When a FPL is activated, a SSR code is generated via ORCAM.
Is the SSR code the squawk issued by Eurocontrol?
IIRC, EC issues this before the FP is activated. The Autorouter used to deliver the code when a FP was filed (and well before you got airborne) but they stopped it due to complaints from some countries (UK being one of them; presumably because it defeated their software for auto detecting CAS busts).
What does an ATCO do when he/she issues an IFR clearance to a flight already airborne VFR?
Guillaume wrote:
The FDPS (flight plan data processing systems) associates the XPDR of the aircraft to the SSR code previously generated. The aircraft is now correlated to the FPL.
I see this working with ModeS on generic 1000/2000 codes and also using Eurocontrol SSR code correlated to my flight plan
I am not sure why it does not work ‘on many other flights’, I load of them when tracking is missing, maybe just a bug?
Guillaume wrote:
When a FPL is activated, a SSR code is generated via ORCAM.
The code is generated before the flight plan is activated. It’s already on the strip when you first call up ATC on the ground.
Peter wrote:
What does an ATCO do when he/she issues an IFR clearance to a flight already airborne VFR?
That’s no different from a flight that’s IFR from the start. The squawk code is on the strip.
Some event starts the Eurocontrol tracking – the topic here.
Peter wrote:
Some event starts the Eurocontrol tracking – the topic here.
That would be when the radar system sees the squawk code — at least if the flight is in a participating country. I know that at least 6 or so years ago, Estonia did not provide tracking. On an IFR flight EETN – ESSV, the tracking started at the Estonian/Latvian FIR border. I asked Achim about that and he said that there was no tracking in Estonia.
This will need a careful test. Sometimes I fly all the way to EGKA on the London Control squawk and sometimes I set 7000 as instructed by LC when dropping out of CAS. Then I will have the ATC recording and can work out when I set 7000.
@Airborne_Again, what about VFR? Does Eurocontrol do anything with VFR flight plans? If not, then who activates them?
EC does nothing; VFR FPs are AFTN messages (which nowadays don’t go via “telex” but go via fast TCP/IP links, and some private lines; I saw a map at NATS ~10 years ago) and ultimately end up entirely in national databases, some ATC-accessible and some not, some maintained for national security usage.
EC still handles Z and Y FPs.
That would be when the radar system sees the squawk code
Maybe necessary but not sufficient? see my example here
I was on radar system but no tracking for whole 1h above radar altitude
Flight was odd versus many I had before: no TWR ATC, no SID, no STAR, no POGO, no HDG
No vectors: omnidirectional departure, direct to overhead, cleared for ILS & RNP
As I mentioned, none of the information around tells me when tracking starts & stops (to some degree it’s random, some flights feels like missing something 
)
