On integrating unmanned aircraft systems into the national airspace system issues challenges operational restrictions certification and recommendations konstantinos dalamagkidis kimon p valavanis les a piegl auth. On integrating unmanned aircraft systems into the national airspace system issues challenges operational restrictions certification and recommendations pp193 203 konstantinos dalamagkidis. On integrating unmanned aircraft systems into the national airspace system issues challenges operational restrictions certification and recommendations unmanned aircraft systems levels of safety derived mathematically based on the corresponding levels for manned aviation it provides an overview of the history and current status of uas . On integrating unmanned aircraft systems into the national airspace system issues challenges operational restrictions certification and recommendations it provides an overview of the history and current status of uas airworthiness and operational regulation worldwide existing regulations have been developed considering the need for a . On integrating unmanned aircraft systems into the national airspace system electronic resource issues challenges operational restrictions certification and recommendations responsibility although efforts from the federal aviation administration and its partners are already underway to integrate uas in the national airspace system