The deployment in the Dominican Republic follows field trials that took place in 2012, and in both cases the UAVs are used to deliver medicines. The inaccessibility of roads during times of extreme rain was cited as one reason why UAVs would be useful to provide supplies in some regions. The UAV is a quadrotor, with four small rotors that provide lift. Electrically powered, the UAV can carry two kilogrammes to a range of 20 kilometres. Speaking at the 8th International Air Transport Association World Cargo Symposium on 11 March in Los Angeles, its inventor, Andreas Raptopoulos, says: "We are getting ready to deploy a small network connecting small clinics in the Dominican Republic." Ths type of UAV is already being used by scientists. The European Southern Observatory has a hexacopter (see picture), which has eight and not four rotors, for photography.