Diamond Aircraft Industries GmbH, in collaboration with Siemens AG, has completed the maiden flight of what it calls the first serial-hybrid electric plane in the world with two electrically powered free-stream propellers and one combustion engine.
Diamond Aircraft Industries GmbH, in collaboration with Siemens AG, has announced the first flight of a jointly developed multi-engine hybrid electric aircraft at Diamond Aircraft’s headquarters in Wiener Neustadt, Austria.
The aircraft is a DA40 modified to serve as a flying testbed for a hybrid propulsion system built up of one genset and multiple electric motors and a system architecture with distributed drives.
On the modified aircraft, one combustion engine powers two independent electric drive systems consisting of one motor, battery and inverter each. Two electric engines have been added on a forward canard, which combined can generate 150kW of take-off power.
The diesel generator is located in the nose of the aircraft and can provide up to 110kW of power. Two batteries with 12kWh each are mounted in the rear passenger compartment, and act as an energy storage buffer. With a dedicated power lever, the pilot can control the energy flow between the generator, batteries and motor. The pilot can select either pure electric mode (generator off), cruise mode (generator provides all power to the motor), and charge mode (generator charges the batteries).
In pure electric mode, the aircraft has an endurance of approximately 30 minutes. The hybrid system extends this to 5 hours. During the 20 minute first flight, the aircraft demonstrated all modes of operation. This included pure hybrid, charging flight and full electric flight. In this last configuration, the aircraft was able to fly pure electric and produces zero emissions. A full-electric takeoff was also demonstrated.
Siemens, which is responsible for the design and development of the electric powertrain, describes the aircraft as the first serial-hybrid electric plane in the world with two electrically powered free-stream propellers and one combustion engine. The project is supported by German and Austrian governement funding.
Siemens is also working with Airbus and Rolls-Royce on the E-Fan X project to explore hybrid electric propulsion for commercial aircraft.