A research team in Zurich has created a flock of helicopter robots that can detect each others' positions and join together to create a larger flying machine. The Distributed Flight Array (DFA) has been developed by a team of researchers at the Institute for Dynamic Systems and Control (IDSC) at Zurich university in Switzerland. Each robot has a 3D-printed hexagonal plastic chassis with magnets fixed to the sides of the frame and a single propeller fitted in the middle.Independently, the honeycomb-shaped robots fly in an erratic and uncontrolled way. However, the robots are able to detect each other, link to form a bigger craft and then fly in a controlled manner as a single unit. The task of keeping the multi-propeller system in flight is distributed across the network of vehicles.Each independent module exchanges information with the others and uses sensors to determine how much thrust it needs for the array to take off and maintain flight."The Distributed Flight Array is a flying platform consisting of multiple autonomous single propeller vehicles that are able to drive, dock with their peers and fly in a coordinated fashion," explains the IDSC. "Once in flight the array hovers for a few minutes, then falls back to the ground, only to repeat the cycle again."