EcoPulse Hybrid-Electric Aircraft Makes First Flight Of Test Program


The EcoPulse, a modified Daher TBM hybrid-electric distributed-propulsion aircraft demonstrator, performed its first test flight on Nov. 29. As part of the 100-minute sortie, the aircraft activated its ePropellers, which are powered by a battery and a turbogenerator. The EcoPulse is a joint development of Daher, Safran and Airbus “to support aviation’s decarbonization roadmap.”

The flight departed from Daher’s headquarters airport in Tarbes, France. The mission was described as the culmination of multiple technical milestones, including a ground-test campaign and 10 hours of flight testing with the electrical power system inactive. Eric Dalbiès, Safran’s Executive VP of Strategy and Chief Technology Officer, said, “We confirmed today that this disruptive propulsion system works in flight, which paves the way for more sustainable aviation. The lessons learned from upcoming flight tests will feed into our technology roadmap and strengthen our position as leader in future all-electric and hybrid-electric propulsive systems.”

Besides activating the electric propulsion system, the crew also verified the functioning of the flight control computer, high-voltage battery pack, distributed electronic propulsion array and the hybrid electric turbogenerator.

Pascal Laguerre, Daher Chief Technology Officer, said, “The flight campaign will give Daher invaluable data on the effectiveness of the onboard technologies, including distributed propulsion, high-voltage batteries and hybrid-electric propulsion.”

Mark Phelps
Mark Phelps is a senior editor at AVweb. He is an instrument rated private pilot and former owner of a Grumman American AA1B and a V-tail Bonanza.


  1. An old concept (been used by locomotives for decades) but new to the skies. Several questions rattle around in my gray matter- how does the efficiency of this system compare to a conventional system? The generators can be operated at max efficiency, but there is loss every time energy is changed (fuel/turbine/generator/motors). Also, how does weight compare (genset, batteries, emotors) vs conventional power plants? More weight requires more energy to get and keep the stuff in the air! It will be interesting to see the specs and results.

    • I am guessing that it is torque, instantly available from electric motors, which gives the advantage. Whether enough advantage to overcome weight of batteries, remains to be seen.

    • I imagine they’re gathering performance data so the system engineers can figure out the answers to those questions for various mission profiles, possibly not on the same airframe. The use of multiple electric motors can very substantially increase the propulsive efficiency by having more propeller area providing the thrust; putting the propellers along the leading edge can provide a “blown wing” which enables a smaller wing to take off and land on current runways while generating a lot less drag in cruise – and so on. It turns out that electric motors – even if ultimately powered by a fossil generator – open up the design space quite a lot and it’s pretty clear that designers haven’t yet fully understood how to optimize that. Among other things, they need real-world data.

  2. WHY?
    Who’s footing the bill for all this virtue signaling research $$$$? The owners and operators of current Daher TBM’s? Keeping aircraft companies out of bankruptcy is a perpetual challenge, how do all these activities help?

  3. This does have the advantage over a battery powered aircraft in as much as it uses a proper internal combustion engine to provide the power. As such it can be safe, have appropriate range, and fast refueling times.

    If it is worth the extra weight, expense, complexity, failure points, and efficiency, that would be hard to say.

    I doubt it.

    • In this precise instance, I suspect the intent is more to prove the functionality of the underlying hybrid system, rather than make this exact airframe better.

    • Like John B alluded to, electric and hybrid electric systems are well over a hundred years old and are as optimized now as gas engines are today. The idea that no one has “researched” this AND the idea that this will help “save the planet” is what brings out the righteous indignation.

      • They’re optimized for trains and cars. The design space, constraints and opportunities for aircraft are very different. Trains don’t usually have takeoff distances, for example. Even cars and trains are optimized differently: hybrid power trains (no pun intended) in locomotives are useful because they offer an infinitely variable clutch that won’t wear out and offers huge torque, which justifies the efficiency reduction and complexity of the hybrid system. In cars, hybrid power trains are useful because they significantly increase efficiency in stop-start driving, which is not an issue for aircraft. It’s a different problem; it involves the interaction of the drive train and airframe with aerodynamics; and there isn’t yet much real-world data on it because no-one has gathered it yet.

        • Unless they have a miracle breakthrough above and beyond current technology then their assemblage of existing parts cannot succeed in their stated goal.

  4. Research is an ongoing endeavor AJ. Technology is changing constantly and new research always explores ways to adapt new technology to old ideas. Unfortunately humans lose the ability to adapt as they older and instead become cranky, often criticizing any change because change is a threat to those who have chosen to be set in their ways.

    You may not like the fact that research into cleaner and more efficient technologies is happening and you may think that doing anything that attempts to improve life and correct the pollution causing ways of the past is a bad idea, but it’s happening anyway, so just deal with it. Your use of platitudes such as “virtue signaling”, et al only reflects your own frustration that you refuse to adapt and have to decided to not care about the future. There were plenty of your type around who were skeptical of the horseless carriage, as well as the Wright brothers, and the internet. They were allmproven wrong in the long run and so will you be.

    • Nope, I was on the forefront of home solar, alternate fuels, electric and hybrid vehicles from the 1970’s till now. I actually installed some of the first IP networks in the late 80’s. The skepticism comes from decades of experience. What we see in this project is that pure electric flying has been proven impractical. Again.

  5. My compliments, Daniel, for your ability to discern a person’s age from an internet post. Much akin to a carnival act guessing someone’s weight and giving them a stuffed toy. A most enviable talent.

    Even more so you can parlay that into a personality trait. You must be good at interpreting horoscopes as well since if everyone at a given age has the same traits, anyone born in a certain month must also share the same traits.

    My Rutgers/Yale/Stanford trained post doctorate brain is humbled.

    Preach on!