New Rolls-Royce Engine For Hybrid-Electric Flight Completes First Fuel Burn

Rolls-Royce has successfully completed its first fuel burn on the new small gas turbine that has been specifically developed to power hybrid-electric flight. Rolls-Royce is developing complete power and propulsion systems for all-electric and hybrid-electric applications. The engine has been designed using combustion technology to produce ultra-low emissions and this achievement confirm the effectiveness of the compact, power-dense turbine that will be integrated into a light-weight turbogenerator system.

The complete turbogenerator system is being developed for the Advanced Air Mobility (AAM) market. This includes electrical vertical take-off and landing (eVTOL) or electric short take-off and landing (eSTOL) aircraft for Urban Air Mobility (UAM) and commuter aircraft applications up to 19 seats. The gas turbine under test also has potential applications within helicopter, auxiliary power unit (APU) and defense markets.

The turbogenerator system will complement Rolls-Royce’s electrical propulsion portfolio by delivering an on-board power source with scalable power offerings between 500 kW and 1,200 kW. This enables an extended range on sustainable aviation fuels and later, as it becomes available, through hydrogen combustion. Further, it will open up new, longer routes than electric battery powered aircraft can support today.

As per Rolls-Royce, the test facilities and equipment, comprising 14 subsystems in total, were designed, procured and built by a global team in a record time of just under a year. The test set-up comprises commodity components such as valves and hoses, and bespoke subsystems such as the fuel injection systems, oil and ventilation systems, engine mount and water brake that were tailored to the specific test requirements for this new technology.

Matheu Parr, Customer Director, Electrical, said: “Rolls-Royce is developing all-electric and hybrid-electric power and propulsion systems for the Advanced Air Mobility market. The first fuel burn of our brand-new small gas turbine is a significant leap forward with successful stages throughout the test from light-up to the pull-away of the system.

“This significant achievement follows the fast-paced development time of the new gas turbine from concept freeze to ‘pass to test’ in under 2 years. The turbogenerator system will enable our customers to extend the routes that electric flight can support and means more passengers will be able to travel further on low and potentially net zero emissions aircraft.”

Matheu added: “With this achievement we have proven we can apply our expertise to novel designs and are able to test them on a very quick timescale. This capability will help Rolls-Royce to deliver the products that will help us on our path to net zero within the ambitious industry timelines of the Advanced Air Mobility market.”

The turbogenerator can be used in serial or parallel hybrid applications. It is designed to recharge batteries as well as provide energy to electrical propulsion units directly and therefore enables aircraft to switch between power sources in flight. The research and development of this technology is being partially funded by the German Ministry for Economic Affairs and Climate Action.