Proposed amendment of the ANO: Mode S
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I've been told that the LPST mentioned needs a chip installed in the aircraft circuitry to uniquely identify the aircraft (for charging purposes??).
A Mode S transponder is indeed programmed with a unique number which decodes to your tail number.
However, Mode S cannot be used for enroute charges because of unsufficient radar coverage (in the context of normal low-level VFR flight). This is a common myth going around this business.
There is no "chip" as such; a transponder is full of chips
The programming of the Mode S code is trivial; you can do it yourself (although you aren't supposed to 
).
A Mode S transponder is indeed programmed with a unique number which decodes to your tail number.
However, Mode S cannot be used for enroute charges because of unsufficient radar coverage (in the context of normal low-level VFR flight). This is a common myth going around this business.
There is no "chip" as such; a transponder is full of chips
The programming of the Mode S code is trivial; you can do it yourself (although you aren't supposed to ).
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Also buried deep in the consultation document is the idea that these ModeS Transponder units they are mandating we fit WILL ONLY BE CERTIFIED FOR VMC USE.
Maybe I've read it incorrectly, but I presume this will mean NO MORE of the following:
Gliding in wave / climbing to the top of a thermal ie within 1000' of cloud (ie IMC) / no more flying on an even slightly hazy day. Am not sure of the effects on IMC flight / night flight.
Yes there's the cost issue, but surely THIS is an even more important issue that could stop virtually all recreational non-powered flying as we know it?
Maybe I've read it incorrectly, but I presume this will mean NO MORE of the following:
Gliding in wave / climbing to the top of a thermal ie within 1000' of cloud (ie IMC) / no more flying on an even slightly hazy day. Am not sure of the effects on IMC flight / night flight.
Yes there's the cost issue, but surely THIS is an even more important issue that could stop virtually all recreational non-powered flying as we know it?
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Indeed & I can't imagine the usefulness of transponders under the conditions below. I guess it would wear them out in a matter of hours - I think perhaps this hasn't been thought through from a free flight perspective...
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the Auntie Returns ...
I work as an ATCO on several airspace sectors at Scottish Centre.
Believe me, the screens are cluttered enough at the moment especially when trying to distinguish 'your own' traffic at say FL100+ from low level VFRs or helicopters.
On a 16 inch monitor on 250 mile sector, it does not take a rocket scientist to work out that the SSR labels on each aircraft can be 15 miles across.
Well seen the dire state of the UK Air and Space Industry as there are obviously no rocket scientists within the CAA.
<rant on>
IMHO there are too many deskbound pen pushers who have never tried to..
a)separate aircraft for a living using the rules THEY create
b)operate an aircraft in the crazy overtaxed and over-regulated UK environment
c)use the crap equipment at Scottish Centre
d)understand that not everyone actually needs to be 'controlled' - (we don't all have to be identified VFR actually works quite well.)
e)understand the needs and rightful freedoms of GA
f)think how badly cluttered radars will become if EVERYONE puts up a Mode S response.
g)think that while Mode S is a good idea in a Class A TMA environment, it is not appropriate to burden users in Class G airpspace.
h)think that it won't work below radar/radio cover in mountains and valleys
i)won't solve the real 'collision' issue of military aircraft without TCAS
Just my £5 worth
<rant off>
Believe me, the screens are cluttered enough at the moment especially when trying to distinguish 'your own' traffic at say FL100+ from low level VFRs or helicopters.
On a 16 inch monitor on 250 mile sector, it does not take a rocket scientist to work out that the SSR labels on each aircraft can be 15 miles across.
Well seen the dire state of the UK Air and Space Industry as there are obviously no rocket scientists within the CAA.
<rant on>
IMHO there are too many deskbound pen pushers who have never tried to..
a)separate aircraft for a living using the rules THEY create
b)operate an aircraft in the crazy overtaxed and over-regulated UK environment
c)use the crap equipment at Scottish Centre
d)understand that not everyone actually needs to be 'controlled' - (we don't all have to be identified VFR actually works quite well.)
e)understand the needs and rightful freedoms of GA
f)think how badly cluttered radars will become if EVERYONE puts up a Mode S response.
g)think that while Mode S is a good idea in a Class A TMA environment, it is not appropriate to burden users in Class G airpspace.
h)think that it won't work below radar/radio cover in mountains and valleys
i)won't solve the real 'collision' issue of military aircraft without TCAS
Just my £5 worth
<rant off>
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"Near"-Missing the Point
Folks,
I think we're really all missing the point in this. We're having the wrong argument. Most of the discussion I've seen here and in other places is about the practicality and cost of installing this in our light aircraft, with the implication that everyone has accepted that it is a done deal. I haven't seen the most fundamental question really addressed in any kind of robust manner, which is:
Where is the sound, data-driven, and solid business case which justifies the requirement of Mode S in light aircraft?
So far I haven't read anything (and, admittedly, my research is very superficial) which shows data, charts, graphs, UK accident history, and a whole shedload of facts to support this requirement at all. Until the CAA makes its case for it, I think dicussions of technical problems, cost and practicality are premature and give the CAA the impression that we're accepting we need it, we're just arguing over the cost.
The UK does not have a history of aircraft mid-airs, near-missses, or even serious separation problems which would make this an undeniable case. I simply fail to see how Mode S in a Tigermoth or PA28 addresses any safety problem because there doesn't appear to actually be one.
Am I missing something here? Are we, in fact, having the right argument and I'm just not clued in?
Pitts2112
I think we're really all missing the point in this. We're having the wrong argument. Most of the discussion I've seen here and in other places is about the practicality and cost of installing this in our light aircraft, with the implication that everyone has accepted that it is a done deal. I haven't seen the most fundamental question really addressed in any kind of robust manner, which is:
Where is the sound, data-driven, and solid business case which justifies the requirement of Mode S in light aircraft?
So far I haven't read anything (and, admittedly, my research is very superficial) which shows data, charts, graphs, UK accident history, and a whole shedload of facts to support this requirement at all. Until the CAA makes its case for it, I think dicussions of technical problems, cost and practicality are premature and give the CAA the impression that we're accepting we need it, we're just arguing over the cost.
The UK does not have a history of aircraft mid-airs, near-missses, or even serious separation problems which would make this an undeniable case. I simply fail to see how Mode S in a Tigermoth or PA28 addresses any safety problem because there doesn't appear to actually be one.
Am I missing something here? Are we, in fact, having the right argument and I'm just not clued in?
Pitts2112
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I'm afraid the issue is that the pressures are on the CAA and NATS to allow routings through the open FIR by commercial jets who still want radar separation on the grounds of 'efficient use of airspace'. They also want to move towards a charging regime for the use of airspace which is another reason why the lo-cost operators are choosing not to use airways
Remember that the CAA has no brief for GA and a notorious lack of understanding of the effects of their decisions.
The RIA is based on an assumption that all traffic in Class G is talking to someone - well, we're not. Partly because we may choose to use the nearest A/G station as LARS isn't working, or because we are simply non-radio (not illegal, yet)
Read the article by Max Seaman in this month's LOOP and see the line the CAA want to go
Remember that the CAA has no brief for GA and a notorious lack of understanding of the effects of their decisions.
The RIA is based on an assumption that all traffic in Class G is talking to someone - well, we're not. Partly because we may choose to use the nearest A/G station as LARS isn't working, or because we are simply non-radio (not illegal, yet)
Read the article by Max Seaman in this month's LOOP and see the line the CAA want to go
Max Seaman is a reasonable chap, but I have to say that his portrayal of the party line from the CAA, complete with gross innaccuracies on things like unit cost, did really make me wonder a bit.
It's clear from the contents of the proposal in the RIA that the CAA consider this a done deal, and that we should all just bow down and accept it.
They really seriously need to get their head around the biggest growth sector in UK recreational aviation and try to see how the heck they are going to implement this regulation. 26% of the UK aircraft fleet is unregistered, unregulated and flown by pilots with no CAA issued licence. I'd just love to hear how they are even going to know of the existence of these aircraft, let alone try to track them down to ensure compliance. I've got a couple like Parapunter, does this mean I need to buy two transponders?
It's plain barking. The class G airprox statistics simply don't support the argument for transponders in any way, shape or form. The CAA are being driven to do this by the argument being put forward by budget carriers like Ryanair and Easy Jet, who wish to avoid airspace charging by operating in "controlled" class G for approaches to cheap out-of town airports.
VP
It's clear from the contents of the proposal in the RIA that the CAA consider this a done deal, and that we should all just bow down and accept it.
They really seriously need to get their head around the biggest growth sector in UK recreational aviation and try to see how the heck they are going to implement this regulation. 26% of the UK aircraft fleet is unregistered, unregulated and flown by pilots with no CAA issued licence. I'd just love to hear how they are even going to know of the existence of these aircraft, let alone try to track them down to ensure compliance. I've got a couple like Parapunter, does this mean I need to buy two transponders?
It's plain barking. The class G airprox statistics simply don't support the argument for transponders in any way, shape or form. The CAA are being driven to do this by the argument being put forward by budget carriers like Ryanair and Easy Jet, who wish to avoid airspace charging by operating in "controlled" class G for approaches to cheap out-of town airports.
VP
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The CAA are being driven to do this by the argument being put forward by budget carriers like Ryanair and Easy Jet, who wish to avoid airspace charging by operating in "controlled" class G for approaches to cheap out-of town airports.
Both yourself and Robin misunderstand how charging works outside controlled airspace. If you are IFR above 5700Kg, then you are charged regardless by way of the en route charge. The UK unit charge rate is the same whether in Controlled Airspace or not, and whether or not you receive an ATC service.
Whether you interpolate that Mode S might be used to charge VFR flights, or those under 5700Kg, is a different argument.
Good point about airspace charging, my error.
The issue is still the same though, in that the low cost carriers are applying pressure to the CAA to increase safety when making "VFR" approaches through class G. Even the CAA admit that this is one of the reasons they want to see Mode S mandated for all flying machines.
VP
The issue is still the same though, in that the low cost carriers are applying pressure to the CAA to increase safety when making "VFR" approaches through class G. Even the CAA admit that this is one of the reasons they want to see Mode S mandated for all flying machines.
VP
Originally Posted by PPRuNe Radar
Both yourself and Robin misunderstand how charging works outside controlled airspace. If you are IFR above 5700Kg, then you are charged regardless by way of the en route charge. The UK unit charge rate is the same whether in Controlled Airspace or not, and whether or not you receive an ATC service.
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I've just finished reading the RIA and it does look like the CAA are convinced this is not only a good thing but the ONLY thing they can do and we should just accept it and start saving up for the installation bill.
The facts and data they give just do not substantiate a programme of this magnitude. The number of total airproxes in an 18 month period (Jan 04 to Jun 05) was only 299. Of those, only 200 would have benefited from some sort of TCAS or Mode S and only 100 took place in Glass G airspace, where most of us operate.
What their data does not say is who these incidents were between. How many were between GA and Commercial Air Transport (CAT), between GA and Mil, Mil to CAT, Mil to Mil, CAT to CAT, or GA to GA. In other words, we don't know what proportion are even related to our aircraft, regardless of the airspace use. Irrespective of the argument about how many incidents are relevant, we're still talking about only 200 out of how many flights took place in that 18 month period.
What I am missing right now, to make my point to the CAA that their case is negligible, is the number of movements of GA, Mil, and CAT. Let's say it's only 100,000 flights per year and let's not even add any multiplier about how many flight paths might cross on each flight (ie - creating a potential airprox but didn't). Of 100,000 flights, only 200 were relevant to Mode S/TCAS, for a total problem set of 0.2% and only 34 of those disrupted commercial operations somewhere.
The other thing is what is the expected growth rate of GA in the next 10 years? Everything I've read lately is that we're becoming a dying breed so the likelihood of incidents involving us should be diminishing over time.
The CAA makes sets no quantifiable target for improvements to safety. Will Mode S take the number from 299 to 199, 150, 0? They don't have a target, which means they don't know how effective it will or won't be. Which also means it could do absolutely sod all for these incidents and they won't be held accountable for an unnecessary and ineffective programme. If they can't quantify a target then they don't really know if it'll have any effect at all. I wouldn't sign off a business case like that in the corporate world.
Finally, Mode S for seperation implies that at least one party is talking to someone on the ground. I never talk to anyone, preferring not to use their airspace and take up their time. What percentage of GA flies like that? Would the various ATC providers be able to hande the volume of traffic that would have to talk to them for Mode S to have the intended value?
So, a question. Does anyone know where the data may exist for the total number of aviation movements in the UK per annum? Also, has anyone seen any official projections on the growth of GA in the UK?
Many thanks and please get involved and make your point to the CAA. Their case has not been made, regardless of how much it'll cost to put one of these things into your airplane. Let's have THAT argument before we talk about cost and practicality.
Pitts2112
The facts and data they give just do not substantiate a programme of this magnitude. The number of total airproxes in an 18 month period (Jan 04 to Jun 05) was only 299. Of those, only 200 would have benefited from some sort of TCAS or Mode S and only 100 took place in Glass G airspace, where most of us operate.
What their data does not say is who these incidents were between. How many were between GA and Commercial Air Transport (CAT), between GA and Mil, Mil to CAT, Mil to Mil, CAT to CAT, or GA to GA. In other words, we don't know what proportion are even related to our aircraft, regardless of the airspace use. Irrespective of the argument about how many incidents are relevant, we're still talking about only 200 out of how many flights took place in that 18 month period.
What I am missing right now, to make my point to the CAA that their case is negligible, is the number of movements of GA, Mil, and CAT. Let's say it's only 100,000 flights per year and let's not even add any multiplier about how many flight paths might cross on each flight (ie - creating a potential airprox but didn't). Of 100,000 flights, only 200 were relevant to Mode S/TCAS, for a total problem set of 0.2% and only 34 of those disrupted commercial operations somewhere.
The other thing is what is the expected growth rate of GA in the next 10 years? Everything I've read lately is that we're becoming a dying breed so the likelihood of incidents involving us should be diminishing over time.
The CAA makes sets no quantifiable target for improvements to safety. Will Mode S take the number from 299 to 199, 150, 0? They don't have a target, which means they don't know how effective it will or won't be. Which also means it could do absolutely sod all for these incidents and they won't be held accountable for an unnecessary and ineffective programme. If they can't quantify a target then they don't really know if it'll have any effect at all. I wouldn't sign off a business case like that in the corporate world.
Finally, Mode S for seperation implies that at least one party is talking to someone on the ground. I never talk to anyone, preferring not to use their airspace and take up their time. What percentage of GA flies like that? Would the various ATC providers be able to hande the volume of traffic that would have to talk to them for Mode S to have the intended value?
So, a question. Does anyone know where the data may exist for the total number of aviation movements in the UK per annum? Also, has anyone seen any official projections on the growth of GA in the UK?
Many thanks and please get involved and make your point to the CAA. Their case has not been made, regardless of how much it'll cost to put one of these things into your airplane. Let's have THAT argument before we talk about cost and practicality.
Pitts2112
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Thanks Bookworm for the correction 
Like most others, I am not convinced by the safety argument that Mode S is required everywhere.
For operations within Controlled Airspace, then I can see the point of Mode 'S', although it should not be beyond the wit of man to allow some dispensations for specific operations. The operator and the controlling authority would formulate a letter of agreement which laid down the conditions for operation without Mode 'S', one of which could be Mode A & C instead, or it could be by treating defined airspace as a Temporary Restricted Area with non Mode 'S' operations within it. This would allow things such as parachute operations or gliding.
For operations close to major Controlled Airspace or specific airfields in Class G without Controlled Airspace, then I think the 'veil' is a good idea. If it is a Mode 'S' veil, then it might not suit all operators but it's at least a bit of a compromise. The size of the veil could be pragmatic, small enough to unhinder some GA operations, but large enough to provide adequate protection from traffic operating close to the edge or infringing. 5-10 miles would be my view.
Some thought would also need to be given as to whether it is also required above a certain altitude outside Controlled Airspace, or whether we just wait for the European programme which will bring Controlled Airspace down to lower levels globally (FL195 soon, a lower level such as FL95 being mooted for later) and then have a Mode 'S' requirement by default based on my initial 'requirement' proposal. This would not affect the major proportion of powered GA, but would still need some debate as to how gliders might be accomodated.
Like most others, I am not convinced by the safety argument that Mode S is required everywhere.
For operations within Controlled Airspace, then I can see the point of Mode 'S', although it should not be beyond the wit of man to allow some dispensations for specific operations. The operator and the controlling authority would formulate a letter of agreement which laid down the conditions for operation without Mode 'S', one of which could be Mode A & C instead, or it could be by treating defined airspace as a Temporary Restricted Area with non Mode 'S' operations within it. This would allow things such as parachute operations or gliding.
For operations close to major Controlled Airspace or specific airfields in Class G without Controlled Airspace, then I think the 'veil' is a good idea. If it is a Mode 'S' veil, then it might not suit all operators but it's at least a bit of a compromise. The size of the veil could be pragmatic, small enough to unhinder some GA operations, but large enough to provide adequate protection from traffic operating close to the edge or infringing. 5-10 miles would be my view.
Some thought would also need to be given as to whether it is also required above a certain altitude outside Controlled Airspace, or whether we just wait for the European programme which will bring Controlled Airspace down to lower levels globally (FL195 soon, a lower level such as FL95 being mooted for later) and then have a Mode 'S' requirement by default based on my initial 'requirement' proposal. This would not affect the major proportion of powered GA, but would still need some debate as to how gliders might be accomodated.
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This may be a completely stupid suggestion but the main aim is for Commercial traffic to have ATC control in what is currently "open" FIR - if this is wrong then skip to next post.
The GA, paragliding, ballooning fraternity etc. mostly use open FIR hence potential conflict, hence suggestion of Mode S.
However a huge percentage (90% - 95%?) of the above GA et al are below 10,000 ft and the majority (90-95%?) of commercials are above 10,000 feet. Why not just make all UK airspace over 10,000 feet controlled (Type B?) in which a mode C (not S) transponder is mandatory?
There must be some fault in my logic but it would seem to fit the requirements of all and would cost bugger all to implement.
The GA, paragliding, ballooning fraternity etc. mostly use open FIR hence potential conflict, hence suggestion of Mode S.
However a huge percentage (90% - 95%?) of the above GA et al are below 10,000 ft and the majority (90-95%?) of commercials are above 10,000 feet. Why not just make all UK airspace over 10,000 feet controlled (Type B?) in which a mode C (not S) transponder is mandatory?
There must be some fault in my logic but it would seem to fit the requirements of all and would cost bugger all to implement.
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Just on PG & HG, I can say that 95% of all pilots actually only ever fly on the ridge from whence they started. Only a very small number will climb high enough to enable a cross country flight & in nearly all cases not in excess of 5,000` AGL, although recently, the UK pg height gain record was broken with a climb to something like 3,400 metres followed by a 40k glide - the exception that proves the rule.
Realistically, us lot are unable to transit controlled airspace to atco's requirements & thus are effectively excluded & so yes, we fly largely in the open FIR, transiting under & over aerodromes as required by current regulations. From my viewpoint therefore, transponders are costly in both weight & financial terms & unneccesary for the regulation of our activities.
I'm watching this thread with interest & I would like to see an argument in support of these things, in order that I may understand the CAA view - doesn't seem to be many participants in favour so far?
Realistically, us lot are unable to transit controlled airspace to atco's requirements & thus are effectively excluded & so yes, we fly largely in the open FIR, transiting under & over aerodromes as required by current regulations. From my viewpoint therefore, transponders are costly in both weight & financial terms & unneccesary for the regulation of our activities.
I'm watching this thread with interest & I would like to see an argument in support of these things, in order that I may understand the CAA view - doesn't seem to be many participants in favour so far?
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Originally Posted by Choxolate
Why not just make all UK airspace over 10,000 feet controlled (Type B?) in which a mode C (not S) transponder is mandatory
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Assuming that the drive to transponders is being done to better manage the airprox situation (particularly the issue with CAS busts by non transponding GA) I don't think mandating Mode C/S above 10,000ft would help in the UK. Almost no GA traffic flies that high.
Even at 5000ft there is hardly anybody.
Adopting the US model, of Class E to 17999ft and Class A from 18000ft up, that would be something else, but nobody in the UK is going to be that bold. Even the French model, Class D above FL115, would be too much to swallow.
One would have to completely re-do the whole airspace thinking to do this.
Incidentally, referring to that paraglider picture above, is there a proposal to mandate Mode S for these?
Even at 5000ft there is hardly anybody.
Adopting the US model, of Class E to 17999ft and Class A from 18000ft up, that would be something else, but nobody in the UK is going to be that bold. Even the French model, Class D above FL115, would be too much to swallow.
One would have to completely re-do the whole airspace thinking to do this.
Incidentally, referring to that paraglider picture above, is there a proposal to mandate Mode S for these?
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Then get your comments in soon.
Remember it is only by making a mass response that the CAA will have to take action to rethink the situation
They are planning to have the Full RIA (including the results of this one) ready during the autumn with proposed legislation by the end of the year.
So plenty of time for them to change their minds - not!
Note: there is a public consultation at Lasham Gliding Club at 19.00hrs tomorrow evening.
Remember it is only by making a mass response that the CAA will have to take action to rethink the situation
They are planning to have the Full RIA (including the results of this one) ready during the autumn with proposed legislation by the end of the year.
So plenty of time for them to change their minds - not!
Note: there is a public consultation at Lasham Gliding Club at 19.00hrs tomorrow evening.