The GAMMA project stems from the recognition that while the SESAR initiative is effectively addressing some security issues in the new global ATM scenarios, there is a need to extend this scope to ensure a comprehensive assessment of the full set of security threats and vulnerabilities affecting ATM, considered as a system of systems and covering operational as well as technological aspects. In addition, there is a need, not completely met by SESAR, to establish a comprehensive framework for managing ATM security once SESAR deployment is engaged to minimise the effects of ATM crises brought about by security incidents.The GAMMA vision is to adopt a holistic approach for assessing ATM security, maintaining alignment with SESAR and reaching the following main objectives:- Extend the scope of threat assessment performed within SESAR to a more comprehensive system of systems level, inclusive of all ATM assets and all forms of threats.- Develop a Global ATM Security Management framework, representing a concrete proposal for the day-to-day operation of ATM Security and the management of crises at European level.- Define the architecture of an ATM security solution, suitable to support the security management of the global ATM system.- Design and implement prototype components of the ATM solution so as to demonstrate the functionalities and operations proposed for the future European ATM.- Set up a realistic validation environment, representative of the target ATM solution, through which to perform validation exercises aimed at validating the feasibility and assessing the adequateness of the procedures, technologies, and human resources issues proposed.GAMMA is strongly driven by the End Users present in the consortium supporting the project activities from the threat and vulnerability analysis to the validation of the developed concepts. The international dimension will also be considered with special reference to interoperability with US systems.