COLOSSUS paves the way for future European aviation products and services which are designed in a truly holistic approach and to thus provide a major contribution to the digital transformation of aviation and air transportation in order to enable European competitiveness in a key industrial sector. The expected outcomes of COLOSSUS provide Europe’s aviation sector with the platform to develop new and breakthrough product and technology in a holistic system-of-systems approach. Main technical objectives of COLOSSUS are: (1) To create a Transformative Digital Collaborative (TDC) Framework that allows European aviation to perform research, technology development and innovation in a holistic system-of-systems approach. The TDC Framework shall support modelling, analysis, optimisation and evaluation of complex products and services under consideration of real-world conditions. (2) To expand and test the capabilities and performance of the TDC Framework with two Use Cases, both of which address needs identified in the Work Programme and thus possess a value of their own: Use Case 1: Creating a business model for sustainable 4D-intermodal mobility and evaluating the concept for performance, competitiveness, environmental impact and life cycle footprint. Use Case 2: Developing an integrated fast-response approach for preventing, detecting and fighting wildfires by combining latest developments in the fields of aircraft design and technology, automation, AI and digitalisation. (3) To perform conceptual studies for two products which could be transverse technology enablers for multi-modal mobility and affordable decarbonisation of aviation: a multi-role seaplane with hybrid propulsion and a product for eVTOL-based advanced air mobility of passengers and goods.