MTU Aero Engines successfully completed multi-week testing of a liquid hydrogen fuel system for its Flying Fuel Cell (FFC). The tests showed that the system architecture is safe, reliable, and works as expected, and can ensure a regulated, need-based supply of preconditioned hydrogen to the fuel cell, said Barnaby Law, FFC Chief Engineer at MTU in Munich.

Together with MT Aerospace AG, the engine specialist is developing a complete liquid-hydrogen fuel system for commercial aviation that consists of tanks, sensors, heat exchangers, valves, safety systems, and controls. MT Aerospace is responsible for the liquid hydrogen tank and successfully tested the first system at its headquarters in Augsburg.

Now MTU is following suit. Testing of a product-specific full-system FFC will begin in 2026. The liquid hydrogen system will be one of its main components.

The FFC is set to be deployed initially on short-haul routes in regional air traffic. It can reduce climate impact by 95%, to virtually zero, which means it is nearly emissions-free: it emits only water. With improved efficiency, plans call for the FFC to be used in short- and medium-haul flights as well starting in 2050, further reducing the climate impact of commercial aviation.

The core components of a high-performance flying fuel cell system are the stacks and an intelligent integration of all lines.

MTU is collaborating with DLR to fly a Do228 as a technology platform and flight demonstrator. The goal is to replace one of the two conventional gas-turbine engines with a 600 kW electric powertrain, with energy supplied by a hydrogen-powered fuel cell. The partners are aiming for this flying lab to complete its first flight by mid-decade. This will be preceded by extensive ground tests and preliminary trials.

MTU’s job is to develop the entire hydrogen-powered fuel cell powertrain, including the liquid hydrogen fuel system and control functions. DLR is heading the Do228 research project, providing the research aircraft and performing the flight experiments. The research center is also responsible for integrating the powertrain into the aircraft.