OSHKOSH, Wisconsin—Airbus Group Innovations has flown its E-fan proof-of-concept electric aircraft with hybrid propulsion, adding an internal-combustion engine as a range extender.                                                                       

The aircraft is making its U.S. debut in the new E-Fan 1.2 configuration at the EAA AirVenture Oshkosh show here July 25-31.

Distinguished by air intakes for the combustion or “thermal” engine on the upper fuselage behind the pilot, the twin-ducted-fan E-Fan still takes off and lands on electric power to minimize noise. The piston engine is used to generate sufficient electricity to sustain level flight at maximum cruise speed while simultaneously recharging the aircraft’s lithium-ion batteries.

The 600-kg (1,320-lb.) aircraft has an endurance on batteries only of 30 min. This is increased to 2 hr. 15 min (plus recharging the batteries to 80%) using the range extender, a two-cylinder, two-stroke piston engine with electronic fuel injection providing 50 kw (68 hp) of power on aviation gasoline. The Solo 2625 02i engine, certified for use in ultralights, weighs 24 kg dry.

In its previous all-electric configuration, as the E-Fan 1.1, the aircraft crossed the English Channel on electric propulsion in July 2015, a flight lasting 37 min. To make room for the hybrid system—engine, motor/generator, power electronics, fuel tank, intakes and exhaust—the rear seat has been removed. The battery system is new, says Airbus, and the avionics are updated.

Airbus is working with general aviation manufacturer Daher and electric motor supplier Siemens to put the two-seat, all-electric E-Fan 2.0 into production as a training aircraft. First flight is planned for 2017. When the E-Fan 2.0 was launched the endurance goal was 1.5 hr., but Airbus now plans to announce the target performance in September or October.