We'll go through what ACARS is, its roots in Telex, through to how it's implemented and used in modern airline operations today over VHF, HF, and SATCOM. We'll talk about how to setup your own ACARS receiver using an RTL-SDR and do a live demo of capturing real ACARS transmissions and attempt to decode what those messages are about. Then we'll take a thought experiment on how potentially malicious transmissions could be made to affect the aircraft. There will also be a discussion around how ACARS is used in modern CPDLC air traffic to pilot data links, instead of voice communications and how these could be vulnerable, and a brief look at SELCAL which reduces the need for pilots to monitor the radio. Lastly we'll look at the future of ACARS over IP and how this will integrate with modern e-enabled aircraft.