For DXB's ATC

[The Zohan]

Hi Guys,

I recently did my annual line check and coming back to DXB it was very busy and we got a very long vectoring to accommodate everybody.
I remember from previous posts that in Dubai’s TMA, below transition level, the minimum rate of descent is 500 fpm and also that there’s no tolerance with speed like in other places.
My TRE wasn’t convinced and I couldn’t say that my source was PPRuNe...
Anybody here who can confirm this, maybe with a reference?

Thanks

TZ

[ab33t]

Never offer information you dont have ready references for , ouch

[Marooned]

Unless specified in I believe the ROD is up to you. Wrt the speed however ATC uses speed to separate traffic and plan approaches. What I find frustrating is those who opt to carry a few extra few knots to remain clean or to avoid using the appropriate flap setting. Carry 5 kts extra over 20 track miles and you encroach on the traffic in front reducing the required separation and increase the risk of a GA. Use the flap and do the speeds requested, what's the problem? Let ATC do it's job so that we can do ours.

[Sonny Hammond]

Marooned.

The problem? Fuel.

Flap = Fuel.

There are no provisions in a fuel policy for extended vectoring with flaps extended.
Often there is no guidance as to how long the vectoring will go for, it can be away from the airport etc etc.

Start throwing flap, start using fuel exponentially.

Did I mention fuel...

[fatbus]

Bin, could you PM that ref as well thanks

[mensaboy]

This is copied from the October Training Newsletter.

''Descent in radar vectors - When under radar vectors, Dubai radar expect a minimum of vertical speed of 500’/min for all descent clearances unless otherwise stated.

Speed management - Dubai radar expect a speed reduction of approximately 10kts per NM when instructions to slow down are issued during a vector

Speed management - In Dubai, when instructions are issued to maintain a certain speed, pilots are expected to fly the exact speed issued, unlike some other ATS units which allow a certain degree of tolerance (for example: Canada ± 10kts, UK
± 5kts).''

[EGGW]

Unless of course, you ask DXB ATC can I fly 186 knots for instance, instead of 180 knots to 10nm. 99% of approach controllers are accommodating to that request in my experience :ok:

Saves chucking out the flaps, did someone mention fuel :ok::ok:

EGGW

[Marooned]

Oh, fuel.

Yeah I do get it :ugh: but if you are requested to maintain a speed and DO NOT request to keep a higher speed to give ATC the heads up, then do the speed. You'll probably do more track miles if you reduce separation and you'll definitely burn more fuel doing a GA if you're intent on doing ATCs job.

The problem is it may be 2 knots for you, 6 for another, 10 for someone else and then you'll complain about the tightness on finals when ones slow to vacate and another is lining up to depart. It's not about the FUEL!

[Trader]

Sorry, but carrying an extra 6 knots means sweet frick all! Over 15 min, with no other speed changes it is roughly 3/4 of a mile. If you were straight in, behind other traffic then things might tighten up but then good airmanship would have you using TCAS to judge the gap.

Otherwise, with several turns before final those 6 knots disappear in ATC vectoring and sequencing. Which is why there is a 5not or 10 knot 'window' in most IFR environments. It is also why ATC always says 'no problem' if you ask them to do 185 instead of 180.

[Marooned]

If you were straight in, behind other traffic then things might tighten up but then good airmanship would have you using TCAS to judge the gap

ATC are trying to do the 'judging' or 'traffic control' for us and if things do 'tighten up a bit' due to the extra speed we've decided to carry then we'll be asked to slow to min app speed sooner than necessary and BURN MORE FUEL. Of course if it's quiet it's slightly different but then ATC doesn't generally assign speeds in this case. When it's busy with traffic behind, in front and waiting to cross and depart it's slightly more complex and we are generally unaware of the picture ATC has.

3/4 of a mile does make a difference as ATC need to ensure minimum separation.... You take a lot of pressure off of yourselves when you do the speed requested. Yes controllers cope as they know we do not fly the speeds requested accurately but look how close it can get with 'expect late landing clearances' and land afters etc. In the current level of management 'support' why risk it?

NB: The image on TCAS is not an accurate indication of an aircrafts position and certainly not a primary tool to determine our own separations. Three main factors which contribute to traffic display misinterpretation:


Nature of the TCAS moving reference display.
Partial traffic picture given by the system.
Limited accuracy of TCAS bearing information.


ATC however have the accurate picture sitting right in front of them... let them use it.

[CRS]

Amazing the UK can deal with +/- 5kts but in DXB they can't. Maybe DXB is busier than LHR!!!!!!!!!!!!!! LHR also tend to recognise the type and will assign speeds accordingly! The requests add to RT in an already busy enviroment.

[ATCO1962]

For most of you regular users of Dubai, you probably know that, at certain times of the day, you're bound to get some holding and extended vectors. To be brutally honest, in the end stages of a tactical session of sequencing, I doubt that fuel considerations are high up on the list of factors and priorities that the controller is thinking about.

Please, just fly the speeds and carry extra fuel from the start! Yes, I know the bean counters aren't going to be happy but the reality is, it's very busy at well-known times of day and only extra fuel will allow pilots and controllers the peace of mind in knowing that planes aren't going to start calling min fuel at awkward moments.

[Capt Groper]

A News Letter is one way but this is still an interpretation by the author.

Can we get the DXB ATC Manual official text displayed..

Stick to the facts..not interpretation of thousands.

[Yellow Snow]

CRS
Amazing the UK can deal with +/- 5kts but in DXB they can't. Maybe DXB is busier than LHR!!!!!!!!!!!!!! LHR also tend to recognise the type and will assign speeds accordingly! The requests add to RT in an already busy enviroment.

Having controlled at both, it's news to me that the UK allow a +-5kt tolerance, interested to see the ref for that. If you're given an ATC speed I would expect it to be complied with not interpreted to what suits.

Plus it's not fair to compare the radar environment between DXB and LHR both very different with own set of challenges and restrictions.

Interestingly we always seemed to get flight crew visit the operation at LHR so they better understood things, in nearly two years I've been at DXB, I've seen only one visit by local crews.

We're open 24 hours a day if any crew would like to visit:)

[Capt Groper]

We're open 24 hours a day if any crew would like to visit

How and who do you call for this invitation to succeed?

Tried in the past but too much red tape, airside passes etc.

[thehulk]

Visit DXB ATC

Hey, would also love to know how to get an invite for a tour.
This would help us better understand controller constraints, etc.. here in
DXB area. If you dont want to put it up, maybe you could PM us?

[Yellow Snow]

Hi,

To answer a PM I received on this, we'd also welcome cabin crew if interested.

Capt Groper hit the nail on the head, assuming you're EK, there is a $hit load of red tape and hoops to jump through, so that could possibly explain lack of visits in the past.

I know Fly Dubai send all their new captains over for a DXB ATC presentation, which is refreshingly proactive for our part of the world.

I'm back in work on Monday and will find out what's required for flight/cabin crew to visit. Until then....

In the long run, we're looking at coming to you, with a mini ATC Q&A stall in EKHQ.

[TheFalcon]

Hi Guys,

If you are interested in visitng Dubai ATC (and you are most welcome) you have to email your Emirates - ATC co-ordinator Ms.Charlotte Desouza. Pm if you get stuck I will be happy to help on my part. Your visit will be fruitful and enjoyable just as much as it is for us when we fly jumpseat.

About ROD in the TMA I personally would ask you a favour and get to your assigned altitude as soon as possible during busy periods. This is beyond any written requirements. Getting to your new level fast means freeing up vertical airspace for the next guy above you and helping us have more airspace available. Lingering between two levels REALLY screws us up big time. About speeds and all the rest, moaning about fuel, track miles etc when its busy does not help, ask nicely and most reasonable requests are accomodated. We understand your problems about fuel constraints and the sh.t you go through to justify any delays but please understand that we have our problems too and that finally our aim is to get you guys and all your pax home to your families fast and safely!
Cheers and see ya soon.:ok:

[Radar Pete]

Great Thread:ok:

From an ATC prespective, can someone please explain FlyDubais new trick of entering the UAE FIR at an IAS of 230?

The problem ATC sits with (UAE ACC) is varying company policies regarding speeds/levels/ROD etc etc. As a gauge, the UAE ACC would prefer traffic to be IAS of between 290 and 320 on entering the UAE FIR, and planned descent to cross DESDI/BUBIN between FL150 and A120 regardless of RWY in use. Air Arabia love to leave the descent late thereby causing problems of catching traffic that is lower. A330's love descending earlier regardless of the RWY thereby forcing the high speed for as long as possible. Bizjets think they can leave FL280 with 20NM to DESDI, yeah right??

Ideally we want to funnel all traffic into similar descent profiles which makes speed control more manageable and realistic. When we say "descend now" we mean now and don't descend at 500 fpm. The winter winds do cause spacing problems and the sooner we can get aircraft lower the easier the spacing becomes.

When holding, please provide a decent ROD, this helps ATC compress the hold. Anything above 1000fpm is appreciated. We will always attempt to provide continuous descent but that is not always possible, just descend to the next issued level as soon as possible as safely as possible, we also want to avoid level busts????

The above criteria are basic guidelines and will obviously change depending on circumstance.

Any feedback is more than welcome:)

[CRS]

Yellow Snow you are of course right, this is quote from LHR section of UK AIP

"Speed Control: Pilots should typically expect the following speed restrictions to be enforced: 220 kt from the holding facility during the
initial approach phase; 180 kt on base leg/closing heading to final approach; between 180 kt and 160 kt when established on final approach
and thereafter 160 kt to 4 DME. These speeds are applied for ATC separation purposes and are mandatory. In the event of a new (nonspeed
related) ATC instruction being issued (eg an instruction to descend on ILS) pilots shall continue to maintain the previously allocated
speed. All speed restrictions are to be flown as accurately as possible. Aircraft unable to conform to these speeds must inform ATC and
state what speeds can be used. In the interests of accurate spacing, pilots are requested to comply with speed adjustments as promptly
as is feasible within their own operational constraints. Pilots should advise ATC if circumstances necessitate a change of speed for aircraft
performance reasons."

rgds

CRS

[Canoehead]

Regarding tower/approach visits: the easiest way to cut through the red tape is simply call us (phone or frequency) before or after a flight, and we can send someone to your gate, or we meet at the door just below the tower, (B13, or F?) on the other side.

Of course your time is precious before a flight, and even more so after, but it's probably the most hassle free way into the fascinating world of DXB ATC.

[Scooby Don't]

Just because a speed is mandatory does not necessarily mean there is no tolerance!
Altitudes are mandatory, but Mode C is allowed to be 200' off and to achieve a CPL you need only maintain within 50' of the assigned altitude.

AFAIR, and no, I don't have the reference to back this up, +/-10kts is an ICAO standard. At
levels below FL 280, speed adjustments will be expressed in multiples of 10 kt based on indicated airspeed (IAS) from the AIP, ENR 1.1.3]
The place where the exact speed matters is on final - there aren't many controllers who will have aircraft close enough elsewhere to make +/-10kts much of an issue.

I have NEVER insisted on an exact speed when a pilot has asked to fly within 10kts of that I've just assigned, other than on final and where wake turbulence separation must be applied.

------------------------------------------------------------------------------------

Now for the ROD - that is also an ICAO standard, and a minimum rate of climb or descent of of 500fpm is mandatory. It really does matter in the Dubai CTA. Often, traffic for Sharjah is in the mix too, and vertical separation is often used between DXB and SHJ traffic given the proximity of the approaches. Also, we often want to get arrivals through DARAX beneath departures via RIKET (30 direction), for example. If you mosey on down to your cleared altitude at a glacial ROD, you're not really helping! When we have busy arriving traffic from both DESDI and BUBIN, we often vector the traffic from the arrival gate closest to the runway (DESDI for 12, BUBIN for 30) to the north of Sharjah, to feed them into the downwind. There is a great deal less pucker factor when vertical separation is assured, as with certain operators we can't rely on their rate of turn to fit into the downwind where we would normally expect them.

I often use the phrase "when ready" with a descent clearance. That means exactly that - in that instance I do NOT need you to maintain any particular rate of descent and if you wish to stop off at the previously cleared altitude, go right ahead. I use "when ready" when there is no vertical separation issue between you and anyone beneath you as far as your cleared altitude, and I give that instruction in order that you can arrange your own descent profile. If I intend to vector you on a profile much shorter or longer than the STAR, I will tell you if time allows.

[Trader]

Morooned---I think Scooby just cleared it up! The few knots that are carried to keep the flaps up mean little when you just passed Desdi on the downwind for 30L and have 20 plus track miles to go. It makes no sense to go flaps 1 etc to slow by 6 knots and drag it around.

In the end, good airmanship says that a simple response to ATC asking to stay at min clean "x knots" clears up any issues - he'll tell us whether that works or not and, as Scooby mentioned, that is generally the case.

My comment about TCAS was about its use on final. If I see the guy 3 miles straight ahead of me I know I am tight and vice versa. Speeds on final are much more straight forward (180 and 160) and so much easier to maintain.

[Marooned]

It's a fair cop. I would however like to see the reference that relates to tolerances in the terminal area and not just below FL 280.

All things being equal I personally try and do the speeds accurately because we can, 'airmanship'. I get the points made but in reality that means someone can be doing 260 below 10K, another 240, one 170 to 10, another 190 and so on. +/- 10 knots can mean 20 in combination. I also find Flaps 1, which after all is only slats, a more efficient, stable and manoeuvrable configuration in the terminal area.

I don't waste fuel and do my best to save as much as possible as safely as possible. An example is using Flap 25 when possible instead of straight to Flap 30 to maintain 160 between 10 and 5 miles... less fuel, less noise...but that of course could mean 150 or 170 :confused:

[Trader]

Actually I think we agree----just on different pages when the discussion first started!