February 29, 2024: An Israeli El Al airliner flying from Thailand to Israel via India and up the Red Sea ran into some strange communication problems. Someone on the ground was trying to take control of the navigation systems used by the airliner electronically. All commercial aircraft use ADS-B, automatic dependent surveillance-broadcast, technology used for aircraft tracking. A second system, called ACARS or Aircraft Communications Addressing and Reporting System, provides a data link system for transmitting messages between aircraft and ground stations via radio or satellite links. Both these systems lack any security features and can be abused by others to exploit vulnerabilities in aircraft flight management systems. Apparently, security was never added to these systems because there were never any, or at least not many, attempts to hijack and manipulate the signals.

These vulnerabilities could be successfully used because most of the time commercial aircraft are in the air, they are flying on autopilot. There are also automatic landing systems that can be used in all but emergency situations. The pilot and co-pilot are at the controls as a safety measure and to take control when things go wrong. The El Al airliner encountered such a hijacking as it passed over Somalia. That was when someone on the ground radioed new flight instructions to the El Al aircraft’s autopilot systems which would have taken the aircraft somewhere else. The new destination was never revealed because the El Al pilots noticed something was wrong and manually made adjustments to get the airliner back on course. This incident is one more reason why security should be added to ADS-B and ASCARS communications systems to prevent signal hijacking.