The threat of CBRN (chemical, biological, radiological and nuclear) incidents has become a growing concern for military and emergency response organizations, requiring innovative strategies to improve preparedness and mitigate risks. One promising approach is the use of reconnaissance drones - agile unmanned aerial vehicles (UAVs) - to support CBRN incident response. Reconnaissance drones can quickly provide an overview of CBRN incidents and gather information without risking people. However, the increasing autonomy of drones requires high levels of trust in the technologies used by emergency services. This paper examines attitudes toward autonomous reconnaissance drones among Austrian military personnel, with a specific focus on how different levels of autonomy affect trust and acceptance. As part of the Semi-autonomous chemical aerial reconnaissance system (C-SALS) research project, soldiers and conscripts of the Austrian Armed Forces specializing in CBRN-Defence were surveyed. The results reveal a generally positive perception of drone technology, with speed of results, clear presentation of information, and accuracy rated as the most important characteristics. The study reveals nuanced preferences regarding autonomy levels, with variations between different personnel groups. The findings challenge some common assumptions about technology acceptance and provide important insights for the responsible integration of autonomous reconnaissance drones into CBRN defence preparedness and emergency response planning.