The research aims to study and experimentally verify the effectiveness of the use of the Quizlet computer-based flashcard program for teaching future air traffic controllers (ATCs) profession-related vocabulary. In this research, we applied a mixed-method research design. The sample of the experiment participants was 57 first-year students majoring in "Aviation transport". To evaluate the efficiency of Quizlet incorporation into aviation English learning, we used tests, speaking activities, observations, and questionnaires (the former two to assess passive and active vocabulary knowledge and the latter to evaluate the students' engagement and motivation). The empirical data proved Quizlet to be an effective vocabulary learning tool that positively influences students' proficiency in speaking skills and interest in learning aviation English. Based on the obtained findings, we claim vocabulary acquisition to be the basis for foreign language learners' general language proficiency contributing to the development of voice communication skills. An important conclusion is made on the need to include in aviation English courses the intentional vocabulary learning component implying explicit vocabulary teaching, which then should be complemented with speaking practice and incidental vocabulary acquisition techniques. The research findings can be implied in aviation English and foreign language teaching presenting an experimental verification of computer-based flashcard program efficiency in the language learning process.