X-TEAM D2D project aims at defining, developing and initially validating a Concept of Operations (ConOps) for a seamless integration of Air Traffic Management (ATM) and Air Transport into an overall intermodal network, including other available transportation modes (road, rail, water). This will contribute to significant enhancement in door-to-door connectivity, supporting to the ACARE SRIA FlightPath 2050 goal of enabling connection in up to 4 hours between any location in Europe. The project provides and validates a Concept of Operations (ConOps) for seamless door-to-door mobility in urban and suburban (up to regional and country-wide level) environment, targeting as scenario the connection of a metropolis with the surrounding area (up to country-wide level) and taking into account the transportation and passengers service scenarios envisaged for the next decades, according to baseline (2025), intermediate (2035) and final (2050) time horizons.