inital spacing.
Alternatively, when you get your IAS readout, let's see who slows early!
What am I missing? If the lead traffic, worst case, instantly slows to 140 @ 5 miles, as it touches down the following fraffic is still @ 6 miles doing 160 if the lead is a 380. As you said above, the separation will reduce by approx 1 mile. Surely this is built into your inital spacing.
Alternatively, when you get your IAS readout, let's see who slows early!
Join Date: Sep 2001
Location: Sandpit
Posts: 312
Likes: 0
Received 0 Likes
on
0 Posts
Yo,
As I said - not sure where the miles go or whose "fault" it is - just relaying my observations and experience. Given that it happens on virtually each and every occasion, there IS a root cause - the above is my way of dealing with it such that sep is maintained and I don't need you to drag absolutely everything out at 10 miles.
As I said - not sure where the miles go or whose "fault" it is - just relaying my observations and experience. Given that it happens on virtually each and every occasion, there IS a root cause - the above is my way of dealing with it such that sep is maintained and I don't need you to drag absolutely everything out at 10 miles.
Join Date: Jun 2002
Location: UAE
Posts: 670
Likes: 0
Received 0 Likes
on
0 Posts
Without wishing to upset anyone, one of the contributing factors is that the number of people reporting 160knts is often unrelated to the number actually flying the speed they report. If you don't fly the assigned speeds accurately how can we be expected to achieve any standardisation in final approach spacing?
Differences in ground speed of sixty knots and more is not that unusual between an a/c at five miles and one at eleven miles and as a Tower controller they are not many options when faced with anything over half mile a minute catch ups.
Differences in ground speed of sixty knots and more is not that unusual between an a/c at five miles and one at eleven miles and as a Tower controller they are not many options when faced with anything over half mile a minute catch ups.
Guy and Tower thanks for that. The 380 seems to hit Vapp around at around 1000' if flap full is taken at 1500' and speed is reduced from 160kts at 5nm. Pretty much the same as the 330/340. I guess as tower says it all depends on what speed is actually flown and when it is actually reduced.
Was given descend to 10000' at 2000fpm and 230kts at 120 miles the other night. Only cost 1500kgs of extra fuel to what the predicted for the approach. It would be nice if DXB was given a bit more upper airspace if it would help with the extremely early descents.
the Don
Was given descend to 10000' at 2000fpm and 230kts at 120 miles the other night. Only cost 1500kgs of extra fuel to what the predicted for the approach. It would be nice if DXB was given a bit more upper airspace if it would help with the extremely early descents.
the Don
Question: when the man on the radio says 180 kts to ten, 160 to 5, what do they really mean? What are they expecting? Is it the same as at LHR where they expect 180 reducing slowly to be 160 at 4?
Join Date: Aug 2002
Location: Back in the Dark Ages
Posts: 76
Likes: 0
Received 0 Likes
on
0 Posts
Question: when the man on the radio says 180 kts to ten, 160 to 5, what do they really mean? What are they expecting? Is it the same as at LHR where they expect 180 reducing slowly to be 160 at 4?
If you need 165 kts or can only give 160kts to 5 miles, speak up. We'll adjust the spacing behind you.
Being within 5-10 kts of assigned speed on arrival or downwind is acceptable. Not on final where we get put over the GCAA's knee and spanked when wake is infringed because someone doesn't do their assigned speeds. Couple too many of those and we might have to start the job application process somewhere else in the world.
Crux of the matter is - Speak up if you can't comply with speeds, or ask if you can fly a certain preferred speed. Throw us a bone!!
Last edited by CEP; 2nd Sep 2012 at 14:34.
Join Date: Sep 2011
Location: earth
Posts: 1,098
Likes: 0
Received 0 Likes
on
0 Posts
Guy, you're rattling at the pride of the dugong jockeys, be careful!
But putting sarcasm aside, why would anyone doubt your observation, with our tunnel and one sided vision anyway?
Fact is the trouble increased exponentially once some dugongs started sharing the airspace. We even experience some taking these things ahead of us, apparently to group arrivals. That might make sense from a global/atc point of view, but not to other aircraft who have been given EATs and 2% STATCON, just to have the times swapped and extended without notice. Don't even dare ask why on the radio .... just commit or divert.
Too many different speed characteristics don't mix well, I get that. I also truly think that time will smooth things out. But there's no doubt that today the 380 slows things down. We all have to adapt, that means comply with the speed constraints, sure, and we do. But that should go both ways! Even the big things could adapt to usual speeds, especially because it seems to slow like a brick, meaning it could keep a civilised speed for a slightly longer period. Just a suggestion .....
But putting sarcasm aside, why would anyone doubt your observation, with our tunnel and one sided vision anyway?
Fact is the trouble increased exponentially once some dugongs started sharing the airspace. We even experience some taking these things ahead of us, apparently to group arrivals. That might make sense from a global/atc point of view, but not to other aircraft who have been given EATs and 2% STATCON, just to have the times swapped and extended without notice. Don't even dare ask why on the radio .... just commit or divert.
Too many different speed characteristics don't mix well, I get that. I also truly think that time will smooth things out. But there's no doubt that today the 380 slows things down. We all have to adapt, that means comply with the speed constraints, sure, and we do. But that should go both ways! Even the big things could adapt to usual speeds, especially because it seems to slow like a brick, meaning it could keep a civilised speed for a slightly longer period. Just a suggestion .....
Last edited by glofish; 2nd Sep 2012 at 18:44.
Join Date: Sep 2006
Location: any town as retired.
Posts: 2,182
Likes: 0
Received 0 Likes
on
0 Posts
3 wire, FMS speed dial up
If a speed reduction is requested, dial it into speed command, and let system adjust, theis should take 3-5 seconds, i suspect.
previous posts suggest 380 should decrease like a brick shute house.
glf
previous posts suggest 380 should decrease like a brick shute house.
glf
Join Date: Jun 2009
Location: Not UK
Posts: 199
Likes: 0
Received 0 Likes
on
0 Posts
Our radar only shows groundspeed at the mo and it usually shows them grounding at 135 kts or so - often already at 5 miles out, where almost everything else is still showing 160-170. That's half a mile a minute of difference, which would already give at least 1 mile of reduction on final.
Would anyone flying it care to comment? 160 to 4 can look pretty fast some times.
This thread is a timely reminder to those that sometimes forget that they are not the only ones in the sky!
Ps. It still doesn't explain the 10k 125 nm out!!
Join Date: Aug 2002
Location: Back in the Dark Ages
Posts: 76
Likes: 0
Received 0 Likes
on
0 Posts
My point is CEP, that large heavy aircraft do not lose 20 kts immediately. What rate are you planning for the speed reduction?
Without wishing to upset anyone, one of the contributing factors is that the number of people reporting 160knts is often unrelated to the number actually flying the speed they report. If you don't fly the assigned speeds accurately how can we be expected to achieve any standardisation in final approach spacing?
Join Date: Apr 2009
Location: Earth
Posts: 683
Likes: 0
Received 0 Likes
on
0 Posts
I must be a simpleton, I was under the impression that when given 160/4 that meant we reduce to this as we can, i.e. as succinctly as possible.
What still truly baffles me is the amount of guys who bitch and moan about ATC speed requirements....and do their own thing...rather than a simple "unable...we require 170/5 etc etc"
I see very senior and junior 777 guys in equal measure struggle with this concept..the concept that whilst we all work together, ATC exist to provide aircraft a service within the regulatory and airspace framework.
Guys if you can't make the speed, just fecking tell them! "UNABLE"
What still truly baffles me is the amount of guys who bitch and moan about ATC speed requirements....and do their own thing...rather than a simple "unable...we require 170/5 etc etc"
I see very senior and junior 777 guys in equal measure struggle with this concept..the concept that whilst we all work together, ATC exist to provide aircraft a service within the regulatory and airspace framework.
Guys if you can't make the speed, just fecking tell them! "UNABLE"