Wiggy, a company aircraft did ask LHR to ACARS them, not sure if that's what got them back in comms

LHCC CPDLC
 

It's worth noting that there is a likelihood that the BA 777 involved was not capable of logging on to Budapest CPDLC, unless a retrofit to the CPDLC interface had been carried out.

Budapest is a non FANS based CPDLC system and in my outfit, only 777s that are around two and a half years or younger can log on to such CPDLC connections. BAs -200 airframes are a little older than that if I can recall correctly. The newer aircraft enable you to select if the CPDLC connection is FANS equipped or not and for Budapest, the FANS selection box should remain unticked when logging on. For connecting to Maastricht (for example), the FANS box would be ticked whilst logging on as that is a FANS based CPDLC system. Older 777 airframes do not allow you to differentiate between a FANS or non FANS based CPDLC connection and default to all connections being FANS equipped. Therefore connecting to the likes of Budapest will not be possible. The same applies to the likes of Rhein and Copenhagen who have a non FANS based CPDLC system.

My basic understanding is that FANS CPDLC connections use ACARS technology to send and receive messages and the alternative uses the ATN network to send and receive messages.

I myself have used CPDLC with Budapest with no problems!

Couldn't CPDLC logging-on be made automatically? In my mind such a system becomes much more useful, specifically as a side-channel for lost comms, if the pilots didn't need to do anything except maybe once at the start of the flight (entering a callsign/ID/authentication, whatever), and it then handles log-ons by itself. I realize this might be difficult for technical and legal reason, such as it not being easy from GPS position to determine where to log in....

Hi All,


The Budapest ATM system was upgraded in line with "VDL Mode 2" CPDLC specs by EU requirements. (The older FANS was out of question).To my knowledge, the deadline for the full implementation in EU states is 2018.

Budapest CPDLC is currently not an approved logon for use on BA aircraft. So other procedure (currently) required to re establish lost comms

Once the ATN-B2 system is operating on VDL2 initial CPDLC logon will be automatic. The current controller is known as the 'Current Data Authority' and on handover the controller's system initiates a 'Next Data Authority' message identifying the next controller's CPDLC identity to the aircraft systems which then will transfer the CPDLC connection to the next controller.

Problem is that CPDLC is rather like sending an SMS text message from your cell phone. You do not know that it has been read by the crew until/unless you get a response.

As a 'frequent flyer' on this route, my sympathy goes out to the BA crew and a strong dose of being thankful for my good luck (thus far) not to be on the receiving end of a 'close inspection'. One of the most insidious issues we have to face is the sectorisation that is invoked in many European FIRs. In the Bucharest FIR there is a frequency change about 40 miles from the Budapest FIR, least when you expect it (too soon for an ATC FIR handover, too soon to expect an inter FIR handover). Germany is another classic case in point, it seems that if you are heading E-W in Germany, you get a freq change every thirty miles (slight exaggeration I know, but the point is made). We can use various techniques to alert us to the passage from one FIR to anther, but we are blissfully unaware of how each FIR is divvied up into sectors.

Question for CPDLC air traffic controllers - does your system give you an option to send a message to an aircraft to inform them they are "lost comms" or similar? The UK has both ATN and FANS CPDLC capabilities but no message available to solve a lost comms issue, there is however a "stuck mic" message!!

We have "CHECK MIKE" msg and "FREQUENCY CHANGE" msg available, the latter would be more useful in COMLOSS cases.

CPDLC is not above fallacy. EK-LH loss of separation incident is a clear example.

There will always be mistakes when humans are involved and failures when technology is involved.

Jack Schidt - I never thought about building range rings over fir entry/ exit points. Thanks for the good idea.

Yeah, or put in abeam lines.

All the above is good for FIR entry/exit but as another frequent flyer on the specific route in question I'd agree with the point Thridle Op Des made about the size of some of the sectors.

Poor us pilots....how about opening your damn enroute chart,select/highlight the FIR entry waypoints in your FMC,and if not called by the relevant ATC then remind them.

Did Europe ever contemplated single FIR? Is it even possible.

Militaries would never allow it. They're the biggest opponents of SES already

That is interesting. 121.5 appears to be a nuisance over Europe and fighter jets on your tail if you miss a call for few minutes. Someone should rethink the entire process.

It is getting close to that. You may not have noticed but the airspace in Europe is being split into 'Functional Airspace Blocks'. These are blocks of airspace that are very similar. So the whole of central Europe is one FAB known as FABEC. UK and Ireland airspace are one FAB. This is part of the move toward user preferred trajectories. The routes are being simplified already and you can plan from entry point of the FABEC to exit point of the FABEC for example. Step 2 of the 'SESAR Master Plan' will see all fixed routes removed from European airspace (more correctly EUROCONTROL States airspace) from exit of the departure TMA to entry of the destination TMA.

This is a huge change.

Concurrent with that the North Atlantic Oceanic Track Structure will cease to be published in 2025. All transatlantic flights will be user preferred trajectories, or in SESAR parlance, Business Trajectories. It might be a good idea to start chatting with your dispatch to see how they intend to work with airspace without air routes. It will not be a simple change for dispatch.

...that will not work in a large portion of UK airspace, and I imagine several other European sectors also. Not forgetting that this principle doesn't allow natural avoidance of Danger or Restricted areas which will add workload to the controller concerned which just means even more restrictive flow measures when these areas are active.

FABEC is a wonderful idea on a politicians piece of paper, which is where it should stay.

FAB's have already demonstrated clearly that they simply don't work. SES is indeed a great idea and a noble cause strongly supported by airspace users but just have a look at the recent attempt to implement a common transition altitude across the EU and you will quickly see how difficult the process of establishing a workable single FABEC is.

Ian W It is not.