Proposed amendment of the ANO: Mode S

[Sedbergh]

MODE S CONSULTATION

Hi all

The CAA "consultation" period on the compulsory fitting of Mode S to all flying machines in 2008 ends on 29th August.

There are comments on the PFA and BGA websites on the subject, also a long document on

www.caa.co.uk/dapconsultations

Which seeks to justify the proposal. Also a response questionnaire which I think we ALL should fill in (no matter which side of the spectrum you fall on)

PS personally I think this should be a sticky until end of August, it's important

[gpn01]

Has everybody filled in their response to the CAA's proposal about amending The Air Navigation Order 2005 "For The Purpose Of Improving The Technical Interoperability Of All Aircraft In UK Airspace"....which translates into mandatory fitting of Mode-S transponders to ALL aircraft ?

I'd urge anybody who flies light aircraft, helicopters, gliders, hang gliders, paragliders, microlights, balloons, etc. to respond before the CAA removes all open airspace in the UK. The PFA and BGA have both published arguments against the proposal:

PFA: http://www.pfa.org.uk/mode_s.asp
BGA: http://www.gliding.co.uk/bgainfo/air...ansponders.htm

Not sure if the BHPA and BMAA have produced a response yet (as this proposal could affect them as well).

The CAA proposal is available at:

http://www.caa.co.uk/default.aspx?ca...90&pageid=6476

This includes an online facility to respond. Replies are needed by 29th August.

Imagine the future - you'll need an approved, servicible Mode-S transponder before you'll be allowed to fly any civilian light aircraft in UK airspace (both controlled and 'uncontrolled').

[Sedbergh]

And don't forget it'll probably cost you at least 2 grand to fit, and £200 a year to run, irrespective of hours flown - even in gliders/microlights worth a total of 2 grand!

The parallels with the government ID card scheme are fascinating - unknown technology (well for battery powered Mode S), very dubious benefits (if any) and undefined but rapidly rising costs - but the hapless taxpayer (GA pilots in this case) will pick up the tab

- oh and total "gold plating" compared with anything Europe may propose.

Try writing to your MP and draw his attention to the similarities (unless your MP is named T Blair of course (or you work for an avionica manufacturer)

[IO540]

£200 a year to run

Do you have a reference for the above?

[Sedbergh]

See Page 28 of the CAA Regulatory Impact Document

Annual check £80 to £140
Biennial check £45 - £67.50 (Don't forget the 50 pence!)
Annual licence £20


So the CAA's low end estimate for annual operation is £122.50
Their high end estimate is £193.75

Do you ever recall a government estimate for electronic equipment that didn't finally cost at least double (cf any military equipment, passports and identity cards!)

So based on the CAA's "estimates" I reckon £200 annually will be optimistic

[pistongone]

Cost/Benefit Considerations?

I dont have exact figures available unfortunately, maybe one of you knows where to find them? for the number of mid air collisions in uncontrolled airspace, over the last ten years . I can only remember a few. So if you consider the cost of upgrading the entire GA fleet to include gliders ballons etc, to stop what is virtually a non-problem, you must come to the conclusion that the benefit DOES NOT WARRANT THE COST, a consideration the FAA has to bear very much in such situations. If you look deeper into the information provided by euro-CON-trol , it would appear the main reason for implementing mode s is to get more commercial traffic into european airspace and increase revenues for the airlines and governments via tax reciepts. Guess who is paying for this? US !! The airlines moan that they were subsiding us with regards to the CAA funding, well i think we will be subsidising them to a much higher degree with this mode s con of the century!! Also notice that Spain and Italy, two of the more bureaucratic European union menbers, are not implementing mode s at this time even though the object of the exercise it to improve the SAFETY in the core euro area. Come to think of it, the only time i can remember commercial traffic hitting each other in european airspace is on the ground in fog. This whole thing stinks of european-un-elected-beaurocrats pushing through proposals for an objective that is not entirely clear, and maybe some pockets of said beaurocrats will be substancially heavier after the succesfull fleecing of the GA population! I am off to the pub to cool down now! Cheers

[NorthSouth]

Can anyone refute any of the following?

1. The new NATS En Route Raytheon radars (which have Mode S SSR) remain capable of detecting Mode A/C transponders

2. There are currently no terminal/approach radar systems in the UK (except Heathrow?) which have Mode S, so making Mode S mandatory in terminal and uncontrolled airspace is pointless until all those units have bought new radars or junked their SSRs and bought a feed from NATS instead.

3. Current approved ACAS systems in airliners etc can detect Mode A/C transponders just as well as Mode S transponders.

If my assumptions are correct there seems to me to be no case for requiring aircraft which have a perfectly serviceable Mode C transponder to bin it and buy a new Mode S one.

NS

[robin]

Originally Posted by pistongone

So if you consider the cost of upgrading the entire GA fleet to include gliders ballons etc, to stop what is virtually a non-problem, you must come to the conclusion that the benefit DOES NOT WARRANT THE COST, :

You might say that but actually the CAA are counting the value of a life as being £1.4m. So they would deny your view

[bookworm]

Originally Posted by NorthSouth

If my assumptions are correct there seems to me to be no case for requiring aircraft which have a perfectly serviceable Mode C transponder to bin it and buy a new Mode S one.

I agree. On a point of detail, it's Terminal Control rather than Heathrow, I think, that has Mode S user-interface capability, but even there the downlink parameters of ELS are not used (i.e. they can't display your registration, even though you're sending it to them).

The argument for requiring Mode S for airways flights was stronger, even though the analysis was flawed, because of the need to track aircraft in high traffic density areas and the shortage of Mode A codes. But the case for throwing out a perfectly good Mode A/C transponder and replacing it with Mode S is paper-thin.

[IO540]

I agree with bookworm in that Mode C is just about every bit as good as Mode S.

However I don't think Mode A is much good because

a) ATC gets no FL readout to confirm what you told them so level busts are much less likely to be detected;
b) TCAS systems in airliners (and who-ever else has them fitted) don't work;
c) there are spurious TCAS warnings;
d) unverified (i.e. non-radio) traffic emitting Mode A and busting CAS whose base is above ground level is necessarily assumed by ATC to be below the CAS, which so far has been OK (no GAT-CAT midairs) due to luck and nothing else, plus of course any airproxes will be undetected unless the pilot gets a visual

As I has said here before many times, if Mode C had been made compulsory in the "obvious" terminal areas (like they do in the USA), many years ago, the fuss would have died down long ago, pilots would be routinely trained by the PPL training sausage machine to fly with Mode C (why? - because they have to ), any plane not fitted with Mode C from day 1 would be useless for all except the most local bimbles, and due to the widespread usage of Mode C there would be a lot less pressure for "all" of GA to install Mode S. We would be muchless likely to have the present situation where a lot of traffic which usually flies very locally (e.g. gliding) is having to look at it.

In my view, the use of Mode C is a reasonable quid pro quo for

a) being able to get CAS transits,
b) being able to use the hugely error-prone map+compass navigation techniques anywhere, close to CAS and within CAS, in the absence of UK-style formal Mode C veils

Widespread Mode C usage also happens to make a radar information service (RIS) considerably better than the present RIS which, due to the majority of targets being non-C, is close to useless. OTOH one could argue that the sky is big so why use a radar service at all?

One problem is that GA (not just UK but all over Europe; remember Mode S is a European initiative) digs itself into the deepest possible hole over the smallest thing, so that when a battle is lost it results in the loser getting decimated, Roman-style. It is a reasonable strategy when fighting a local planning issue which will otherwise result in an airfield closure, but in this case one needs to be more subtle about it. The environment here is dictated from Europe, where airline interests rule the committees.

[HEATHROW DIRECTOR]

<<There are currently no terminal/approach radar systems in the UK (except Heathrow?) which have Mode S>>

Heathrow Approach Control uses the same radar facilities as the London TMA and the Approach Controls for Luton, Gatwick and Stansted. Heathrow Approach also controls a great deal of Northolt Traffic. These control functions are located in Terminal Control, West Drayton. Thames Radar (Approach Control for London City and Biggin Hill) and the Heathrow Special VFR Director are also located there and use the same radar equipment.

Speaking as a retired controller who spent many years working light aircraft on 119.9 I would say that any system which provides accurate information to ATC has to be worthwhile for all users.

[SkyHawk-N]

Originally Posted by IO540

Widespread Mode C usage also happens to make a radar information service (RIS) considerably better than the present RIS which, due to the majority of targets being non-C, is close to useless.

"Close to useless"? a bit of an extreme view IMHO. I'd rather be told there was traffic in my vicinity even if in reality there is no factor due to it's altitude. I usually fly in a glider and military 'rich' environment, types which climb and descend very quickly and I would imagine that ATC would have a very hard time informing us of the exact situation at a moment in time. To be informed there is traffic in my area with a half decent range accuracy is good enough for me.

Why is this "Close to useless"?

'any plane not fitted with Mode C from day 1 would be useless for all except the most local bimbles'? Define a 'most Local Bimble'?

[IO540]

On a given 150nm flight in the south of England I might get 50 traffic reports (from say Farnborough/Brize/Shawbury) of which I guess 80% are "unknown level". How useful that is is a matter of opinion but it's an awful lot of resource wasted, on both the ATC and the pilot end of things.

From those that I do spot, and from the fact that I usually fly as high as I can without getting an IFR clearance into Class A (which complicates matters unnecessarily) I "know" most of them are way below me.

By "local bimble" I meant flight within a narrow range of one's airfield. With most UK airfields, one cannot venture very far in any one direction without reaching CAS. If Mode C was mandatory, you can bet that almost every plane that has a normal electrical system would have a Mode C fitted - simply because it would otherwise be all but useless for training or for self fly hire. If one had the US-style Mode C veils, while it would still be possible to fly a long way without needing a transponder, in practice one would choose to not restrict the utility of the plane to such a degree.

It's curious to observe that in America, often described as the land of aviation freedom, they have mandatory Mode C in the "obvious" places, while in Europe everybody has been fighting it.

[SkyHawk-N]

So you should have said 'close to useless where I regularly fly'.
I fly mostly around East Anglia and across to the Midlands. I find RIS very helpful and guess that the majority of the traffic reports are of traffic NOT being controlled by any ATC unit, gliders being the main 'culprits'. I never rely on RIS but to have someone else looking out for me as well is very welcome.

[Sedbergh]

I find it interesting that the CAA RIA quoted the 1999 Tornado/Cessna midair as their example of what Mode S could avoid (4 deaths @ £1.4 million each) - plus the cost of a new Tornado of course.

Is this actually a valid example?

The Cessna is said to have had a transponder, but it was switched off.
The collision occurred at 650 feet AGL in open airspace. IF the Cessna had been fitted with Mode S, would an FIS controller have been able to see it (by radar) at that level? Would an FIS controller have had time to warn the Cessna pilot of an impending collision?

Would the FIS controller have been able to see and contact the Tornado?
The Tornado did not have TACAS and as far as I understand, the RAF are not about to fit it.

The accident investigation report made six recommendations as to how the accident could have been avoided. The sixth (and last) recommendation covered improved technology (strobe recognition and Mod S).

So at that time the CAA were not hanging their hat on Mode S as the wonder cure. Now it seems they are.

Views please?

[gasax]

For one reaqson or another the CAA seem smitten with the idea of Mode S. you only have to glance at the material on their site to see have the arguement for it is spun to make it all things to all people.

Will it improve the lot of GA - of course not - we will either be filtered out or as now occurs ignored out in the FIR.

However none of that matters - this group of people have identified their next project and if a few things have to be bent to make the argument fit - who cares - they apparently don't.

The arguments against are all main based on cost and practicality which does n't seem to much bother the CAA. At its heart I suspect their is a desire to be seen to be doing 'something', to do 'something' that might be seen to lead Europe, to do 'something' which will stop them looking like a branch office for EASA. Oh and it might open the way for charging by the hour for the use of the air and other innovative uses of technology.

Will it make GA any safer - highly unlikely unless the military also have to fit ACAS and there are real improvements to air traffic services for ATC - which of course would cost money...........................

[NorthSouth]

Originally Posted by Sedbergh

The Cessna is said to have had a transponder, but it was switched off. The collision occurred at 650 feet AGL in open airspace. IF the Cessna had been fitted with Mode S, would an FIS controller have been able to see it (by radar) at that level?

Probably not, because as the report states:
"Analysis of the recordings of local military and civil radars failed to show traces of the tracks of either aircraft. It is considered that this was because both aircraft were below the base of primary radar cover and neither aircraft appeared to be using its secondary radar transponder." (SSR has a base level too and they'd have to have been above that)

Originally Posted by Sedbergh

Would an FIS controller have had time to warn the Cessna pilot of an impending collision?

Probably not because (a) on a FIS the controller could only have guessed which radar contact (if he could see one) was the Cessna, (b) both the Cessna and the Tornado would have been unverified, (c) traffic on a FIS unlikely to be given traffic info except in very general terms, and (d) in circumstances where a light aircraft and fast jet are on a collision course, giving traffic info to the light aircraft is highly unlikely to resolve the conflict since the conflicting FJ could be anywhere in the light a/c's 360 degrees and the light a/c can't move quick enough to get out of the way. Give tfc info to the FJ and you have a chance of resolving - except when the pilot's heads-down changing frequency as I believe he was thought to be in this case.

Originally Posted by Sedbergh

Would the FIS controller have been able to see and contact the Tornado?

Only if the Tornado pilot was in contact with that particular controller. Otherwise it would have required a phone call to the controller whose squawk the Tornado was wearing or, more likely, a feeling of helplessness at an observed squawk of 7001 which indicated that the Tornado was in the low flying system and therefore almost certainly talking to no-one.

Well done for spotting a debatable case in the CAA's RIA. Is someone doing a thorough analysis of all the quoted cases to see how many others there are?

Another factor in this case is that it implies that in future Mode S will allow LARS controllers to provide a RIS to everyone previously getting a FIS - or that TCAS will sort everyone out. On the first, what do all you LARS controllers think about the workload implications? On the second, NB this is not an argument for Mode S, it's an argument for current ACAS and Mode C.
NS

[chevvron]

Firstly as LARS controller, I don't want my radar display swamped with unnecessary SSR labels. We already have problems with label overlap and one only has to watch the gliders out of Lasham on their competitions this week to see how close together they are and how close the labels will be, rendering the SSR returns useless.
Secondly, has everyone seen the reports in todays papers about all road vehicles being fitted with tracking devices ostensibly for taxation purposes? Well it strikes me a Mode S transponder could be used by an unscrupulous government (if we ever had one) to monitor and thereby impose taxation on all airspace users. Course it could be argued that they are necessary for security reasons, but then you only have to read reports about people using false number plates to get round Red Ken's congestion charge to realise that someone somewhere will eventually invent a 'false identity' attachment for mode S transponders.

[englishal]

Well I don't mind Mode S if I get something in return. If I could be provided with traffic info services similar to what you get in terminal airspace in the USA by virtue of myself having a mode S transponder, then I think it is a good investment.

As for costs, and portability, have a look at:

this



I personally think it is a good thing for all traffic to transpond, though I tend to agree that rather than force Mode S down everyones neck, I think the sensible option would be to implement Mode C vales around commercial airports.

[IO540]

Anybody can reconfigure a Mode S transponder, to show any identification.

Getting into the factory config is just a matter of holding down a button while the unit powers up, and the maintenance manuals are freely available.

I don't think this would be a lot of use for revenue collection, not because a lot of people would fly with "fake number plates" but because the radar coverage isn't there (not by a very long way) and nobody will even dream of paying for any enhancement to it just to collect enroute revenue from UK's barely significant GA population.