The Arrow-Copter is entirely constructed from composite materials. Aluminum inserts have been laminated into the composite material and distribute all forces evenly within the cell (e.g., rotor head, engine mount, etc.). All stucturally relevant parts have undergone a Finite-Element analysis (FEM analysis) for a design MTOM of 600 kg according to the British CAP 643 Section T guidelines. These guidelines also allows for generous safety margins. It is a big advantage of the all composite construction that all parts are structurally joined together to form a single, highly stable airframe and chassis. This is how we manage to achieve maximum structural integrity at minimal weight.