An alarming experience

[Fuji Abound]

I had an interesting day recently which may change my view of light aviation.

It started with a visit to a radar control tower for the benefit of my friend. In this case the “tower” offered a LARS and an approach service, in addition to the normal air traffic services. The professionalism of the guys in charge was as usual impressive.

Far less impressive was the equipment. Primary radar has a number of disadvantages that are well known. Moreover, maintaining the primary head is clearly a very expensive business particularly when, so it would seem no subsidies or other financial assistance is provided to those offering this service, unless the military are involved (and they were not in this case.) when it would be funded from the defense budget.

It would seem logical to stream the data from a local NATS head with all the benefits this would bring. I gather to do so would be relatively simple. So what’s the hitch. Well, as I understand it, an annual bill of getting on for £100K for the privilege - just for the stream.

NATS is a commercial organisation - that we all understand. They exist to make money. However I question the wisdom of their effectively denying vital safety information to those that can and do provide an excellent service in open FIR.

They are not providing a NATIONAL air traffic service, they are providing a COMMERCIAL air traffic service, and in my opinion that should not have been permitted by government.

I know - but who is going to pay. Firstly, I would be surprised if the actual cost of a feed was anything close to the proposed charge. Secondly, the structure of the airspace in some parts of the country forces OCAS traffic to operate in confined corridors with little availability of vertical separation. The existence of CAS is therefore in itself increasing the risk of an OCAS mid air. Finally, and just maybe there is an argument that some of the fees light aircraft pay in the form of duty and CAA fees should be applied to radar services or that GA should make an additional contribution.

That was of course hardly sufficient to change my view of light aviation.

There was a very harsh lesson to follow.

Shortly after I had the closest mid air occurrence I wish to ever experience.

Personally, if I can get a service I do. I don’t care if it is outside CAS, and I don’t care if the unit would far rather give me a FI or even nothing at all. I know I cant insist on the service and often have to make do - but at least I always try. I also reckon that in a great many years and hours of flying I have a pretty good scan helped a little by plenty of aeros.

In this case I was getting a RIS. The incident occurred in the few moments between changing service providers. I completely missed seeing the other aircraft and he me. In hindsight I suspect we had been converging in such a way that we crossed at right angles. We were doing 160 knots and he a little faster I would guess. I would be “interested” to know the separation. I have done some formation flying and have some judgement of distance. I would guess it was less than 50 feet of vertical separation and there was no horizontal separation. I can only assume he was not receiving a RIS as the controller commented as soon as I signed on (moments later) that the returns had merged. He gave no indication he had been working the other aircraft. From the direction the other aircraft came, it is very unlikely he would have been changing service providers.

I am still wondering if I could have done anything more. However, it has left me wondering whether there is any excuse for “fast” aircraft not to obtaining a RIS whenever possible, not to be fitted with mode C or S (and I would assume they just about all are) but also no excuse for the government not requiring NATS to provide a more coherent and integrated service. It seems to me that often the radar feeds are available and it also seems to me that it is to a great degree the impact of controlled airspace that has increased the risk. Statistically the risk of a collision in Scotland must be far less. However in southern England the result of CAS is to bottle OCAS traffic into narrow low level “corridors” and to boot in some of the busiest air space.

I do not have the statistics but I have a suspicion that the number of light aircraft in some of these areas has increased and, perhaps more importantly, the average speed of that traffic has also increased and will continue to do so as the quest for faster light and very light aircraft becomes a reality with modern designs. Moreover, I also have a suspicion that there are a great many who don’t bother to request or “insist” on a RIS where available, because it is simpler for them not to do so; yet I find myself not in favour of of pilots following this practice.

Despite the criticism of mode S it has made be reassess the need for all aircraft to transpond so at least the faster traffic has a better opportunity of avoiding slower traffic, it has left me reconsidering the urgent need for an integrated low level service being made available to OCAS traffic and left me wondering whether to fit TCAS or PCAS on the basis that anything that reduces the risk of collision cant be a bad thing.

[Mike Cross]

As you say, an alarming experience.

Difficult though to find an answer. As your experience demonstrates, the receipt of a RIS does not eliminate the risk, and I'd suggest that radar is not a viable methodology. After over 100 ears of development a system has evolved in which the major means of separation is procedural, using controlled airspace, with aircraft flying along assigned tracks, separated by height and timing, rather than by a process of radar control.

A look at the process for vectoring aircraft into Heathrow and Gatwick demonstrates the system that has evolved. It's not a reactive system, it's a procedural one. Aircraft are placed in stacks, separated by height, and are then pulled from them in sequence onto pre-determined tracks. They form a very distinctive pattern on the screen, making it easier to spot an intruder.

If the use of reactive systems like RIS or RAS were a viable alternative to procedural systems the airlines would be pumping money into their development, It isn't and they're not.

[Rod1]

Not nice!

If I have understood correctly it is hard to see how mode s would have helped, unless you have TCAS on your aircraft?

“The incident occurred in the few moments between changing service providers”

You were changing to a new LARS unit so not actuality getting a service? I assume you have mode C and that the other aircraft was doing 160kn + it probably had c or s. Mode C or Mode S are excellent ways of avoiding collision if the aircraft concerned are TCAS equipped, but of little value otherwise.

I had the following incident some years ago.

Tracking to a VOR in quite solid IMC, on a RIS. I had traffic reported 1000 ft below unverified. I had class A above me, so stayed at my height with a theoretical 1000 ft of clearance. Popped out of the side of a cloud to see the other aircraft flash under me at about 50 ft separation. The controller confirmed it was the reported contact, still indicating 1000 ft below. The encoder must have been out by 950 ft! In this instance even TCAS would have been of no use. I “modified” my approach to flying IFR after this, I now like to see what is coming the other way.

Rod1

[IO540]

Fuji

They are not providing a NATIONAL air traffic service, they are providing a COMMERCIAL air traffic service, and in my opinion that should not have been permitted by government

I agree 100%.

Also the marginal cost of providing the feed is close to zero, but these people have decided to make money out of it. This sort of thing should be publicised; I'd start with letters to the media.

It would be possible for smaller GA airfields to have a radar feed too. I bet it would be handy. Easily delivered over the internet. In this case, the anally retentive rules about ATCO pay grades / qualifications prevent this being provided to a non radar qualified ATCO; of course a radar qualified ATCO gets paid more so if it was provided to one of the "lesser" grades there would likely be objections from the ATC unions.

It's difficult to say that mid-airs are rare after your experience but they are indeed rare. 4 in the last 10 years and all below 1000ft. Nowadays, a life is valued at some figure (£100k-£1M or so) and given that only about 5-10 lives have been lost in UK mid-airs in the last 10 years I can't see the powers to be in paying for anything better.

Rod1 - yes TCAS (with mandatory Mode C) is the only way to solve this and the price of TCAS is coming down all the time. You can get a top-notch system installed for the cost of a top-notch IFR GPS, and a portable (but directional and fairly effective) system is far less than that.

I'd favour mandatory Mode C/S above some level e.g. 2000ft AGL, for all powered aircraft with an electrical system.

A lookout doesn't work - much as this flies in the face of everything we have been taught since the Boer War. Assuming straight trajectories, a target on a genuine collision course will be stationary in your field of view and you will not see it until too late. Probably the only time a lookout does anything much is in the circuit, or in proximity to a gliding site, where the trajectories are rarely straight.

[robin]

I'd favour mandatory Mode C/S above some level e.g. 2000ft AGL, for all powered aircraft with an electrical system.

The problem there is that there are a lot of aircraft operating above that height without electrical systems, so the problem will remain.

A lookout doesn't work

But then neither do the technical options either.
TCAS relies on both parties carrying a serviceable transponder and a radar service requires both the infrastructure and sufficient staff - where I am you can whistle for a LARS service at weekends and during the summer holidays

[chevvron]

What you have to remember is that NATS has two halves; NATS En Route Limited (NERL) (ATCCs) and NATS Services Limited (NSL)(Airports). SSR interrogators are generally (but not always) 'owned' by NERL and the information is 'bought' by airport operators, even those where ATS is provided by NSL. Although some RAF airfields have their own interrogator, some 'buy' their SSR from NERL too.
All airports have to be treated equally, hence the cost to the airport, whether or not NATS(NSL) provide ATS, is the same.
There was a company (Stormscope I think) who offered a low cost SSR receiver several years ago; what happened to it I don't know but it was NOT the Mode S only receiver offered by the SBS-1, it could receive mode A and C too.

[Mike Cross]

It's an interesting paradox between the conflicting demands of commerce, safety, and security.

Systems exist to integrate the data from a multiplicity of radar heads and provide a feed of the raw data. Having poured liberal amounts of wonga into developing this and providing and running the infrastructure to deliver it you then have to come up with a viable way of paying for it. It's not unlike the situation that exists with any map or chart producer.

While it's an attractive proposition to suggest low-cost feeds you get stuck with a number of issues. ATC provider A might justifiably complain at having to pay considerably more than ATC provider B for the same data.

From a safety point of view it's not difficult to foresee situation where pilots think they are getting one service but are getting another. (I have enough of a problem remembering the difference between RIS & RAS). If you add in the possibility of radar information being provided by units that are not radar qualified it gets more tricky.

And finally from a security perspective it's not difficult to see that certain persons would find easier access to radar feeds of some practical use for nefarious activities.

[aluminium persuader]

The airprox (I hope you reported it) was probably not down to the changing of units - under a RIS you should ideally be getting handed-over unit to unit rather than a "freecall", and both controllers should be looking at your return & any adjacent ones. The problem is, I suspect, likely to be one of a/c type and flight profile, with a bit of radar equipment thrown in. In general -

The smaller & less-metallic an a/c, the harder it is for the primary radar to see.

tangential fade/critical relative speed - primary radar won't see it.

No transponder - SSR won't see it

If synthetic (processed) radar loses a target (eg if it's manoeuvring) it will produce a return for where it thinks the a/c should be, rather than for where it is.

The only real way to get to the answer is to file an airprox & have the incident investigated. Have to say, though, top marks for always using the best service you can get. I get so many people calling me and blithely announcing "squawking standby" - who's that helping?!

ap

[IO540]

If you add in the possibility of radar information being provided by units that are not radar qualified it gets more tricky.

I think that's a bit of a circular argument, because "radar qualified" is defined in terms of the existing system, under which a RAS is based on massive (for GA) spacing and is thus next to useless (even if it is available which is unlikely on days you need it) and RIS is not allowed to give you avoidance suggestions.

ATC provider A might justifiably complain at having to pay considerably more than ATC provider B for the same data.

That's the fault of the accounting system. The marginal cost of the data is close to zero.

And finally from a security perspective it's not difficult to see that certain persons would find easier access to radar feeds of some practical use for nefarious activities

I wouldn't suggest having it on an open website. Anyway, terrorists can get good enough info (where to position oneself with a stinger missile) from notams right now.

The other thing is that you can already buy that box from Kinetic which gives you virtual radar. The cat is out of the bag as far as tracking CAT traffic goes. The only defence CAT has from shoulder launched (heat seeking) missiles is a fairly rapid climb/descent; above about 10k feet they won't work.

[Mike Cross]

Not arguing with you, marginal cost is indeed near to zilch. However if unit A is legally required to have the service and unit B is not you have to have some system that allows unit B to get it at very low cost if you want to encourage them to provide it. It's human nature that Unit A will then argue for Unit B to pay a "Fairer" proportion of the cost. Problem is also that while the marginal cost of providing the data is zilch, the cost of delivering it is not. If you want a point to point secure circuit with assured bandwidth and latency you have to pay for it. I think we recently got a 2 Mb/Sec point to point put in around 10-12 miles radial distance and the rental is around 7.5k p.a.

There is of course also the issue of how much of a service you can provide. Any radar service is very manpower intensive. No doubt one of the controller chappies can advise us of how many contacts can reasonably be handled per controller.

I wasn't just thinking about Stingers, "OK lad's the police chopper's on it's way, drive away carefully and look natural" springs to mind. Establishing a pattern of operation could also be useful.

[S-Works]

Actually the NATS data network is an MPLS based cloud no point to point circuits. The core bearers are 100mb and the tail circuits run to the local POP. A 2mb MPLS circuit is around £4.5k, the core network is where the real costs are. But that is already being paid for on current levels.

I would question the need for a such a big circuit for local access to a data stream. More in the region of 512k to 1mb.

But what would I know.

[High Wing Drifter]

From bose-x's description it reads like it is based on the BT Wholesale Ethernet product (http://www.btwholesale.com/application?origin=prod_az_list.jsp&event=bea.portal.framework.internal.refresh&pageid=product&nodeId=navigation/node/data/Products/Data/MegaStream_Ethernet/navNode_MegaStream_Ethernet)

[IO540]

You could deliver a radar picture on a 38400 baud RS232 link! It's vector data, not raster.

It's true that a 2mbit/sec leased line costs a few k but

a) you don't need that speed

b) the "leased line" actually runs on the BT ATM network anyway (unless you got a point to point microwave link for some special reason) so there is no special reliability or redundancy.

You can still rent a traditional leased line from BT. I don't know what they cost but everybody knows that BT resisted providing ADSL for years, because this was going to cut into the big revenue they were getting from 64kbit/sec leased lines. Those lines were physical wires, I believe; certainly in the old days.

Anyway, these are details; the problem is in the organisation and the regs governing who is allowed to use the data.

[S-Works]

Nah, it is the MPLS product, search BT you will find all the data.

I have the NATS network diagrams on my laptop somewhere. Its been awhile since they went in.

[aluminium persuader]

I think we're getting a bit deep here. Weekends excepted, the vast majority of the country has radar coverage to some degree. You've just got to select the right unit, and it doesn't matter whether or not it's a published "LARS" unit - the same services are available from all, although of course their primary task takes priority.

Weekends are a bit trickier with most military bases closed.

The cost of upgrading an airfield to a radar unit is astronomical. Not just the cost of the equipment, but surveying, flightchecking, design of new approaches, re-writing the airfield manual, training of new controllers etc etc. If you haven't got the commercial back-up, it's not going to happen.

What may become more prevalent, however, is the remote siting of a radar unit, as for instance at Finningley. The radar there is done from Liverpool. The commercial case there though is that both airfields are Peel Holdings so the ATCOs work for one company, and airlines pay!

The drawback, however, is that the radar controllers have no local knowledge.

ap

[Spitoon]

Speaking as one of those controller chappies I should point out that there are a number of misconceptions in the thoughts being aired in this thread.

Time does not permit the necessary dissertation about the need for reliable radar data before using it for any type of air traffic service and the services that might be offered. But I must just refute the statement that Livepool controllers '.... have no local knowledge' around and about Finningley. If you take the trouble to get a controller's licence and appropriate 'pages' attached to it, you'll then have pass a Certificate of Competence for any particular working position - and, trust me, you don't pass unless you have knowledge of the areas in which you are providing the service....regardless of where you happen to be sitting!

[scooter boy]

Avoidance of scenarios like this one is why I love TCAS so much.:ok:

Yes I know that some aircraft are not transponder equiped, and also that there are still people out there who neglect to switch their transponder on, or activate mode C but most traffic (talking on LARS frequencies in the Southwest) appears as a little blip on my MFD.

I can think of at least 3 occasions in the past year when I have been thankful for it and it has definitely saved me from airproxes if not worse.

And yes I still look out the window...:rolleyes:

Now all I need is XM:WX weather radio or onboard weather radar...

SB

[Saab Dastard]

Fuji,

Look on the positive side - you've had your near-hit, or close shave, and got away with it!

Statistically you are now among the safest in the sky! ;)

I had a very similar incident a few years ago, open FIR south of Farnbro's coverage, so no LARS available.

Within 30 feet vertical separation.

So you and I should go flying together - nothing could poss

[Roffa]

IO540 wrote...


It would be possible for smaller GA airfields to have a radar feed too. I bet it would be handy. Easily delivered over the internet. In this case, the anally retentive rules about ATCO pay grades / qualifications prevent this being provided to a non radar qualified ATCO; of course a radar qualified ATCO gets paid more so if it was provided to one of the "lesser" grades there would likely be objections from the ATC unions.

Gawd, you do love banging on about our unions and the like don't you :ugh:

Yet again you are way off the mark, it's got nothing to do with them!

We work under a harmonised European ATC licence, who can do what is decided at a European level not by some NATS union atcos sitting round a table in a smoke filled room drinking beer and eating sandwiches. Go and look at CAP744 (http://www.caa.co.uk/docs/33/CAP744.PDF) and then get on your hobby horse to Europe whilst at the same time getting off the one that's always going on about NATS trade unions.

Improved radar services outside CAS in the SE is on NATS agenda...

[Fuji Abound]

Thank you for all your helpful comments.

I have to say I still find the experience unsettling, I think, as irrational as it is, because it was so close - but Saab the same thought occurred to me.

So far the rate seems to be around 1 every 500 hours, although the others were no no where near as close and one was in CAS due to controller error.

I would like to pick up on a few comments.

You were changing to a new LARS unit so not actuality getting a service? I assume you have mode C and that the other aircraft was doing 160kn + it probably had c or s. Mode C or Mode S are excellent ways of avoiding collision if the aircraft concerned are TCAS equipped, but of little value otherwise.

The previous unit was a LARS the "new" unit a radar service. The change over (a hand over was refused although requested) took maybe 5 minutes. I was mode S, and becasue the other aircraft was also a twin, I am guessing at least mode C. As I commented earlier I find it strange he was not receiving a service. I wonder whether as seems to be increasingly the case he couldnt be bothered to ask or had been refused a service. The same unit had flatly refused me a service on route to my destination. Is it the case that many are becoming reluctant to ask?

under a RIS you should ideally be getting handed-over unit to unit rather than a "freecall", and both controllers should be looking at your return & any adjacent ones.

I wish. In my experience hand overs are becoming increasingly rare.

and I'd suggest that radar is not a viable methodology. After over 100 ears of development a system has evolved in which the major means of separation is procedural, using controlled airspace, with aircraft flying along assigned tracks, separated by height and timing, rather than by a process of radar control.

The fact remains it is the best we have at the moment.

In my experience a RIS provides an excellent mechanism for reducing the risk of a mid air. Most fast aircraft are fitted with a transponder. There is more time to see slower moving aircraft (although I accept not necessarily that much). Some service providers have improved. Gatwick for example was often reluctant to provide any service and had to be coerced into doing so - that has improved enormously. On the other hand Farnborough (as helpful as they are) rapidly get overwhelmed, Thames are usually a right pain and Stanstead are even worse (shame on you), whereas Lyneham, Brise, Bristol, and many of those providers in the Midlands and further North are excellent. I recall returning from Dundee in particularly unpleasant IMC OCAS and Stanstead flatly refusing any service what so ever. I recall being less than pleased, but at least the weather was sufficiently poor that I doubt there was much traffic.

Any how shame on you - maybe we should start a name and shame thread in a similiar way that has happened with pilots being refused class D transits - and in consequence that has greatly improved.

I know of a number of airports that would gladly install a feed from NATS - it is the same story - they cant afford it. I believe Manston is in the process of doing so, I can imagine Lyd would benefit if for no other reason to assist with all the cross channel traffic and there are many others.

As others have commented NATS should be compelled by government to provide this data to any qualifying party at least at cost - their failure to do so is in my opinion a disgrace. I find it difficult to believe that any organisation can justify with holding vital safety data - which in effect is exactly what they are doing.

The thought of a mid air collision is horrifying, and brought painfully home to me by this experience. A collision of even two light twins over a built up area could have severe ramifications. Any efforts that can be made to ensure there is integrated coverage from service providers who are willing and able to provide the service in areas of conjestion and where air space is restricted should in my opinion be encouraged, particularly when it is the very presence of areas of CAS that are closely compacted with open FIR that so dramatically increases the risk of collision.

[IO540]

Gawd, you do love banging on about our unions and the like don't you
I have no idea who you are, except that you make no contribution to the debate here, yet somehow manage to surface every time the subject comes up and have a shot at the writer.

Are you by any chance somebody I know from elsewhere, but posting under a duplicate ID?

The stuff about "unions" has been pretty well aired at another forum a while ago, where a bunch of ATCOs vigorously demolished various proposals, on the usual basis of circular arguments based on regulations and ... wait for it ... working practices.

Union rules will always be wrapped up with the job description; if they were significantly different the whole lot would be out on strike ;)

[aluminium persuader]

Spitoon -

I too am a controller, with a bit more than 15 yrs in the job. Whilst yes, I'm sure the FYY guys @ LPL have some general knowledge of the area, they will be missing the depth of local knowledge that aids the pilots of light a/c. How can you describe the shape of a hill you've not seen?

It's not a criticism of the ATCOs and, after all, some radar is better than none. The benefits do outweigh the negatives but you still need to be aware of th limitations.

ap

[mm_flynn]

What you have to remember is that NATS has two halves; NATS En Route Limited (NERL) (ATCCs) and NATS Services Limited (NSL)(Airports). SSR interrogators are generally (but not always) 'owned' by NERL and the information is 'bought' by airport operators, even those where ATS is provided by NSL. Although some RAF airfields have their own interrogator, some 'buy' their SSR from NERL too.
All airports have to be treated equally, hence the cost to the airport, whether or not NATS(NSL) provide ATS, is the same.
So the 'government' has created a system where it is in many cases cheaper to install your own SSR interrogator than to buy into the existing infrastructure. This can only be a bad thing for the total cost and the amount of RF pollution. I wonder if this is part of the reason that RF pollution is alleged to be so much worse in the UK than the US (a deduction from one of the key needs to rapidly move to mode S).
There seems to be a fundamental regulatory/cultural problem with organising how to provide a reasonably cost/safety balanced service to the GA community. Having watched various controllers in action and visioning a bit into the Mode S world - It seems what the average GA aircraft would like is a radar FIS where the FIS provider is prompted using something akin to the short term conflict alert and the airspace intrusion predictor to provide information. Using the mode S data you can even imagine a tele-prompter type script (i.e. G-BBBB - twin traffic 2 o'clock 3 miles crossing left to right 300 feet below, unverified, or on your course you will enter CAS in three miles)

There was a company (Stormscope I think) who offered a low cost SSR receiver several years ago. There are a range of these, but you are probably talking about the Ryan 9900B (or possibly one of the range and altitude only ones for about $1k)

[chevvron]

To instal/operate your own interrogator would need CAA approval, which is unlikely in the south east due to problems of 'over' interrogation causing fruiting; might be possible oop norf though.
Farnborough already provides the service you describe; STCA? Watch this space.

[mm_flynn]

I suspect the southeast already has too many interrogators and that if approval were available to use the mosaic data, and it was provided economically, the total cost of the system could be reduced and improve the RF environment as well! My (limited) understanding is this is basically what happens in the US.

Farnborough do provide a fantastic service. However, if someday they get class D, I suspect the LARS service will fall by the way as 'too expensive and GA don't pay'. My vision was for how one might cost effectively provide a service tailored to the needs of GA, at a price GA can afford, rather than what CAT operators need (and not requiring the installation of TIS software)

[IO540]

What are the chances of Farnborough getting Class D?

The # of movements there is severely limited.

If they can get Class D then Deanland will be getting one too :)

[Roffa]

IO540, I don't believe we've ever met and I only bring the subject up when I see misguided statements being made but you obviously know best so will leave it there :rolleyes:

Now, if you're an airfield controlling traffic in the immediate vicinity then the best solution may well be a primary and co-located secondary feed at the airfield itself rather than getting a remote feed in from somewhere else.

The further away from the area one is looking at the worse the low level coverage will be. Thames, for example, suffers from this as it is forced to use both both primary and secondary feeds that are some distance from its area of operation.

A name and shame campaign has been suggested, well what exactly does one think it will achieve? Aside from Farnborough none of the London area airfields mentioned are in any way obliged to provide services outside CAS so in what way are they being shamed? In most cases though a service is provided if capacity allows, if it doesn't then no service may be provided. In other words you often get more than the service provider is strictly required to provide.

The decision was effectively taken at government level to turn NATS in to a commercial organisation and in the last few years the management have embraced that challenge with relish. But it's has also bitten the company in one or two areas, think infringements perhaps, and the disengagement from the light end of the customer base that had taken place over the last few years.

That disengagement though is hopefully now being addressed to some degree. Don't expect radical changes overnight but there are moves afoot that should ultimately provide better services outside CAS in the busy SE.

[Slopey]

You mean this? http://www.kinetic-avionics.co.uk/sbs-1.php

[Fuji Abound]

A name and shame campaign has been suggested, well what exactly does one think it will achieve?

I recall that for many years class D transits were difficult to obtain. In many cases that has changed since a "name and shame" scheme was introduced.

none of the London area airfields mentioned are in any way obliged to provide services outside CAS

Of course true, however many do. Moreover, there seems to be no correlation between those that do, and their workload. Perhaps some more subtle forces are at work.

You will hardly ever get a service from Solent outside CAS (shame on you with the amount of transit traffic through the solent) and the service on offer from both Stansted and Thames is shocking. In contrast Gatwick does an excellent job. I wonder why the variation? I wonder who is determining the policy?

After my experience there we all go for the grace of God.

Do not believe however good your scan, you will spot conflicting traffic. The evidence is not good that you will.

I find myself pondering whether the great unwashed realise we are flying without some form of radar service for most of the time. God forbid, but I also ponder the fallout from a mid air over one of the nice towns in London surbia. I hope GA will not get the blame if the press get to grips with the reluctance of NATS to provide a NATIONAL service and their insistance on charging for the data they collect, when it could be cheaply distributed to those that are willing and able to provide a service, but cannot afford to do so.

Me thinks I would not want to be the press officer for NATS.

Personally, I would also not wish to be the Stansted controller who refused me a service around their zone when I was in IMC had I been unfortunate enough to run into some one else doing the same thing - but that is just my opinion you understand.

[Roffa]

I recall that for many years class D transits were difficult to obtain. In many cases that has changed since a "name and shame" scheme was introduced.


I'm not sure what effect said name and shame scheme had, but there was never anything pointed in our (ATCs) direction saying we had to change the way we operated.

Some statistics were collected but no directives ever came down from the CAA. A lot of the transit issue is subjective. Those that don't have an issue tend not to say anything, those that do have an issue tend to shout loudest and a picture is painted that perhaps doesn't always reflect reality.

I find myself pondering whether the great unwashed realise we are flying without some form of radar service for most of the time. God forbid, but I also ponder the fallout from a mid air over one of the nice towns in London surbia. I hope GA will not get the blame if the press get to grips with the reluctance of NATS to provide a NATIONAL service and their insistance on charging for the data they collect, when it could be cheaply distributed to those that are willing and able to provide a service, but cannot afford to do so.

What about the reluctance of many, many pilots out there to fitting radios, transponders or making use of the ATC services that are available? Even when operating beside and below this country's busiest airspace.

No point blaming an ATC provider for failing to provide a service to those that might want it when many others don't, it's not mandatory anyway and they are reluctant to fit equipment that would greatly increase the available safety net coverage now for those operating both inside and outside CAS.

Bit of pot/kettle syndrome there.

Oh, the N in NATS doesn't stand for "National" any more by the way. We were rebranded. Maybe that helps explain a little the company/management ethos these days.

Personally, I would also not wish to be the Stansted controller who refused me a service around their zone when I was in IMC had I been unfortunate enough to run into some one else doing the same thing - but that is just my opinion you understand.

The Stansted controller's, like all the approach controllers working the various London airport positions, primary responsibilty is to traffic operating in and out of the airport concerned <full stop>

Personally I'd hate to be the Stansted controller who screwed up inside CAS because he/she was at the time distracted by providing a service to traffic outside CAS.

As for saying Thames is shocking, all I can say is you don't know the issues they have with regards equipment and procedures. They have a hard enough time dealing with what they have inside CAS without going outside their prime operational remit.

Don't jump to conclusions when you don't really know the full story.

[IO540]

What about the reluctance of many, many pilots out there to fitting radios, transponders or making use of the ATC services that are available?
I am not sure if you fly, Roffa, but the problem is this:

If you are flying VFR, or the non-Eurocontrol OCAS IFR which is common in UK Class G, then you have to have

Plan A - the route you would like, and

Plan B - the (longer) route you fly if you don't get the transit(s) for A)

So everybody (with a brain) has to have a plan based on not getting a transit - because sometimes they don't get it. And if you have that plan, loaded into your GPS, why not save yourself the extra workload of doing the radio and just fly Plan B, non-radio? My radio is actually pretty good; after nearly 800hrs it's better than many I hear, yet I prefer to go around e.g. LCY airspace quietly because it's less work for me. I might call up Southend instead but they don't have SSR - presumably because they don't want to pay the going rate for the feed.

So one can't blame pilots for not talking to ATC. One can get transits but it's sporadic, I guess depending a lot on the controller on duty, and after a while most people don't bother to ask.

Thames Radar are the losers here because they might be vectoring traffic to Biggin's ILS in Class G, yet the inability to provide a universal service to Class G in their area means that they will have nontransponding contacts in the same place. They probably get away with it because when the weather is OVC010 or worse the sky is relatively devoid of GA and there won't be many non-C contacts in the ALKIN area to start with.

Biggin pay for the Thames Radar service, I gather.

Don't jump to conclusions when you don't really know the full story.

I doubt many private pilots know even a bit of the story. But here's your chance to set the record straight. Why not tell us all about it?

[Roffa]

I doubt many private pilots know even a bit of the story. But here's your chance to set the record straight. Why not tell us all about it?

In all honesty I would love to write more than I do here on some subjects but even under the veil of anonymity that PPRuNe does, to a degree, provide there's only so far one can go before the breaching of one's conditions of service is a significant issue. Delving deeply into operational procedures from the MATS Pt 2 is a bit too far.

The bottom line, when it comes to transits, is that UK Class D is often over controlled when you apply the strict definitions of the level of service/separation between IFR and VFR that is actually required by the rules.

There are also good reasons why it's over controlled that have been explored here more than once before. In short "duty of care" and also the need to provide avoiding action to the IFR traffic against any VFR traffic if it should request it, not tenable in busy airspace.

With a PPL hat on I might feel hard done by, with an ATPL hat or commercial pax hat on I might be more understanding. To go back to one of Fuji's posts, the great unwashed might not be too impressed to know exactly what separation, or lack thereof, is actually required between their B7** and a passing Cherokee inside what is meant to be controlled airspace.

Whatever, the "but I was only following the rules" defence probably wouldn't stand up very well in court.

When it comes to transits I'm actually quite sympathetic really, but I'm also realistic. Many times the difference in track miles/time is minimal between increasing your own and ATC's workload by requesting transit compared to routing round the outside. If there's a major saving to be had, of course. If not, why bother?

I also have certain other opinions relating to our performance/attitudes as a company but, due to their nature they're not ones that I'm going to go in to on this particular forum. Rather I need to progress them internaly within the company.

[IO540]

Isn't the MATS document public domain?

IMHO you are right about transits not usually saving a lot of time. It's probably the lack of a service to the pilot that is a bigger problem. You have to remember that in PPL training one is taught to reveal one's inside leg measurement to every possible frequency along the route. Couple this with another old time PPL favourite - dead reckoning - and you have a recipe for plenty of CAS busts.

The more long-distance pilots just load up the GPS and fly with a listening watch. Unless they make a fairly obscure c0ckup, they should not bust airspace, and they don't ask for a service unless it's radar.

The French have it more right. They don't have an RIS/RAS to VFR traffic, but it's fairly obvious that everybody on the radio has a radar screen in front of them, and they will pass you traffic info if they think it's worth doing.

[ShyTorque]

It's easy enough to criticise ATC in frustration about not getting a transit service, or being otherwise inconvenienced, but many has been the time I have listened to the workload of the ATCO (and had a good idea what else was going on, behind the scenes / off air) and was glad I've only got one aircraft to worry about.
Plans A & B - yes, from experience its a very good idea.
For example, transitting the Luton zone through the overhead without a delay may well be possible, 8 or 9 times out of ten. On my regular run, this saves me about 3 miles distance, actually less than two minutes flying; however, the law of sod determines that the one time I really want this I won't get it, or will get held. One rate one orbit will take two minutes and causes my pax to worry about his meeting, so I would have been better off not asking for such a crossing in those circumstances.
I therefore plan to go via a route that is more likely to be available and call that 'plan A'. Plan B is the shortcut, if available. By listening out for a short while before making my initial call I try to get a mental picture of which might be the best request.
I also have plan C, which involves not actually having to talk to ATC at all and hopefully will not cause ATC any concern if I can't actually get a word in. I transit 'round and under' and make sure I'm clear of the airspace base by at least a couple of hundred of feet, rather than just on the base.

Mandatory transponders, IMHO, for aircraft able to carry them, are a good idea. In my case it means I have a better chance of becoming aware of a possible confliction with other traffic before it becomes critical because I can often do something about it myself, using the TCAS / TAS fitted to my aircraft, in the absence of a full service from ATC. If transponders have to be updated to mode S, so be it. Having said that, I might feel slightly different (but only slightly different), if I had to pay for it myself.

[Fuji Abound]

As the sponsor of this thread it was not about zone transits. I only introduced zone transits in relationship to the improvement in the service which has taken place since zone transit denials were reportable. My perception is the approval of zone transits has improved immeasurably, but I am not aware of any quantitative study (the sort of thing AOPA do in the States, but mores the pity not here). Frankly most of the time I couldn’t give a damn about zone transits from the view point of saving time - when it suites me I will ask for them but am equally happy to go round if needs me. As others have said it rarely adds significantly to the journey.

However, the safety aspect with which this thread started is a different issue.

The problem with controllers denying zone transits is that an increasing number route around the edge of the zone. Rightly or wrongly with GPS they are also inclined to route close to the zone boundary. If you have ever spent some time watching the radar display you will know what I mean. So in consequence you now end up with traffic being constrained in corridors around the zone and often into other corridors between the zone. Add to that the consequence of the London TMA in the south and you have relatively high speed traffic operating within a vertical ceiling of no more than 900 feet. (The London TMA is 2,500, no one wants to be exactly at 2,500 so the highest level is 2,400 and you hardly want to be running around at less than 1,500 en route if you can avoid it).

For that reason if I am not airways personally I will go for a zone transit every time, not to save time, but because it places me in a “protected environment”.

You can imagine that I am slightly p**£”! when the transit is refused, AND the controller refuses a RIS and I have no other available service and, as I now know, I might well have got an alternative service but for the fact that NATS price everyone else out of the market.

NEMA will continue its policy of providing a crossing service to aircraft requiring to transit Class D Airspace and an appropriate level of service to traffic flying in the vicinity of Class D Airspace.

This was what NEMA said when they requested and got an airspace increase. I hope they will not forget their policy and will not interpret the part emphasised (my emphasis) in another way. I wonder what other assurances were given with other changes in airspace policy in the South. When I get a moment I will have a look.

Roffa you seem to be very hung up on the personal criticism of controllers - I fully appreciate you are one, and want to protect your integrity. This is not my case. The purpose of the example of a mid air around Stanstead after the refusal of a controller to provide a RIS is not to discuss whether avoiding the loss of life of 200 passengers in some LoCo is more or less valuable than 8 passengers in a twin, but to raise the issue that NATS and the Government's policy has increased the risk of a mid air collision outside CAS in the south. NATS in particular are guilty of not providing data already within their remit and at marginal cost to other services providers who would be only to happy to try and redress that balance.

If you allow people to walk across a bridge that is ten feet wide with railings down each side you are entitled to be surprised when the fall off the edge, but if you allow people to walk across a bridge that is two feet wide with no railings dont be too surprised when they fall off. Tell the judge that you could have fitted a safety net to catch them at next to no cost, but thought you would add to your shareholders profits by not doing so, and you had better look out.

[Roffa]

Fuji, I'm quite open to criticism where valid. If you were talking of LARS units willfully refusing to provide a service outside CAS then valid point, but you're not.

Resources are finite and for non-LARS approach units providing services outside CAS to traffic that is not inbound or outbound is way down there at the bottom of the pecking order. Unfortunate but that's the way it is.

Services will be provided if capacity allows but won't be when/if it doesn't. If you want more than that then resources are going to have to be found and paid for or something else is going to need to happen. I've already alluded to the latter...

IO540, the MATS Pt 1, general instructions relating to all ATC units, is in the public domain and can be downloaded from the CAA web site.

The MATS Pt 2, which all units also have, is the book of local instructions/procedures relating to that particualr unit. In the case of NATS units all the Pt 2s are "NATS Commercial in Confidence" so one would be taking a bit of a risk if going in to them too deeply in a forum such as this.

[Fuji Abound]

Resources are finite and for non-LARS approach units providing services outside CAS to traffic that is not inbound or outbound is way down there at the bottom of the pecking order. Unfortunate but that's the way it is.

Honestly, I really have got to grip with this usual mantra.

If you read all my posts the thrust of my argument was not this.

Let me summarise for you.

In my opinion CAS (particularly in the south) has, as it has increased, constricted OCAS traffic in to ever smaller corridors in terms of both lateral and vertical seperation. Transit reusals add to the problem.

In at least some cases when CAS is enlarged assurances have been given that an appropriate service WILL be given to OCAS traffic.

and finally NATS could provide the data to enable others to provide the service they dont at marginal costs to them, but it would seem are unwilling to do so.

Yes, and we know, thats the way it is .. .. ..

but sometimes the way it is, is not a good thing, and when you have just missed another aircraft by 50 feet it brings it home to you thats not the answer to a few dead people if it could be avoided.

... .. .. time for things to change, me thinks.

[IO540]

Roffa, why is Pt 2 confidential? It's not as if somebody is going to set up down the road in competition ;)

[chevvron]

It's so that if there is a change to ATS provider, the new one can't just copy the old procedures and they have to provide their own safety case to prove to the CAA that they are capable of taking over the task.

[IO540]

Chevron,

It's so that if there is a change to ATS provider, the new one can't just copy the old procedures and they have to provide their own safety case to prove to the CAA that they are capable of taking over the task

I am sorry but I don't understand that at all.

Surely, NATS didn't pay for this work in the first place; it goes back to the days when it was nationalised.

Also, how can the ATS provider be changed?

[Spitoon]

Bit of thread drift perhaps, but...........

In addition to an ATS provider having to justify the safety of its procedures, the local ATC procedures are considered by some companies to represent valuable intellectual property.

NATS is not the only ATC service provider at UK airports - I think in total there are something in the region of 40 to 50 separate prover orgnisations. Many airports will contract out the ATC service provision and one of the things that makes it harder for a new provider to bid is not having access to the existing local procedures (and therefore taking time and effort to develop them. Of course they don't have time to do this when they take over a contract, the airport will want the service provided on day 1. Hence although on paper it is an open and competitive market, in reality it is a generally static market with very little change over of service provider.

The intellectual property rights of local procedures were not really an issue before the privatisation of NATS but have since become keenly protected. Maybe this is just a change in the general view on IPR or maybe it is something that NATS made an issue of in the ATS business - doesn't really matter I guess.....

Although it is primarily a commercial matter it is sad to see that this form of protectionism has been permitted by the CAA. Historically the CAA has typically steered well clear of anything that can be vaugely considered commercial but there are some safety issues bound up in all of this as well.

[Roffa]

As far as the TC MATS Pt 2 is concerned there is also other sensitive information, and I'm not thinking in commercial terms, that is best kept out of the public domain.

Fuji,

In my opinion CAS (particularly in the south) has, as it has increased, constricted OCAS traffic in to ever smaller corridors in terms of both lateral and vertical seperation. Transit reusals add to the problem.

Aside from the relatively recent LCY CTA shelf (much of the area it covers is not sensibly accessible in a single) CAS at lower levels in the SE has been relatively static for a number of years. The changes to the north of Luton a little while ago shouldn't have had a massive impact on GA. The London Control Zone the last time it changed reduced in size. I can't really think of any other significant changes...?

Yes, and we know, thats the way it is .. .. ..
but sometimes the way it is, is not a good thing, and when you have just missed another aircraft by 50 feet it brings it home to you thats not the answer to a few dead people if it could be avoided.
... .. .. time for things to change, me thinks.

Things are hopefully changing in the not too distant future, watch this space, but for maximum benefit make sure all your PPL compatriots take part as and when the service becomes available by using the radio and squawking with altitude... ahhhh... right... :hmm:

[Fuji Abound]

Roffa

I agree that the south east suffers from air space restriction more than any other. Not only is the area of CAS significant but it probably has a higher desity of GA fields that any other area. It also suffers from vertical constriction because of the London TMA

I shall look forward to hearing more about the changes. I hope that these arent rolled out with the usual lack of consultation that seems endemic in aviation.

I was and still remain opposed to the compulsory introdcution of mode S. I do not see it offers any material advantages to GA over mode C. However my view on transponders has changed. In my opinion all aircraft should be fitted with a transponder. The fact of the matter maybe that mode S transponders will become as "cheap" as mode C before to long.

Until then your fears are justified and as you would say - sadly that is the way it is. Hopefully times are gradually changing in that respect as well.

[Roffa]

Fuji,

I shall look forward to hearing more about the changes. I hope that these arent rolled out with the usual lack of consultation that seems endemic in aviation.

There shouldn't be any consultation necessary as what is hopefully coming is something that is actually wanted by the majority of the GA community I'd say.

I was and still remain opposed to the compulsory introdcution of mode S. I do not see it offers any material advantages to GA over mode C. However my view on transponders has changed. In my opinion all aircraft should be fitted with a transponder. The fact of the matter maybe that mode S transponders will become as "cheap" as mode C before to long.

It's actually an ICAO requirement now, has been for some time, that all aircraft should carry an altitude reporting transponder so mandatory carriage has always been on the cards, just that no-one took much notice of it.

However if all aircraft were to be fitted with Mode A/C transponders the simple fact is the infrastructure couldn't cope. One of the reasons for mandating S instead of A/C is that the nature of S allows more transponders to be in the air at any one time than there ever could be with A/C without overloading the system.

In short mandate A/C, the sytem can't cope. Mandate S it can.

No doubt a mix of A/C and S could probably be accomodated but I've no idea what a workable ratio might be.

[Fuji Abound]

Things are hopefully changing in the not too distant future

So approximately when should we be on the look out for these changes?


by using the radio and squawking with altitude... ahhhh... right...

I was reflecting on your comment. It is to everyones disadvantages if some choose not to talk or squawk altitude. However, I suppose there is a chicken and egg. There are those who dont because they perceive no benefit from doing so. Perhaps that might change (as you have hinted). If a service was available of the type seen in America aircraft should be mandated to have a transponder.

[Roffa]

Fuji,

So approximately when should we be on the look out for these changes?

Difficult to say at the moment and can't say much about them just now either but the mere fact they are being worked on is a major step forward.

[chevvron]

Roffa; if it's what I think you're referring to please don't say any more as a positive decision is not due for a couple of weeks.

[Fuji Abound]

SSSShh dont say anything or you might have to shoot yourselves.

It is the usual Chinese Wispers we see in Government, Public bodies and so many other organisations today.

It is even more annoying when the Government manage to privatise something concerned with public safety and then claim it is in the private sector despite their golden shareholding when it suites them.

Pathetic, a bunch of complete morons.

Frankly I have given up caring, and I am so cynical I am expecting if anything is ever done it will be the usual hash up.

In so far is aviation is concerned we have had in recent months:

1. The mode S farce - cost me £6,000 four or five years ago because everyone needed one and then the CAA changed its mind,

2. Lifejackets, transponders and the like. The ANO was changed, the CAA now interpret the ANO to apparently suite themselves, and even then have to issue a dispensation,

3. Proposed changes to the the PPL/IR which no one knows about .. .. ..

and so it goes on.

I have come to the conclusion that the whole lot are a complete shower. :)

[chevvron]

I just don't want people getting their hopes up and it all falls through (as often happens)

[Roffa]

Fuji wrote...

SSSShh dont say anything or you might have to shoot yourselves.

It is the usual Chinese Wispers we see in Government, Public bodies and so many other organisations today.

It is even more annoying when the Government manage to privatise something concerned with public safety and then claim it is in the private sector despite their golden shareholding when it suites them.

Pathetic, a bunch of complete morons.

Psst Fuji, have you seen what the morons are putting in place, foc, for you yet?

Your apology, should it arrive, is accepted.

[Fuji Abound]

Very very well done to all the morons involved :).

Thank you.

[Fuji Abound]

In fact have changed my mind.

My previous post was because I couldn’t be bothered to say what I felt - which seems a shame.

It is far easy to say well done, and I apologise .. .. ..

When actually I feel there is a growing tendency for people to want praise and thanks for the most extraordinary things.

Elsewhere someone wants thanks for creating an easier PPL IR when the utterly ridiculous system we have should never have come into existence in the first place had the relevant organisations and regulatory authorities been doing there job properly. The only person that should get any thanks is the new fella on the block that decided to do something about it.

Now we are expected to thank NATS (or however they have re-branded themselves) for providing a London LARS.

Lest we forget, the reason a London LARS is needed is because of the minimal amount of open FIR around London. As I said before there are significant areas where traffic is corridored into 1,000 feet of airspace with numerous bottlenecks. CAT causes these bottlenecks. NATS claims their mission is to protect commercial traffic and they don’t have the funding to provide a reliable service outside CAS. However, since commercial carriers require protected airspace, it does not seem unreasonable they should pay for the airspace they use. After all telecommunication providers pay the government a very large sum for their privileged use of certain frequencies.

I have taken many people flying who have never been in a light aircraft before. Without exception they are horrified when told to keep their eyes peeled for traffic - “but surely you are on radar”. God forbid there is ever a mid air over one of the “nice” London suburbs, but certain newspapers are going to make hay out of all these aircraft flying overhead without any form of separation from other traffic. NATS are going to protest that its not part of their brief, and the government will say they are a “private” organisation. Someone is going to spot that the Government own a golden share, mention that the CAA is responsible for safety and that really it is a misnomer that NATS provide a “national” air traffic service. No one will come out of it well, never mind that it might have been one of the small commercial flights operating form a London satellite airport that had twenty or so people on board.

Fact is in such congested airspace the service should always have existed. When I started flying Dunsfold did a very good job and Manston covered the whole of the south east corner. Both have ceased to offer a service and whilst even then it wasn’t perfect my guess is the airspace was less congested and the traffic slower moving.

So forgive me if I sound ungrateful, but I cant bring myself to say “well done” or “I apologise” for the parties involved only now providing a service that they should have felt compelled to provide for the last 15 years. I cant forgive them wanting to charge others, who could well have provided the service in the past, £100K for a radar feed, when the real cost was a fractional part of the proposed charge. Finally, no apology will be forthcoming form me to those involved in the Chinese whispers that say just wait and see, you will get what you want, but we are not going to tell you what it is or when it will come, but when it does, aren’t we clever because we knew something everyone else didn’t. Good luck to you if that is what rows your boat.

Now it aint rocket science you lot, provide the service you know you should. If you doubt it is possible take a trip to the States and see how it should be done. I know, our airspace is sooo much busier, we couldn’t possibly do that .. .. .. , b&88"3** !

[Roffa]

:rolleyes: