https://www.aerobuzz.fr/breves-helicoptere/bell-helicopter-devoile-taxi-aerien/
http://www.aerovfr.com/2018/05/pipistrel-se-met-a-levtol/
https://www.flightglobal.com/news/articles/embraer-reveals-evtol-concept-448429/
[youtube https://www.youtube.com/watch?v=isLm0v_PhBE&w=560&h=315]