Although the technology for fully autonomous swarms of robots is rapidly progressing, the human operator will continue to play an important role during any swarming mission due to safety, monitoring and control constraints. In this paper, we present the set of features that a Ground Control Interface (GCI) must incorporate to allow monitoring, control and safety of outdoor missions with a swarm of Small Drones (drones of less than 1 kg). We propose a new extension to a widely used GCI by incorporating those features and we demonstrate its usage on a swarm of 10 Small Drones flying outdoor.