The current process using multi-part metal core tools to fabricate complex primary structural carbon fibre reinforced polymer (CFRP) components via resin transfer moulding (RTM) is costly and complicated. The proposed solution within the CoCoNut proposal involves the use of advanced water-soluble materials that will replace the use of metallic cores. The scope of the proposed project consists of the development of technologies using assets already tried and tested by the partners. It will include the production of a demonstrator part that will provide both a POC (proof of concept) demonstration of the feasibility of the technology, and production of a full-scale part based on the configuration of a composite landing gear part designed for the HECOLAG project, using RTM and incorporating cores designed for the current project. This is expected to drive the technology from TRL 3-4 to TRL 5-6. A comparison will be made between the new technology that will be designed, produced, and tested for the HECOLAG project and the existing Legacy technology based on metallic cores. The applicants have extensive experience both in advanced cores development and manufacturing, and in advanced aerospace composites production processes, in particular resin transfer moulding (RTM).