Based on data collected in the Republic of Poland, the average rescue arrival time in suburban areas is 15 min, while brain tissue begins to die after 4 min. An unmanned aerial system (UAS) could deliver an automated external defibrillator (AED) to the scene in under 5 min over an 8-km distance. This chapter aims to present the design assumptions and rationale for implementing a UAS in public spaces. The proposed system is a fast, mission-capable flying wing aircraft intended to deliver a defibrillator to cardiac arrest victims. It will be based on the tail sitter vertical take-off and landing (VTOL) concept, which combines the advantages of effective level flight with the vertical landing capabilities of multirotor drones. Current designs lack the speed and manoeuvrability required to reach victims in a timely manner, making the proposed tail sitter VTOL design a promising alternative for rapid AED delivery.