What we know about the US CPDLC trial



There is a CPDLC trial running in the US, but it isn’t open for everyone…

General CPDLC stuff

CPDLC is basically a sort of ‘text messaging’ system that lets ATC contact you, and you contact them.

Combine it with ADS-C and you’ve got Datalink, which is mandated in a bunch of places like the NAT HLA, Europe and the UK above FL290 etc.

Some other useful info:

  • Europe have a logon list. If you want an answer then register.
  • Europe use ATN, everywhere else uses FANS. If you only have FANS then you can still call yourself ‘CPDLC in Europe’ if your original certificate of registration is pre 2018.
  • Just to be clear, the US requires FANS 1/A.
  • If your airplane is younger than 2014 then the system also needs a message recording function.
  • PBCS tracks need a performance standard of RCP240 (ADS-C is RSP180).
  • AO56 is the LOA to get (or maybe A003).

We actually made A little Opsicle on CPDLC just the other day. It is quite a silly one, but here it is if you want a look:

Click for PDF.

CPDLC in the US

The US has CPDLC in a bunch of places. It isn’t really mandatory yet though. At least not the domestic en-route CPDLC. This is the bit they are running a trial for, and they’re doing it with L3Harris.

The trial is actually, specifically, for the business and general aviation community. The likes of Boeing and Airbus (or rather their avionics configurations) have already been approved.

So, here is the FAA info on it. Or rather, this is the notice talking about who can participate in the trial. They released this because a bunch of folk were participating, but their avionics version or configuration wasn’t good enough and it was messing up the results.

Trial Notice

So how do you know if you’ve got what it takes?

All the systems are listed on the L3Harris site. If your aircraft type is missing from the Trial List (shown below), this means that operational acceptability hasn’t been determined yet for that specific aircraft type. If that’s you, you can fill in the form and email it to them at DCIT@L3Harris.com and they will check to see whether you have the spec to participate in the trial.

If your aircraft type (system) is not on it, then don’t file as capable of en-route CPDLC and don’t try and ‘participate’.

For those of you who are on it…

Here is a map of current active CPDLC sites:

ZID/Indianapolis, ZKC/Kansas City, ZMP/Minneapolis, ZDC/Washington, ZOA/Oakland, and ZMA/Miami en-route control facilities are all up and running 24/7 now.

We’ve so far only found a table showing 61 airports where CPDLC DCL services are currently available:

But we know this is a bit out of date. We’ve counted 65 airports currently operational including these:

  • KJAX/Jacksonville
  • KPBI/Palm Beach
  • KCVG/Cincinnati/Northern Kentucky
  • KADW/Joint Base Andrews

Some stuff on using it

OK, so if you take-off from an airport that has CPDLC DCL and which is in an en-route CPDLC area then KUSA (because they’re who you’ll basically be logged onto on the ground) is going to stay active and there is nothing else to do once airborne.

If you take-off logged onto KUSA and only get into the en-route CPDLC bit later then again, KUSA stays on and there’s nothing more for you to do.

If you take-off logged onto KUSA and then are leaving all CPDLC airspace, it will auto log off when it needs to.

For all other scenarios, you probably need to manually log on when you reach the place where CPDLC is available.

KUSA is available on the ground in the lower 48 states, San Juan and Puerto Rico.

This info is all available here.

L3Harris are very active in all this and get in touch if they spot any irregularities with aircraft involved in the trial (nice to know they’re out there, watching).

Handing over the ‘info baton’

So far, all this has been snatched from a bunch of very handy guides that L3Harris publish, so here are the links to those for further info:

And if you are an operator in the US with questions about this, then speak to these folk – DCIT@L3Harris.com


More on the topic:

More reading:



Question for us? Write to blog.team@ops.group.


  • Joe says:

    As of now you cannot simply list your aircraft as Enroute until you have been put on the “Return to Service List”. This includes the aircraft / avionics on the “U.S. Domestic En Route CPDLC Trial Avionics” which you have above. Please update this article to reflect the correct information. If you need to verify what I’m saying please see following text from the latest L3 Harris “U.S. Domestic En Route CPDLC Avionics Trial” document on their website.

    “During testing certain avionics configurations for business aviation aircraft have shown that they meet operational
    acceptability in U.S. Domestic En Route CPDLC, below is the Business and General Aviation Trial List with the associated
    aircraft types and avionics configurations. If you believe your aircraft meets operational acceptability, please use the Trial
    List below in conjunction with the Verification of Avionics Configurations and please fill out the U.S. Domestic En Route
    Eligibility form. Once the information for the applicable aircraft has been reviewed and determined to meet the
    requirements, the aircraft will be added to the “Return to Service” list for U.S. Domestic En Route CPDLC operations.
    Please note that the current Trial List is not inclusive of all aircraft types, the Trial List is continuously being revised and
    updated throughout the testing phase. If the aircraft type is missing from the Trial List, this means that operational
    acceptability hasn’t been determined yet for that specific aircraft type at this time. As testing continues more aircraft
    types will continue to be added to the Trial List.”

    As you can see it says to fill out the US Domestic En Route Eligibility form even if your aircraft is on that chart you have listed above.

  • Robert McNease says:


    I don’t believe the trial allowing anyone who believes their aircraft are properly equipped can give en route CPDLC a try. I know they are talking about it, but haven’t set a date (got this from L3 Harris a few minutes ago). We’ve had to have our aircraft tested and approved by the FAA to participate.
    I just attended a datalink conference hosted by Eurocontrol. They are looking at ending the requirement to have your aircraft registered.

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