He did not experiment on real airplanes, which would be both dangerous and illegal, according to his own account. Instead Teso acquired aircraft hardware and software from different places, including from vendors offering simulation tools that use actual aircraft code and from eBay, where he found a flight management system (FMS) manufactured by Honeywell and a Teledyne ACARS aircraft management unit.
Using these tools, he set up a lab where he simulated virtual airplanes and a station for sending specifically crafted ACARS messages to them in order to exploit vulnerabilities identified in their flight management systemsspecialized computers that automate in-flight tasks related to navigation, flight planning, trajectory prediction, guidance and more.