Specialised aviation communication has been regulated by international and domestic provisions so as to standardise the language use according to the internationally accepted rules for flight safety purposes. Such rules are aimed at the simplification of global aeronautical communication to minimise language-related human factor errors. Adherence to the rules has been incorporated in the plain language (English) requirements for pilots and air traffic controllers, which are to be confirmed by a certificate for licensure purposes. The plain English requirements are proposed by the International Civil Aviation Organization (ICAO) language proficiency scale. However, the challenge is the assessment system quality to meet the requirements. Currently, aviation personnel can select a test provider available on the market on condition that it is recognised by the appropriate national aviation authority. The aim of this article is to analyse three tests of Aviation English available in Europe, and particularly in Poland, according to the criteria of their appropriateness to the ICAO plain language requirements described in the ICAO language proficiency rating scale. The tests are compared by their formats and test task types, while the appropriateness is evaluated by the ‘tests’ ability’ to obtain speech samples measurable against the scale descriptors. Resulting from the analysis, some suggestions for improvement are presented to shed new light on the aviation personnel language testing effectiveness in the future.