Issued in November 2010. The overall Concept report comprises five volumes and one supplement: ER-004_Volume 1: General Considerations for Civilian Operation of Unmanned Aircraft ER-004_Volume 2: Unmanned Aircraft System Operations ER-004_Volume 3: Unmanned Aircraft Systems Airworthiness Certification ER-004_Volume 4: Unmanned Aircraft Systems for Visual Line of Sight Operations ER-004_Volume 5: Command and Control Considerations for Unmanned Aircraft Note: At the time of publication of ER-004 volumes 1 to 4, volume 5 is still in the process of being developed. ER-004_Supplement: Abbreviations and Terminology for Unmanned Aircraft Systems. The five volumes of this report, together with a terminology supplement, present concepts for the airworthiness certification, operational approval, radio spectrum provision, and security management of unmanned aircraft systems. The goal is to contribute to the establishment of a regulatory framework based on the existing regulatory environment for civil aviation that will allow qualified unmanned aircraft to operate in airspace without segregation from manned aircraft and without degrading airspace efficiency and safety.