Aerial manipulation aims at combining the manoeuvrability of aerial vehicles\nwith the manipulation capabilities of robotic arms. This, however, comes at the\ncost of the additional control complexity due to the coupling of the dynamics\nof the two systems. In this paper we present a NMPC specifically designed for\nMAVs equipped with a robotic arm. We formulate a hybrid control model for the\ncombined MAV-arm system which incorporates interaction forces acting on the end\neffector. We explain the practical implementation of our algorithm and show\nextensive experimental results of our custom built system performing multiple\naerial-writing tasks on a whiteboard, revealing accuracy in the order of\nmillimetres.\n