This is the homepage for the Skipoles ACARS Bridge. If you are happy with what this is and why you need to use it then go ahead and Run The Bridge.
ACARS (Aircraft Communications Addressing and Reporting System) is a digital datalink system for transmission of short messages between aircraft and ground stations. The ground stations are typically ATC (Air Traffic Control) or Airline Companies.
Each ACARS message consists of a sender id (e.g. airplane call sign), a recipient id (e.g. airline company ICAO id), a message type and a packet payload.
CPDLC (Controller-pilot data link communications) is a means of communication between a pilot and ATC. It provides a way to exchange non-time-sensitive ATC related requests and responses. The primary aim is to free up congested voice comms channels by routing non-urgent via an asynchronous message based system.
A pilot logs into CPDLC using their airplane call sign. They connect to an ATSU (Air Traffic Service Unit) to which messages are sent and received. Typical messages include:
The use of ACARS and CPDLC is becoming more common in the FlightSim world, as a way of creating a more immersive experience. There are a number of aircraft that have ACARS and CPDLC support built directly into their FMC/CDU systems. Alternatively, there are a number of standalone applications that can be used to send and receive ACARS and CPDLC messages.
The VATSIM network has a CPDLC service that can be used to send and receive CPDLC messages as part of the VATSIM ATC experience. Additionally, SayIntentions.ai, the AI based ATC service, also supports CPDLC messages and ACARS. Both of these solutions allow pilots and ATC to communicate via messaging in addition to voice channels.
The original ACARS solution for FlightSims is the Hoppie.nl ACARS network. This implements a web-based API for sending and receiving ACARS messages, including those with the CPDLC type. As the original implementation, this is the ACARS network that is defaulted in most of the ACARS compatible airplanes. It is also the network used by VATSIM.
SayIntentions.ai have also implemented their own ACARS network, which is tightly integrated with their AI based ATC service. It implements an identical web-based API to the Hoppie.nl network, so in theory should just be a drop-in replacement for anyone using SayIntentions.ai as their ATC solution. The idea is that it should be possible to reconfigure a FlightSim airplane to talk to acars.sayintentions.ai instead of www.hoppie.nl.
Unfortunately, many of the existing FlightSim airplanes are hardcoded to use only the Hoppie.nl network. Most of these airplanes seem to have the Hoppie ACARS URL hardcoded into their source code rather than in configuration, so that makes it impossible to change which ACARS network they are using. Hopefully in the future these airplanes will make this more configurable, but for the moment this is where we are.
The ACARS Bridge is a solution to this problem. It is a standalone application that listens on both the Hoppie.nl and SayIntentions.ai ACARS networks and routes messages between them. Once it knows the Airplane call sign for the current flight it can poll the Hoppie.nl network for messages from that call sign sent to the SayIntentions.ai ATSU and route these to the SayIntentions.ai ACARS network. In reverse it can poll the SayIntentions.ai network for messages from the ATSU for the call sign and route them to the Hoppie.nl network.