Both cleared to same level inthe hold?
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Not to be dismissive, but would it help if we told you that you were in the most screwed up airspace many of us have ever seen?
FL280 isn't too standard for the BUBIN hold, but the routing via DARAX arrival has been going on for months.
There are pages and pages on this forum about what is wrong with the UAE, I won't make this one of them - 2 planes at the same level isn't standard but without more facts about distance to run to the hold, no one can tell you exactly how wrong.
As a side note, I did see a guy have two at the same level in a pattern at FL260! He was very lucky as they both did direct entry and went round and round not getting within 5nm.
FL280 isn't too standard for the BUBIN hold, but the routing via DARAX arrival has been going on for months.
There are pages and pages on this forum about what is wrong with the UAE, I won't make this one of them - 2 planes at the same level isn't standard but without more facts about distance to run to the hold, no one can tell you exactly how wrong.
As a side note, I did see a guy have two at the same level in a pattern at FL260! He was very lucky as they both did direct entry and went round and round not getting within 5nm.
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FWIW, as an OJTI I always instruct to assign a level/radar heading that will be safe against known traffic at that time. Clearing an ac into a hold level already assigned, even though it is anticipated that the ac occupying that piece of sky will have vacated by the time the ac in question arrives, is to my mind bad practice. Hold levels can be adjusted once separation has physically been achieved with little or no hit on expedition.
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I tried in the simulator once and had two aircraft in the hold at the same level (FL90 if I recall correctly). The STCA never went off and with both aircraft at opposite ends of the holding pattern and fixed speeds were never going to collide.
It's NOT something I would do in real life though. I don't like the idea of having two aricraft assigned the same level in the same piece of sky without another form of separation (ie headings).
It's NOT something I would do in real life though. I don't like the idea of having two aricraft assigned the same level in the same piece of sky without another form of separation (ie headings).
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jackofalltrades:
By "fixed speeds," do you mean both aircraft were operating at identical indicated airspeeds?
I tried in the simulator once and had two aircraft in the hold at the same level (FL90 if I recall correctly). The STCA never went off and with both aircraft at opposite ends of the holding pattern and fixed speeds were never going to collide.
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captainsmiffy and others
Let´s talk business, not "computer gamers mentality"! May be I am a dinosauer compared to those that run that discussion, but as a retired CoO ATC I remember a few rules we were trained on
1. Never base control on assumptions
2. It´s either 1000 ft. vertical or 3 or more miles horizontal
3. Never assighn identical altitudes to aircraft on converging courses or to the same clearance limit.
4. Same altitude can only be assighned if there is either constant speed / constant distance or the tracks of the planes involved diverge.
Of course from my own experience I know that the one or the other rule may be in jeopardy for a moment in heavy workload situations, but to consider something like was mentioned here in this thread as standard control procedures is far away from "safe and orderly flow of traffic"
Jo
1. Never base control on assumptions
2. It´s either 1000 ft. vertical or 3 or more miles horizontal
3. Never assighn identical altitudes to aircraft on converging courses or to the same clearance limit.
4. Same altitude can only be assighned if there is either constant speed / constant distance or the tracks of the planes involved diverge.
Of course from my own experience I know that the one or the other rule may be in jeopardy for a moment in heavy workload situations, but to consider something like was mentioned here in this thread as standard control procedures is far away from "safe and orderly flow of traffic"
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By "fixed speeds," do you mean both aircraft were operating at identical indicated airspeeds?
Let´s talk business, not "computer gamers mentality"!
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The solution is very simple to the AUH/UAE/DXB problems, however, its implementation may not be quite so simple.
You move the Dubai and Abu Dhabi approach units and the UAE centre to a neutral site, maybe just south of Jebel Ali, straddling the border. This would then place all controllers involved in the same building and preferably in the same room so that each knows and can see the problems of the other. They can then, at least, start working as a single cohesive unit.
You would then undergo a recruitment campaign to bring in fresh management for both the approach and en-route sides. The task ahead of you requires personnel who can think "outside the box" and don't come with any previous baggage. Then you'd need to recruit enough experienced ATCOs to fully staff all the positions, with some contingency.
A complete redesign of the airspace would then need to be done to optimise the traffic flows to/from DXB and AUH and Jebel Ali World together with a redesign of the overflying airways. Let's face it you're going to have to do that anyway when you've got 6 runways up and running and Emirates have another 150 aircraft, plus the 100 new planes that Etihad start accepting this year.
And how long would all this take? Well, my guess is if you had started the process about 5 years ago you would just about now be approaching a satisfactory solution.
In the meantime, I think I'll be stopping off in Doha more frequently, once their new airport is up and running. Can't be bothered with the increasing hassle at DXB any more.
Anyway chaps, good luck & stay safe. Got to go, is that the sound of an "oink" I just heard flying past the window?
On the beach
You move the Dubai and Abu Dhabi approach units and the UAE centre to a neutral site, maybe just south of Jebel Ali, straddling the border. This would then place all controllers involved in the same building and preferably in the same room so that each knows and can see the problems of the other. They can then, at least, start working as a single cohesive unit.
You would then undergo a recruitment campaign to bring in fresh management for both the approach and en-route sides. The task ahead of you requires personnel who can think "outside the box" and don't come with any previous baggage. Then you'd need to recruit enough experienced ATCOs to fully staff all the positions, with some contingency.
A complete redesign of the airspace would then need to be done to optimise the traffic flows to/from DXB and AUH and Jebel Ali World together with a redesign of the overflying airways. Let's face it you're going to have to do that anyway when you've got 6 runways up and running and Emirates have another 150 aircraft, plus the 100 new planes that Etihad start accepting this year.
And how long would all this take? Well, my guess is if you had started the process about 5 years ago you would just about now be approaching a satisfactory solution.
In the meantime, I think I'll be stopping off in Doha more frequently, once their new airport is up and running. Can't be bothered with the increasing hassle at DXB any more.
Anyway chaps, good luck & stay safe. Got to go, is that the sound of an "oink" I just heard flying past the window?
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jackieofalltrades
Just to clarify. My greatest respect to those that have taken the burden and do their best efforts to transform trainees into real controllers. And of course, this is unthinkable in nowadays environment of ATC without computer simulation.
My wording was directed to those that may think, just as on a computer game, one can freeze the life picture to look for solutions. ATC is an kind of art, just like flying, that needs professionals not gamers.
Jo
My wording was directed to those that may think, just as on a computer game, one can freeze the life picture to look for solutions. ATC is an kind of art, just like flying, that needs professionals not gamers.
Jo
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Captainsmiffy, you sound like a sensible chap, Bluesky however?! Not sure about your atc training but in my experience "what if" scenarios are very much apart of what i do. Considering what could happen if something fails allows you to form alternate plans should you need them.
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Clearing two aircraft into the hold at the same level is a sure invitation for Mr Murphy to put in an unwelcome appearance. It may be seen as acceptable by some of the more gung-ho guys, but as you get older you become much more wary of the insidious ways the wily Murphy can creep up on you.
I once got totally maxed out during a mass F-111 recovery into Lakenheath, but managed to squeeze a vital couple of aircraft into the top of the hold by using 500ft levels. Certainly not SOP, but done by using 'experience, trust, faith and self-belief'.
Perhaps this might be an unofficial solution to the OP's scenario. Better 500ft separation than a paint job.
I once got totally maxed out during a mass F-111 recovery into Lakenheath, but managed to squeeze a vital couple of aircraft into the top of the hold by using 500ft levels. Certainly not SOP, but done by using 'experience, trust, faith and self-belief'.
Perhaps this might be an unofficial solution to the OP's scenario. Better 500ft separation than a paint job.
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On the beach, you must be on something else. Something goooood.
GVaviator, yes it has been.
Novation, nothing wrong with my training or my pre-planning. I'm fully aware of the consequences of something going wrong. 20+ years of awareness to be exact. The difference seems that most people count on things going wrong. I count on things going right. I have two responsibilities: Give the correct clearance and make sure the read-back is correct. After that I trust the pilot. 100%. As much as I sometimes rue the fact, my influence on the operation of an aircraft ends there.
It's an exercise based on trust. Pilots trust their co-pilots. Pilots trust the engineers. ATCs trust the pilots. Pilots trust the ATCs. So if you hear me clear you into the hold at the same level as someone else, trust me to have you at a different level when you actually get to the holding fix. If all seven of my radios and your radios fail, then trust in TCAS.
Some of you guys make it sound as if having two planes at the same level going to the same point as being tantamount to mass murder. It happens everywhere, everyday.
I treat my responsibilities and limitations like I treat a firearm, I respect it but I'm sure as f..k not scared of it.
GVaviator, yes it has been.
Novation, nothing wrong with my training or my pre-planning. I'm fully aware of the consequences of something going wrong. 20+ years of awareness to be exact. The difference seems that most people count on things going wrong. I count on things going right. I have two responsibilities: Give the correct clearance and make sure the read-back is correct. After that I trust the pilot. 100%. As much as I sometimes rue the fact, my influence on the operation of an aircraft ends there.
It's an exercise based on trust. Pilots trust their co-pilots. Pilots trust the engineers. ATCs trust the pilots. Pilots trust the ATCs. So if you hear me clear you into the hold at the same level as someone else, trust me to have you at a different level when you actually get to the holding fix. If all seven of my radios and your radios fail, then trust in TCAS.
Some of you guys make it sound as if having two planes at the same level going to the same point as being tantamount to mass murder. It happens everywhere, everyday.
I treat my responsibilities and limitations like I treat a firearm, I respect it but I'm sure as f..k not scared of it.
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Remind me again.........where do you work?!!
Having been through a simultaneous failure of radios/radar/navaids/airfield lighting/control room lighting in this part of the world, I'm afraid I prefer to err a little more on the side of caution these days!
Keep em safe
Orderly and expeditious are options.
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Blueskye- i myself have experienced both rt fails and radar fails and on neither of the ocassions have i felt it necessary to trust Tcas, the situation having failed safe due to good technique. I have a feeling you might be insane. Likening your responsibilities to your use of firearms confirms it. Thankfully where I'm from poor technique is frowned upon and guns are illegal.
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In post #25, Annex14 said :
" 3. Never assighn identical altitudes to aircraft on converging courses"
I wonder how many cadets were failed on their APR exam by "Chopper *****" at Hurn for doing just that ?
" 3. Never assighn identical altitudes to aircraft on converging courses"
I wonder how many cadets were failed on their APR exam by "Chopper *****" at Hurn for doing just that ?
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jackieofalltrades,
2 ACFT at the same level during a simulation, why not ?
As a trainer, I would ask the trainee what must be the minimum (same) speed to get a minimal separation between outbound and inbound leg.
I won't bother you with the calculations.
My results :
- 200 kts IAS at FL100 / 140kts IAS at FL200 to get a 5 NM separation.
- 235 kts IAS at FL100 / 185kts IAS at FL 200 to get a 6 NM separation.
The problem is that the protection areas around the hold would not be compatible anymore (at least in lower levels), so we would have to vector the rest of the traffic far-far-away. Not easy in an overcrowded sector.
And if my trainee doesn't aim at least 6 NM, then Murphy-me would implement a RNAV failure.
Furthermore if the outbound leg is upwind (drift towards the opposite traffic can be funny when already just above the minima).
Another solution would be to vector the new-coming close enough behind/before the other so we get a 6 Nm separation over the fix. Thus they are both in the same in/outbound leg, with only the wake-turbulence-separation.
Totally unsafe, I wouldn't do it for real.... as long as I've got another solution (never say never...).
But it must be fun in the simulator !
Maybe as "fun" as changing a sequence...
captainsmiffy,
In your case, you were 25 NM to the fix, so there were 3 mins remaining. The cleared level was 280.
Counting 10 secs per clearance/readback/pilot's reaction, 1000' per minute assigned. The controller needs only one gap at FL120 or above so the FL280 is vacated in time.
But this means no failure at all (radio, radar,...) in the next 3 minutes : TCAS-RA in a hold can have surprising consequences. So this should not be considered SOP, anywhere.
It seems the situation was unusual, so I believe some of the solutions they found that evening were unusual too...
You wrote :
People who work in aviation (pilot, controller, fuel supplyer, snow plough company manager...) and don't play the "What if game" have probably forgotten that aviation is all about locking hunreds of human beings in an alluminium tin, throw the tin 8 miles high, 500 knots, thousands miles away.
People who don't play the "What if game" only believe this will land safely on a 50 m-wide concrete strip on the other side of the Earth.
People who do play the game do the necessary to let it happen tens of thousands times every day.
I tried in the simulator once and had two aircraft in the hold at the same level (FL90 if I recall correctly).
As a trainer, I would ask the trainee what must be the minimum (same) speed to get a minimal separation between outbound and inbound leg.
I won't bother you with the calculations.
My results :
- 200 kts IAS at FL100 / 140kts IAS at FL200 to get a 5 NM separation.
- 235 kts IAS at FL100 / 185kts IAS at FL 200 to get a 6 NM separation.
The problem is that the protection areas around the hold would not be compatible anymore (at least in lower levels), so we would have to vector the rest of the traffic far-far-away. Not easy in an overcrowded sector.
And if my trainee doesn't aim at least 6 NM, then Murphy-me would implement a RNAV failure.
Furthermore if the outbound leg is upwind (drift towards the opposite traffic can be funny when already just above the minima
).Another solution would be to vector the new-coming close enough behind/before the other so we get a 6 Nm separation over the fix. Thus they are both in the same in/outbound leg, with only the wake-turbulence-separation.
Totally unsafe, I wouldn't do it for real.... as long as I've got another solution (never say never...).
But it must be fun in the simulator !
Maybe as "fun" as changing a sequence...
captainsmiffy,
In your case, you were 25 NM to the fix, so there were 3 mins remaining. The cleared level was 280.
Counting 10 secs per clearance/readback/pilot's reaction, 1000' per minute assigned. The controller needs only one gap at FL120 or above so the FL280 is vacated in time.
But this means no failure at all (radio, radar,...) in the next 3 minutes : TCAS-RA in a hold can have surprising consequences. So this should not be considered SOP, anywhere.
It seems the situation was unusual, so I believe some of the solutions they found that evening were unusual too...
You wrote :
i play the 'what if?' game every time I drag my weary butt into the sky!
People who don't play the "What if game" only believe this will land safely on a 50 m-wide concrete strip on the other side of the Earth.
People who do play the game do the necessary to let it happen tens of thousands times every day.
Last edited by BrATCO; 3rd Jan 2011 at 21:53.
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Capainsmiffy, why don't you PM me and schedule a visit to the ACC center in Abu Dhabi (assuming you are based in the UAE). I'm sure a lot of your questions will be answered.
P.S. If you don't, I'll shoot you.
P.S. If you don't, I'll shoot you.