CPDLC
Thread Starter
Joined: Apr 2008
Posts: 1,037
Likes: 1
From: Playing Golf!
CPDLC
Hi guys,
On my fleet we dont have it but.....
In populated areas is this data being sent over VHF ACARS networks, ARINC / SITA...
Or is it sent on its own dedicated network, or only by HFDL / SATCOM.
Just curious!
On my fleet we dont have it but.....
In populated areas is this data being sent over VHF ACARS networks, ARINC / SITA...
Or is it sent on its own dedicated network, or only by HFDL / SATCOM.
Just curious!
Joined: Mar 2007
Posts: 1,235
Likes: 0
From: USofA
Usually programmed to use the least expensive mode available at the moment of use. VHF,HFDL and lastly SATCOM. You can usually see what it's using at anyone time by looking at the Comm Manager on the 777,747-400 and the 787. As for ARINC or SITA, I think that is a company decision.

Joined: Jun 2001
Aviation Qualifications: ATPL
Posts: 1,187
Likes: 59
From: OZ
From personal observation, last week actually, CPDLC works on VHF or satcom. With a satcom failure there was no CPDLC until we were in VHF range.
Most inconvenient talking on the wireless!!
Most inconvenient talking on the wireless!!
Joined: Aug 2013
Posts: 30
Likes: 0
From: PA
Last edited by underfire; 12th November 2016 at 21:51.
Joined: Jul 2000
Posts: 399
Likes: 0
From: West
It depends on the avionics suite and network you plan to use for your CPDLC. If you are going to use FANS 1/A, which allows datacom directly with the Oceanic Controller (instead of via a Radio operator), then you are using the ACARS "network" (SATCOM when outside of VHF coverage) for CPDLC. FANS CPDLC can also be used over continental airspace, such as Canada and Europe. However, in Europe the current plan remains to use VDL Mode 2 which uses ATN network. It is costly to carry both FANS and ATN CPDLC avionics. For this reason a lot of people are doing their best to avoid this "dual stack."
FANS is the initial version of the Future Air Navigation System, which includes CPDLC and ADS-C.
• “FANS-1” is a Boeing derived system.
• “FANS-A” is an Airbus derived system.
• “FANS 1/A” refers to both Boeing and Airbus FANS.
• “FANS 1/A+” means that the aircraft completely complies with Revision A of the initial standard, which includes a message latency monitor.
• “FANS 2” and “FANS B” are the second generation of FANS and will not use the ACARS network, but rather the ATN network.
CPDLC in Europe is not yet performing as required. Some aircraft within limited areas are utilizing CPDLC, and hopefully they have "best in class" avionics in order to avoid "Provider Aborts." However, if you read the ELSA report you will learn that multi-frequency, separate frequency (terminal vs. enroute ops), and improved use of VHF Ground Stations are just two of the items that need to be addressed in order to move European CPDLC forward.
FANS is the initial version of the Future Air Navigation System, which includes CPDLC and ADS-C.
• “FANS-1” is a Boeing derived system.
• “FANS-A” is an Airbus derived system.
• “FANS 1/A” refers to both Boeing and Airbus FANS.
• “FANS 1/A+” means that the aircraft completely complies with Revision A of the initial standard, which includes a message latency monitor.
• “FANS 2” and “FANS B” are the second generation of FANS and will not use the ACARS network, but rather the ATN network.
CPDLC in Europe is not yet performing as required. Some aircraft within limited areas are utilizing CPDLC, and hopefully they have "best in class" avionics in order to avoid "Provider Aborts." However, if you read the ELSA report you will learn that multi-frequency, separate frequency (terminal vs. enroute ops), and improved use of VHF Ground Stations are just two of the items that need to be addressed in order to move European CPDLC forward.
Joined: Aug 2013
Posts: 30
Likes: 0
From: PA
Yes, many different providers depending on the area and manufacturer.
I was thinking that the poster was wondering if CPDLC uses the ACARS 'system' on the aircraft for communication.
There are SITA and ARINC networks.
ACARS systems are designed for the transmission of character-based messages to and from the aircraft, whereas the CPDLC and ADS applications intended for the ATN were defined using a binary bit-coded message set.
I was thinking that the poster was wondering if CPDLC uses the ACARS 'system' on the aircraft for communication.
There are SITA and ARINC networks.
ACARS systems are designed for the transmission of character-based messages to and from the aircraft, whereas the CPDLC and ADS applications intended for the ATN were defined using a binary bit-coded message set.
Last edited by underfire; 13th November 2016 at 00:51.


Joined: Nov 2007
Aviation Qualifications: ATPL
Posts: 1,954
Likes: 30
From: Texas
An aircraft with CPDLC has one of the following panels:
Joined: Jul 2016
Posts: 27
Likes: 0
From: Everywhere
ACARS
To answer the original question, yes ACARS is the communication conduit for FANS CPDLC. ACARS uses VHF, SATCOM and (if enabled) HF, usually in that order of preference as specified by the operator.
Joined: Aug 2013
Posts: 30
Likes: 0
From: PA
To answer the original question, yes ACARS is the communication conduit for FANS CPDLC.
Joined: Jul 2016
Posts: 27
Likes: 0
From: Everywhere
I say again, FANS uses the ACARS network! Some aircraft use VDL0 and some VDL2 which is higher speed but VDL2 is NOT required for FANS CPDLC. VDL2 IS required for the European ATN system, which is not used elsewhere.





