Zone infringement today

[Local Variation]

at East Midlands this afternoon.

In the zone virtually on top of the field, then out, then back in again. Flights temporarily grounded, queuing up on the Alpha, one moved off the runway and us stuck on right base for fifteen odd minutes waiting.

And not a single word spoken from the person responsible. I hope they find them. They can have the fuel bills. This does GA no favours whatsoever.

Infringements can and do happen, but to keep stum over such a large field is totally unacceptable.

Rant over.

[foxmoth]

Any clues - type etc?

[Local Variation]

Low wing apparently, possibly PA28 type or similar.

ATC concerns at one point that an approach might be being attempted, hence the removal of the one lined up ready to go. And not a word spoken. Scarey stuff.

I understand we may have been very close to them at one point in the holding turn, but never saw them. Bit uncomfortable to be honest.

Spoke with ATC after we landed. Seemed confident they could find them. Follow the screen blips till they dissapear then call the location was what they said.

Some guesses as to where it went. But not for sharing here. We shall see.

[AdamFrisch]

I understand the annoyance having to hold on base, but this sounds like ATC were full of their own importance. They can't let you land, in I'm assuming VFR conditions (since you mention a base entry) because some PA28 is infringing on top of the zone? A visual one at that, since it has been determined it was a low wing. How exactly is this different than class G? You don't see them there either, at least here he's on a radar screen. And how exactly is holding you there safer than letting you land when they're visual with him? I don't get it. It seems like usual high vis west mania to me, but in a tower.

Not condoning his behaviour - it is unacceptable of course. Just curious why they treat it like there were 1000 infringing aircraft, rather than one known one.

[good egg]

So hang on, unauthorised infringement with intentions unknown and you think it's a good idea to throw in a few airliners?!?!?!? :ugh:

[Talkdownman]

Oh, I suppose you could throw in a few of those LoCo CAT operators whose company Safety Management System permits flight in an unknown traffic environment...

[Mariner9]

So hang on, unauthorised infringement with intentions unknown and you think it's a good idea to throw in a few airliners?!?!?!?


The OP said he was holding on right base for 15 minutes. How can keeping him holding there be any safer than letting him turn final and land? Surely unknown traffic could just as easily wonder off in the right base direction?

Depends upon the position of the infringer during those 15 mins presumably, and we don't know that.

[good egg]

Nor do we know the rest of the traffic. My comment was for balance after a lambasting of ATC.
this sounds like ATC were full of their own importance.
Without knowing the whole picture - which none of us know - I find it astonishing that some views are so polarised...

(OPs post was well-balanced)

Ps Shall try and use this 'quote' thingy more often in future!

[soaringhigh650]

Another infringement. :} Okay, extremely annoying for everyone. Can't some pilots learn to call up over the radio?

Is this Class D?

Just treat the unknown traffic as IFR, separate known IFR using standard means and provide traffic updates to known VFR leaving them to self-separate.

Shouldn't need to hold for 15 minutes if inbound traffic was VFR.

[Local Variation]

Some clarity.

This aircraft was inside the zone, not on top of the zone. This aircraft was flying erratically and mute and was seen low level close to the runway. There were at least 3 airliners ready to go, I lined up. Wake turbulence on departure could have got him/her.

Takes a brave sole in ATC to do anything other than freeze the frame. I would imagine they have well thought out procedures and adopt them to protect everyone including the bandit.

[good egg]

Just treat the unknown traffic as IFR, separate known IFR using standard means and provide traffic updates to known VFR leaving them to self-separate.

How can you provide separation when there is no way of knowing what the infringer is doing??

I'd suggest best course for ATC is to hold off the known traffic/clear runway (which appears to have been the case) whilst the infringer weaves about so that if the infringer gets close to one of the known aircraft then ATC are in a better position to resolve potential conflicts.
Once the infringer's intentions are known, e.g. RT contact is made/aircraft lands (emergency), or the aircraft leaves CAS - with extra ATC radar monitoring (if available) to check he/she isn't coming back - then it's time to start resuming normal service.

Infringers can cause a huge increase in ATCO workload because, quite simply, their intentions are unknown...inadvertent infringement? Emergency? Malicious?
Rest assured ATC would like to get back to normal operation ASAP too, but safety is always the primary concern.

I'm not surprised that a specific aircraft had to be held for 15mins, others may have held for less, others more.

[NorthSouth]

MATS Part 1 says when avoiding action is issued to an IFR aircraft under a Radar Control Service in Class D or E airspace, and the pilot reports that he has the unknown aircraft in sight and has positively stated that he will maintain his own separation from it, further controller action may then be limited to passing traffic informationSo IFR traffic has that option - but IFR pilots may not know that they can ask for that. Otherwise, a controller faced with an unknown aircraft inside Class D has to provide 5nm separation from it for all his IFR traffic. Given that EMA is only 5nm from the zone boundary in both north and south directions, that doesn't give a lot of options.
NS

[Local Variation]

Spot on.

It was clear from listening, that due to lack of comms, intentions were unknown.

That was a great deal of surprise from us, when they re-appeared for the second time.

A lost solo student who panicked, a wanderer who got lost or a nutter with barking intentions.

And it is Class D. The cloud base was variable around 2000 feet over the airfield and we never saw him. I suspect, given the gloomy day, they got lost.....big time.

[soaringhigh650]

How can you provide separation when there is no way of knowing what the infringer is doing??

In the same way ATC fields works in uncontrolled or Class E airspace where there may be multiple unknown contacts that may fly straight across standard approach paths without talking to anyone.

[Echo Romeo]

I just hope they find the idiot, there is rarely a valid excuse for busting controlled airspace in my book.

[flybymike]

I just hope they find the idiot, there is rarely a valid excuse for busting controlled airspace in my book.
The usual "excuse" for busting CAS is a simple unintentional honest to goodness human mistake.

Why infringe deliberately?

If all mistakes were to be prosecuted, we would all be in the nick.

[2 sheds]

Quote:
How can you provide separation when there is no way of knowing what the infringer is doing??
In the same way ATC fields works in uncontrolled or Class E airspace where there may be multiple unknown contacts that may fly straight across standard approach paths without talking to anyone.

That is the whole point - it was not either Class G or E!

2 s

[Warped Factor]

soaringhigh (and possibly one or two others),

Apply here for training...

Apply now | NATS (http://www.nats.co.uk/careers/atc/how-to-apply/apply/)

With your obvious knowledge and expertise they might fast track you through.

[Pilot.Lyons]

I just hope they find the idiot, there is rarely a valid excuse for busting controlled airspace in my book.
The usual "excuse" for busting CAS is a simple unintentional honest to goodness human mistake.

Why infringe deliberately?

If all mistakes were to be prosecuted, we would all be in the nick.

Well said.

[Silvaire1]

I have never seen US airport operations shut down as a result of an aircraft in the Class D not having established communication with the tower, and it certainly does occur at many airports on a regular (i.e. several times daily) basis. What I have believe would happen is that communicating traffic would be advised of the non-communicating traffic so the pilot in command could decide what to do. The pilot in command is given that title for a reason.

Obviously high performance aircraft including airliners fly though non-radio VFR traffic regularly (in Class E airspace) so mixing traffic in that manner is not intrinsically an issue

[Armchairflyer]

Completely agree with flybymike and Pilot.Lyons (and not just because I am aware of my own navigational shortcomings). On the other hand, being unaware of own position with CAS nearby and apparently unreachable on R/T (let alone proactively talking to ATC) strikes me as slightly odd.

Was once guilty of a minor infringement myself (without any consequences for other traffic as far as I know, just clipped the edge of a "CAS above 2500ft" piece of airspace when I believed I was still in a "CAS above 3500ft" piece). As I was quite close to my home aerodrome and still on their frequency, the ATC guy/gal from the big airport nearby made an educated guess, phoned the aerodrome tower and asked them to gently tell me to descend or buzz off (I did both, quickly and red-headed, and that was it, no further complaints from anyone). Point is: to be completely unreachable for ATC it would appear that one has to almost make an effort, or maybe I was just lucky.

[Echo Romeo]

flybymike, fair comment, I was maybe a bit hasty jumping to that conclusion and certainly wasn't suggesting every infringement should be prosecuted.

But reading the OP's 3rd post I would be interested to know what his or her excuse was, if indeed there was one.

[ShyTorque]

How can you provide separation when there is no way of knowing what the infringer is doing??

And exactly how much separation would normally be provided for VFR traffic by ATC in Class D airspace.....?

A one word answer will do.

[Rod1]

“Happy landings, we're watching you! “:

Hear that click? It is pilots switching off their transponders for fear of BBWolf. We need to work together to reduce infringements, not encourage a them and us mentality.:ugh:

Rod1

[wb9999]

Silvaire1, class D in the UK is more like Class C or B in the US in terms of size and type of movements. US class D is more like a UK Class G ATZ with ATC (Shoreham, Carlisle etc).

The airfield I learnt at in the US was uncontrolled (unicom). Within a year it had become class D without a single commercial aircraft or a jet.

[Talkdownman]

a UK Class G ATZ with ATC (Shoreham, Carlisle etc)
Uncontrolled airspace with control.
Crazy.

[wb9999]

Uncontrolled airspace with control.
Crazy.

Just one of many crazy things in the UK.

[Silvaire1]

Silvaire1, class D in the UK is more like Class C or B in the US in terms of size and type of movements. US class D is more like a UK Class G ATZ with ATC (Shoreham, Carlisle etc).

My US base is tower controlled within Class D airspace. We have 650 operations per day mixing traffic ranging from a Breezy to Gulfstreams, and everything in between. I have never seen or heard of arrivals or departures being delayed as a result of non-communicating traffic.

[wb9999]

My US base is tower controlled within Class D airspace. We have 650 operations per day mixing traffic ranging from a Breezy to Gulfstreams,

How about at a class C with 737s? Would they be delayed by unknown traffic less than 2000ft over the airfield? That's what the OP is talking about - 3 airliners, which are likely to be 737s at East Mids.

[Silvaire1]

How about at a class C with 737s? Would they be delayed by unknown traffic less than 2000ft over the airfield? That's what the OP is talking about - 3 airliners, which are likely to be 737s at East Mids. The Class D airport I mentioned is directly underneath Class B airspace used by airliners and military traffic, with a total of about 2500 operations per day for all the airports combined. I have never heard of operations at any of the airports in the area being delayed by non-communicating traffic.

I could however relate some stories about people flying uncleared into the local Class B, it happens every day, including a guy I knew (now sadly passed on) making his last ever solo flight after 70 years of flying. He was told on the phone not to do that again - and decided he wouldn't!

I occasionally fly a non-transponder equipped aircraft directly over the primary commercial airport within the Class B area, without being in radio contact with anybody. At about 3500 ft directly over the airport its legal. I prefer to do it in an Electrical/Mode C equipped aircraft so they can see me, and know my altitude, even if they specifically don't want to talk to me.

[good egg]

And exactly how much separation would normally be provided for VFR traffic by ATC in Class D airspace.....?

(A) None, possibly with a smidgeon of;
(B) Duty of Care.

But both of the above rely on it being a known traffic environment, i.e. ATC know what everyone is doing. Once an infringement occurs it becomes an unknown environment because ATC has no earthly idea what the 'rogue' aircraft will do...in exactly the same way that none of the airlines nor the other GA has any idea.

Effectively the 'controlled' airspace now has an element of the 'uncontrolled'. ATC will do it's best to separate all the other traffic from the 'uncontrolled' aircraft (this may well be less than "standard" separation but it's better than nothing!) whilst maintaining separation (where required) between the known traffic.

Would you honestly prefer if ATC told you "Unknown traffic, 1 o'clock, range 3nm, I think it's a PA28, possibly crossing right to left, maybe turning towards you, no height information available. Cleared to Land"??

I'd say, given that you, nor I, have any idea what was going on in the cockpit of the infringer (Head down? Head up? Emergency? Equipment failure? Weather deterioration? Pilot experience? Malicious intent? Etc, etc), that the actions taken by ATC (clearing the runway, holding aircraft) seem pretty appropriate. That we are talking about delays rather than an AIRPROX (or worse) suggests to me that the situation was well-managed.

(Also bear in mind that, whilst RT exchanges between ATC and the various aircraft being provided with a service can be overheard, there was probably a lot of unseen work going on in ATC, e.g. Extra eyes trying to track 'rogue' aircraft, telephone co-ordinations between the Tower and adjacent units, alerting the aerodrome fire service/aerodrome authority to prepare for an emergency.)

Re: book-throwing... That is unlikely in my opinion to have a significant long-term effect on infringements. Infringements (vast majority) are unintentional errors. Pilots don't set out to infringe CAS. Improved use of LARS, "listening out" frequencies/codes, etc, is more likely IMO to reduce the number and severity of infringements. Some ATC units and local flying clubs/local operators have good, constructive dialogue - this is surely what we should all be promoting, rather than debating whether the ATC service, based on the classification of airspace, was appropriate.

(Supportive Class D ATCO)

[NorthSouth]

ShyTorque:
Quote:

How can you provide separation when there is no way of knowing what the infringer is doing??
And exactly how much separation would normally be provided for VFR traffic by ATC in Class D airspace.....?

A one word answer will do. Clearly the answer you're after is "none" but unfortunately a one-word answer won't do because (unlike the US as numerous contributors have pointed out) while there is no formal requirement for separation between IFR and VFR in UK Class D, the normal and accepted practice is to provide 3nm or 1000ft between IFR traffic and VFR traffic, except when it is inside the ATZ. This is great for IFR traffic but does make it much more difficult for VFR traffic which is regularly denied entry to CAS, held and orbited while IFRs get in/out.

I've flown VFR in CAS in the States and found it really disconcerting how much freedom you're given, but it clearly works because the safety record there is excellent.

NS

[JDA2012]

I too have found myself unexpectedly near East Midlands - having managed to become lost by following the wrong valley down from the Pennines in a rather low cloud base and being unable to contact Doncaster on my first "proper" cross-country post-PPL.

I found ATC to be very supportive when I called them up, advised uncertain of position and, on tying a significant landmark to a position on my map, realised at approximately the same time as they did precisely where I was. Apologising profusely and high-tailing it away from the area (with the controller's confirmation) were the order of the day, followed up by a phone call when I landed - they'd also made one back to my club whilst I was in the air.:O

I did not affect any traffic that day, but learnt several valuable lessons. If you don't talk, you're endangering, or at least inconveniencing, a lot more people than just yourself - and let's face it, you're the only person whose skin you're trying to save by staying quiet, correct? Being a pilot is more than flying the aircraft, and the latter is not an attitude that befits the responsibility in my view. Admittedly, judgemental attitudes will not encourage pilots to do the right thing - we all must work together - but I have no complaints at all about East Midlands ATC in this area.

[good egg]

Great post :ok:

Great tip too...once you know (or think!) you've made a mistake talk to someone (preferably on the RT and to the right ATC unit!), but let someone know - even if it's not the right unit. This will help to resolve the situation more quickly than keeping schtum...and may well benefit you afterwards.

I suspect it is better to own up to a genuine error at the time than to receive a tap on the shoulder later - can any GA pilots confirm this?

It's also amazing what a follow-up phone call to the ATC unit involved can do. We're all human, pilots, ATC, and (in my experience) the regulator. We all make mistakes. But the earlier you recognise it and notify the relevant person/unit etc the better in my book.

I encourage GA pilots/flying clubs etc to engage with ATC (not just "post-incident"!). Understanding each others realm is beneficial to both parties.

[flybymike]

“Happy landings, we're watching you! “:

Hear that click? It is pilots switching off their transponders for fear of BBWolf. We need to work together to reduce infringements, not encourage a them and us mentality.

Rod1

Have to agree with Rod there. Very poor PR.

[Rod1]

I have always found East Mids to be quite good but they did once accuse me of infringing. Fortunately for me I was test flying an aircraft and was in a turn looking straight down the stack at Rugeley power station at the time – they had got the wrong aircraft. A low hour PPL in a less certain location would have been in for some high stress though. Both pilots and controllers make mistakes – we are all human. Good news is there has never been a fatal accident due to an infringement in the UK – let’s ALL work to keep it that way.

Rod1

[Rod1]

I have had some requests to give a little more background;

As many of you will know I have spent considerable time and effort increasing awareness of Collision Avoidance. If you have a device that detects transponders it does not take very long to realise that a fair number of transponder equipped aircraft do not have the unit’s switched on. If you challenge people on the ground it soon becomes obvious that there is a fear that “Big Bad Wolf will get you if you make a slip up – so why make it easy for him”.

How did this state of affairs come about? Well that is a complex question but one or two events had a big impact. A few years ago a Red Arrows display was ruined by 4 infringing aircraft. The “Daily Mail readers” were outraged and we were told that the culprits would be brought to book. Of the 4, only one was ever traced – the only one squawking – and he was prosecuted. This event has entered pilot folklore. Common belief is that if you do not squawk and you just make a small mistake, Big Bad Wolf will not see you and if he does, he will not see you well and will not trace you. I am not saying the above is technically correct, but it did happen once and people believe it.

The second issue is one of regulation. If you are an owner pilot and you do not fly IFR then if you have a transponder you are what is called a “user chooser”. This means you are under no obligation at all to have a transponder and if you have one you do not need to turn it on. I have spent many years trying to get people to use the kit, it makes everyone safer, but fear of Big Bad Wolf is a powerful thing. We are now at a crossroads in transponder fitment. Many none “IFR” owners have left their old Mode C units in the aircraft and such a unit has a huge upside to safety. So what is the problem? Well the installations are getting old and the kit is starting to fail. The owner of a failed Mode A/C transponder has two choices. He can replace it with a mode s unit at a cost on a permit of around £1500 - £2500 or on C of A £3500 - £4500 (averages based on work done some time ago), or he fits a blanking plate at close to zero cost. I am very keen that people choose to fit new units and I think everyone will see that that is good for the aviation community. In order for this to happen we need to dismantle the fear culture and win a hearts and minds campaign that we are all keen on safety, we all make mistakes and we must all work together to try to improve, not hang people out to dry. I have upgraded my transponder to mode s, I keep it on and I hope I am helping. If I removed the unit and sold it on ebay it would have almost zero impact on my flying (except I would have more cash!), but my small composite aircraft is almost invisible to radar without the kit.

Rod1

[robin]

I am very keen that people choose to fit new units and I think everyone will see that that is good for the aviation community. In order for this to happen we need to dismantle the fear culture and win a hearts and minds campaign that we are all keen on safety, we all make mistakes and we must all work together to try to improve, not hang people out to dry. I have upgraded my transponder to mode s, I keep it on and I hope I am helping. If I removed the unit and sold it on ebay it would have almost zero impact on my flying (except I would have more cash!), but my small composite aircraft is almost invisible to radar without the kit.

...and of course to bring the price down. The CAA could show a lead by waiving the mod fees.

[Echo Romeo]

Rod1

Good post:ok:

[maxred]

...and of course to bring the price down. The CAA could show a lead by waiving the mod fees

I am sorry, but I really do not get this.

When people go flying, especially around Control Zones, or known areas of low faster traffic, surely you would employ all means possible to make your trip as safe as possible.Transponders are a pre requisite for this. Regardless of cost.

I was at a very interesting discussion on this topic yesterday, where amongst other things, Airprox events were on the agenda. The RAF are trying extremely hard to get GA aircraft flying around at low level to transpond and speak to FISO's, therefore getting everyone more visual to fast jet traffic, and controllers. The side benefit is infringement, or more of a chance to alert would be infringers, and yet, people are still moaning about, the cost, the hastle, 'I dont want to talk to anyone', I am happy with my freedoms etc etc.

I have no issue with non radio/non transponder/non anything, as long as it is away from any potentail infringements or busy areas.

On the way home, I listened into an aeroplane transmit, who had been at the event, asking for a control zone transit, the controller was very busy, he then stated he was non transponder - Transit Refused , Stay Out Of Controlled Airpace. This has an overall negative effect, on the perceptions and attitudes of controllers, and the overall experience of the pilot, and yet individuals who either do not want, or cannot, fit an adequtae transponder, are still looking for Control Zone transits.

I honestly think pilots require to take a long hard look at the world we now live in and come up to speed.

[ShyTorque]

Good Egg, I think you missed my point. I posted after someone spoke of "ATC separation" in Class D.

ATC will normally tell you in no uncertain terms that there is none provided by them. ATC inform pilots of other traffic and separation is the responsibility of the pilots. That's the rules.


Would you honestly prefer if ATC told you "Unknown traffic, 1 o'clock, range 3nm, I think it's a PA28, possibly crossing right to left, maybe turning towards you, no height information available. Cleared to Land"??

Yes, in many circumstances I'd be reasonably OK to use my own discretion, take my own separation and land. I do so in Class G airspace quite often, without the benefit of ATC. I don't need runways though so it's unlikely that a PA28 would be aiming for the same place or even be able to follow my flightpath. :)

[EastMids]

When people go flying, especially around Control Zones, or known areas of low faster traffic, surely you would employ all means possible to make your trip as safe as possible.Transponders are a pre requisite for this. Regardless of cost.


Not correct about Cost... If this were the case, we'd all have approved panel GPS integrated to ADS-B out/in and traffic alerting systems. Cost almost always comes into the equation, balancing what we think we need to be safe. And transponders aren't pre requisite "around Control Zones" - they may be inside, but not outside. Where do you draw the line of "around"? Is it ok not to have a transponder 10 miles from a zone? 5 miles? 1 mile?

Don't get me wrong, I fly with a transponder and I always have it on. But it annoys me intensely that we have regulation from the CAA that makes it significantly more expensive than necessary to upgrade to the next level should our existing bit of kit fail. I don't need mode-s, the airport we fly from doesn't have a mode-s radar, and yet the CAA insists we have to fit a mode-s transponder should we need to change the transponder, and wants to charge us a hefty mod fee for the privilege, making the job more costly than it realy needs to be. Whilst I have no doubt we will fit a mode-s transponder when we need to and continue too use it on every occasion, it is very easy for me to understand why some in similar situations will elect to fit the proverbial blanking plate, especially when the transponder is not mandatory and the men from the ministry put financial road-blocks in the way.

[good egg]

While I accept that the minimum ATC could have done would be to pass traffic info to other VFR and watch what happens, I'd find it pretty hard to justify those actions in a court of law (should it come to that!) when we're talking about a "known unknown" inside CAS.

This aircraft was inside the zone, not on top of the zone. This aircraft was flying erratically and mute and was seen low level close to the runway.

ATC concerns at one point that an approach might be being attempted, hence the removal of the one lined up ready to go. And not a word spoken. Scarey stuff.

It was clear from listening, that due to lack of comms, intentions were unknown.
That was a great deal of surprise from us, when they re-appeared for the second time.
A lost solo student who panicked, a wanderer who got lost or a nutter with barking intentions.
The cloud base was variable around 2000 feet over the airfield and we never saw him. I suspect, given the gloomy day, they got lost.....big time.


You argue that the responsibility for separation against the infringer (given pertinent traffic info - which may not be possible!) rests with the VFR pilots, and you are right :ok: - I'd argue that ATC still have a 'duty of care' to prevent collisions...and do indeed care about preventing them!

The OP held on right base for 15 minutes (presumably, unlike you, the OP did need/want a runway at some point). Given the quotes above (gloomy day, not visual with infringer who was low-level to runway, flying erratically, possibly making an approach) I'd be surprised if any traffic in the vicinity (GA or otherwise) didn't understand the need for caution.

If the OP was a transit then yes I'd say it was odd to be stuck out somewhere for 15 minutes...but if ATC suspect the infringer may attempt to land in an emergency situation then holding off other runway traffic surely seems eminently sensible? (And indeed no doubt prescribed in unit MATS 2.)

So no I don't miss your point ShyTorque. YOU are ultimately responsible. Just you, nobody else but you.

This really shouldn't be a p*ssing contest. We're talking about what is a reasonable action to take given the situation. If VFR traffic can't accept an ATC instruction inside controlled airspace they will report it surely(?) and ATC will do what's necessary to assist.

This situation, whilst inconvenient to EVERYONE involved - and probably a lot more than just "inconvenient" to the infringer (who I have sympathy for) sounds like it was well handled to me. You, obviously, have a different opinion.

I, for one, enjoy the variation/challenge that integrating VFR flights creates. Working life would be dull without it. I am a great proponent of Class D airspace and would much rather there wasn't a proliferation of Class C in its place. A sentiment that maybe we can agree on?

[abgd]

events had a big impact. A few years ago a Red Arrows display was ruined by 4 infringing aircraft. The “Daily Mail readers” were outraged and we were told that the culprits would be brought to book. Of the 4, only one was ever traced – the only one squawking – and he was prosecuted. This event has entered pilot folklore. Common belief is that if you do not squawk and you just make a small mistake, Big Bad Wolf will not see you and if he does, he will not see you well and will not trace you. I am not saying the above is technically correct, but it did happen once and people believe it.

I've come very close to inadvertently infringing, but managed to avoid it thanks to being in contact with Farnborough who set me right. I intend to go on talking to people, and using a transponder when fitted. However in view of what you've posted above why would anybody not question whether that's the rational option?

[good egg]

Excerpt from http://www.iaopa.eu/mediaServlet/storage/gamag/dec07/GA_pp20-24.pdf

For pity’s sake, squawk!

The man from the Airprox Board, the air traffic controller, the CAA safety expert, the military men all said the same thing – if you’ve got a transponder, turn it on, altitude mode if you have it. You can make few greater contributions to your own safety than having a working transponder, preferably Mode-C.
There is a widespread and unfortunate perception in GA that the transponder is an instrument of CAA retribution, more likely to get you into trouble than out of it. This has its roots in the notorious Elvington case in 2003 when four aircraft infringed a Red Arrows display, but the CAA prosecuted only one pilot – the least culpable – because he had his transponder on and was thus the only one they could catch. AOPA warned then that throwing the book at him would have serious safety implications, and we have been proved right. At a recent seminar on infringements, well-known examiner Irv Lee said that 50 percent of the instructors and even examiners he flew with failed to turn on their transponders.
But at the same seminar, the CAA’s head of enforcement Ian Weston pointed out that a pilot who had his transponder turned on would be considered by the CAA to be a more responsible aviator than one who did not. In case of infringement, having a working transponder would militate against prosecution, rather than facilitate it.
It is true that since the Elvington case, no pilot has been prosecuted for an infringement in similar circumstances, and the advice to pilots from all quarters is to turn on your transponder, Mode-C if you have it. Airprox Board Director Peter Hunt said: “A transponder that is not switched on is like fuel in the bowser, runway behind and altitude above. Wherever you are, you’re better off squawking.”
TCAS systems need transponders to operate, and that in itself is enough reason for you to turn yours on. Why not add a ‘T’ to the end of your FREDA check and make sure your transponder is on, and that you have changed codes if necessary when changing radio frequencies? With the increasing use of local area codes like 1177 for London Information, 0013 for Luton/Stansted and 7366 for Manchester, leaving the old code up after you’ve changed frequency is going to become an increasing problem.
________________________________________________________


Oh, and I noticed these quotes in press relating to more recent prosecutions (2005 & 2009) relating to infringement of restricted airspace around other Red Arrows events:

"XXXX's plane was later traced from several photographs taken by shocked spectators at the event."

"YYYY's single engine aircraft was spotted by police in an exclusion zone just minutes before the RAF's flying aces were due to start a display above...

(Names removed as they are of no relevance to this)

[Lost in Cloud]

During my PPL training, one flight I turned on mode c on the transponder only for the instructor to turn it back to mode a only i.e. no altitude information.

When I quizzed him why, he simply stated 'you wouldn't tell the police how fast you a driving at would you'.

Fair point I thought, and at least he left it switched on but since completing my PPL I use, when available, mode c all the time.

[Level Attitude]

Mistakes apart, I would always turn on a transponder as part
of pre-Take Off checks.

However, contrary to NATS/ATC advice, on older transponders I would only
select Mode A unless/until I had been given a Squawk by a radar unit.

I've heard of too many erroneous altitude outputs (6,000', 20,000') when
aircraft are actually flying around 2,000'.

Not a problem with Mode S transponders as these show you what FL you
are reporting.

[Rod1]

The older style encoders took time to literally warm up and stabilize. The manual I have seen says 10 – 15 min from power up. Almost all old style mode A/C units will have a similar issue. Some new mode S units have been installed using the old encoder and will also have the same issue.

[Rod1]

These were transponders that used valves. Surely there can't be many of them left in service?

Not Transponders – the pre solid state Encoders as used typically with BK KT76a etc;
Operation

Place the aircraft transponder in altitude reporting mode (MODE C).

Place the aircraft transponder in the standby mode, unless power to the
encoder is supplied directly from the aircraft bus. In this case, follow the
power-up procedure recommended by the transponder manufacturer.

A warm-up time of approximately 10 minutes is necessary after power is
applied to the encoder. If power to the encoder is interrupted
momentarily after the unit has warmed up, a period of approximately one
minute after power is restored is required for the unit to stabilize

Or if you want an AK350 example which takes 15 min;

http://www.ameri-king.com/pdf/01%20AK%20350%20Installation%20Manual.pdf

Rod1

[Level Attitude]

A bit of a misunderstanding, Level, I think. All mode C transponders report level
assuming ISA, that is, as a flight level.

You are correct, a slip of the pen on my part.

However my point was that, as far as I am aware, all Mode S transponders
in GA aircraft have an LCD display which will/can show the FL being transmitted.
So a pilot could see if their their transponder is sending out an incorrect
value (especially if way out).

The older, twiddle a knob, transponders do not have this facility and
the pilot would therefore have to assume/hope that it is functioning
correctly. Once in contact with an SSR unit if the transponder is
misreading then they are likely to tell you smartish.

If you read the Incident Reports there are quite a few cases of pilots
flying perfectly legally below controlled airspace, but their transponder telling
ATC that they were up, without clearance, in their controlled airspace.

[flybymike]

The older, twiddle a knob, transponders do not have this facility
Plenty of new Mode S units have twiddly knobs;)