from the illustrations, /E_Volo/Volocopter-VC1

from the illustrations, /PZL__Swidnik/Sokol-W_3A

from the blog, /2015/06

from the illustrations, /Airbus__Helicopters/Dauphin__2-SA365-C3

from the blog, /2016/09

from the illustrations, /Eagle__R__and__D/Helicycle-Helicycle

from the blog, /2017/07

from the illustrations, /Solution__F/Chretien__Helicopter-Chretien__Helicopter