EPIFAN is about the development of a hybrid-electric propulsion system consisting of an electric motor and a boundary-layer-ingestion fan, with experimental off-design testing. The project aims to make a significant contribution to the medium- and long-term emission reduction targets in aviation. This is to be achieved through highly integrated and disruptive propulsion concepts that combine high performance with low weight, high efficiency and low emissions. Electrically or hybrid-electrically powered propulsion in particular, which enables synergy effects such as boundary-layer-ingestion, is a promising concept. The main objective of EPIFAN is therefore the detailed investigation and quantification of the interactions within these propulsion concepts, especially in near-ground operation and along different aircraft missions. Within the project timeframe, experiments are to be conducted that provide data for the verification of numerical simulations. The identification of new evaluation parameters and limiting parameters for safe operation are therefore part of the research.