Safran Aircraft Engines has launched a ground testing campaign at its Istres site for the PHILEAS demonstrator. 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. Hybrid-electric propulsion is one of the three pillars of Safran's decarbonisation strategy, alongside disruptive engine architectures such as the Open Fan and the introduction of sustainable aviation fuels.

PHILEAS is a full-scale engine demonstrator equipped with two electric machines sized for use on the next generation of short- and medium-range aircraft engines. Installed on the high-pressure and low-pressure shafts, these machines can operate either as electric motors or as power generators. The demonstrator also incorporates onboard power electronics and an electrical power distribution system. PHILEAS will be used to validate the physical and functional integration of these technologies within the engine under conditions representative of real-world operations. The test campaign will run for approximately six months, comprising nearly 300 hours of testing.

"We're proud to launch this ground test campaign, which marks another milestone in the maturation of hybrid-electric technologies. It represents a key step toward their integration into our future aircraft engines," said Pierre Cottenceau, Vice President, Engineering, Research & Technology for Safran Aircraft Engines.

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. The test programme includes 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 for aircraft systems while optimising engine performance throughout all phases of flight.

The PHILEAS test campaign is fully aligned with the technology objectives of the CFM RISE programme, which aims to reduce CO₂ emissions by 20% compared with today's engines. The RISE programme is being developed by CFM International, a 50/50 joint venture between Safran Aircraft Engines and GE Aerospace. The design of the electrical equipment has been entrusted to Safran Electrical & Power, the Group's centre of excellence in this field. Identified by Safran as a promising solution for the next generation of aircraft engines, hybrid-electric propulsion requires close collaboration between the Group's experts in electrical systems, engine control systems and engine integration.

This test campaign also builds on Safran Aircraft Engines' 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 & Power and integrated into the Silvercrest engine. During that programme, 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 in Niort on a test bench simulating an 800-volt aircraft electrical network.