<p>A study with eleven pilots was conducted to derive requirements for a future assistance system to support decision-making with regard to the selection of the most suitable alternate airport. As part of the study, the pilots had to deal with two case examples focusing on obtaining information, analysis and decision-making in the event of a system failure. The case examples were designed as static scenarios without time pressure in order to analyse the decision-making process in detail and at the same time served as a basis for a discussion on further possibilities to support the pilots. This paper presents the findings from the study. Differences and similarities in the pilots’ decision-making process are analysed and evaluated. Answers to a supporting questionnaire are used to analyse the influence of the pilots’ background knowledge, personal preferences and experience on the entire process from obtaining and analysing information to the final decision. The paper concludes giving a rough sketch of a derived concept for a new assistance system and presenting some exciting directions and promising system functionalities for continued and future research.</p>