Mode A code shortages
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Minesapint
There should be 6143 individual codes available accounting for 3 lost to emergency use.
Perhaps a rethink on how to use these would have been in order, with the option of having a smarter ground based system for handover purposes etc.
However it is obvious things have moved a lot further down the skyways.
It is still difficult to see how 6134 numbers can be used up in the relatively localised coverage radar provides.
I can see how bandwith can be saturated, but by interrogating at intervals, which may well be how it is done a present, should have alleviated the problem.
Is it the same committee designed approach that has resulted in a population of 60 million including babies requiring some 10 billion telephone numbers to cope?
There should be 6143 individual codes available accounting for 3 lost to emergency use.
Perhaps a rethink on how to use these would have been in order, with the option of having a smarter ground based system for handover purposes etc.
However it is obvious things have moved a lot further down the skyways.
It is still difficult to see how 6134 numbers can be used up in the relatively localised coverage radar provides.
I can see how bandwith can be saturated, but by interrogating at intervals, which may well be how it is done a present, should have alleviated the problem.
Is it the same committee designed approach that has resulted in a population of 60 million including babies requiring some 10 billion telephone numbers to cope?
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I think that the commitee approach is a part of the problem. People from all over Europe meet to divide up the available codes.
When you take into account civil domestic, transit, super domestic, sector codes, orcam etc its very easy to see where they all go.
Our radar can often see foreign military codes over France and Holland causing numerous problems. In the octal system with 4 digits you get 4096 codes. 7000 / 77/76/7500 are obviously reserved but so are many others...... each ATSU has its own block of codes allocated to it. Often these units are closed at evenings and weekends. Why not use these codes when they are as a short term measure? Complicated but could be done.
When you take into account civil domestic, transit, super domestic, sector codes, orcam etc its very easy to see where they all go.
Our radar can often see foreign military codes over France and Holland causing numerous problems. In the octal system with 4 digits you get 4096 codes. 7000 / 77/76/7500 are obviously reserved but so are many others...... each ATSU has its own block of codes allocated to it. Often these units are closed at evenings and weekends. Why not use these codes when they are as a short term measure? Complicated but could be done.
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BEX;
I wouldn't hold my breath for our remake of NAS. We are indeed working on it, but the final contract hasn't been signed yet, and I have no doubt that the FAA could muck it up if they really put their mind to it. There are a couple of folks at the puzzle palace who may or may not want to wait the time required to do it right. We will hope and wait and see.
regards
I wouldn't hold my breath for our remake of NAS. We are indeed working on it, but the final contract hasn't been signed yet, and I have no doubt that the FAA could muck it up if they really put their mind to it. There are a couple of folks at the puzzle palace who may or may not want to wait the time required to do it right. We will hope and wait and see.
regards
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Bookworm,
>5) What is the FAA policy on aircraft equipage with Mode S? Is it required on aircraft over a certain size, or Part 121/135 or something else? What's the plan for the future?
You might ask Scott Voigt ( [email protected] he also participates in the ATC conference) this question as he is more knowledgeable than I am on Mode S and the FAR's.
>6) What are the consequences of the code shortage? Does it delay flights? Do you limit capacity to cope with the extra workload of having to use these local codes? What's the "cost" of the problem?
Running out of transponder codes, is an indication that we are probably busier than one arm paper hangers, and that there are probably delays being encountered within the system, these delays could be a result of weather, equipment failures, or heavy traffic.
When we run out of transponder codes we usually see messages from the Flow Control desk asking that facilities not enter VFR flight plans into the NAS.
As for extra workload of entering local codes it takes a controller less than a minute to enter a local code via the FIDO. Again Scott works at a much busier facility than I do so he may be able to share how this problem affects our larger facilities.
Mike
NATCA Local FWA
>5) What is the FAA policy on aircraft equipage with Mode S? Is it required on aircraft over a certain size, or Part 121/135 or something else? What's the plan for the future?
You might ask Scott Voigt ( [email protected] he also participates in the ATC conference) this question as he is more knowledgeable than I am on Mode S and the FAR's.
>6) What are the consequences of the code shortage? Does it delay flights? Do you limit capacity to cope with the extra workload of having to use these local codes? What's the "cost" of the problem?
Running out of transponder codes, is an indication that we are probably busier than one arm paper hangers, and that there are probably delays being encountered within the system, these delays could be a result of weather, equipment failures, or heavy traffic.
When we run out of transponder codes we usually see messages from the Flow Control desk asking that facilities not enter VFR flight plans into the NAS.
As for extra workload of entering local codes it takes a controller less than a minute to enter a local code via the FIDO. Again Scott works at a much busier facility than I do so he may be able to share how this problem affects our larger facilities.
Mike
NATCA Local FWA
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Actually, the e-mail is [email protected] <G>... But with that.....
Mode S is only required due to TCAS. If you are a commercial aircraft with 30 ore more pax ( I believe that is still the limit) then you must have TCAS on board. The more pax that you have the more advanced the TCAS system.
If you have a TCAS on board for your own feeling of bliss, but aren't required by regulation to have it, you will still have a mode S transponder so that it can talk to other TCAS units.
As to running out of codes. It happens from time to time, however, we don't really ever run out of codes for active aircraft. What we run out of codes for are those who are waiting to come into our airspace or those on the ground who haven't recieved clearances yet. What the causes, is the controller will not be able to allow an aircraft to use the same code that he / she was using when they were in the last facility due to someone already using it in your facility. You then assign another code. The problems that you will run into on the ground is that you may not have codes available to you until just a few minutes prior to departure, vrs. 30 min. to an hour.
regards
Mode S is only required due to TCAS. If you are a commercial aircraft with 30 ore more pax ( I believe that is still the limit) then you must have TCAS on board. The more pax that you have the more advanced the TCAS system.
If you have a TCAS on board for your own feeling of bliss, but aren't required by regulation to have it, you will still have a mode S transponder so that it can talk to other TCAS units.
As to running out of codes. It happens from time to time, however, we don't really ever run out of codes for active aircraft. What we run out of codes for are those who are waiting to come into our airspace or those on the ground who haven't recieved clearances yet. What the causes, is the controller will not be able to allow an aircraft to use the same code that he / she was using when they were in the last facility due to someone already using it in your facility. You then assign another code. The problems that you will run into on the ground is that you may not have codes available to you until just a few minutes prior to departure, vrs. 30 min. to an hour.
regards
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Bexil160 - NAS
Despite some thoughts on here that CASPIAN (Commercially Available System Promoting Integration Across NATS or Commit All SDI People Into A Nuthouse!) would replace NAS, thats not the case. CASPIAN is only a platform.
The Flight Data Programme Replacement (FDPR - Project 1843) originally envisaged a replacement with collaboration from Europe and a rollout in 2007/8. However, as at last week, the plan is to re-engineer changes to NAS with a rollout in 3 years time.
Not quite sure how this fits in with the move of NAS out of West Drayton to either LACC or Tech Centre though.
The Flight Data Programme Replacement (FDPR - Project 1843) originally envisaged a replacement with collaboration from Europe and a rollout in 2007/8. However, as at last week, the plan is to re-engineer changes to NAS with a rollout in 3 years time.
Not quite sure how this fits in with the move of NAS out of West Drayton to either LACC or Tech Centre though.
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I did say CASPIAN was the plan - not that it would or could replace NAS.
Although there are those out there that may not agree with me, NAS is a truly excellent system. A single NAS is designed to propel a single centre - not four. We often think that we have squeezed about the last drop of blood out of the old girl an then we add even more. It just shows how excellent the original design was. The people who designed it were truly gifted.
Its also rubbish to say that the software is 30 - 40 years old. Software does not grow old. It is only replaced by something better. Hence we still have NAS cos there is nothing better.
NAS software is (mainly) written in a language called JOVIAL. JOVIAL is still used is flight management systems - C17 Skytruck to name but one 'old aircraft'.
If it aint broke don't fix it.....
Although there are those out there that may not agree with me, NAS is a truly excellent system. A single NAS is designed to propel a single centre - not four. We often think that we have squeezed about the last drop of blood out of the old girl an then we add even more. It just shows how excellent the original design was. The people who designed it were truly gifted.
Its also rubbish to say that the software is 30 - 40 years old. Software does not grow old. It is only replaced by something better. Hence we still have NAS cos there is nothing better.
NAS software is (mainly) written in a language called JOVIAL. JOVIAL is still used is flight management systems - C17 Skytruck to name but one 'old aircraft'.
If it aint broke don't fix it.....
Beady Eye
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Not saying NAS is poo, as stated it does a remarkable job for which it was never designed.
However Jovial is a very old language and can induce errors which cannot be trapped by error checking, 'cause there's no error checker for it! So its LONG overdue to be dragged kicking and screaming into the 21st century. For my preference into an object oriented language so we don't introduce regression into areas where no change was made.
However Jovial is a very old language and can induce errors which cannot be trapped by error checking, 'cause there's no error checker for it! So its LONG overdue to be dragged kicking and screaming into the 21st century. For my preference into an object oriented language so we don't introduce regression into areas where no change was made.
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Minesapint
There are a lot of reasons to dump NAS. Not to mention being able to program in something modern that doesn't take forever to make a useable change. The kernal that started out in the IBM 9020 all those years ago, was GREAT at doing what it needed to do on 80 K of core memory. However we have grown past that and there are indeed needs to be able to get way past what NAS was designed to do, and what it is design limited to do.
Why have all of your eggs in one basket per se? You lose one function with in NAS now, and you lose them ALL. Go to a distributed system so that if one bit goes bad in a program, all you lose is that one function, not the entire program.
You also want to be able to start tying in newer functions to the software and not have to continually rewrite the host software to accept things. Coming off of a 30 year old platform is a good thing... Now, just taking the old software and rewriting it is NOT in itself a good thing... For some of the above stated reasons.
Shoot, if you folks want NAS that does a LOT of stuff as is right now, we could sell you ours rather cheap <G>.... Soon to be getting interactive data blocks that interact from sector to sector as well as center to center. I don't just mean altitude changes either. We are going to be getting a fourth line in the data block which will give us a scratch pad ability if we need it, but will also have a way of passing speeds and headings ( not supposed to tell the pilots to do that sort of thing) we are also looking at the time share of aircraft type and other info...... Soon to have input stuff between the URET conflict probe and the radar glass...
regards
There are a lot of reasons to dump NAS. Not to mention being able to program in something modern that doesn't take forever to make a useable change. The kernal that started out in the IBM 9020 all those years ago, was GREAT at doing what it needed to do on 80 K of core memory. However we have grown past that and there are indeed needs to be able to get way past what NAS was designed to do, and what it is design limited to do.
Why have all of your eggs in one basket per se? You lose one function with in NAS now, and you lose them ALL. Go to a distributed system so that if one bit goes bad in a program, all you lose is that one function, not the entire program.
You also want to be able to start tying in newer functions to the software and not have to continually rewrite the host software to accept things. Coming off of a 30 year old platform is a good thing... Now, just taking the old software and rewriting it is NOT in itself a good thing... For some of the above stated reasons.
Shoot, if you folks want NAS that does a LOT of stuff as is right now, we could sell you ours rather cheap <G>.... Soon to be getting interactive data blocks that interact from sector to sector as well as center to center. I don't just mean altitude changes either. We are going to be getting a fourth line in the data block which will give us a scratch pad ability if we need it, but will also have a way of passing speeds and headings ( not supposed to tell the pilots to do that sort of thing) we are also looking at the time share of aircraft type and other info...... Soon to have input stuff between the URET conflict probe and the radar glass...
regards
Beady Eye
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Thanks Scott, another (and better!) reason for going with an object oriented computing language. Only the part of the programme with the 'problem' would fail, not the whole thing as happens now!
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All agreed. As long as its as good or better than the system its replacing and is as upgradable. (30 years worth at least).
Putting 'new' code into pretty grey boxes may suit many but if it don't work in the first place don't bother.
I would appreciate information on any COTS system, available now, that has at least the current capacity to shift 2 million movements with 4 centres ( 2 en-route, 1 sub-centre and one TMA) and has the capacity to handle 4 - 5 million? I have said this before. Let the US spend the money deveopling a new system then buy it. ONCE ITS PROVEN!
Putting 'new' code into pretty grey boxes may suit many but if it don't work in the first place don't bother.
I would appreciate information on any COTS system, available now, that has at least the current capacity to shift 2 million movements with 4 centres ( 2 en-route, 1 sub-centre and one TMA) and has the capacity to handle 4 - 5 million? I have said this before. Let the US spend the money deveopling a new system then buy it. ONCE ITS PROVEN!
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Getting back to the topic, wasnt there a procedure that came in a few years ago when we were still at LATCC for times when we ran out of codes? I seem to remember that the letters SATN would be printed on the pending strips instead of an allocated sqwawk... if we saw this happen we were supposed to run to flight plans and tell them, and manually unpair sqwawks on aircraft that had left our airspace, so that the codes could then be reallocated a.s.a.p to aircraft waiting to depart (which could not depart until they had been allocated a sqwawk)... was this not the case or am I just imagining it? What happens now we are at Swanwick where we don't have pending strips? Is this procedure still in? How do we know if the system is running short of codes?
I seem to remember this coming in about the same time as those awful ''half strips'' were being banded about... do you remember? Those strips that had different fonts and would be printed in half the time as normal strips when it was busy cos the dear old printers couldn't get them out quick enough... only thing was they looked awful and had crap fonts on them... hmmm sounds familiar!!! Never saw any of those operationally either...
I seem to remember this coming in about the same time as those awful ''half strips'' were being banded about... do you remember? Those strips that had different fonts and would be printed in half the time as normal strips when it was busy cos the dear old printers couldn't get them out quick enough... only thing was they looked awful and had crap fonts on them... hmmm sounds familiar!!! Never saw any of those operationally either...
