Safran launches full-scale hybrid-electric demonstrator tests for next-generation aircraft engines
French aerospace company Safran Aircraft Engines has announced the launch of a new ground testing campaign for the PHILEAS demonstrator engine at its Istres site in southern France.
Supported by the French Civil Aviation Authority (DGAC), the programme aims to accelerate the maturity of hybrid-electric technologies for the next generation of aircraft engines.
Safran develops its PHILEAS hybrid-electric engine
Hybrid-electric propulsion has been made into one of the key pillars of the company’s decarbonization strategy over recent years, alongside disruptive engine architectures such as Open Fan technologies and the introduction of sustainable aviation fuels.
PHILEAS is being seen as a potential technological breakthrough that could pave the way for the next generation of aero engine design.
PHILEAS is a full-scale hybrid-electric aircraft engine demonstrator developed by Safran. Rather than being a production engine, it is an experimental platform used to test technologies that could power the next generation of short- and medium-haul airliners.
According to a statement issued by Safran on 16 July, the PHILEAS demonstrator engine with its pair of 250kW motor-generators has been installed on both the high-pressure and low-pressure shafts of the test rig. This allows the power units to operate either as electric motors or as power generators.
The demonstrator also incorporates onboard power electronics and an electrical power distribution system. The company added that PHILEAS will be used to “validate the physical and functional integration of these technologies within the engine under conditions representative of real-world operations.”
Safra will also analyse advanced power management scenarios such as balancing power extraction between the shafts, transferring power between the shafts, and managing power exchanges between the engine and the aircraft.
The test campaign will run for approximately six months, comprising nearly 300 hours of testing, as the company builds up expertise and operational data on how the PHILEAS engine performs under certain conditions. Tests are due to begin within days, according to the French company.
Testing to analyse key engine performance metrics
Conducted on one of Safran Aircraft Engines’ open-air test stands in Istres, the campaign is designed to evaluate power extraction from and injection into the high-pressure and low-pressure shafts under various engine operating conditions and throughout the different phases of flight.
Safran said that the test program will also include advanced power management scenarios such as balancing power extraction between the high-pressure and low-pressure shafts (power balancing), transferring power from one shaft to the other (power transfer) and managing power exchanges between the engine and the aircraft (power sharing).
The integration of these technologies is intended to maximise the electrical power available to aircraft systems while optimising engine performance across all phases of flight, added the company.
Identified by Safran as a “promising solution” for the next generation of aircraft engines, hybrid-electric propulsion requires close collaboration between the Safran Group’s experts in electrical systems, engine control systems and engine integration. The design of the electrical equipment, for example, has been subcontracted to Safran Electrical and Power, the Safran Group’s specialists in this area.
“We’re proud to launch this ground test campaign, which marks another milestone in the maturation of hybrid-electric technologies,” said Pierre Cottenceau, Vice President, Engineering, Research & Technology for Safran Aircraft Engines. “It represents a key step toward their integration into our future aircraft engines,” he added.
PHILEAS is being designed for the aircraft of tomorrow
Safran sees the application of hybridisation technology as being a fully aligned contributor to achieving the 20% fuel-burn reduction needed for the next generation of narrowbody engines. It is also aligned with the technological objectives of the CFM RISE aero engine programme, being developed through its CFM International subsidiary, a 50/50 joint venture with GE Aerospace.
CFM RISE is an open fan demonstrator being developed to incorporate hybrid-electric systems to produce optimised performance through every stage of flight.
The PHILEAS test campaign is also building upon Safran’s ambitious technology roadmap for advancing hybrid-electric propulsion. In 2023, the DOPEE project successfully validated the operation of a 300 kW electric machine designed by Safran Electrical and Power, which was integrated into the company’s Silvercrest engine that was intended to be used on a series of business jets.
During that program, the teams carried out the first power extraction and injection tests on the high-pressure turbine shaft. Since late 2025, system-level testing has also been underway on a test bench simulating an 800-volt aircraft electrical network.
