The LEAF project designs a family of low-emission regional aircraft powered by hydrogen combustion turboprop engines. Two variants were developed: LEAF-A for 84 passengers over 1,500 km and LEAF-B for 58 passengers over 1,300 km, with 75.6% component commonality to reduce costs and simplify maintenance.

The aircraft uses a strut-braced wing, lightweight recyclable materials, and a liquid hydrogen tank in the tail for improved efficiency and lower emissions. Compared to conventional aircraft, the design significantly reduces carbon emissions and lowers NOx emissions by 60–90%, depending on flight phase.

Economically, the design is competitive, with direct operating costs below or close to benchmark regional aircraft and a projected 5% return on investment. The main challenges remain hydrogen infrastructure, market adoption, and managing technical risks such as hydrogen safety. ... Read more

Incremental Nonlinear Dynamic Inversion (INDI) is effective at controlling nonlinear aircraft dynamics by inversion of the control effectiveness matrix, but relies on accurate and time-synchronized measurements of the control input and the state derivative. Hybrid INDI address this limitation by blending sensor measurements with model-based estimates, most commonly through Complementary Filtering. In this work, an Extended Kalman Filter (EKF) is proposed as an alternative angular acceleration estimation method within a Hybrid INDI attitude control framework. A real-time EKF is developed and integrated into the control architecture of a nonlinear aircraft model, and its performance is compared against a baseline Complementary Filter approach.
The parameters of both estimators are tuned using a robust multi-model optimization procedure that accounts for sensor noise, delay, and model-plant uncertainties. Simulation results under nominal and degraded conditions demonstrate that the EKF-based Hybrid INDI approach provides estimation performance comparable to that of the Complementary Filter, with improvements in scenarios of combined sensor noise and delay degradation. ... Read more

Following an extensive evaluation of subsystem options outlined in the mid-term report, the multi-rotor swarm configuration was selected as the final design, accompanied by a preliminary operational strategy. This decision has guided the project into its final detailed design phase. This report demonstrates how the design proceeds using the selected analytical methods. A series of detailed analyses further illustrates how the design meets the updated performance requirements, supported by numerical results and visualisations. Finally, post-project actions and future plans are outlined to ensure the project’s continued development and success. ... Read more

In the renewed race for the Moon, there will be a high demand for transportation services to and from the lunar surface. The next generation of landers needs to have many capabilities, such as supporting longer exploration and global access, sustainability and versatility. ARCH-E, developed together with Airbus Defence and Space UK, fills this need as a reusable, crew/cargo-capable lander architecture. The lander's requirements and market are analysed, mission trajectory and landing are designed, followed by detailed subsystem design. The operations, risks, costs and sustainability considerations are assessed and highlighted. Finally, the design overview of a feasible lunar landing system is presented. Further design activities are recommended and a project timeline is laid out. ... Read more