AbstractForeign object ingestion into engines has been studied for many years, but the focus has been on soft bodies (i.e., birds, ice). Recently, there has been a dramatic increase of uncrewed aircraft systems (UAS) in the airspace that represent a new threat to aircraft engines due to key components like the motor, battery, and camera being composed of hard components. Due to the differences between hard bodies and soft bodies, studies are required to understand the new threat these UAS pose to aircraft. The objective of this study is to investigate the impact of various factors such as impact orientation, fan rotational speed, relative translational speed, and radial impact location on the damage caused to a representative fan assembly. This study aims to analyze the sensitivity of these factors and their influence on the overall damage to the fan. The ingestion simulations will use a representative fan assembly model and a UAS model that has been experimentally validated at the conditions of an ingestion. This work will identify critical parameters of the ingestion and then utilize them to anticipate the extent of damage that may arise during specific stages of a flight where an ingestion is most probable. Moreover, it also compares these cases with some known baseline cases, such as a fan blade out (FBO) and bird ingestion of similar mass, to understand the likely severity compared to more studied common cases.