Fire-related accidents always pose enormous challenges to battle with. In this study, a novel approach for firefighting is proposed by the formation of multiple aerial water-powered systems. Each is equipped with a water-conveying hose and jet propulsion such that it is able to take off, follow the desired formation, take high ground advantage, and extinguish the fire from above. The proposed control consists of two parts: a formation law controls every device to follow its desired trajectory and achieve the formation reference, while a collision avoidance law ensures the safeness of the system with multiple devices. A simulation study with a system of five devices is conducted to validate the potential of the proposed system. The results show that all devices converge to the desired formation while maintaining safety distances between them during the formation.