ICAO’s member states synchronize their national laws with ICAO standards and practices because of the importance of standardizing on the international level. Due to that, all participants of air traffic (pilots and air traffic controllers) must adhere to the imposed rules, including the air traffic control students who must try to follow all of the regulations at the simulators. Errors in radio-telephony communications at the ATC simulators occur as a result of many variables. To better understand and realize the reasons why errors are made, it is required to analyze each of those variables so that in the future, actions can be taken preemptively. Moreover, it is necessary to analyze errors that the students make in order to remedy them.