Be it snow, volcanic ash or strikes, crisis events impose high costs on the air transport system and society. The objectives of A-CDM (Airport Collaborative Decision Making) are to reduce delays and improve system predictability, while optimizing the utilization of resources and reducing environmental impact. Several European airports have by now obtained the A-CDM label. MetaCDM aims at examining how airside and landside CDM can be interlinked with other transport modes to minimize the impact of severe disruptions, from the stakeholders' and the passengers' perspectives. This paper presents the final outcome of the project. First, we analyze past representative disruptive events via a series of on-site interviews with stakeholders at airports across Europe. We then evaluate the benefits of information sharing at the airport and at the network level. We also survey the initiatives to bridge the landside, airside and multimodal operations. A set of recommendations based on best practices for European or global airports, a new concept of operations and a roadmap for future research areas are developed.