Similar to a gyroplane, a gyrodyne is an aircraft that generates lift during flight using a large, free-spinning top rotor, and uses forward thrusters to develop forward movement. Unlike gyroplanes which require at least a short runway, gyrodynes have the ability to power up their top rotors for completely vertical takeoff and landing.
Gyrodynes have been around for a long time, but the electric aviation revolution might finally give them their day in the sun. Fast, efficient, well-understood and vastly safer than multirotor eVTOLs, they may have a head start in the air taxi race.
This eVTOL air taxi design looks like a weird helicopter/plane hybrid, but it's the safest of all the eVTOL designs we've ever seen, and it has another killer advantage in that it requires no special certification. Very cool news for 3D commuting.