A system to manage transmissions of data between a flight management system (e.g., of an avionics type) of an aircraft and a portable electronic (e.g., of an open world type) is proposed. The data management system may be implemented in flight management system architecture with core and supplementary modules that are distinct from each other. The core module may implement a set of generic functionalities related to a flight management of the aircraft, and the supplementary module may implement supplementary functionalities specific to an entity to which the aircraft belongs. The data management system may comprise a data securing module that monitors data to be transmitted between the flight management system and the portable electronic device, and allows or prevents the data transmission based on the monitoring results.