CPDLC handoffs on VHF ?

[JetScan1]

I was listening to Maastricht Control on VHF channel 132.615 this morning and heard United 945 climbing out from FRA/EDDF, they checked on climbing out of FL230 for FL280 and advised they were CPDLC, they were cleared direct MIMVA and up to FL340. A few minutes later Maastricht called them and asked if they had received the datalink handoff that they had just sent. The flight replied affirmative and that they would change to 132.635 at this time.

CPDLC handoffs to VHF voice frequencies are common from Oceanic areas, but this is the first time I've heard it being used in VHF sectors when the flight is in voice contact with the controller. Anyone know how long Maastricht has been doing this ? Is it standard ops or just a trial ?

DJ

[znymz]

My assumption is that the aircraft is heading into oceanic airspace and will no longer be in VHF voice contact.

[JetScan1]

My assumption is that the aircraft is heading into oceanic airspace and will no longer be in VHF voice contact.

On that route they wouldn't be out of VHF range and into oceanic airspace for almost another 2 hours, they still had around another 5 or 6 VHF sectors to pass through (Maastricht, London, Scottish), before the CPDLC log on with Shanwick. The handoff was from one domestic Maastricht VHF sector to another domestic Maastricht VHF sector.

After digging around a bit I found this.

http://www.eurocontrol.be/agdl/public/news/CPDLCreviewJanMar2005.html

So it appears Maastricht has been running trials with domestic flights for a while now. What I'm wondering is to what extent Maastricht is actually using CPDLC with aircraft that are equipped. Are they giving clearences with it now, or is it just used for requests, transponder code changes, handoffs, etc ? The United flight I heard appered to be using voice comm for all clearences, except for the handoff.

DJ

[znymz]

Reading the article, it appears they are using it for control messages.

For “Contact” instructions [where CPDLC is used to instruct an aircraft to call the next frequency] 4978 messages have been used, compared to 3699 in the last quarter of 2004. “NSSR” messages have risen from 553 to 1003, “Route” messages have increased from 2048 to 2714, and “Level” messages have also increased from 287 to 1417.

Though I don't know what NSSR messages are, they are giving route and altitude "level" messages which would be atc clearances. We've been using CPDLC in the North Atlantic airspace for a year now. We're just waiting for the airlines to get it in the planes. An expensive proposition but it is happening slowly.