ABSTRACT. Model-based testing is considered state-of-the-art in verification and validation of safety critical systems. This paper discusses some experiences of applying the model-based testing tool RTT-MBT for the evacuation function of an aircraft cabin controller. A major challenge of this project was the parametric design of the software, which allows to tailor the software to a certain aircraft configuration via a large number of application parameters. Application parameters thus need to be integrated in the test models. Further challenges consisted of mapping multiple detailed signals of the system under test to a single abstract model variable and vice versa, and handling incremental test model development during an ongoing test campaign. We discuss solutions that we developed to successfully conduct this test campaign.