Airbus, Daher and Safran’s hybrid demonstrator makes first test flight

EcoPulse, the hybrid-electric demonstrator aircraft, co-developed by Airbus, Daher and Safran has taken to the skies.

The first flight marks the beginning of an eight-month flight testing campaign of the distributed hybrid-propulsion systems and the associated technologies, led by Daher. The system combines a high-voltage battery with a turbomachine equipped with an electrical generator. These feed power to multiple propulsion ‘pods’ spread along the wings.

Airbus sees hybridisation as an important investment area, its estimates show that it could reduce an aircraft’s environmental footprint up to 5%. Project leader William Llobregat said: “This project was launched in 2019. It’s really exciting to have reached the concrete stage of the project where we are flight testing the technologies we have developed.”  

EcoPulse took off from Tarbes–Lourdes–Pyrénées Airport, nestled at the foot of the Pyrénées mountain range in southwest France. Two experimental Daher pilots were onboard the modified Daher TBM 900 turboprop aircraft. While take off and landing used the traditional propulsion engine, the hybrid-propulsion system was activated at cruising altitude, where the pilots spent around 20 minutes running on battery power.

“Technological demonstrators like Ecopulse play a key role in advancing our industry’s decarbonisation roadmap,” added Llobregat. “The demonstrators themselves are not intended to ever enter into service, but they allow us to evaluate, mature and validate individual technologies that can then be integrated into future aircraft.” 

Airbus, Daher and Safran divided responsibilities. Airbus contributed the high-energy-density battery that powers the propulsors; the aerodynamic and acoustic integration of the distributed-propulsion system and the development of a flight control computer system. The battery on EcoPulse had to be custom designed by Airbus Defence and Space, each is capable of powering six electric propulsors. Testing it in flight is the result of more than four years’ of groundwork.

“The battery system is able to achieve 800 Volts DC and deliver up to 350 kilowatts of power,” explained Llobregat. “We are pioneering new voltage levels for the aerospace industry and we hope to one day integrate this technology into commercial aircraft.”

Airbus also modified the shape of the aircraft to assess the performance impact of having a distributed propulsion system. 

“We have separate, smaller sources of propulsion distributed across the wing. This means that you could theoretically increase the thrust on only the outboard engines, or just the centre ones. We can then assess how these differences impact flight performance, which is very valuable data,” said Llobregat. “Using asymmetrical thrust to control the aircraft is a totally new technology that is only possible to test out because we are using an electrical system that has better dynamic response than traditional jet fuel engines.”

Flight testing of the demonstrator will last until mid-2024 at the latest, and will include up to 30 test flights. “This partnership between Airbus, Daher and Safran – three French companies – worked so well because it was founded on our common ambition of paving the path to decarbonisation for the European aerospace industry,” said Llobregat.