Peter wrote:
What about NATO obligations and air defence? I know this is not “fashionable” anymore (among the “enlightened classes” ) but times are probably changing…
More than enough military radars here 
huge siloed ones, mobile ones in the air, ground and sea. Ørland is the base of the e3a for instance.
Peter wrote:
Sure radiation from an aircraft is more visible than a radar reflection from it, but it makes some assumptions… Maybe Norway is a highly compliant society? It would never work in most places.
The only assumption made is: IF you have a transponder, it must be turned on. For people wanting to fly off the grid, they can indeed do so now. There is no requirement for transponder anywhere except in controlled airspace. This WAM will come everywhere. It’s the same as ADS-B in the US, there will be no use for ATC radars there either. Austria has already had WAM for a while. The thing about it is the requirement for a transponder. No problem for commercial aviation, but some “manufactured” problems for GA. I find it a bit odd though, I have heard so little about it, nothing. No one talks about it.
On the other hand, a mode S transponder “squits” all the time, once a second. It’s exactly like an ADS-B, only it “squits” the tail number only. WAM will come everywhere.
a mode S transponder “squits” all the time, once a second
No, it doesn’t. Only when pinged by SSR.
As regards WAM the thing to always consider is how visiting aircraft will be dealt with. One aspect of aviation, which many in the regulatory sphere find uncomfortable, is that planes fly between countries. So provision has to be made for visitors.
Australia doesn’t have that problem, because virtually nobody flies in or out of it, except airlines and other jets which are all ADS-B.
Not sure you will when departing from France, from L2K for example. I never do in France.
For some reason I did.
Peter wrote:
No, it doesn’t. Only when pinged by SSR.
I think the confusion may arise out of two different usages of “Mode S”. This quote from Garmin sums it up nicely:
The FAA has designated two options for airborne equipment that will satisfy the ADS-B “Out” requirement: One is the dedicated 978 MHz universal access transceiver (or UAT), and the other is the pairing of a 1090 MHz Mode S “extended squitter” transponder with an approved GPS navigation source (such as WAAS GPS) to provide the required position, vector, altitude and velocity data.
So technically, if you broadcast your position etc. via 1090 MHz (as will be the case in Europe), this is still a mode of “Mode S”. And this will actively transmit every second.
Mode S without ES only answers active interrogations.
All AFAIK and maybe someone knows better.
Peter wrote:
As regards WAM the thing to always consider is how visiting aircraft will be dealt with.
To quote from the Wikipedia page that you linked to:
WAM operates with SSR Mode A/C, Mode S, and Mode S ES messages; no aircraft equipage change or mandate is necessary.
LeSving wrote:
The only assumption made is: IF you have a transponder, it must be turned on. For people wanting to fly off the grid, they can indeed do so now. There is no requirement for transponder anywhere except in controlled airspace.
Now I am confused. Wasn’t it you who started off this thread claiming that the Norwegian AIP required any XPDR to be on? Where does it say this only concerns controlled airspace?
So technically, if you broadcast your position etc. via 1090 MHz (as will be the case in Europe), this is still a mode of “Mode S”. And this will actively transmit every second.
Mode S without ES only answers active interrogations.
Mode S, if switched on in any current GA transponder, will radiate the 24 bit code and the aircraft reg, plus IIRC a flag saying whether the aircraft can go above 150kt. I went through this with my GTX330 in 2005.
After that, you get into the Elementary Mode S versus Enhanced Mode S business, which is a purely Eurocontrol invention and there is no config for it in the transponder(s) which were designed in the USA. If Elementary (basically below 250kt TAS, below 5.7T etc) then you are not supposed to radiate additional parameters. If Enhanced (which say a TBM has to be) then you can radiate them, and what gets radiated is according to what data is connected to the transponder’s input. At some higher point you are required to radiate stuff like the autopilot preselect. We had past threads on this, with me posting the reference to the EU prohibition on radiating the extra stuff (and mentioning a magazine article by one avionics shop who posts here saying he had to remove the said wiring from some huge number of Mode S transponder installations after that ruling) and with people saying I was talking crap and that their well known German avionics shop just left the connections in place. I do think that stuff has since moved on and you are welcome to radiate anything you can – as indeed any plane visiting Euroland from outside (it does happen, though extremely rarely 
) is doing anyway But most GA planes don’t have the data (GS, GPS position, autopilot altitude preselect, etc) available nicely in ARINC429 or a compatible RS232 format.
Now I am confused. Wasn’t it you who started off this thread claiming that the Norwegian AIP required any XPDR to be on? Where does it say this only concerns controlled airspace?
It’s gonna be moot after October anyway.
Aviathor wrote:
Now I am confused. Wasn’t it you who started off this thread claiming that the Norwegian AIP required any XPDR to be on? Where does it say this only concerns controlled airspace?
What I meant is that a transponder (a physical one) is not a requirement in an aircraft. It’s only a requirement for controlled airspace. It’s an airspace requirement, like radio, BRNAV for IFR and so on. An additional requirement is that IF a serviceable transponder is installed, it must be turned on, regardless of airspace.
As I said, it’s cool, in an odd sort of way. It doesn’t make all that much sense to me. The radars will all be de-commissioned, so the ATC will have no way of detecting a non-transponding aircraft. It will be invisible to them. How this WAM is going to work without modes S/ADS-B being mandatory for every aircraft is not very clear.
Also, Silvaire has a point. Forcefully transmitting the reg number so programs like FR24 can transmit worldwide, in real-time, the position of private flights, will not go home well at Datatilsynet. It will be against the law. here in Norway, pure and simple. But, I haven’t seen anywhere it is a requirement that the reg-number shall be coded into the mode S transponder. There is no reason why it should either IMO.
Peter wrote:
No, it doesn’t. Only when pinged by SSR.
My understanding (right or wrong) is that a mode S transponder will squit the reg number (or whatever is coded into it) every second as a default. It will not squit altitude or any other information. When interrogated with a SSR or similar, it will also squawk whatever the interrogator ask: It could be reg number + alt, or just mode A/C. Mode S with ES is typically ADS-B, it will squit extended information. This is why Mode S and WAM go hand in hand. It is rather cool. The WAM can operate in passive mode (only listening), and a perfectly good aircraft position in 3D is obtained without being dependent on GPS or radar.
LeSving wrote:
Also, Silvaire has a point. Forcefully transmitting the reg number so programs like FR24 can transmit worldwide, in real-time, the position of private flights, will not go home well at Datatilsynet.
I wonder why they have not already taken action against FR24… Maybe because it is way down on their list of priorities?
For non-Norwegians, Datatilsynet is responsible for the enforcement of data privacy
Maybe because it’s a Swedish company?
My experience having lived in Sweden for a year is that the concept of privacy is basically non-existent there. You just don’t have anything to hide.
Rwy20 wrote:
You just don’t have anything to hide.
In that case there would be no such thing as Datatilsynet, would there?
I studied computer science in Norway and I can tell you they are very much preoccupied by data privacy. But it is true that they are transparent about things that continental Europeans prefer to hide.
Aviathor wrote:
In that case there would be no such thing as Datatilsynet, would there?
They do, it’s called Datainspektionen (English). And in fact, all the EU privacy laws obviously also apply (in theory), and I think the views on data protection also have changed over the last decades. But we have many Swedes on here, they are in a better position to give their views.
