Dufour Aerospace announced on March 7, 2018 that it was developing a tilt-wing eVTOL called the "aEro2." The company stated that the aEro2 would build on the success of its aEro 1 electric CTOL aerobatic plane. The eVTOL aEro2 will use a modular hybrid-electric power system.
The company says "Our aircraft uses a proven tilt-wing design concept which keeps the wings constantly under airflow and therefore offers outstanding stability and control even in very slow flight. An efficient tail fan provides pitch control in hover flight and ensures that aEro 2 is robust against changes in center of gravity and gusty conditions."
"Four motors (two on each side) provide redundancy, with each motor temporarily able to provide twice the power to keep full hover capacity in case of a failure. The laminar airflow around the wing makes it less vulnerable to vortex ring state, strong wind and gust conditions in hover than any other aircraft."
The winged design of aEro 2 ensures if that any rotors fail, the aircraft can land on an airfield.
The company's aEro 1 eCTOL aircraft was started in March 2015 and first flew in June 2016. Dufour began the first conceptual designs of aEro 2 in Sept. 2016. In Dec. 2017, the company began testing different concepts (especially tilt-wing and tilt-rotor) and the first model prototypes to simulate different steering and flying configurations. By March 2018, Dufour the company had tested different scale models for a total of 20 flight hours in real flight conditions in all configurations. The company highlighted its inspiration from the Canadair CL-84 tiltwing demonstrator.
In Jan. 2018, the company flew a full flight simulation of the full-scale aircraft in the simulator. The full-scale configuration of the aircraft had with all the basic parameters, like weights, balance, aerodynamic profiles, power and RPM settings.
In Oct. 2018, the company stated that it planned to conduct flights with a one-third scale aircraft. The company said it would also have the final CFD simulation results to freeze the design. Dufour said it intended to have a working prototype in 2019. However, little was announced by the company about the progress until July 27, 2020, when it released a short video on YouTube of the now four-propeller concept and a blog post, which began:
Building on our experience in manned electric flight with our aerobatic plane aEro 1, we are proud to announce that we have completed the first phase of flight testing of our VTOL technology demonstrator aircraft. Over the course of 550 test flights, expanding the flight envelope incrementally, we have demonstrated a high degree of stability and control in all conditions, including transitions from hover to cruise and back again.
-- Dufour Aerospace, July 27, 2020
Characteristics (March 2018):
- 320 km/h speed cruise
- Hover Performance at 2,000 m at ISA +20 deg C.
- 2 seats
- optional piloted
- hybrid or fully electric
- range 800 km in hybrid mode and 120 km in full electric mode
- low noise profile and low downwash profile makes it best in class for Urban Air Transport and operation in populated areas
- Dufour website
- Blog post: Dufour completes first phase of VTOL tech demonstrator flight testing, Dufour, July 27, 2020
- Blog post: Dufour aEro 2 Design Philosophy, Dufour, Sept. 5, 2018
- Article: Dufour Aerospace announces aEro 2 hybrid eVTOL aircraft, Vertical Magazine, March 7, 2018
- Article: Dufour Unveils electric VTOL tiltwing, evtol.news, March 31, 2018
- Podcast: Dufour Aerospace Co-Founder Thomas Pfammatter on the aEro2 VTOL Electric Aircraft, Aerospace Engineering Blog, July 10, 2018