The LEITWERK‑VTP Multispar project, funded by the Niedersachsen Aviation Research Programme (NiFö), aimed to create a new manufacturing route for a side‑aileron box built in a multi‑laminate configuration from partially cured, continuously fabricated profiles. The goal was to reduce overall product costs by up to 30 % while maintaining the high structural quality required for a large commercial aircraft. To achieve this, the consortium focused on developing a multi‑stage curing process that would lower tooling complexity, improve process reproducibility, and allow the use of inexpensive, novel prepreg‑CFK materials whose cure kinetics had to be re‑determined and adapted to existing lay‑up and processing equipment.
In the first work package (HAP 1) the team established laboratory‑scale process fundamentals for the new prepreg materials and built a small‑scale demonstrator featuring two complete laminate cells with reduced height and length. This demonstrator enabled the evaluation of the proposed curing routes and provided the input data for the subsequent full‑scale process development. The second work package (HAP 2) expanded the process to a full‑scale production chain, incorporating a new tool design that optimised tolerances for the interlinked laminate structures. The tool development was guided by simulations of the entire component and its manufacturing process, ensuring that the complex interactions between the partially cured layers were controlled to minimise set‑back and resin network formation. Continuous manufacturing of the laminate profiles was also adapted, allowing the production of long, continuous sections that could be integrated into the multi‑laminate build.
HAP 3 focused on the structural design of the side‑aileron box, including the attachment to the aircraft fuselage and the integration of actuator loads for the rudder. Detailed structural tests validated the design assumptions and confirmed that the multi‑laminate approach met the required stiffness and strength criteria. The final design of the medium‑size technology demonstrator, incorporating the core elements of the side‑aileron, was produced in HAP 4. This demonstrator was manufactured using the developed process chain and accompanied by process‑monitoring instrumentation. Comprehensive evaluation of the component’s performance and the economic viability of the manufacturing route confirmed that the new process could deliver the targeted cost savings while meeting all quality and tolerance specifications.
The project’s technical achievements include the successful demonstration of a multi‑stage curing strategy for novel prepreg‑CFK materials, the design of a tolerance‑optimised tool for complex laminate structures, and the validation of a continuous manufacturing approach for the side‑aileron box. These results provide a solid technological foundation for the Airbus strategy of modular composite component design and open the way for further cost reductions in future aircraft structures.
Collaboration was carried out by a consortium of four partners. Airbus Operations GmbH served as the project leader and coordinated all activities, ensuring close alignment with the broader Airbus research and development strategy. The German Aerospace Center (DLR) contributed expertise in composite material science and process simulation. Broetje Automation GmbH supplied advanced automation solutions for the continuous lay‑up and curing processes. A subcontractor, CTC GmbH, supported the application of the “BlisterVac” technology, which played a key role in controlling resin flow during curing. Regular consortium meetings were held alternately at each partner site, fostering continuous exchange and enabling the project to maintain a high level of collaboration throughout its duration. The project’s outcomes not only advance composite manufacturing technology but also strengthen the high‑skill workforce in Niedersachsen, contributing to the long‑term sustainability of the regional aerospace industry.