Peter wrote:
That surprises me.
According to AIP-UK GEN 1.5 section 5.3.1.3 VFR traffic must have a mode S transponder if operating
(IFR traffic, of course, must always have a mode S transponder in both the UK and the EU.)
arj1 wrote:
It is is either or, from my last discussion with a CAA person – you either … or you contact the ATC responsible and ask for a transit.
According to AIP-UK GEN 1.5 section 5.3.5, you need a written exemption from the CAA if you don’t have a mode S transponder. In practice, it is of course possible that individual ATC units are more flexible.
IFR traffic, of course, must always have a mode S transponder in both the UK
Only for Eurocontrol IFR. IFR in G here doesn’t need a TXP, or even a radio 
The question remains of what Mode S actually does today in Europe. I’ve mentioned the UK experiment from many years ago. They were basically making use of the aircraft reg being available, which Mode C doesn’t give you.
Please keep this on topic. ADS-B is something else.
In Norway neither Mode S nor 8.33 kHz radios are mandatory for GA. 8.33 will be mandatory at some point, but don’t remember exactly when anymore. I have heard no such thing about Mode S. It probably never will become mandatory below fl 195. It’s all rather confusing IMO. Avinor just finished their installation of WAM (Wide Aera Multilateration) this spring. I think that system needs Mode S? but ADS-B also works just fine according to Avinor. But why ADS-B and WAM? One checks the other? Other places/operations, as in the sea/coast/helicopters, it’s all ADS-B. IF something becomes mandatory at some point in the future, it looks like it will be ADS-B, not Mode S, at least to me that seems to be the case. At the same time, making ADS-B mandatory in Norway for GA when it’s not in the rest of EASA seems very far fetched.
Does ADS-B fulfil the requirements for Mode-S ? For instance, in Germany, if you install ADS-B instead of Modes S in your brand new Cirrus Will that be OK in relation to regulations?
Peter wrote:
The question remains of what Mode S actually does today in Europe. I’ve mentioned the UK experiment from many years ago. They were basically making use of the aircraft reg being available, which Mode C doesn’t give you.
Peter, I think you’ve summed it up here – with Mode-S you’ve got an aircraft reg straight away, that is for the benefit of the ATC.
In practice it means that an ATC doesn’t have to ask for the individual discrete codes to be assigned to be able to “manage” the aircraft and more convenient when they need to address the aircraft on listenning squawk (“are you on frequency?”).
Peter wrote:
The question remains of what Mode S actually does today in Europe.
Mode S ES is great for safety, if/when ATC upgrades their radars to make use of it, it adds a supplemental slice of cheese with respect to the Swiss cheese model. I once set my altitude bug incorrectly, ATC saw it and “reminded” me to check (before I even got to the said altitude, so Mode S ES is the only way they could have seen anything; and it was literally the week after they got their new radar…). I also once forgot to switch to QNE and levelled at the wrong level, again ATC challenged me on it after some time, but this one they could have seen just through plain old Mode C. Also it gives them your FL in 25 ft increments.
Does all of Europe have Mode S in ATC radars?
According to AIP-UK GEN 1.5 section 5.3.5, you need a written exemption from the CAA if you don’t have a mode S transponder. In practice, it is of course possible that individual ATC units are more flexible.
I think it’s worth looking at rules for each TMZ
Many allow ModeC if you call the right unit and some even allow “based aircraft” landing/takeoff without transponder in TMZ
If you do not want to talk to anyone in TMZ, you need ModeS
In other words, in CAA land, most TMZ become an RMZ for those without ModeS (modeC or no TXP), this includes +FL100 TMZ that sits on the whole country
LeSving wrote:
In Norway neither Mode S nor 8.33 kHz radios are mandatory for GA
Mode S is mandatory for GA under IFR, per EU regulation 1207/2011 (with amendments). (Whether ATC in Norway will notice or care if you only have mode C, I have no idea.)
Peter wrote:
Only for Eurocontrol IFR. IFR in G here doesn’t need a TXP,
AIP-UK GEN 1.5 section 5.3.1.3 states that “…aircraft operating in accordance with instrument flight rules within UK airspace.” must have “mode S elementary surveillance” with no restriction to particular airspace classes. (I only quote what the AIP says. Again, I have no idea about how this rule is actually enforced.)
AIP-UK GEN 1.5 section 5.3.1.3 states that “…aircraft operating in accordance with instrument flight rules within UK airspace.” must have “mode S elementary surveillance” with no restriction to particular airspace classes. (I only quote what the AIP says. Again, I have no idea about how this rule is actually enforced.)
That’s very funny, since you don’t even need a radio to do cloud hole drilling in G I reckon it’s a drafting cockup. Well, it obviously is a drafting cockup since > 5.7T and > 18 seats, twin TP, etc etc you are required to have Enhanced Mode S.
