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!
Last edited by Emma Royds; 3rd May 2016 at 23:28.