OTBD Radar Perspective
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OTBD Radar Perspective
Hi All, I am new to this site in-so-far as posting threads are concrened, but have been reading the many entries with a somewhat bemused detachment over the past year or so.
My main motivation for deciding to "get involved" as-it-were, is merely to provide a perspective,.....that of an ATC at OTBD radar.
Giving countenance to the fact that the aviation fraternity on a global scale is subservient to various pressures, I simply wish to provide an insight to certain procedures and methodologies employed by the OTBD approach radar ATC's.
Several pilots have in their threads, I am not too certain as to the date of the entries, made reference to being a little bewildered to excessive speed control at OTBD. The answer is sourced in simplicity itself; sequencing requires a number one, two, three etc,etc.
Influencing factors in application of speed contol at OTBD, or anywhere for that matter are;
1) Track miles to TD
2) Aircraft type
3) Runway in use
4) FL or ALT of Acft on first contact
5) Prevailing traffic scenario ( very often only fully understood by the OTBD Radar ATC purely by virtue of the fact that he has a radar )
6) Prevailing weather conditions
7) On occasion late transfers of control from neibouring FIR's, often through no fault of their own, as invariably they too were extremely busy, i.e., frequency congestion.
There are other peripherals, but by-en-large, the above covers it.
OTBD Radar in-house factors are staff, (one ATC on duty to manage two AFD's, monitor six frequencies, manage ten Direct Speech Lines etc, etc)
and continuous duty without a break. Monings shift controllers do get a one hour break or are sent home an hour earlier, however, every other shift, the ATC is on duty with one ATCA (extremely busy himself) and no break until the arrival of the new shift, which obviously comprises one ATC. The shift length varies from five hours to eight hours.
Naturally a soon-to-be-replaced ageing radar system does little more than aid-and-abet the workload.
Yet, having stated the above, the ATC staff at OTBD are hardened and weathered ATC veterans with vast experience and very often I marvel at what we achieve with the available tools.
Automation and Data Link as off-spring from the FANS initiative at airports(TRACON+ACC/En-route) with multiple runways, CAT III-c, SMR, RNP1 Capability, RITA, GNSS derivatives WAAS+LAAS, Mode S, ACARS,sectorization(layered/lateral) etc,etc.....service traffic loading per ATC on a much smaller scale than the OTBD ATC's. The overall ASM and Movement structure may have greater figures, but in definitive Controller/Worload percentages, OTBD ATC's carry a greater workload.
Anyway, just a perspective.........do with it what you will, Tks.
My main motivation for deciding to "get involved" as-it-were, is merely to provide a perspective,.....that of an ATC at OTBD radar.
Giving countenance to the fact that the aviation fraternity on a global scale is subservient to various pressures, I simply wish to provide an insight to certain procedures and methodologies employed by the OTBD approach radar ATC's.
Several pilots have in their threads, I am not too certain as to the date of the entries, made reference to being a little bewildered to excessive speed control at OTBD. The answer is sourced in simplicity itself; sequencing requires a number one, two, three etc,etc.
Influencing factors in application of speed contol at OTBD, or anywhere for that matter are;
1) Track miles to TD
2) Aircraft type
3) Runway in use
4) FL or ALT of Acft on first contact
5) Prevailing traffic scenario ( very often only fully understood by the OTBD Radar ATC purely by virtue of the fact that he has a radar )
6) Prevailing weather conditions
7) On occasion late transfers of control from neibouring FIR's, often through no fault of their own, as invariably they too were extremely busy, i.e., frequency congestion.
There are other peripherals, but by-en-large, the above covers it.
OTBD Radar in-house factors are staff, (one ATC on duty to manage two AFD's, monitor six frequencies, manage ten Direct Speech Lines etc, etc)
and continuous duty without a break. Monings shift controllers do get a one hour break or are sent home an hour earlier, however, every other shift, the ATC is on duty with one ATCA (extremely busy himself) and no break until the arrival of the new shift, which obviously comprises one ATC. The shift length varies from five hours to eight hours.
Naturally a soon-to-be-replaced ageing radar system does little more than aid-and-abet the workload.
Yet, having stated the above, the ATC staff at OTBD are hardened and weathered ATC veterans with vast experience and very often I marvel at what we achieve with the available tools.
Automation and Data Link as off-spring from the FANS initiative at airports(TRACON+ACC/En-route) with multiple runways, CAT III-c, SMR, RNP1 Capability, RITA, GNSS derivatives WAAS+LAAS, Mode S, ACARS,sectorization(layered/lateral) etc,etc.....service traffic loading per ATC on a much smaller scale than the OTBD ATC's. The overall ASM and Movement structure may have greater figures, but in definitive Controller/Worload percentages, OTBD ATC's carry a greater workload.
Anyway, just a perspective.........do with it what you will, Tks.
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Thanks for that TOPO. I appreciate the daily input from the OTBD ATCOs, especially in the evening rush, but why the long seperation between aircraft. Could it be that pilots are erratic in their speed management or is it the fact that taxi speed is reached long before the runway turnoff (autobrake!) and runway occupancy is too long? Personally I would like to see speed controlled by ATC from first contact to the final fix al la LHR and other very efficient airports. This is probably theoretical as runway efficiency is useless if there is nowhere to park it on arrival! Keep up the good work. 
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Very interesting to finally here a point of view from the guys on the other side of the MIC.
I have had allready the same reflections as the Captain here said: why those vectorings wher you put aircraft with 10+miles seperation on the ILS?
Speed vectoring from the moment you enter the OTBD Control Zone together with SLPs ( e.g. 160Kts 4 miles final) like most major airports do could help a lot.
The main reason for this is the fact that a lot of pilots here have forgotten the basics of flying. In a descent they just follow the " calculated vertical profile" of the FMGS. This is a VERY conservative calculation mode usually bringing you 4000ft low on profile. People do not calculate anymore their profiles. On top of that they use a CI of 40 ( A330 ) which gives you a descent speed of 285kts. A std ATC speed in descent is 300kts or more.
So that is why a lot of airplanes come in TOO low /too slow making life for ATC very difficult.
Speed constraints, SLPs etc could help this problem a lot.
RWY OCC time I think remains the limitting factor. QR unfortunately put an autobrake LO recommended note in their SOPs. Although this is actually an airbus recommendation it is totally useless in OTBD because the first exit ( C) is far enough from the TDP. Even a heavy A330, when landed the correct way ( no 3 Retard calls heard by trying to achieve the kiss landing of the century!!!), will easily vacate C by using idle reverse and some mild braking when approaching the exit.
This as well is a High speed exit so no need to brake all the way to 5 kts taxispeed on the RWY!
I have had allready the same reflections as the Captain here said: why those vectorings wher you put aircraft with 10+miles seperation on the ILS?
Speed vectoring from the moment you enter the OTBD Control Zone together with SLPs ( e.g. 160Kts 4 miles final) like most major airports do could help a lot.
The main reason for this is the fact that a lot of pilots here have forgotten the basics of flying. In a descent they just follow the " calculated vertical profile" of the FMGS. This is a VERY conservative calculation mode usually bringing you 4000ft low on profile. People do not calculate anymore their profiles. On top of that they use a CI of 40 ( A330 ) which gives you a descent speed of 285kts. A std ATC speed in descent is 300kts or more.
So that is why a lot of airplanes come in TOO low /too slow making life for ATC very difficult.
Speed constraints, SLPs etc could help this problem a lot.
RWY OCC time I think remains the limitting factor. QR unfortunately put an autobrake LO recommended note in their SOPs. Although this is actually an airbus recommendation it is totally useless in OTBD because the first exit ( C) is far enough from the TDP. Even a heavy A330, when landed the correct way ( no 3 Retard calls heard by trying to achieve the kiss landing of the century!!!), will easily vacate C by using idle reverse and some mild braking when approaching the exit.
This as well is a High speed exit so no need to brake all the way to 5 kts taxispeed on the RWY!
Last edited by Qatari515; 1st Feb 2006 at 06:19.
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Doha ATC
Why does Qatar and OTBD make part of Bahrain FIR? I think that Doha is a lot busier than Bahrain so I think it should have it's own FIR (when the manpower and equipment required will be in place).
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On The Money!!!
Thanks Crusty Ol Cap'n, Qatari515 and Boeing 787, you are all bang on in your assertions.
Runway occupancy time is the 'governing' factor if-you-will, with close and distant relations to all the other points you raised. The socio-economic growth of Qatar has been nothing short of phenominal in recent years. The resulting increase in the Qatari Fleet and others and demand to explore the Middle East (Qatar), either as a destination or as an in-transit stop-over exploration en-route to Europe by travellers has and is taking its toll on the available resolution capabilities of OTBD.
The front-line 'regiment' here is the OTBD Tower ATC,s and their artillery is reliable effective two way communication, available and reliable met and nav equipment, uninterrupted AFD visual detection, some 21 parking bays with 8 on the eastern side and pure staying power. These gents, once recipients of my cynicism in their methodoligies, now have have my utmost respect and admiration. Their available parking bays are quickly consumed during busy periods, including the eastern ones to the point at times acft have had to hold on taxiways while waiting for a parking bay to open. Their taxi routes are often inventive due to w.i.p. somewhere on either the movement or manouevring area, all the while fielding at times somewhat irate operations phone calls from various airlines enquiring as to the where-abouts of a particular flight. I was sitting next to one of my Tower colleagues on such a paticular day and watched as a smile of resignation spread across his face when the Approach ATC informed him of a further arriving sequence, acft for which their quite simply was No space.................what eloquence this young man displayed, such courage and coolness under fire within ATC parameters is indeed rare. Not that it is of great importance, but I beamed with pride as this young fellow was an ex-student of mine.
The above scenario however does have consequences where-in the Aproach ATC then needs to increase the spacing on final and at times even simply slow the traffic down such that events are given a chance to resolve itself on the ground. Some of my colleagues have informed me that holds have had to be used as a delaying tactic tool to alleviate some of the pressure on the tower controller. Taxi speeds and at what point that is reached is in essence an operators parameter, but during busy periods when Rwy34 is in use I have heard the Tower ATC advise an aircraft on final to plan their Rwy vacation via a certain Txwy, in most cases the chaps in the Twr attempt to use Txwy 'C' as it is as close to a high speed txwy that we have. The other factor that does affect Runway occupation is that the Tower ATC manages the ground frequency as well, which is very busy with aircraft being towed that need to use the runway either in a straight cross-over or as a 'txwy' to a published txwy to a parking bay. This also applies to active flights either post arrival or pre-departure because as stated above w.i.p. dictates as such.
Spacing on Final Rwy 34 has no requiement for 10NM.s, the standard ICAO separation of 5NM's is suffice, requiring 6NM's when the preceeding is WT catagory, a 'heavy'. 10NM's is possibly applied at times when the Approach ATC is fighting frequency congestion and activates his base and attack headings later than intended, when surface wind conditions are calm and you have say a A330 preceeding a B737/A320 type or if Tower requires it in order to start getting a growing line of holding point departures up and away. Rwy 16 is the 'jono', if-you-will, in so many ways. The most apparant is the awkward intercept angle if you are appraching from the east, airspace restrictions and the Runway/Taxiway configuration when landing from that direction. I still push for the icao minimum when Rwy16 is in use, but the general guideline here in order to assist the Tower Controller in his Surface Movement Management is 8NM's. Again, the Tower ATC's here are the heroes. I have witnessed them slip a little vaseline on the Runway and wings of pending departures and expedite their despatch in my world in-between my sustained and rapid fire of 5NM spacing, all the while never missing a beat in placating and soothing disgruntled delay queries and the ever-changing parking bay allocations!
Speed Control and the correct application there-of and adherence there-to is a subject I used to love throwing myself into, both as participant and spectator. I have sat with three pilots in years past, who all flew for the same small private airline, the same type of acft, the same routes more or less, naturally the same airspaces and pretty much not too dissimilar weather conditions and remember distinctly that three very different positions/appoaches were held. That particular occasion stuck with me as a sort of yard-stick, in that there will always be a counter-opinion. However, in OTBD airspace it is vital, by-en-large due to airspace configuration and traffic loading and yes, there are one or two gents who stay true to form and seldom if ever comply with speed rectrictions placed on them. When they do the RT work on a leg such that I recognize whom it is, I apply 'alternative' medicine. For the most part, I honestly cannot say there is a problem with non-compliance with speed control by pilots using OTBD airspace. In point of fact, at times my own speed control, despite being adhered-to proves ineffective, where-in vectors and other parameters are applied. Following ICAO is easiest, so I never apply speed control less then 250 Kts above FL250 (if acft under my control). Applying less than 250Kts is best left and more effective at or below 10 000', sometimes opting for a designated layering of speed reductions, for e.g., 7000' 220/230Kts , 3000' 200/180Kts.......obviously all dependant on prevailing traffic scenario etc,etc. I imagine most of my colleagues are pretty much on the same page here. Of course speed control and the adherence there-to is best served by Mode 'S' Enhanced Surveillance Radar and the acft being equipped with Mode 'S' Level 2 Transponder and DAP avionics interfaces.
OTBD having its own FIR,...well of that I am not sure, however, smoother traffic flow with its benefits is easily achieved by deferring to the application of ATFM. During a workshop/seminar at the Ecole Nationale de L'Aviation Civile In Toulouse some years back a very knowledgable and sauve Dominique Colin de Verdiere gave a lecture on Demand Capacity Balancing that I warmed to immediately as it is the very heart of Collaborative Decision Making and is in my opnion the very next logical step for OTBD/NDIA relating to effective ATFM. At the moment any application thereof will be purely Ad-Hoc as is required in the tactical stage.
Ensuring minimal delays, reducing Rwy occupancy time and effective speed control is very much now individual controller capability dominated/driven. A wonderfully eccentric british radar instructor of mine from my college days that used to bash around in the old Canberra in his glory days, shared a little gem with me and so many others that were trained by him and is still used today. It is a pearl of wisdom that one day he decided to share with me as he must have noticed that my incesant need for approval of my perfomance was'nt being met. Taking pity on me he took me into his office, rustled us up a cop of coffee each, lit up a Vantage Plain (imported, as not available in my country at the time), reclined just enough to rest his legs on the desk and proceeded to gently loosen my tightly wound stomach and neck muscles by regaling me with some 'war' stories. Many of which, I am sure were a tad 'coloured', as they always ended with him either out-flying a combattent, out-thinking/maouvering a higher rank or out-witting an opponent in their rivalry affections for a particular young lady. None-the-less, they always served to enthrall whoever was listening and I was no different. So when he thought I was sufficiently at ease, he lowered his feet from the desk, leaning forward he clasped his hands in front of him, looked me straight in the eye and said, " Look old boy, in the end it comes down to you and you alone, when all is said and done, if it looks good on radar, it is good, if it looks sh#t, well then old chap, quite frankly it is sh#t!" Essentially he was saying that I was the judge of my own peformance and no amount of posturing or hindsight will impact on your perforamnce and warned me never to go on duty without my side-arm,....as he said it, " the seven 'P's son, thats what it is all about, Proper Pe-Planning Prevents Piss Poor Performance!"
Currently at OTBD that is the most effective 'tool'
Tks.
Runway occupancy time is the 'governing' factor if-you-will, with close and distant relations to all the other points you raised. The socio-economic growth of Qatar has been nothing short of phenominal in recent years. The resulting increase in the Qatari Fleet and others and demand to explore the Middle East (Qatar), either as a destination or as an in-transit stop-over exploration en-route to Europe by travellers has and is taking its toll on the available resolution capabilities of OTBD.
The front-line 'regiment' here is the OTBD Tower ATC,s and their artillery is reliable effective two way communication, available and reliable met and nav equipment, uninterrupted AFD visual detection, some 21 parking bays with 8 on the eastern side and pure staying power. These gents, once recipients of my cynicism in their methodoligies, now have have my utmost respect and admiration. Their available parking bays are quickly consumed during busy periods, including the eastern ones to the point at times acft have had to hold on taxiways while waiting for a parking bay to open. Their taxi routes are often inventive due to w.i.p. somewhere on either the movement or manouevring area, all the while fielding at times somewhat irate operations phone calls from various airlines enquiring as to the where-abouts of a particular flight. I was sitting next to one of my Tower colleagues on such a paticular day and watched as a smile of resignation spread across his face when the Approach ATC informed him of a further arriving sequence, acft for which their quite simply was No space.................what eloquence this young man displayed, such courage and coolness under fire within ATC parameters is indeed rare. Not that it is of great importance, but I beamed with pride as this young fellow was an ex-student of mine.
The above scenario however does have consequences where-in the Aproach ATC then needs to increase the spacing on final and at times even simply slow the traffic down such that events are given a chance to resolve itself on the ground. Some of my colleagues have informed me that holds have had to be used as a delaying tactic tool to alleviate some of the pressure on the tower controller. Taxi speeds and at what point that is reached is in essence an operators parameter, but during busy periods when Rwy34 is in use I have heard the Tower ATC advise an aircraft on final to plan their Rwy vacation via a certain Txwy, in most cases the chaps in the Twr attempt to use Txwy 'C' as it is as close to a high speed txwy that we have. The other factor that does affect Runway occupation is that the Tower ATC manages the ground frequency as well, which is very busy with aircraft being towed that need to use the runway either in a straight cross-over or as a 'txwy' to a published txwy to a parking bay. This also applies to active flights either post arrival or pre-departure because as stated above w.i.p. dictates as such.
Spacing on Final Rwy 34 has no requiement for 10NM.s, the standard ICAO separation of 5NM's is suffice, requiring 6NM's when the preceeding is WT catagory, a 'heavy'. 10NM's is possibly applied at times when the Approach ATC is fighting frequency congestion and activates his base and attack headings later than intended, when surface wind conditions are calm and you have say a A330 preceeding a B737/A320 type or if Tower requires it in order to start getting a growing line of holding point departures up and away. Rwy 16 is the 'jono', if-you-will, in so many ways. The most apparant is the awkward intercept angle if you are appraching from the east, airspace restrictions and the Runway/Taxiway configuration when landing from that direction. I still push for the icao minimum when Rwy16 is in use, but the general guideline here in order to assist the Tower Controller in his Surface Movement Management is 8NM's. Again, the Tower ATC's here are the heroes. I have witnessed them slip a little vaseline on the Runway and wings of pending departures and expedite their despatch in my world in-between my sustained and rapid fire of 5NM spacing, all the while never missing a beat in placating and soothing disgruntled delay queries and the ever-changing parking bay allocations!
Speed Control and the correct application there-of and adherence there-to is a subject I used to love throwing myself into, both as participant and spectator. I have sat with three pilots in years past, who all flew for the same small private airline, the same type of acft, the same routes more or less, naturally the same airspaces and pretty much not too dissimilar weather conditions and remember distinctly that three very different positions/appoaches were held. That particular occasion stuck with me as a sort of yard-stick, in that there will always be a counter-opinion. However, in OTBD airspace it is vital, by-en-large due to airspace configuration and traffic loading and yes, there are one or two gents who stay true to form and seldom if ever comply with speed rectrictions placed on them. When they do the RT work on a leg such that I recognize whom it is, I apply 'alternative' medicine. For the most part, I honestly cannot say there is a problem with non-compliance with speed control by pilots using OTBD airspace. In point of fact, at times my own speed control, despite being adhered-to proves ineffective, where-in vectors and other parameters are applied. Following ICAO is easiest, so I never apply speed control less then 250 Kts above FL250 (if acft under my control). Applying less than 250Kts is best left and more effective at or below 10 000', sometimes opting for a designated layering of speed reductions, for e.g., 7000' 220/230Kts , 3000' 200/180Kts.......obviously all dependant on prevailing traffic scenario etc,etc. I imagine most of my colleagues are pretty much on the same page here. Of course speed control and the adherence there-to is best served by Mode 'S' Enhanced Surveillance Radar and the acft being equipped with Mode 'S' Level 2 Transponder and DAP avionics interfaces.
OTBD having its own FIR,...well of that I am not sure, however, smoother traffic flow with its benefits is easily achieved by deferring to the application of ATFM. During a workshop/seminar at the Ecole Nationale de L'Aviation Civile In Toulouse some years back a very knowledgable and sauve Dominique Colin de Verdiere gave a lecture on Demand Capacity Balancing that I warmed to immediately as it is the very heart of Collaborative Decision Making and is in my opnion the very next logical step for OTBD/NDIA relating to effective ATFM. At the moment any application thereof will be purely Ad-Hoc as is required in the tactical stage.
Ensuring minimal delays, reducing Rwy occupancy time and effective speed control is very much now individual controller capability dominated/driven. A wonderfully eccentric british radar instructor of mine from my college days that used to bash around in the old Canberra in his glory days, shared a little gem with me and so many others that were trained by him and is still used today. It is a pearl of wisdom that one day he decided to share with me as he must have noticed that my incesant need for approval of my perfomance was'nt being met. Taking pity on me he took me into his office, rustled us up a cop of coffee each, lit up a Vantage Plain (imported, as not available in my country at the time), reclined just enough to rest his legs on the desk and proceeded to gently loosen my tightly wound stomach and neck muscles by regaling me with some 'war' stories. Many of which, I am sure were a tad 'coloured', as they always ended with him either out-flying a combattent, out-thinking/maouvering a higher rank or out-witting an opponent in their rivalry affections for a particular young lady. None-the-less, they always served to enthrall whoever was listening and I was no different. So when he thought I was sufficiently at ease, he lowered his feet from the desk, leaning forward he clasped his hands in front of him, looked me straight in the eye and said, " Look old boy, in the end it comes down to you and you alone, when all is said and done, if it looks good on radar, it is good, if it looks sh#t, well then old chap, quite frankly it is sh#t!" Essentially he was saying that I was the judge of my own peformance and no amount of posturing or hindsight will impact on your perforamnce and warned me never to go on duty without my side-arm,....as he said it, " the seven 'P's son, thats what it is all about, Proper Pe-Planning Prevents Piss Poor Performance!"
Currently at OTBD that is the most effective 'tool'
Tks.
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Sigh!
Collaborative decision making. What a concept!!
In Muscat, the notion that we would sit down with our surrounding ATM experts and arrange some sane and comprehensible procedures is relatively unheard of. Instead, we get lumbered with the wish lists of our adjacent units by way of letters of agreement that are quite the opposite i.e. we haven't agreed to these procedures. Even though the LOAs have the signature of our ATS boss, they often haven't discussed the ramifications of the various items agreed to with operational staff, who are, in accordance with the Japanese model of employer/employee relationships and a very good paradigm indeed, the very ones who could bring to the table some good fixes , especially as the pit-face controllers are the ones who have to live with the consequences. Yeah, I know, I'm not privy to all that goes on in the LOA world, but I do know that there are better ways to come to agreement, rather than just seeing blatant empire building or politics enter the equation.
I know that this is off topic and needs a thread of its own, but just seeing "collaborative" written down sent a wave of delicious possibility rolling down my spine. If only!!
Collaborative decision making. What a concept!!
In Muscat, the notion that we would sit down with our surrounding ATM experts and arrange some sane and comprehensible procedures is relatively unheard of. Instead, we get lumbered with the wish lists of our adjacent units by way of letters of agreement that are quite the opposite i.e. we haven't agreed to these procedures. Even though the LOAs have the signature of our ATS boss, they often haven't discussed the ramifications of the various items agreed to with operational staff, who are, in accordance with the Japanese model of employer/employee relationships and a very good paradigm indeed, the very ones who could bring to the table some good fixes , especially as the pit-face controllers are the ones who have to live with the consequences. Yeah, I know, I'm not privy to all that goes on in the LOA world, but I do know that there are better ways to come to agreement, rather than just seeing blatant empire building or politics enter the equation.
I know that this is off topic and needs a thread of its own, but just seeing "collaborative" written down sent a wave of delicious possibility rolling down my spine. If only!!
