Case Study 71 The Aircraft Communications Addressing and Reporting System (ACARS) On June 22, EDIE, LOT, the stateowned Pohsh airline, had to ground at least ID national and international ights because hackers breached the network at Warsattfs lChopin airport and intercepted the ight plans that pilot needs before taking 013'. The grounding a'ected about 1,4 passengers and lasted over ve hours before the problem was solved. A month earlier, United Airlines was reported to have experienced the same problem in the United States, and pilots reported bogus ight plans repeatedly popping up on the system. A consultant explained that the radio network that carried ight plans did not need authentication and was designed to trust the communications. A committee was then set up to develop a proposed stande for ight plan security. Fortunately, the ight plan did not control the plane, and a pilot had to accept and enter the plan. A strange result, such as heading to a distant city in the wrong direction, would not be entered or accepted. Even if the bogus plan were entered and accepted by the pilot, there was no danger of collision or crash because of the fraudulent plans. Any changes received to the plan while in ight had to be conrmed with air trafc controllers, who analyzed the new plan for safety. Alarms would also indicate a possible collision