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National CAA policies around Europe on busting pilots who bust controlled airspace (and danger areas)

gallois wrote:

Oh come on. Most aircraft have an altimeter, that altimeter is subject to recalibration and checking on a regular basis, in the PPL we are taught how to use it. ATS give us a QNH to put in the window, and generally that doesn’t change much over a short timescale of a GA flight. Even if you don’t change your QNH going from one region to another you’ll most likely only be 30 feet out. OK you have to know whether you are operating on altitude, height or level, but surely everyone is operating the same system. If people are being fined, sent on courses or otherwise penalised for operating within that framework including the margins for error as set out in ICAO and EASA guidelines then that is just stupid and the people doing the penalising need to be held to account. After all CTA’s are supposed to be designed to take into account these margins for error.

Unfortunately this does appear to be what is happening in the UK now if the reports on here (and the flyer forum) are to be believed. Im glad I fly predominantly in a place where I get an FIS associated with the controlled airspace and only fly in the UK about once a year.

Regards, SD..

Really?

Have we heard of any cases where someone is sanctioned for a bust and their explanation is that it was all down to instrument error – i.e. they set the correct pressure and according to their altimeter they did not infringe, but the transponder seemingly showed that they did?

Last Edited by Graham at 15 Jul 10:38
EGLM & EGTN

The transponder always radiates pressure altitude (flight level), and setting the wrong QNH doesn’t change that. More here.

The recent CAA data shows that somebody (1 or 2?) got off by submitting evidence from a “licensed engineer” that their transponder was radiating the wrong pressure altitude. Fairly obviously this is not supposed to be trivially easy to do; a transponder test and a report will be a few hundred quid.

Then I wonder who gets busted for the plane being potentially unairworthy?? If the pilot is a renter, he will be ok. Not same for an owner… So one needs to be careful trying to use this defence.

Administrator
Shoreham EGKA, United Kingdom

Peter wrote:

The recent CAA data shows that somebody (1 or 2?) got off by submitting evidence from a “licensed engineer” that their transponder was radiating the wrong pressure altitude. Fairly obviously this is not supposed to be trivially easy to do; a transponder test and a report will be a few hundred quid.

The “beauty” of the CAA’s approach is that this never gets tested in court…

The CAA is relying on the transmission of the encoder to prove that an offence has been committed. There are permissible tolerances for encoders. They would have to prove that, at the time of the alleged offence, that encoder was more accurate than the tolerance, and failing any specific evidence that is was any better, would only be able to prove that the offence was committed if the encoder, minus tolerance, definitely transmitted an altitude inside the allegedly infringed airspace.

Biggin Hill

Peter wrote:

Fairly obviously this is not supposed to be trivially easy to do; a transponder test and a report will be a few hundred quid.

Most Mode S Transponders read out the encoded altitude right on the display so what is difficult about that? You should be aware that something is amiss rather quickly.

LSZH(work) LSZF (GA base), Switzerland

The “beauty” of the CAA’s approach is that this never gets tested in court…

Yes; I wonder how that worked. It takes anything up to 2 months from the CAS bust to getting the CAA “sentencing” letter sending you to Gasco or whatever. In the case of a suspected transponder you would have to act much faster and got it tested quickly.

If it was a school plane which you rented, I would not expect them to rent to you again

Most Mode S Transponders read out the encoded altitude right on the display so what is difficult about that? You should be aware that something is amiss rather quickly.

They do, but most people don’t know that

Also most CAS busts in the UK are of airspace below the transition, which is mostly 6000ft or so. So anytime the QNH is not 1013, you would need to do maths on the transponder displayed number to get an idea of what the radar controller is seeing on his screen. That maths is not trivial unless you are good at it, and generally exactly 50% of people work it out in the wrong direction. That is why all the flying exams (including the dodgy infringement online exam) are stuffed with these altimetry questions

There is an easy test: set 1013 on the altimeter on the ground and the transponder should read the altimeter setting. But again most people don’t know this. It also breaks if your altimeter is also the encoder for the transponder…

In real life a pilot never does these altimetry calculations. You set a QNH for altitude-based airspace (or flight) and you set 1013 for FL-based airspace (or flight).

Administrator
Shoreham EGKA, United Kingdom

Peter wrote:

Also most CAS busts in the UK are of airspace below the transition, which is mostly 6000ft or so. So anytime the QNH is not 1013, you would need to do maths on the transponder displayed number to get an idea of what the radar controller is seeing on his screen. That maths is not trivial unless you are good at it, and generally exactly 50% of people work it out in the wrong direction. That is why all the flying exams (including the dodgy infringement online exam) are stuffed with these altimetry questions

I don’t buy the math QNH/QFE/FL argument, I don’t think changing CAS case base to 6350ft from 6000ft make any difference to the number of busts most of us will bust airspace as they completely forgot about it rather than flying precisely 30ft beneath it on their wrong QNH settings

Now transponder FLXX<FL22 number is all I care about now when flying under LTMA in flyable high pressure days (I set a warning on GTX at FL22, this now scares me every time I depart from elsewhere )

Also, anyone to confirm if SD use get airspace warnings without adjustment for FLs/QNH? I had the impression only GPS altitude is used…

Last Edited by Ibra at 15 Jul 13:29
Paris/Essex, France/UK, United Kingdom

I don’t think changing CAS case base to 6350ft from 6000ft make any difference to the number of busts most of us will bust airspace as they completely forgot about it rather than flying precisely 30ft beneath it on their wrong QNH settings

I think that is probably true.

The main reason is probably that most pilots set the altimeter to the airport elevation initially, and given that most intra-UK flights (especially non radio ones) are short, that will work well enough.

No idea how tablet apps do it. I know my Aera 660 (and the Garmin 496 before that) did airspace warnings purely on GPS altitude. How it did it for FL-based airspace I have no idea; I suspect it warned a few hundred feet below it too.

Administrator
Shoreham EGKA, United Kingdom

Peter wrote:

That maths is not trivial unless you are good at it, and generally exactly 50% of people work it out in the wrong direction.

It’s sub-GCSE level arithmetic of the kind you learn by the time you’re 12, it’s the very definition of trivial, and it’s the kind of thing that can be put on a small laminated card for quick reference. We’re hardly talking partial differential equations here.

Andreas IOM

It’s not the arithmetic that is tricky. It’s the way the question is phrased.

EGLM & EGTN
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