Lilium has announced that its technology demonstrator Phoenix 2 is the first ever full-size electric jet aircraft to transition from hover to wing-borne flight, a landmark moment for Lilium and for electric aviation as a whole.

From a flight physics perspective, completing transition means the airflow going over the flaps attaches and becomes smooth, allowing the lift to be generated by the wing as in conventional fixed wing aircraft, rather than by the engines, which is the case during the hovering phase.

Phoenix 2 has now achieved this milestone across the entire main wing while remaining stable and behaving as predicted by Lilium’s proprietary flight dynamics model.

Phoenix chief engineer and Lilium co-founder Matthias Meiner, said: “Main wing transition is a huge step forward on our path to launch and full credit goes to the outstanding Lilium team who worked so hard to get us here.”

Lilium will continue the flight test campaign throughout the summer, including transition of the forward canards and high-speed flights.

Last month, Lilium began the next phase of flight testing for Phoenix 2 at the Atlas Flight Test Centre in Villacarrillo, southern Spain, after successful flight testing in southern Germany last year.

Lilium also plans to introduce Phoenix 3, an additional demonstrator aircraft scheduled to arrive in Spain for the first flight this summer, allowing Lilium to increase learnings and reduce program risks.

Meanwhile, the company has identified and licensed battery cell technology for eVTOL applications to meet specific performance requirements and achieve a range over 250 km, and a manufacturing partner with the competence to build cells on a scale to achieve its commercial and sustainability goals.

Lilium’s engineers collaborated with Zenlabs for over two years, and concluded that its pouch cell lithium-ion batteries using high-silicon anode and high-nickel cathode offered the best solution for achieving performance, certification and scale production.

Zenlabs released test data from Energy Assurance, a third-party testing laboratory, which demonstrates that its cell can maintain a high specific power of 2500 W/kg even at a low state of charge.

Yesterday, Lilium and Livent, one of the world’s leading producers of high-performance lithium battery cells, announced a research and development (R&D) collaboration agreement.