Daher CEO Didier Kayat reported on Monday at NBAA-BACE that the EcoPulse distributed propulsion technology demonstrator will fly for the first time on electric power “within the next two weeks or so.” Kayat has committed Daher to launching a hybrid power aircraft by 2027, with the specification expected to be defined next year.
The fixed-wing EcoPulse demo aircraft, which uses the Daher TBM 900 as its platform, has been flying with inactive wing-mounted electric thrusters installed since earlier this year, following baseline trials last year with just the PT6 turboprop.
Two of the 50-kW electric power units were fitted in March, with two more added in April. A full complement of six electric motors was flown in time for the aircraft to appear at the Paris Air Show in June.
Flight trials with the six electric thrusters have been completed with the propellers feathered, and ground tests of the electric power and management system are complete. Now the team is ready to begin tests of the electric propulsion in flight from Daher’s facility at Tarbes in southern France.
EcoPulse is a joint program begun in 2019 by Daher, Airbus (aerodynamic optimization and battery technology), and Safran (hybrid propulsion system). The project aims to reduce fuel consumption and emissions by using the electric propulsion system alongside the thermal unit, while also addressing other environmental concerns such as noise.
Initially, the thermal and electric power systems will operate separately, but the goal is to use the PT6 for some electricity generation.
Installing electric motors along the wing leading edge has introduced some challenges, such as the need to protect the wing’s fuel tanks. There is also the question of interference on aircraft systems from the high-voltage propulsion system.
Daher reports that these issues have been attended to, but one that remains is the question of battery capacity. Currently, that limits the use of the electric system to less than an hour, but that is expected to improve.
Battery capacity is one of the issues that affects what sort of hybrid power aircraft Daher intends to bring to market in 2027. Kayat said that it would not be a clean-sheet design, being based on one of Daher’s current product lines: the TBM 900 series or Kodiak utility aircraft. The hybrid power system is likely to be introduced as a supplemental type certificate applied to whichever of the existing types is selected.
