Rolls

Rolls-Royce (R-R) announced yesterday, June 19, it is ready to begin testing on a small, as yet unnamed gas turbine engine designed specifically for hybrid-electric flight. The target market includes electrical vertical takeoff and landing (eVTOL) aircraft for urban air mobility, as well as regional “commuter aircraft” seating up to 19, according to R-R. The gas-turbine engine is said to be part of a developmental turbogenerator system.

“The turbogenerator system will complement the Rolls-Royce Electrical propulsion portfolio by delivering an on-board power source with scalable power offerings between 500kW and 1200kW [roughly equivalent to 670 to 1,600 shaft horsepower], enabling extended range on sustainable aviation fuels (SAF) and later, as it becomes available, through hydrogen combustion,” R-R said in an announcement released during this week’s Paris Air Show.

Rolls-Royce currently holds manufacturing rights for the M250, originally developed in the late 1950s as a helicopter (turboshaft) engine. The company said new technology applied to its latest project engine enables a “step change in efficiency” for small gas turbines. “The turbogenerator can be used in serial or parallel hybrid applications,” said R-R, adding, “It is well suited to recharge batteries as well as provide energy to electrical propulsion units directly and therefore enables aircraft to switch between power sources in flight.”

Trials will be conducted at Rolls-Royce’s test facility in Dahlewitz, Germany, near Berlin. Testing will also include running the engine on sustainable aviation fuel SAF “in the coming months.” The German Ministry for Economic Affairs and Climate Action is contributing to funding the research and development of the turbogenerator hybrid-electric technology involved in the Rolls-Royce project.